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Posted to commits@lucene.apache.org by jp...@apache.org on 2018/01/31 13:55:02 UTC

[1/3] lucene-solr:master: LUCENE-4198: Give codecs the opportunity to index impacts.

Repository: lucene-solr
Updated Branches:
  refs/heads/master ebb346d58 -> f410df811


http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/sandbox/src/java/org/apache/lucene/codecs/idversion/VersionBlockTreeTermsWriter.java
----------------------------------------------------------------------
diff --git a/lucene/sandbox/src/java/org/apache/lucene/codecs/idversion/VersionBlockTreeTermsWriter.java b/lucene/sandbox/src/java/org/apache/lucene/codecs/idversion/VersionBlockTreeTermsWriter.java
index e9187af..078ca8b 100644
--- a/lucene/sandbox/src/java/org/apache/lucene/codecs/idversion/VersionBlockTreeTermsWriter.java
+++ b/lucene/sandbox/src/java/org/apache/lucene/codecs/idversion/VersionBlockTreeTermsWriter.java
@@ -23,6 +23,7 @@ import java.util.List;
 import org.apache.lucene.codecs.BlockTermState;
 import org.apache.lucene.codecs.CodecUtil;
 import org.apache.lucene.codecs.FieldsConsumer;
+import org.apache.lucene.codecs.NormsProducer;
 import org.apache.lucene.codecs.PostingsWriterBase;
 import org.apache.lucene.codecs.blocktree.BlockTreeTermsWriter;
 import org.apache.lucene.index.FieldInfo;
@@ -221,7 +222,7 @@ public final class VersionBlockTreeTermsWriter extends FieldsConsumer {
   }
 
   @Override
-  public void write(Fields fields) throws IOException {
+  public void write(Fields fields, NormsProducer norms) throws IOException {
 
     String lastField = null;
     for(String field : fields) {
@@ -241,7 +242,7 @@ public final class VersionBlockTreeTermsWriter extends FieldsConsumer {
         if (term == null) {
           break;
         }
-        termsWriter.write(term, termsEnum);
+        termsWriter.write(term, termsEnum, norms);
       }
 
       termsWriter.finish();
@@ -729,8 +730,8 @@ public final class VersionBlockTreeTermsWriter extends FieldsConsumer {
     }
     
     /** Writes one term's worth of postings. */
-    public void write(BytesRef text, TermsEnum termsEnum) throws IOException {
-      BlockTermState state = postingsWriter.writeTerm(text, termsEnum, docsSeen);
+    public void write(BytesRef text, TermsEnum termsEnum, NormsProducer norms) throws IOException {
+      BlockTermState state = postingsWriter.writeTerm(text, termsEnum, docsSeen, norms);
       // TODO: LUCENE-5693: we don't need this check if we fix IW to not send deleted docs to us on flush:
       if (state != null && ((IDVersionPostingsWriter) postingsWriter).lastDocID != -1) {
         assert state.docFreq != 0;

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/suggest/src/java/org/apache/lucene/search/suggest/document/CompletionFieldsConsumer.java
----------------------------------------------------------------------
diff --git a/lucene/suggest/src/java/org/apache/lucene/search/suggest/document/CompletionFieldsConsumer.java b/lucene/suggest/src/java/org/apache/lucene/search/suggest/document/CompletionFieldsConsumer.java
index 9df9d60..5ab16a9 100644
--- a/lucene/suggest/src/java/org/apache/lucene/search/suggest/document/CompletionFieldsConsumer.java
+++ b/lucene/suggest/src/java/org/apache/lucene/search/suggest/document/CompletionFieldsConsumer.java
@@ -22,6 +22,7 @@ import java.util.Map;
 
 import org.apache.lucene.codecs.CodecUtil;
 import org.apache.lucene.codecs.FieldsConsumer;
+import org.apache.lucene.codecs.NormsProducer;
 import org.apache.lucene.codecs.PostingsFormat;
 import org.apache.lucene.index.FieldInfo;
 import org.apache.lucene.index.Fields;
@@ -44,7 +45,7 @@ import static org.apache.lucene.search.suggest.document.CompletionPostingsFormat
 
 /**
  * <p>
- * Weighted FSTs for any indexed {@link SuggestField} is built on {@link #write(Fields)}.
+ * Weighted FSTs for any indexed {@link SuggestField} is built on {@link #write(Fields,NormsProducer)}.
  * A weighted FST maps the analyzed forms of a field to its
  * surface form and document id. FSTs are stored in the CompletionDictionary (.lkp).
  * </p>
@@ -80,8 +81,8 @@ final class CompletionFieldsConsumer extends FieldsConsumer {
   }
 
   @Override
-  public void write(Fields fields) throws IOException {
-    delegateFieldsConsumer.write(fields);
+  public void write(Fields fields, NormsProducer norms) throws IOException {
+    delegateFieldsConsumer.write(fields, norms);
 
     for (String field : fields) {
       CompletionTermWriter termWriter = new CompletionTermWriter();

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/test-framework/src/java/org/apache/lucene/codecs/asserting/AssertingPostingsFormat.java
----------------------------------------------------------------------
diff --git a/lucene/test-framework/src/java/org/apache/lucene/codecs/asserting/AssertingPostingsFormat.java b/lucene/test-framework/src/java/org/apache/lucene/codecs/asserting/AssertingPostingsFormat.java
index a89b508..e71903d 100644
--- a/lucene/test-framework/src/java/org/apache/lucene/codecs/asserting/AssertingPostingsFormat.java
+++ b/lucene/test-framework/src/java/org/apache/lucene/codecs/asserting/AssertingPostingsFormat.java
@@ -22,6 +22,7 @@ import java.util.Iterator;
 
 import org.apache.lucene.codecs.FieldsConsumer;
 import org.apache.lucene.codecs.FieldsProducer;
+import org.apache.lucene.codecs.NormsProducer;
 import org.apache.lucene.codecs.PostingsFormat;
 import org.apache.lucene.index.AssertingLeafReader;
 import org.apache.lucene.index.FieldInfo;
@@ -133,8 +134,8 @@ public final class AssertingPostingsFormat extends PostingsFormat {
     }
     
     @Override
-    public void write(Fields fields) throws IOException {
-      in.write(fields);
+    public void write(Fields fields, NormsProducer norms) throws IOException {
+      in.write(fields, norms);
 
       // TODO: more asserts?  can we somehow run a
       // "limited" CheckIndex here???  Or ... can we improve

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/test-framework/src/java/org/apache/lucene/codecs/cranky/CrankyPostingsFormat.java
----------------------------------------------------------------------
diff --git a/lucene/test-framework/src/java/org/apache/lucene/codecs/cranky/CrankyPostingsFormat.java b/lucene/test-framework/src/java/org/apache/lucene/codecs/cranky/CrankyPostingsFormat.java
index 2ca1bc7..00e168b 100644
--- a/lucene/test-framework/src/java/org/apache/lucene/codecs/cranky/CrankyPostingsFormat.java
+++ b/lucene/test-framework/src/java/org/apache/lucene/codecs/cranky/CrankyPostingsFormat.java
@@ -21,6 +21,7 @@ import java.util.Random;
 
 import org.apache.lucene.codecs.FieldsConsumer;
 import org.apache.lucene.codecs.FieldsProducer;
+import org.apache.lucene.codecs.NormsProducer;
 import org.apache.lucene.codecs.PostingsFormat;
 import org.apache.lucene.index.Fields;
 import org.apache.lucene.index.SegmentReadState;
@@ -61,11 +62,11 @@ class CrankyPostingsFormat extends PostingsFormat {
     }
     
     @Override
-    public void write(Fields fields) throws IOException {
+    public void write(Fields fields, NormsProducer norms) throws IOException {
       if (random.nextInt(100) == 0) {
         throw new IOException("Fake IOException from FieldsConsumer.write()");
       }  
-      delegate.write(fields);
+      delegate.write(fields, norms);
     }
 
     @Override

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/test-framework/src/java/org/apache/lucene/codecs/ramonly/RAMOnlyPostingsFormat.java
----------------------------------------------------------------------
diff --git a/lucene/test-framework/src/java/org/apache/lucene/codecs/ramonly/RAMOnlyPostingsFormat.java b/lucene/test-framework/src/java/org/apache/lucene/codecs/ramonly/RAMOnlyPostingsFormat.java
index 4b85f13..37c078f 100644
--- a/lucene/test-framework/src/java/org/apache/lucene/codecs/ramonly/RAMOnlyPostingsFormat.java
+++ b/lucene/test-framework/src/java/org/apache/lucene/codecs/ramonly/RAMOnlyPostingsFormat.java
@@ -31,17 +31,21 @@ import java.util.concurrent.atomic.AtomicInteger;
 import org.apache.lucene.codecs.CodecUtil;
 import org.apache.lucene.codecs.FieldsConsumer;
 import org.apache.lucene.codecs.FieldsProducer;
+import org.apache.lucene.codecs.NormsProducer;
 import org.apache.lucene.codecs.PostingsFormat;
 import org.apache.lucene.codecs.TermStats;
 import org.apache.lucene.index.PostingsEnum;
 import org.apache.lucene.index.FieldInfo;
 import org.apache.lucene.index.Fields;
+import org.apache.lucene.index.ImpactsEnum;
 import org.apache.lucene.index.IndexFileNames;
 import org.apache.lucene.index.IndexOptions;
 import org.apache.lucene.index.SegmentReadState;
 import org.apache.lucene.index.SegmentWriteState;
+import org.apache.lucene.index.SlowImpactsEnum;
 import org.apache.lucene.index.Terms;
 import org.apache.lucene.index.TermsEnum;
+import org.apache.lucene.search.similarities.Similarity.SimScorer;
 import org.apache.lucene.store.IndexInput;
 import org.apache.lucene.store.IndexOutput;
 import org.apache.lucene.util.Accountable;
@@ -227,7 +231,7 @@ public final class RAMOnlyPostingsFormat extends PostingsFormat {
     }
 
     @Override
-    public void write(Fields fields) throws IOException {
+    public void write(Fields fields, NormsProducer norms) throws IOException {
       for(String field : fields) {
 
         Terms terms = fields.terms(field);
@@ -472,6 +476,10 @@ public final class RAMOnlyPostingsFormat extends PostingsFormat {
       return new RAMDocsEnum(ramField.termToDocs.get(current));
     }
 
+    @Override
+    public ImpactsEnum impacts(SimScorer scorer, int flags) throws IOException {
+      return new SlowImpactsEnum(postings(null, PostingsEnum.FREQS), scorer.score(Float.MAX_VALUE, 1));
+    }
   }
 
   private static class RAMDocsEnum extends PostingsEnum {

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/test-framework/src/java/org/apache/lucene/index/AssertingLeafReader.java
----------------------------------------------------------------------
diff --git a/lucene/test-framework/src/java/org/apache/lucene/index/AssertingLeafReader.java b/lucene/test-framework/src/java/org/apache/lucene/index/AssertingLeafReader.java
index c87697b..dfec1db 100644
--- a/lucene/test-framework/src/java/org/apache/lucene/index/AssertingLeafReader.java
+++ b/lucene/test-framework/src/java/org/apache/lucene/index/AssertingLeafReader.java
@@ -23,6 +23,7 @@ import java.util.Objects;
 import org.apache.lucene.index.PointValues.IntersectVisitor;
 import org.apache.lucene.index.PointValues.Relation;
 import org.apache.lucene.search.DocIdSetIterator;
+import org.apache.lucene.search.similarities.Similarity.SimScorer;
 import org.apache.lucene.util.Bits;
 import org.apache.lucene.util.BytesRef;
 import org.apache.lucene.util.StringHelper;
@@ -209,6 +210,15 @@ public class AssertingLeafReader extends FilterLeafReader {
       }
     }
 
+    @Override
+    public ImpactsEnum impacts(SimScorer scorer, int flags) throws IOException {
+      assertThread("Terms enums", creationThread);
+      assert state == State.POSITIONED: "docs(...) called on unpositioned TermsEnum";
+      assert (flags & PostingsEnum.FREQS) != 0 : "Freqs should be requested on impacts";
+
+      return new AssertingImpactsEnum(super.impacts(scorer, flags));
+    }
+
     // TODO: we should separately track if we are 'at the end' ?
     // someone should not call next() after it returns null!!!!
     @Override
@@ -439,6 +449,84 @@ public class AssertingLeafReader extends FilterLeafReader {
     }
   }
 
+  /** Wraps a {@link ImpactsEnum} with additional checks */
+  public static class AssertingImpactsEnum extends ImpactsEnum {
+
+    private final AssertingPostingsEnum assertingPostings;
+    private final ImpactsEnum in;
+    private int lastShallowTarget;
+
+    AssertingImpactsEnum(ImpactsEnum impacts) {
+      in = impacts;
+      // inherit checks from AssertingPostingsEnum
+      assertingPostings = new AssertingPostingsEnum(impacts);
+    }
+
+    @Override
+    public int advanceShallow(int target) throws IOException {
+      assert target >= lastShallowTarget : "called on decreasing targets: target = " + target + " < last target = " + lastShallowTarget;
+      assert target >= docID() : "target = " + target + " < docID = " + docID();
+      int upTo = in.advanceShallow(target);
+      assert upTo >= target : "upTo = " + upTo + " < target = " + target;
+      lastShallowTarget = target;
+      return upTo;
+    }
+
+    @Override
+    public float getMaxScore(int upTo) throws IOException {
+      assert upTo >= lastShallowTarget : "uTo = " + upTo + " < last shallow target = " + lastShallowTarget;
+      float maxScore = in.getMaxScore(upTo);
+      return maxScore;
+    }
+
+    @Override
+    public int freq() throws IOException {
+      return assertingPostings.freq();
+    }
+
+    @Override
+    public int nextPosition() throws IOException {
+      return assertingPostings.nextPosition();
+    }
+
+    @Override
+    public int startOffset() throws IOException {
+      return assertingPostings.startOffset();
+    }
+
+    @Override
+    public int endOffset() throws IOException {
+      return assertingPostings.endOffset();
+    }
+
+    @Override
+    public BytesRef getPayload() throws IOException {
+      return assertingPostings.getPayload();
+    }
+
+    @Override
+    public int docID() {
+      return assertingPostings.docID();
+    }
+
+    @Override
+    public int nextDoc() throws IOException {
+      assert docID() + 1 >= lastShallowTarget : "target = " + (docID() + 1) + " < last shallow target = " + lastShallowTarget;
+      return assertingPostings.nextDoc();
+    }
+
+    @Override
+    public int advance(int target) throws IOException {
+      assert target >= lastShallowTarget : "target = " + target + " < last shallow target = " + lastShallowTarget;
+      return assertingPostings.advance(target);
+    }
+
+    @Override
+    public long cost() {
+      return assertingPostings.cost();
+    }
+  }
+
   /** Wraps a NumericDocValues but with additional asserts */
   public static class AssertingNumericDocValues extends NumericDocValues {
     private final Thread creationThread = Thread.currentThread();

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/test-framework/src/java/org/apache/lucene/index/BaseIndexFileFormatTestCase.java
----------------------------------------------------------------------
diff --git a/lucene/test-framework/src/java/org/apache/lucene/index/BaseIndexFileFormatTestCase.java b/lucene/test-framework/src/java/org/apache/lucene/index/BaseIndexFileFormatTestCase.java
index ab92946..f5b5223 100644
--- a/lucene/test-framework/src/java/org/apache/lucene/index/BaseIndexFileFormatTestCase.java
+++ b/lucene/test-framework/src/java/org/apache/lucene/index/BaseIndexFileFormatTestCase.java
@@ -334,8 +334,30 @@ abstract class BaseIndexFileFormatTestCase extends LuceneTestCase {
     SegmentReadState readState = new SegmentReadState(dir, segmentInfo, fieldInfos, IOContext.READ);
 
     // PostingsFormat
+    NormsProducer fakeNorms = new NormsProducer() {
+
+      @Override
+      public void close() throws IOException {}
+
+      @Override
+      public long ramBytesUsed() {
+        return 0;
+      }
+
+      @Override
+      public NumericDocValues getNorms(FieldInfo field) throws IOException {
+        if (field.hasNorms() == false) {
+          return null;
+        }
+        return oneDocReader.getNormValues(field.name);
+      }
+
+      @Override
+      public void checkIntegrity() throws IOException {}
+      
+    };
     try (FieldsConsumer consumer = codec.postingsFormat().fieldsConsumer(writeState)) {
-      consumer.write(MultiFields.getFields(oneDocReader));
+      consumer.write(MultiFields.getFields(oneDocReader), fakeNorms);
       IOUtils.close(consumer);
       IOUtils.close(consumer);
     }

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/test-framework/src/java/org/apache/lucene/index/BaseNormsFormatTestCase.java
----------------------------------------------------------------------
diff --git a/lucene/test-framework/src/java/org/apache/lucene/index/BaseNormsFormatTestCase.java b/lucene/test-framework/src/java/org/apache/lucene/index/BaseNormsFormatTestCase.java
index 617a721..6b301f9 100644
--- a/lucene/test-framework/src/java/org/apache/lucene/index/BaseNormsFormatTestCase.java
+++ b/lucene/test-framework/src/java/org/apache/lucene/index/BaseNormsFormatTestCase.java
@@ -450,9 +450,10 @@ public abstract class BaseNormsFormatTestCase extends BaseIndexFileFormatTestCas
     }
     
     Directory dir = applyCreatedVersionMajor(newDirectory());
-    Analyzer analyzer = new MockAnalyzer(random(), MockTokenizer.KEYWORD, false);
-    IndexWriterConfig conf = newIndexWriterConfig(analyzer);conf.setMergePolicy(NoMergePolicy.INSTANCE);
-    conf.setSimilarity(new CannedNormSimilarity(norms));
+    Analyzer analyzer = new MockAnalyzer(random(), MockTokenizer.WHITESPACE, false);
+    IndexWriterConfig conf = newIndexWriterConfig(analyzer).setMergePolicy(NoMergePolicy.INSTANCE);
+    CannedNormSimilarity sim = new CannedNormSimilarity(norms);
+    conf.setSimilarity(sim);
     RandomIndexWriter writer = new RandomIndexWriter(random(), dir, conf);
     Document doc = new Document();
     Field idField = new StringField("id", "", Field.Store.NO);
@@ -471,7 +472,8 @@ public abstract class BaseNormsFormatTestCase extends BaseIndexFileFormatTestCas
       } else {
         long value = norms[j++];
         dvField.setLongValue(value);
-        indexedField.setStringValue(Long.toString(value));
+        // only empty fields may have 0 as a norm
+        indexedField.setStringValue(value == 0 ? "" : "a");
         writer.addDocument(doc);
       }
       if (random().nextInt(31) == 0) {
@@ -530,7 +532,13 @@ public abstract class BaseNormsFormatTestCase extends BaseIndexFileFormatTestCas
 
     @Override
     public long computeNorm(FieldInvertState state) {
-      return norms[index++];
+      assert state.length > 0;
+      while (true) {
+        long norm = norms[index++];
+        if (norm != 0) {
+          return norm;
+        }
+      }
     }
 
     @Override
@@ -642,7 +650,7 @@ public abstract class BaseNormsFormatTestCase extends BaseIndexFileFormatTestCas
     }
 
     Directory dir = applyCreatedVersionMajor(newDirectory());
-    Analyzer analyzer = new MockAnalyzer(random(), MockTokenizer.KEYWORD, false);
+    Analyzer analyzer = new MockAnalyzer(random(), MockTokenizer.WHITESPACE, false);
     IndexWriterConfig conf = newIndexWriterConfig(analyzer);conf.setMergePolicy(NoMergePolicy.INSTANCE);
     conf.setSimilarity(new CannedNormSimilarity(norms));
     RandomIndexWriter writer = new RandomIndexWriter(random(), dir, conf);
@@ -663,7 +671,7 @@ public abstract class BaseNormsFormatTestCase extends BaseIndexFileFormatTestCas
       } else {
         long value = norms[j++];
         dvField.setLongValue(value);
-        indexedField.setStringValue(Long.toString(value));
+        indexedField.setStringValue(value == 0 ? "" : "a");
         writer.addDocument(doc);
       }
       if (random().nextInt(31) == 0) {

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/test-framework/src/java/org/apache/lucene/index/BasePostingsFormatTestCase.java
----------------------------------------------------------------------
diff --git a/lucene/test-framework/src/java/org/apache/lucene/index/BasePostingsFormatTestCase.java b/lucene/test-framework/src/java/org/apache/lucene/index/BasePostingsFormatTestCase.java
index f69ca55..51b418e 100644
--- a/lucene/test-framework/src/java/org/apache/lucene/index/BasePostingsFormatTestCase.java
+++ b/lucene/test-framework/src/java/org/apache/lucene/index/BasePostingsFormatTestCase.java
@@ -32,6 +32,7 @@ import org.apache.lucene.analysis.Token;
 import org.apache.lucene.codecs.FieldsConsumer;
 import org.apache.lucene.codecs.FieldsProducer;
 import org.apache.lucene.codecs.FilterCodec;
+import org.apache.lucene.codecs.NormsProducer;
 import org.apache.lucene.codecs.PostingsFormat;
 import org.apache.lucene.document.Document;
 import org.apache.lucene.document.Field;
@@ -398,8 +399,8 @@ public abstract class BasePostingsFormatTestCase extends BaseIndexFileFormatTest
 
               return new FieldsConsumer() {
                 @Override
-                public void write(Fields fields) throws IOException {
-                  fieldsConsumer.write(fields);
+                public void write(Fields fields, NormsProducer norms) throws IOException {
+                  fieldsConsumer.write(fields, norms);
 
                   boolean isMerge = state.context.context == IOContext.Context.MERGE;
 

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/test-framework/src/java/org/apache/lucene/index/RandomPostingsTester.java
----------------------------------------------------------------------
diff --git a/lucene/test-framework/src/java/org/apache/lucene/index/RandomPostingsTester.java b/lucene/test-framework/src/java/org/apache/lucene/index/RandomPostingsTester.java
index d5eb105..278f4b2 100644
--- a/lucene/test-framework/src/java/org/apache/lucene/index/RandomPostingsTester.java
+++ b/lucene/test-framework/src/java/org/apache/lucene/index/RandomPostingsTester.java
@@ -32,10 +32,14 @@ import java.util.Random;
 import java.util.Set;
 import java.util.SortedMap;
 import java.util.TreeMap;
+import java.util.function.IntToLongFunction;
 
 import org.apache.lucene.codecs.Codec;
 import org.apache.lucene.codecs.FieldsConsumer;
 import org.apache.lucene.codecs.FieldsProducer;
+import org.apache.lucene.codecs.NormsProducer;
+import org.apache.lucene.search.DocIdSetIterator;
+import org.apache.lucene.search.similarities.Similarity.SimScorer;
 import org.apache.lucene.store.Directory;
 import org.apache.lucene.store.FlushInfo;
 import org.apache.lucene.store.IOContext;
@@ -60,6 +64,9 @@ import static org.junit.Assert.assertTrue;
 /** Helper class extracted from BasePostingsFormatTestCase to exercise a postings format. */
 public class RandomPostingsTester {
 
+  private static final IntToLongFunction DOC_TO_NORM = doc -> 1 + (doc & 0x0f);
+  private static final long MAX_NORM = 0x10;
+
   /** Which features to test. */
   public enum Option {
     // Sometimes use .advance():
@@ -599,6 +606,11 @@ public class RandomPostingsTester {
       }
       return getSeedPostings(current.getKey().utf8ToString(), current.getValue().seed, maxAllowed, allowPayloads);
     }
+
+    @Override
+    public ImpactsEnum impacts(SimScorer scorer, int flags) throws IOException {
+      throw new UnsupportedOperationException();
+    }
   }
 
   private static class ThreadState {
@@ -653,10 +665,70 @@ public class RandomPostingsTester {
 
     Fields seedFields = new SeedFields(fields, newFieldInfos, maxAllowed, allowPayloads);
 
+    NormsProducer fakeNorms = new NormsProducer() {
+
+      @Override
+      public void close() throws IOException {}
+
+      @Override
+      public long ramBytesUsed() {
+        return 0;
+      }
+
+      @Override
+      public NumericDocValues getNorms(FieldInfo field) throws IOException {
+        if (newFieldInfos.fieldInfo(field.number).hasNorms()) {
+          return new NumericDocValues() {
+            
+            int doc = -1;
+            
+            @Override
+            public int nextDoc() throws IOException {
+              if (++doc == segmentInfo.maxDoc()) {
+                return doc = NO_MORE_DOCS;
+              }
+              return doc;
+            }
+            
+            @Override
+            public int docID() {
+              return doc;
+            }
+            
+            @Override
+            public long cost() {
+              return segmentInfo.maxDoc();
+            }
+            
+            @Override
+            public int advance(int target) throws IOException {
+              return doc = target >= segmentInfo.maxDoc() ? DocIdSetIterator.NO_MORE_DOCS : target;
+            }
+            
+            @Override
+            public boolean advanceExact(int target) throws IOException {
+              doc = target;
+              return true;
+            }
+            
+            @Override
+            public long longValue() throws IOException {
+              return DOC_TO_NORM.applyAsLong(doc);
+            }
+          };
+        } else {
+          return null;
+        }
+      }
+
+      @Override
+      public void checkIntegrity() throws IOException {}
+      
+    };
     FieldsConsumer consumer = codec.postingsFormat().fieldsConsumer(writeState);
     boolean success = false;
     try {
-      consumer.write(seedFields);
+      consumer.write(seedFields, fakeNorms);
       success = true;
     } finally {
       if (success) {
@@ -975,6 +1047,136 @@ public class RandomPostingsTester {
         }
       }
     }
+
+    if (options.contains(Option.SKIPPING)) {
+      final IntToLongFunction docToNorm;
+      if (fieldInfo.hasNorms()) {
+        docToNorm = DOC_TO_NORM;
+      } else {
+        docToNorm = doc -> 1L;
+      }
+      for (int s = 0; s < 3; ++s) {
+        final int scoreMode = s;
+        SimScorer scorer = new SimScorer(field) {
+          @Override
+          public float score(float freq, long norm) {
+            switch (scoreMode) {
+              case 0:
+                return freq; // make sure the postings record the best freq
+              case 1:
+                return 1f / norm; // make sure the postings record the best norm
+              default:
+                return freq - norm + MAX_NORM; // now a combination that could make intermediate pairs more competitive
+            }
+          }
+        };
+
+        // First check max scores and block uptos
+        int max = -1;
+        float maxScore = 0;
+        int flags = PostingsEnum.FREQS;
+        if (doCheckPositions) {
+          flags |= PostingsEnum.POSITIONS;
+          if (doCheckOffsets) {
+            flags |= PostingsEnum.OFFSETS;
+          }
+          if (doCheckPayloads) {
+            flags |= PostingsEnum.PAYLOADS;
+          }
+        }
+
+        ImpactsEnum impacts = termsEnum.impacts(scorer, flags);
+        PostingsEnum postings = termsEnum.postings(null, flags);
+        for (int doc = impacts.nextDoc(); ; doc = impacts.nextDoc()) {
+          assertEquals(postings.nextDoc(), doc);
+          if (doc == DocIdSetIterator.NO_MORE_DOCS) {
+            break;
+          }
+          int freq = postings.freq();
+          assertEquals("freq is wrong", freq, impacts.freq());
+          for (int i = 0; i < freq; ++i) {
+            int pos = postings.nextPosition();
+            assertEquals("position is wrong", pos, impacts.nextPosition());
+            if (doCheckOffsets) {
+              assertEquals("startOffset is wrong", postings.startOffset(), impacts.startOffset());
+              assertEquals("endOffset is wrong", postings.endOffset(), impacts.endOffset());
+            }
+            if (doCheckPayloads) {
+              assertEquals("payload is wrong", postings.getPayload(), impacts.getPayload());
+            }
+          }
+          if (doc > max) {
+            max = impacts.advanceShallow(doc);
+            assertTrue(max >= doc);
+            maxScore = impacts.getMaxScore(max);
+          }
+          assertEquals(max, impacts.advanceShallow(doc));
+          assertTrue(scorer.score(impacts.freq(), docToNorm.applyAsLong(doc)) <= maxScore);
+        }
+
+        // Now check advancing
+        impacts = termsEnum.impacts(scorer, flags);
+        postings = termsEnum.postings(postings, flags);
+
+        max = -1;
+        while (true) {
+          int doc = impacts.docID();
+          boolean advance;
+          int target;
+          if (random.nextBoolean()) {
+            advance = false;
+            target = doc + 1;
+          } else {
+            advance = true;
+            int delta = Math.min(1 + random.nextInt(512), DocIdSetIterator.NO_MORE_DOCS - doc);
+            target = impacts.docID() + delta;
+          }
+
+          if (target > max && random.nextBoolean()) {
+            int delta = Math.min(random.nextInt(512), DocIdSetIterator.NO_MORE_DOCS - target);
+            max = target + delta;
+            int m = impacts.advanceShallow(target);
+            assertTrue(m >= target);
+            maxScore = impacts.getMaxScore(max);
+          }
+
+          if (advance) {
+            doc = impacts.advance(target);
+          } else {
+            doc = impacts.nextDoc();
+          }
+
+          assertEquals(postings.advance(target), doc);
+          if (doc == DocIdSetIterator.NO_MORE_DOCS) {
+            break;
+          }
+          int freq = postings.freq();
+          assertEquals("freq is wrong", freq, impacts.freq());
+          for (int i = 0; i < postings.freq(); ++i) {
+            int pos = postings.nextPosition();
+            assertEquals("position is wrong", pos, impacts.nextPosition());
+            if (doCheckOffsets) {
+              assertEquals("startOffset is wrong", postings.startOffset(), impacts.startOffset());
+              assertEquals("endOffset is wrong", postings.endOffset(), impacts.endOffset());
+            }
+            if (doCheckPayloads) {
+              assertEquals("payload is wrong", postings.getPayload(), impacts.getPayload());
+            }
+          }
+
+          if (doc > max) {
+            int delta = Math.min(1 + random.nextInt(512), DocIdSetIterator.NO_MORE_DOCS - doc);
+            max = doc + delta;
+            int m = impacts.advanceShallow(doc);
+            assertTrue(m >= doc);
+            maxScore = impacts.getMaxScore(max);
+          }
+
+          float score = scorer.score(impacts.freq(), docToNorm.applyAsLong(doc));
+          assertTrue(score <= maxScore);
+        }
+      }
+    }
   }
 
   private static class TestThread extends Thread {

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/solr/core/src/java/org/apache/solr/query/SolrRangeQuery.java
----------------------------------------------------------------------
diff --git a/solr/core/src/java/org/apache/solr/query/SolrRangeQuery.java b/solr/core/src/java/org/apache/solr/query/SolrRangeQuery.java
index 7e54f8d..1b81c7f 100644
--- a/solr/core/src/java/org/apache/solr/query/SolrRangeQuery.java
+++ b/solr/core/src/java/org/apache/solr/query/SolrRangeQuery.java
@@ -20,6 +20,7 @@ import java.io.IOException;
 import java.util.ArrayList;
 import java.util.List;
 
+import org.apache.lucene.index.ImpactsEnum;
 import org.apache.lucene.index.IndexReader;
 import org.apache.lucene.index.LeafReaderContext;
 import org.apache.lucene.index.PostingsEnum;
@@ -42,6 +43,7 @@ import org.apache.lucene.search.ScoreMode;
 import org.apache.lucene.search.Scorer;
 import org.apache.lucene.search.TermQuery;
 import org.apache.lucene.search.Weight;
+import org.apache.lucene.search.similarities.Similarity.SimScorer;
 import org.apache.lucene.util.AttributeSource;
 import org.apache.lucene.util.BytesRef;
 import org.apache.lucene.util.DocIdSetBuilder;
@@ -239,6 +241,11 @@ public final class SolrRangeQuery extends ExtendedQueryBase implements DocSetPro
     }
 
     @Override
+    public ImpactsEnum impacts(SimScorer scorer, int flags) throws IOException {
+      return te.impacts(scorer, flags);
+    }
+
+    @Override
     public BytesRef next() throws IOException {
       if (positioned) {
         positioned = false;

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/solr/core/src/java/org/apache/solr/uninverting/DocTermOrds.java
----------------------------------------------------------------------
diff --git a/solr/core/src/java/org/apache/solr/uninverting/DocTermOrds.java b/solr/core/src/java/org/apache/solr/uninverting/DocTermOrds.java
index b56d462..daaf00d 100644
--- a/solr/core/src/java/org/apache/solr/uninverting/DocTermOrds.java
+++ b/solr/core/src/java/org/apache/solr/uninverting/DocTermOrds.java
@@ -26,6 +26,7 @@ import org.apache.lucene.codecs.PostingsFormat;
 import org.apache.lucene.index.DocValues;
 import org.apache.lucene.index.DocValuesType;
 import org.apache.lucene.index.FieldInfo;
+import org.apache.lucene.index.ImpactsEnum;
 import org.apache.lucene.index.LeafReader;
 import org.apache.lucene.index.LegacySortedSetDocValues;
 import org.apache.lucene.index.LegacySortedSetDocValuesWrapper;
@@ -34,6 +35,7 @@ import org.apache.lucene.index.SortedSetDocValues;
 import org.apache.lucene.index.Terms;
 import org.apache.lucene.index.TermsEnum;
 import org.apache.lucene.search.DocIdSetIterator;
+import org.apache.lucene.search.similarities.Similarity.SimScorer;
 import org.apache.lucene.util.Accountable;
 import org.apache.lucene.util.Bits;
 import org.apache.lucene.util.BytesRef;
@@ -607,6 +609,11 @@ public class DocTermOrds implements Accountable {
     }
 
     @Override
+    public ImpactsEnum impacts(SimScorer scorer, int flags) throws IOException {
+      return termsEnum.impacts(scorer, flags);
+    }
+
+    @Override
     public BytesRef term() {
       return term;
     }


[2/3] lucene-solr:master: LUCENE-4198: Give codecs the opportunity to index impacts.

Posted by jp...@apache.org.
http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/core/src/java/org/apache/lucene/codecs/lucene50/Lucene50ScoreSkipReader.java
----------------------------------------------------------------------
diff --git a/lucene/core/src/java/org/apache/lucene/codecs/lucene50/Lucene50ScoreSkipReader.java b/lucene/core/src/java/org/apache/lucene/codecs/lucene50/Lucene50ScoreSkipReader.java
new file mode 100644
index 0000000..cb1f54a
--- /dev/null
+++ b/lucene/core/src/java/org/apache/lucene/codecs/lucene50/Lucene50ScoreSkipReader.java
@@ -0,0 +1,106 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.lucene.codecs.lucene50;
+
+import java.io.IOException;
+import java.util.Arrays;
+import java.util.Objects;
+
+import org.apache.lucene.search.similarities.Similarity.SimScorer;
+import org.apache.lucene.store.ByteArrayDataInput;
+import org.apache.lucene.store.IndexInput;
+import org.apache.lucene.util.ArrayUtil;
+
+final class Lucene50ScoreSkipReader extends Lucene50SkipReader {
+
+  private final SimScorer scorer;
+  private final float[] maxScore;
+  private final byte[][] impacts;
+  private final int[] impactsLength;
+  private final float globalMaxScore;
+  private final ByteArrayDataInput badi = new ByteArrayDataInput();
+
+  public Lucene50ScoreSkipReader(int version, IndexInput skipStream, int maxSkipLevels,
+      boolean hasPos, boolean hasOffsets, boolean hasPayloads, SimScorer scorer) {
+    super(version, skipStream, maxSkipLevels, hasPos, hasOffsets, hasPayloads);
+    if (version < Lucene50PostingsFormat.VERSION_IMPACT_SKIP_DATA) {
+      throw new IllegalStateException("Cannot skip based on scores if impacts are not indexed");
+    }
+    this.scorer = Objects.requireNonNull(scorer);
+    this.maxScore = new float[maxSkipLevels];
+    this.impacts = new byte[maxSkipLevels][];
+    Arrays.fill(impacts, new byte[0]);
+    this.impactsLength = new int[maxSkipLevels];
+    this.globalMaxScore = scorer.score(Float.MAX_VALUE, 1);
+  }
+
+  @Override
+  public void init(long skipPointer, long docBasePointer, long posBasePointer, long payBasePointer, int df) throws IOException {
+    super.init(skipPointer, docBasePointer, posBasePointer, payBasePointer, df);
+    Arrays.fill(impactsLength, 0);
+    Arrays.fill(maxScore, globalMaxScore);
+  }
+
+  /** Upper bound of scores up to {@code upTo} included. */
+  public float getMaxScore(int upTo) throws IOException {
+    for (int level = 0; level < numberOfSkipLevels; ++level) {
+      if (upTo <= skipDoc[level]) {
+        return maxScore(level);
+      }
+    }
+    return globalMaxScore;
+  }
+
+  private float maxScore(int level) throws IOException {
+    assert level < numberOfSkipLevels;
+    if (impactsLength[level] > 0) {
+      badi.reset(impacts[level], 0, impactsLength[level]);
+      maxScore[level] = readImpacts(badi, scorer);
+      impactsLength[level] = 0;
+    }
+    return maxScore[level];
+  }
+
+  @Override
+  protected void readImpacts(int level, IndexInput skipStream) throws IOException {
+    int length = skipStream.readVInt();
+    if (impacts[level].length < length) {
+      impacts[level] = new byte[ArrayUtil.oversize(length, Byte.BYTES)];
+    }
+    skipStream.readBytes(impacts[level], 0, length);
+    impactsLength[level] = length;
+  }
+
+  static float readImpacts(ByteArrayDataInput in, SimScorer scorer) throws IOException {
+    int freq = 0;
+    long norm = 0;
+    float maxScore = 0;
+    while (in.getPosition() < in.length()) {
+      int freqDelta = in.readVInt();
+      if ((freqDelta & 0x01) != 0) {
+        freq += 1 + (freqDelta >>> 1);
+        norm += 1 + in.readZLong();
+      } else {
+        freq += 1 + (freqDelta >>> 1);
+        norm++;
+      }
+      maxScore = Math.max(maxScore, scorer.score(freq, norm));
+    }
+    return maxScore;
+  }
+
+}

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/core/src/java/org/apache/lucene/codecs/lucene50/Lucene50SkipReader.java
----------------------------------------------------------------------
diff --git a/lucene/core/src/java/org/apache/lucene/codecs/lucene50/Lucene50SkipReader.java b/lucene/core/src/java/org/apache/lucene/codecs/lucene50/Lucene50SkipReader.java
index 8c037c5..b92cd42 100644
--- a/lucene/core/src/java/org/apache/lucene/codecs/lucene50/Lucene50SkipReader.java
+++ b/lucene/core/src/java/org/apache/lucene/codecs/lucene50/Lucene50SkipReader.java
@@ -52,7 +52,8 @@ import static org.apache.lucene.codecs.lucene50.Lucene50PostingsFormat.BLOCK_SIZ
  * Therefore, we'll trim df before passing it to the interface. see trim(int)
  *
  */
-final class Lucene50SkipReader extends MultiLevelSkipListReader {
+class Lucene50SkipReader extends MultiLevelSkipListReader {
+  private final int version;
   private long docPointer[];
   private long posPointer[];
   private long payPointer[];
@@ -65,8 +66,11 @@ final class Lucene50SkipReader extends MultiLevelSkipListReader {
   private long lastDocPointer;
   private int lastPosBufferUpto;
 
-  public Lucene50SkipReader(IndexInput skipStream, int maxSkipLevels, boolean hasPos, boolean hasOffsets, boolean hasPayloads) {
+  public Lucene50SkipReader(int version,
+      IndexInput skipStream, int maxSkipLevels,
+      boolean hasPos, boolean hasOffsets, boolean hasPayloads) {
     super(skipStream, maxSkipLevels, BLOCK_SIZE, 8);
+    this.version = version;
     docPointer = new long[maxSkipLevels];
     if (hasPos) {
       posPointer = new long[maxSkipLevels];
@@ -192,6 +196,17 @@ final class Lucene50SkipReader extends MultiLevelSkipListReader {
         payPointer[level] += skipStream.readVLong();
       }
     }
+    readImpacts(level, skipStream);
     return delta;
   }
+
+  // The default impl skips impacts since they are only useful if we have a SimScorer
+  // to compute the scores that impacts map to.
+  protected void readImpacts(int level, IndexInput skipStream) throws IOException {
+    if (version >= Lucene50PostingsFormat.VERSION_IMPACT_SKIP_DATA) {
+      // The base implementation skips impacts, they are not used
+      skipStream.skipBytes(skipStream.readVInt());
+    }
+  }
+
 }

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/core/src/java/org/apache/lucene/codecs/lucene50/Lucene50SkipWriter.java
----------------------------------------------------------------------
diff --git a/lucene/core/src/java/org/apache/lucene/codecs/lucene50/Lucene50SkipWriter.java b/lucene/core/src/java/org/apache/lucene/codecs/lucene50/Lucene50SkipWriter.java
index a4556c6..cc94ed0 100644
--- a/lucene/core/src/java/org/apache/lucene/codecs/lucene50/Lucene50SkipWriter.java
+++ b/lucene/core/src/java/org/apache/lucene/codecs/lucene50/Lucene50SkipWriter.java
@@ -19,9 +19,14 @@ package org.apache.lucene.codecs.lucene50;
 
 import java.io.IOException;
 import java.util.Arrays;
+import java.util.Set;
+import java.util.SortedSet;
 
-import org.apache.lucene.store.IndexOutput;
+import org.apache.lucene.codecs.CompetitiveFreqNormAccumulator;
+import org.apache.lucene.codecs.CompetitiveFreqNormAccumulator.FreqAndNorm;
 import org.apache.lucene.codecs.MultiLevelSkipListWriter;
+import org.apache.lucene.store.IndexOutput;
+import org.apache.lucene.store.RAMOutputStream;
 
 /**
  * Write skip lists with multiple levels, and support skip within block ints.
@@ -60,6 +65,7 @@ final class Lucene50SkipWriter extends MultiLevelSkipListWriter {
   private long curPayPointer;
   private int curPosBufferUpto;
   private int curPayloadByteUpto;
+  private CompetitiveFreqNormAccumulator[] curCompetitiveFreqNorms;
   private boolean fieldHasPositions;
   private boolean fieldHasOffsets;
   private boolean fieldHasPayloads;
@@ -79,6 +85,10 @@ final class Lucene50SkipWriter extends MultiLevelSkipListWriter {
       }
       lastPayloadByteUpto = new int[maxSkipLevels];
     }
+    curCompetitiveFreqNorms = new CompetitiveFreqNormAccumulator[maxSkipLevels];
+    for (int i = 0; i < maxSkipLevels; ++i) {
+      curCompetitiveFreqNorms[i] = new CompetitiveFreqNormAccumulator();
+    }
   }
 
   public void setField(boolean fieldHasPositions, boolean fieldHasOffsets, boolean fieldHasPayloads) {
@@ -105,10 +115,15 @@ final class Lucene50SkipWriter extends MultiLevelSkipListWriter {
         lastPayFP = payOut.getFilePointer();
       }
     }
+    if (initialized) {
+      for (CompetitiveFreqNormAccumulator acc : curCompetitiveFreqNorms) {
+        acc.clear();
+      }
+    }
     initialized = false;
   }
   
-  public void initSkip() {
+  private void initSkip() {
     if (!initialized) {
       super.resetSkip();
       Arrays.fill(lastSkipDoc, 0);
@@ -122,6 +137,11 @@ final class Lucene50SkipWriter extends MultiLevelSkipListWriter {
           Arrays.fill(lastSkipPayPointer, lastPayFP);
         }
       }
+      // sets of competitive freq,norm pairs should be empty at this point
+      assert Arrays.stream(curCompetitiveFreqNorms)
+          .map(CompetitiveFreqNormAccumulator::getCompetitiveFreqNormPairs)
+          .mapToInt(Set::size)
+          .sum() == 0;
       initialized = true;
     }
   }
@@ -129,7 +149,8 @@ final class Lucene50SkipWriter extends MultiLevelSkipListWriter {
   /**
    * Sets the values for the current skip data. 
    */
-  public void bufferSkip(int doc, int numDocs, long posFP, long payFP, int posBufferUpto, int payloadByteUpto) throws IOException {
+  public void bufferSkip(int doc, CompetitiveFreqNormAccumulator competitiveFreqNorms,
+      int numDocs, long posFP, long payFP, int posBufferUpto, int payloadByteUpto) throws IOException {
     initSkip();
     this.curDoc = doc;
     this.curDocPointer = docOut.getFilePointer();
@@ -137,11 +158,15 @@ final class Lucene50SkipWriter extends MultiLevelSkipListWriter {
     this.curPayPointer = payFP;
     this.curPosBufferUpto = posBufferUpto;
     this.curPayloadByteUpto = payloadByteUpto;
+    this.curCompetitiveFreqNorms[0].addAll(competitiveFreqNorms);
     bufferSkip(numDocs);
   }
-  
+
+  private final RAMOutputStream freqNormOut = new RAMOutputStream();
+
   @Override
   protected void writeSkipData(int level, IndexOutput skipBuffer) throws IOException {
+
     int delta = curDoc - lastSkipDoc[level];
 
     skipBuffer.writeVInt(delta);
@@ -165,5 +190,35 @@ final class Lucene50SkipWriter extends MultiLevelSkipListWriter {
         lastSkipPayPointer[level] = curPayPointer;
       }
     }
+
+    CompetitiveFreqNormAccumulator competitiveFreqNorms = curCompetitiveFreqNorms[level];
+    assert competitiveFreqNorms.getCompetitiveFreqNormPairs().size() > 0;
+    if (level + 1 < numberOfSkipLevels) {
+      curCompetitiveFreqNorms[level + 1].addAll(competitiveFreqNorms);
+    }
+    writeImpacts(competitiveFreqNorms, freqNormOut);
+    skipBuffer.writeVInt(Math.toIntExact(freqNormOut.getFilePointer()));
+    freqNormOut.writeTo(skipBuffer);
+    freqNormOut.reset();
+    competitiveFreqNorms.clear();
+  }
+
+  static void writeImpacts(CompetitiveFreqNormAccumulator acc, IndexOutput out) throws IOException {
+    SortedSet<FreqAndNorm> freqAndNorms = acc.getCompetitiveFreqNormPairs();
+    FreqAndNorm previous = new FreqAndNorm(0, 0);
+    for (FreqAndNorm freqAndNorm : freqAndNorms) {
+      assert freqAndNorm.freq > previous.freq;
+      assert Long.compareUnsigned(freqAndNorm.norm, previous.norm) > 0;
+      int freqDelta = freqAndNorm.freq - previous.freq - 1;
+      long normDelta = freqAndNorm.norm - previous.norm - 1;
+      if (normDelta == 0) {
+        // most of time, norm only increases by 1, so we can fold everything in a single byte
+        out.writeVInt(freqDelta << 1);
+      } else {
+        out.writeVInt((freqDelta << 1) | 1);
+        out.writeZLong(normDelta);
+      }
+      previous = freqAndNorm;
+    }
   }
 }

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/core/src/java/org/apache/lucene/codecs/lucene70/IndexedDISI.java
----------------------------------------------------------------------
diff --git a/lucene/core/src/java/org/apache/lucene/codecs/lucene70/IndexedDISI.java b/lucene/core/src/java/org/apache/lucene/codecs/lucene70/IndexedDISI.java
index 24eaf7a..6138896 100644
--- a/lucene/core/src/java/org/apache/lucene/codecs/lucene70/IndexedDISI.java
+++ b/lucene/core/src/java/org/apache/lucene/codecs/lucene70/IndexedDISI.java
@@ -100,7 +100,13 @@ final class IndexedDISI extends DocIdSetIterator {
   private final long cost;
 
   IndexedDISI(IndexInput in, long offset, long length, long cost) throws IOException {
-    this.slice = in.slice("docs", offset, length);
+    this(in.slice("docs", offset, length), cost);
+  }
+
+  // This constructor allows to pass the slice directly in case it helps reuse
+  // see eg. Lucene70 norms producer's merge instance
+  IndexedDISI(IndexInput slice, long cost) throws IOException {
+    this.slice = slice;
     this.cost = cost;
   }
 

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/core/src/java/org/apache/lucene/codecs/lucene70/Lucene70DocValuesProducer.java
----------------------------------------------------------------------
diff --git a/lucene/core/src/java/org/apache/lucene/codecs/lucene70/Lucene70DocValuesProducer.java b/lucene/core/src/java/org/apache/lucene/codecs/lucene70/Lucene70DocValuesProducer.java
index 386655e..7bea274 100644
--- a/lucene/core/src/java/org/apache/lucene/codecs/lucene70/Lucene70DocValuesProducer.java
+++ b/lucene/core/src/java/org/apache/lucene/codecs/lucene70/Lucene70DocValuesProducer.java
@@ -28,6 +28,7 @@ import org.apache.lucene.index.CorruptIndexException;
 import org.apache.lucene.index.DocValues;
 import org.apache.lucene.index.FieldInfo;
 import org.apache.lucene.index.FieldInfos;
+import org.apache.lucene.index.ImpactsEnum;
 import org.apache.lucene.index.IndexFileNames;
 import org.apache.lucene.index.NumericDocValues;
 import org.apache.lucene.index.PostingsEnum;
@@ -37,6 +38,7 @@ import org.apache.lucene.index.SortedNumericDocValues;
 import org.apache.lucene.index.SortedSetDocValues;
 import org.apache.lucene.index.TermsEnum;
 import org.apache.lucene.index.TermsEnum.SeekStatus;
+import org.apache.lucene.search.similarities.Similarity.SimScorer;
 import org.apache.lucene.store.ChecksumIndexInput;
 import org.apache.lucene.store.IndexInput;
 import org.apache.lucene.store.RandomAccessInput;
@@ -1158,6 +1160,11 @@ final class Lucene70DocValuesProducer extends DocValuesProducer implements Close
     }
 
     @Override
+    public ImpactsEnum impacts(SimScorer scorer, int flags) throws IOException {
+      throw new UnsupportedOperationException();
+    }
+
+    @Override
     public int docFreq() throws IOException {
       throw new UnsupportedOperationException();
     }

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/core/src/java/org/apache/lucene/codecs/lucene70/Lucene70NormsProducer.java
----------------------------------------------------------------------
diff --git a/lucene/core/src/java/org/apache/lucene/codecs/lucene70/Lucene70NormsProducer.java b/lucene/core/src/java/org/apache/lucene/codecs/lucene70/Lucene70NormsProducer.java
index eb7c41a..c7310e8 100644
--- a/lucene/core/src/java/org/apache/lucene/codecs/lucene70/Lucene70NormsProducer.java
+++ b/lucene/core/src/java/org/apache/lucene/codecs/lucene70/Lucene70NormsProducer.java
@@ -40,11 +40,14 @@ import org.apache.lucene.util.IOUtils;
 /**
  * Reader for {@link Lucene70NormsFormat}
  */
-final class Lucene70NormsProducer extends NormsProducer {
+final class Lucene70NormsProducer extends NormsProducer implements Cloneable {
   // metadata maps (just file pointers and minimal stuff)
   private final Map<Integer,NormsEntry> norms = new HashMap<>();
-  private final IndexInput data;
   private final int maxDoc;
+  private IndexInput data;
+  private boolean merging;
+  private Map<Integer, IndexInput> disiInputs;
+  private Map<Integer, RandomAccessInput> dataInputs;
 
   Lucene70NormsProducer(SegmentReadState state, String dataCodec, String dataExtension, String metaCodec, String metaExtension) throws IOException {
     maxDoc = state.segmentInfo.maxDoc();
@@ -87,6 +90,22 @@ final class Lucene70NormsProducer extends NormsProducer {
     }
   }
 
+  @Override
+  public NormsProducer getMergeInstance() throws IOException {
+    Lucene70NormsProducer clone;
+    try {
+      clone = (Lucene70NormsProducer) super.clone();
+    } catch (CloneNotSupportedException e) {
+      // cannot happen
+      throw new RuntimeException(e);
+    }
+    clone.data = data.clone();
+    clone.dataInputs = new HashMap<>();
+    clone.disiInputs = new HashMap<>();
+    clone.merging = true;
+    return clone;
+  }
+
   static class NormsEntry {
     byte bytesPerNorm;
     long docsWithFieldOffset;
@@ -193,6 +212,34 @@ final class Lucene70NormsProducer extends NormsProducer {
     }
   }
 
+  private RandomAccessInput getDataInput(FieldInfo field, NormsEntry entry) throws IOException {
+    RandomAccessInput slice = null;
+    if (merging) {
+      slice = dataInputs.get(field.number);
+    }
+    if (slice == null) {
+      slice = data.randomAccessSlice(entry.normsOffset, entry.numDocsWithField * (long) entry.bytesPerNorm);
+      if (merging) {
+        dataInputs.put(field.number, slice);
+      }
+    }
+    return slice;
+  }
+
+  private IndexInput getDisiInput(FieldInfo field, NormsEntry entry) throws IOException {
+    IndexInput slice = null;
+    if (merging) {
+      slice = disiInputs.get(field.number);
+    }
+    if (slice == null) {
+      slice = data.slice("docs", entry.docsWithFieldOffset, entry.docsWithFieldLength);
+      if (merging) {
+        disiInputs.put(field.number, slice);
+      }
+    }
+    return slice;
+  }
+
   @Override
   public NumericDocValues getNorms(FieldInfo field) throws IOException {
     final NormsEntry entry = norms.get(field.number);
@@ -209,7 +256,7 @@ final class Lucene70NormsProducer extends NormsProducer {
           }
         };
       }
-      final RandomAccessInput slice = data.randomAccessSlice(entry.normsOffset, entry.numDocsWithField * (long) entry.bytesPerNorm);
+      final RandomAccessInput slice = getDataInput(field, entry);
       switch (entry.bytesPerNorm) {
         case 1:
           return new DenseNormsIterator(maxDoc) {
@@ -245,7 +292,8 @@ final class Lucene70NormsProducer extends NormsProducer {
       }
     } else {
       // sparse
-      final IndexedDISI disi = new IndexedDISI(data, entry.docsWithFieldOffset, entry.docsWithFieldLength, entry.numDocsWithField);
+      final IndexInput disiInput = getDisiInput(field, entry);
+      final IndexedDISI disi = new IndexedDISI(disiInput, entry.numDocsWithField);
       if (entry.bytesPerNorm == 0) {
         return new SparseNormsIterator(disi) {
           @Override

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/core/src/java/org/apache/lucene/codecs/perfield/PerFieldPostingsFormat.java
----------------------------------------------------------------------
diff --git a/lucene/core/src/java/org/apache/lucene/codecs/perfield/PerFieldPostingsFormat.java b/lucene/core/src/java/org/apache/lucene/codecs/perfield/PerFieldPostingsFormat.java
index 281b08f..36f0358 100644
--- a/lucene/core/src/java/org/apache/lucene/codecs/perfield/PerFieldPostingsFormat.java
+++ b/lucene/core/src/java/org/apache/lucene/codecs/perfield/PerFieldPostingsFormat.java
@@ -34,6 +34,7 @@ import java.util.TreeSet;
 
 import org.apache.lucene.codecs.FieldsConsumer;
 import org.apache.lucene.codecs.FieldsProducer;
+import org.apache.lucene.codecs.NormsProducer;
 import org.apache.lucene.codecs.PostingsFormat;
 import org.apache.lucene.index.FieldInfo;
 import org.apache.lucene.index.Fields;
@@ -117,7 +118,7 @@ public abstract class PerFieldPostingsFormat extends PostingsFormat {
     }
 
     @Override
-    public void write(Fields fields) throws IOException {
+    public void write(Fields fields, NormsProducer norms) throws IOException {
       Map<PostingsFormat, FieldsGroup> formatToGroups = buildFieldsGroupMapping(fields);
 
       // Write postings
@@ -137,7 +138,7 @@ public abstract class PerFieldPostingsFormat extends PostingsFormat {
 
           FieldsConsumer consumer = format.fieldsConsumer(group.state);
           toClose.add(consumer);
-          consumer.write(maskedFields);
+          consumer.write(maskedFields, norms);
         }
         success = true;
       } finally {
@@ -148,7 +149,7 @@ public abstract class PerFieldPostingsFormat extends PostingsFormat {
     }
 
     @Override
-    public void merge(MergeState mergeState) throws IOException {
+    public void merge(MergeState mergeState, NormsProducer norms) throws IOException {
       Map<PostingsFormat, FieldsGroup> formatToGroups = buildFieldsGroupMapping(new MultiFields(mergeState.fieldsProducers, null));
 
       // Merge postings
@@ -161,7 +162,7 @@ public abstract class PerFieldPostingsFormat extends PostingsFormat {
 
           FieldsConsumer consumer = format.fieldsConsumer(group.state);
           toClose.add(consumer);
-          consumer.merge(pfMergeState.apply(group.fields));
+          consumer.merge(pfMergeState.apply(group.fields), norms);
         }
         success = true;
       } finally {

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/core/src/java/org/apache/lucene/index/CheckIndex.java
----------------------------------------------------------------------
diff --git a/lucene/core/src/java/org/apache/lucene/index/CheckIndex.java b/lucene/core/src/java/org/apache/lucene/index/CheckIndex.java
index c676568..7dd1aa9 100644
--- a/lucene/core/src/java/org/apache/lucene/index/CheckIndex.java
+++ b/lucene/core/src/java/org/apache/lucene/index/CheckIndex.java
@@ -48,6 +48,7 @@ import org.apache.lucene.search.DocIdSetIterator;
 import org.apache.lucene.search.LeafFieldComparator;
 import org.apache.lucene.search.Sort;
 import org.apache.lucene.search.SortField;
+import org.apache.lucene.search.similarities.Similarity.SimScorer;
 import org.apache.lucene.store.AlreadyClosedException;
 import org.apache.lucene.store.Directory;
 import org.apache.lucene.store.FSDirectory;
@@ -1598,8 +1599,109 @@ public final class CheckIndex implements Closeable {
             }
           }
         }
+
+        // Test score blocks
+        // We only score on freq to keep things simple and not pull norms
+        SimScorer scorer = new SimScorer(field) {
+          @Override
+          public float score(float freq, long norm) {
+            return freq;
+          }
+        };
+
+        // First check max scores and block uptos
+        int max = -1;
+        float maxScore = 0;
+        ImpactsEnum impacts = termsEnum.impacts(scorer, PostingsEnum.FREQS);
+        postings = termsEnum.postings(postings, PostingsEnum.FREQS);
+        for (int doc = impacts.nextDoc(); ; doc = impacts.nextDoc()) {
+          if (postings.nextDoc() != doc) {
+            throw new RuntimeException("Wrong next doc: " + doc + ", expected " + postings.docID());
+          }
+          if (doc == DocIdSetIterator.NO_MORE_DOCS) {
+            break;
+          }
+          if (postings.freq() != impacts.freq()) {
+            throw new RuntimeException("Wrong freq, expected " + postings.freq() + ", but got " + impacts.freq());
+          }
+          if (doc > max) {
+            max = impacts.advanceShallow(doc);
+            if (max < doc) {
+              throw new RuntimeException("max block doc id " + max + " must be greater than the target: " + doc);
+            }
+            maxScore = impacts.getMaxScore(max);
+          }
+          int max2 = impacts.advanceShallow(doc);
+          if (max != max2) {
+            throw new RuntimeException("max is not stable, initially had " + max + " but now " + max2);
+          }
+          float score = scorer.score(impacts.freq(), 1);
+          if (score > maxScore) {
+            throw new RuntimeException("score " + score + " is greater than the max score " + maxScore);
+          }
+        }
+
+        // Now check advancing
+        impacts = termsEnum.impacts(scorer, PostingsEnum.FREQS);
+        postings = termsEnum.postings(postings, PostingsEnum.FREQS);
+
+        max = -1;
+        while (true) {
+          int doc = impacts.docID();
+          boolean advance;
+          int target;
+          if (((field.hashCode() + doc) & 1) == 1) {
+            advance = false;
+            target = doc + 1;
+          } else {
+            advance = true;
+            int delta = Math.min(1 + ((31 * field.hashCode() + doc) & 0x1ff), DocIdSetIterator.NO_MORE_DOCS - doc);
+            target = impacts.docID() + delta;
+          }
+
+          if (target > max && target % 2 == 1) {
+            int delta = Math.min((31 * field.hashCode() + target) & 0x1ff, DocIdSetIterator.NO_MORE_DOCS - target);
+            max = target + delta;
+            int m = impacts.advanceShallow(target);
+            if (m < target) {
+              throw new RuntimeException("Block max doc: " + m + " is less than the target " + target);
+            }
+            maxScore = impacts.getMaxScore(max);
+          }
+
+          if (advance) {
+            doc = impacts.advance(target);
+          } else {
+            doc = impacts.nextDoc();
+          }
+
+          if (postings.advance(target) != doc) {
+            throw new RuntimeException("Impacts do not advance to the same document as postings for target " + target + ", postings: " + postings.docID() + ", impacts: " + doc);
+          }
+          if (doc == DocIdSetIterator.NO_MORE_DOCS) {
+            break;
+          }
+          if (postings.freq() != impacts.freq()) {
+            throw new RuntimeException("Wrong freq, expected " + postings.freq() + ", but got " + impacts.freq());
+          }
+
+          if (doc >= max) {
+            int delta = Math.min((31 * field.hashCode() + target & 0x1ff), DocIdSetIterator.NO_MORE_DOCS - doc);
+            max = doc + delta;
+            int m = impacts.advanceShallow(doc);
+            if (m < doc) {
+              throw new RuntimeException("Block max doc: " + m + " is less than the target " + doc);
+            }
+            maxScore = impacts.getMaxScore(max);
+          }
+
+          float score = scorer.score(impacts.freq(), 1);
+          if (score > maxScore) {
+            throw new RuntimeException("score " + score + " is greater than the max score " + maxScore);
+          }
+        }
       }
-      
+
       if (minTerm != null && status.termCount + status.delTermCount == 0) {
         throw new RuntimeException("field=\"" + field + "\": minTerm is non-null yet we saw no terms: " + minTerm);
       }

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/core/src/java/org/apache/lucene/index/DefaultIndexingChain.java
----------------------------------------------------------------------
diff --git a/lucene/core/src/java/org/apache/lucene/index/DefaultIndexingChain.java b/lucene/core/src/java/org/apache/lucene/index/DefaultIndexingChain.java
index fd24105..4e05aa6 100644
--- a/lucene/core/src/java/org/apache/lucene/index/DefaultIndexingChain.java
+++ b/lucene/core/src/java/org/apache/lucene/index/DefaultIndexingChain.java
@@ -31,6 +31,7 @@ import org.apache.lucene.codecs.DocValuesConsumer;
 import org.apache.lucene.codecs.DocValuesFormat;
 import org.apache.lucene.codecs.NormsConsumer;
 import org.apache.lucene.codecs.NormsFormat;
+import org.apache.lucene.codecs.NormsProducer;
 import org.apache.lucene.codecs.PointsFormat;
 import org.apache.lucene.codecs.PointsWriter;
 import org.apache.lucene.document.FieldType;
@@ -126,6 +127,7 @@ final class DefaultIndexingChain extends DocConsumer {
     if (docState.infoStream.isEnabled("IW")) {
       docState.infoStream.message("IW", ((System.nanoTime()-t0)/1000000) + " msec to write norms");
     }
+    SegmentReadState readState = new SegmentReadState(state.directory, state.segmentInfo, state.fieldInfos, IOContext.READ, state.segmentSuffix);
     
     t0 = System.nanoTime();
     writeDocValues(state, sortMap);
@@ -159,7 +161,16 @@ final class DefaultIndexingChain extends DocConsumer {
       }
     }
 
-    termsHash.flush(fieldsToFlush, state, sortMap);
+    try (NormsProducer norms = readState.fieldInfos.hasNorms()
+        ? state.segmentInfo.getCodec().normsFormat().normsProducer(readState)
+        : null) {
+      NormsProducer normsMergeInstance = null;
+      if (norms != null) {
+        // Use the merge instance in order to reuse the same IndexInput for all terms
+        normsMergeInstance = norms.getMergeInstance();
+      }
+      termsHash.flush(fieldsToFlush, state, sortMap, normsMergeInstance);
+    }
     if (docState.infoStream.isEnabled("IW")) {
       docState.infoStream.message("IW", ((System.nanoTime()-t0)/1000000) + " msec to write postings and finish vectors");
     }
@@ -693,6 +704,9 @@ final class DefaultIndexingChain extends DocConsumer {
           normValue = 0;
         } else {
           normValue = similarity.computeNorm(invertState);
+          if (normValue == 0) {
+            throw new IllegalStateException("Similarity " + similarity + " return 0 for non-empty field");
+          }
         }
         norms.addValue(docState.docID, normValue);
       }

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/core/src/java/org/apache/lucene/index/FilterLeafReader.java
----------------------------------------------------------------------
diff --git a/lucene/core/src/java/org/apache/lucene/index/FilterLeafReader.java b/lucene/core/src/java/org/apache/lucene/index/FilterLeafReader.java
index 0450038..4a9b660 100644
--- a/lucene/core/src/java/org/apache/lucene/index/FilterLeafReader.java
+++ b/lucene/core/src/java/org/apache/lucene/index/FilterLeafReader.java
@@ -20,6 +20,7 @@ package org.apache.lucene.index;
 import java.io.IOException;
 import java.util.Iterator;
 
+import org.apache.lucene.search.similarities.Similarity.SimScorer;
 import org.apache.lucene.util.AttributeSource;
 import org.apache.lucene.util.Bits;
 import org.apache.lucene.util.BytesRef;
@@ -214,6 +215,10 @@ public abstract class FilterLeafReader extends LeafReader {
       return in.postings(reuse, flags);
     }
 
+    @Override
+    public ImpactsEnum impacts(SimScorer scorer, int flags) throws IOException {
+      return in.impacts(scorer, flags);
+    }
   }
 
   /** Base class for filtering {@link PostingsEnum} implementations. */

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/core/src/java/org/apache/lucene/index/FilteredTermsEnum.java
----------------------------------------------------------------------
diff --git a/lucene/core/src/java/org/apache/lucene/index/FilteredTermsEnum.java b/lucene/core/src/java/org/apache/lucene/index/FilteredTermsEnum.java
index 6498dc0..411b435 100644
--- a/lucene/core/src/java/org/apache/lucene/index/FilteredTermsEnum.java
+++ b/lucene/core/src/java/org/apache/lucene/index/FilteredTermsEnum.java
@@ -20,6 +20,7 @@ package org.apache.lucene.index;
 import java.io.IOException;
 
 import org.apache.lucene.util.BytesRef;
+import org.apache.lucene.search.similarities.Similarity.SimScorer;
 import org.apache.lucene.util.AttributeSource;
 
 /**
@@ -181,7 +182,12 @@ public abstract class FilteredTermsEnum extends TermsEnum {
   public PostingsEnum postings(PostingsEnum reuse, int flags) throws IOException {
     return tenum.postings(reuse, flags);
   }
-  
+
+  @Override
+  public ImpactsEnum impacts(SimScorer scorer, int flags) throws IOException {
+    return tenum.impacts(scorer, flags);
+  }
+
   /** This enum does not support seeking!
    * @throws UnsupportedOperationException In general, subclasses do not
    *         support seeking.

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/core/src/java/org/apache/lucene/index/FreqProxFields.java
----------------------------------------------------------------------
diff --git a/lucene/core/src/java/org/apache/lucene/index/FreqProxFields.java b/lucene/core/src/java/org/apache/lucene/index/FreqProxFields.java
index fb78a92..c3e7d71 100644
--- a/lucene/core/src/java/org/apache/lucene/index/FreqProxFields.java
+++ b/lucene/core/src/java/org/apache/lucene/index/FreqProxFields.java
@@ -24,6 +24,7 @@ import java.util.List;
 import java.util.Map;
 
 import org.apache.lucene.index.FreqProxTermsWriterPerField.FreqProxPostingsArray;
+import org.apache.lucene.search.similarities.Similarity.SimScorer;
 import org.apache.lucene.util.AttributeSource;
 import org.apache.lucene.util.BytesRef;
 import org.apache.lucene.util.BytesRefBuilder;
@@ -273,6 +274,11 @@ class FreqProxFields extends Fields {
       return docsEnum;
     }
 
+    @Override
+    public ImpactsEnum impacts(SimScorer scorer, int flags) throws IOException {
+      throw new UnsupportedOperationException();
+    }
+
     /**
      * Expert: Returns the TermsEnums internal state to position the TermsEnum
      * without re-seeking the term dictionary.

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/core/src/java/org/apache/lucene/index/FreqProxTermsWriter.java
----------------------------------------------------------------------
diff --git a/lucene/core/src/java/org/apache/lucene/index/FreqProxTermsWriter.java b/lucene/core/src/java/org/apache/lucene/index/FreqProxTermsWriter.java
index d953f8d..ac70669 100644
--- a/lucene/core/src/java/org/apache/lucene/index/FreqProxTermsWriter.java
+++ b/lucene/core/src/java/org/apache/lucene/index/FreqProxTermsWriter.java
@@ -24,6 +24,7 @@ import java.util.List;
 import java.util.Map;
 
 import org.apache.lucene.codecs.FieldsConsumer;
+import org.apache.lucene.codecs.NormsProducer;
 import org.apache.lucene.util.CollectionUtil;
 import org.apache.lucene.util.IOUtils;
 
@@ -78,8 +79,9 @@ final class FreqProxTermsWriter extends TermsHash {
   }
 
   @Override
-  public void flush(Map<String,TermsHashPerField> fieldsToFlush, final SegmentWriteState state, Sorter.DocMap sortMap) throws IOException {
-    super.flush(fieldsToFlush, state, sortMap);
+  public void flush(Map<String,TermsHashPerField> fieldsToFlush, final SegmentWriteState state,
+      Sorter.DocMap sortMap, NormsProducer norms) throws IOException {
+    super.flush(fieldsToFlush, state, sortMap, norms);
 
     // Gather all fields that saw any postings:
     List<FreqProxTermsWriterPerField> allFields = new ArrayList<>();
@@ -105,7 +107,7 @@ final class FreqProxTermsWriter extends TermsHash {
     FieldsConsumer consumer = state.segmentInfo.getCodec().postingsFormat().fieldsConsumer(state);
     boolean success = false;
     try {
-      consumer.write(fields);
+      consumer.write(fields, norms);
       success = true;
     } finally {
       if (success) {

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/core/src/java/org/apache/lucene/index/ImpactsEnum.java
----------------------------------------------------------------------
diff --git a/lucene/core/src/java/org/apache/lucene/index/ImpactsEnum.java b/lucene/core/src/java/org/apache/lucene/index/ImpactsEnum.java
new file mode 100644
index 0000000..8deccff
--- /dev/null
+++ b/lucene/core/src/java/org/apache/lucene/index/ImpactsEnum.java
@@ -0,0 +1,53 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.lucene.index;
+
+import java.io.IOException;
+
+import org.apache.lucene.search.DocIdSetIterator;
+
+/**
+ * Extension of {@link PostingsEnum} which also provides information about the
+ * produced scores.
+ * @lucene.experimental
+ */
+public abstract class ImpactsEnum extends PostingsEnum {
+
+  /** Sole constructor. */
+  protected ImpactsEnum() {}
+
+  /**
+   * Advance to the block of documents that contains {@code target} in order to
+   * get scoring information about this block. This method is implicitly called
+   * by {@link DocIdSetIterator#advance(int)} and
+   * {@link DocIdSetIterator#nextDoc()}. Calling this method doesn't modify the
+   * current {@link DocIdSetIterator#docID()}.
+   * It returns a number that is greater than or equal to all documents
+   * contained in the current block, but less than any doc IDS of the next block.
+   * {@code target} must be &gt;= {@link #docID()} as well as all targets that
+   * have been passed to {@link #advanceShallow(int)} so far.
+   */
+  public abstract int advanceShallow(int target) throws IOException;
+
+  /**
+   * Return the maximum score that documents between the last {@code target}
+   * that this iterator was {@link #advanceShallow(int) shallow-advanced} to
+   * included and {@code upTo} included.
+   */
+  public abstract float getMaxScore(int upTo) throws IOException;
+
+}

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/core/src/java/org/apache/lucene/index/MultiTermsEnum.java
----------------------------------------------------------------------
diff --git a/lucene/core/src/java/org/apache/lucene/index/MultiTermsEnum.java b/lucene/core/src/java/org/apache/lucene/index/MultiTermsEnum.java
index 7db838b..7de8427 100644
--- a/lucene/core/src/java/org/apache/lucene/index/MultiTermsEnum.java
+++ b/lucene/core/src/java/org/apache/lucene/index/MultiTermsEnum.java
@@ -21,6 +21,7 @@ import java.io.IOException;
 import java.util.Arrays;
 import java.util.Comparator;
 
+import org.apache.lucene.search.similarities.Similarity.SimScorer;
 import org.apache.lucene.util.ArrayUtil;
 import org.apache.lucene.util.BytesRef;
 import org.apache.lucene.util.BytesRefBuilder;
@@ -367,6 +368,11 @@ public final class MultiTermsEnum extends TermsEnum {
     return docsEnum.reset(subDocs, upto);
   }
 
+  @Override
+  public ImpactsEnum impacts(SimScorer scorer, int flags) throws IOException {
+    throw new UnsupportedOperationException();
+  }
+
   final static class TermsEnumWithSlice {
     private final ReaderSlice subSlice;
     TermsEnum terms;

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/core/src/java/org/apache/lucene/index/SegmentMerger.java
----------------------------------------------------------------------
diff --git a/lucene/core/src/java/org/apache/lucene/index/SegmentMerger.java b/lucene/core/src/java/org/apache/lucene/index/SegmentMerger.java
index c67b92d..ad60a94 100644
--- a/lucene/core/src/java/org/apache/lucene/index/SegmentMerger.java
+++ b/lucene/core/src/java/org/apache/lucene/index/SegmentMerger.java
@@ -24,6 +24,7 @@ import org.apache.lucene.codecs.Codec;
 import org.apache.lucene.codecs.DocValuesConsumer;
 import org.apache.lucene.codecs.FieldsConsumer;
 import org.apache.lucene.codecs.NormsConsumer;
+import org.apache.lucene.codecs.NormsProducer;
 import org.apache.lucene.codecs.PointsWriter;
 import org.apache.lucene.codecs.StoredFieldsWriter;
 import org.apache.lucene.codecs.TermVectorsWriter;
@@ -109,10 +110,33 @@ final class SegmentMerger {
 
     final SegmentWriteState segmentWriteState = new SegmentWriteState(mergeState.infoStream, directory, mergeState.segmentInfo,
                                                                       mergeState.mergeFieldInfos, null, context);
+    final SegmentReadState segmentReadState = new SegmentReadState(directory, mergeState.segmentInfo, mergeState.mergeFieldInfos,
+                                                                   IOContext.READ, segmentWriteState.segmentSuffix);
+
+    if (mergeState.mergeFieldInfos.hasNorms()) {
+      if (mergeState.infoStream.isEnabled("SM")) {
+        t0 = System.nanoTime();
+      }
+      mergeNorms(segmentWriteState);
+      if (mergeState.infoStream.isEnabled("SM")) {
+        long t1 = System.nanoTime();
+        mergeState.infoStream.message("SM", ((t1-t0)/1000000) + " msec to merge norms [" + numMerged + " docs]");
+      }
+    }
+
     if (mergeState.infoStream.isEnabled("SM")) {
       t0 = System.nanoTime();
     }
-    mergeTerms(segmentWriteState);
+    try (NormsProducer norms = mergeState.mergeFieldInfos.hasNorms()
+        ? codec.normsFormat().normsProducer(segmentReadState)
+        : null) {
+      NormsProducer normsMergeInstance = null;
+      if (norms != null) {
+        // Use the merge instance in order to reuse the same IndexInput for all terms
+        normsMergeInstance = norms.getMergeInstance();
+      }
+      mergeTerms(segmentWriteState, normsMergeInstance);
+    }
     if (mergeState.infoStream.isEnabled("SM")) {
       long t1 = System.nanoTime();
       mergeState.infoStream.message("SM", ((t1-t0)/1000000) + " msec to merge postings [" + numMerged + " docs]");
@@ -139,17 +163,6 @@ final class SegmentMerger {
       long t1 = System.nanoTime();
       mergeState.infoStream.message("SM", ((t1-t0)/1000000) + " msec to merge points [" + numMerged + " docs]");
     }
-    
-    if (mergeState.mergeFieldInfos.hasNorms()) {
-      if (mergeState.infoStream.isEnabled("SM")) {
-        t0 = System.nanoTime();
-      }
-      mergeNorms(segmentWriteState);
-      if (mergeState.infoStream.isEnabled("SM")) {
-        long t1 = System.nanoTime();
-        mergeState.infoStream.message("SM", ((t1-t0)/1000000) + " msec to merge norms [" + numMerged + " docs]");
-      }
-    }
 
     if (mergeState.mergeFieldInfos.hasVectors()) {
       if (mergeState.infoStream.isEnabled("SM")) {
@@ -225,9 +238,9 @@ final class SegmentMerger {
     }
   }
 
-  private void mergeTerms(SegmentWriteState segmentWriteState) throws IOException {
+  private void mergeTerms(SegmentWriteState segmentWriteState, NormsProducer norms) throws IOException {
     try (FieldsConsumer consumer = codec.postingsFormat().fieldsConsumer(segmentWriteState)) {
-      consumer.merge(mergeState);
+      consumer.merge(mergeState, norms);
     }
   }
 }

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/core/src/java/org/apache/lucene/index/SlowImpactsEnum.java
----------------------------------------------------------------------
diff --git a/lucene/core/src/java/org/apache/lucene/index/SlowImpactsEnum.java b/lucene/core/src/java/org/apache/lucene/index/SlowImpactsEnum.java
new file mode 100644
index 0000000..9ba27e2
--- /dev/null
+++ b/lucene/core/src/java/org/apache/lucene/index/SlowImpactsEnum.java
@@ -0,0 +1,94 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.lucene.index;
+
+import java.io.IOException;
+
+import org.apache.lucene.util.BytesRef;
+
+/**
+ * {@link ImpactsEnum} that doesn't index impacts but implements the API in a
+ * legal way. This should typically be used for short postings that do not need
+ * skipping.
+ */
+public final class SlowImpactsEnum extends ImpactsEnum {
+
+  private final PostingsEnum delegate;
+  private final float maxScore;
+
+  /** Wrap the given {@link PostingsEnum}. */
+  public SlowImpactsEnum(PostingsEnum delegate, float maxScore) {
+    this.delegate = delegate;
+    this.maxScore = maxScore;
+  }
+
+  @Override
+  public int nextDoc() throws IOException {
+    return delegate.nextDoc();
+  }
+
+  @Override
+  public int docID() {
+    return delegate.docID();
+  }
+
+  @Override
+  public long cost() {
+    return delegate.cost();
+  }
+
+  @Override
+  public int advance(int target) throws IOException {
+    return delegate.advance(target);
+  }
+
+  @Override
+  public int startOffset() throws IOException {
+    return delegate.startOffset();
+  }
+
+  @Override
+  public int nextPosition() throws IOException {
+    return delegate.nextPosition();
+  }
+
+  @Override
+  public BytesRef getPayload() throws IOException {
+    return delegate.getPayload();
+  }
+
+  @Override
+  public int freq() throws IOException {
+    return delegate.freq();
+  }
+
+  @Override
+  public int endOffset() throws IOException {
+    return delegate.endOffset();
+  }
+
+  @Override
+  public int advanceShallow(int target) {
+    return NO_MORE_DOCS;
+  }
+
+  @Override
+  public float getMaxScore(int maxDoc) {
+    return maxScore;
+  }
+
+}

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/core/src/java/org/apache/lucene/index/SortedDocValuesTermsEnum.java
----------------------------------------------------------------------
diff --git a/lucene/core/src/java/org/apache/lucene/index/SortedDocValuesTermsEnum.java b/lucene/core/src/java/org/apache/lucene/index/SortedDocValuesTermsEnum.java
index ccee7a3..70d4387 100644
--- a/lucene/core/src/java/org/apache/lucene/index/SortedDocValuesTermsEnum.java
+++ b/lucene/core/src/java/org/apache/lucene/index/SortedDocValuesTermsEnum.java
@@ -19,6 +19,7 @@ package org.apache.lucene.index;
 
 import java.io.IOException;
 
+import org.apache.lucene.search.similarities.Similarity.SimScorer;
 import org.apache.lucene.util.BytesRef;
 import org.apache.lucene.util.BytesRefBuilder;
 
@@ -110,6 +111,11 @@ class SortedDocValuesTermsEnum extends TermsEnum {
   }
 
   @Override
+  public ImpactsEnum impacts(SimScorer scorer, int flags) throws IOException {
+    throw new UnsupportedOperationException();
+  }
+
+  @Override
   public void seekExact(BytesRef term, TermState state) throws IOException {
     assert state != null && state instanceof OrdTermState;
     this.seekExact(((OrdTermState)state).ord);

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/core/src/java/org/apache/lucene/index/SortedSetDocValuesTermsEnum.java
----------------------------------------------------------------------
diff --git a/lucene/core/src/java/org/apache/lucene/index/SortedSetDocValuesTermsEnum.java b/lucene/core/src/java/org/apache/lucene/index/SortedSetDocValuesTermsEnum.java
index eba95c9..9099ac8 100644
--- a/lucene/core/src/java/org/apache/lucene/index/SortedSetDocValuesTermsEnum.java
+++ b/lucene/core/src/java/org/apache/lucene/index/SortedSetDocValuesTermsEnum.java
@@ -17,6 +17,7 @@
 package org.apache.lucene.index;
 
 
+import org.apache.lucene.search.similarities.Similarity.SimScorer;
 import org.apache.lucene.util.BytesRef;
 import org.apache.lucene.util.BytesRefBuilder;
 
@@ -110,6 +111,11 @@ class SortedSetDocValuesTermsEnum extends TermsEnum {
   }
 
   @Override
+  public ImpactsEnum impacts(SimScorer scorer, int flags) throws IOException {
+    throw new UnsupportedOperationException();
+  }
+
+  @Override
   public void seekExact(BytesRef term, TermState state) throws IOException {
     assert state != null && state instanceof OrdTermState;
     this.seekExact(((OrdTermState)state).ord);

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/core/src/java/org/apache/lucene/index/SortingTermVectorsConsumer.java
----------------------------------------------------------------------
diff --git a/lucene/core/src/java/org/apache/lucene/index/SortingTermVectorsConsumer.java b/lucene/core/src/java/org/apache/lucene/index/SortingTermVectorsConsumer.java
index dff808e..054ca50 100644
--- a/lucene/core/src/java/org/apache/lucene/index/SortingTermVectorsConsumer.java
+++ b/lucene/core/src/java/org/apache/lucene/index/SortingTermVectorsConsumer.java
@@ -21,6 +21,7 @@ import java.io.IOException;
 import java.util.Iterator;
 import java.util.Map;
 
+import org.apache.lucene.codecs.NormsProducer;
 import org.apache.lucene.codecs.TermVectorsReader;
 import org.apache.lucene.codecs.TermVectorsWriter;
 import org.apache.lucene.search.DocIdSetIterator;
@@ -37,8 +38,8 @@ final class SortingTermVectorsConsumer extends TermVectorsConsumer {
   }
 
   @Override
-  void flush(Map<String, TermsHashPerField> fieldsToFlush, final SegmentWriteState state, Sorter.DocMap sortMap) throws IOException {
-    super.flush(fieldsToFlush, state, sortMap);
+  void flush(Map<String, TermsHashPerField> fieldsToFlush, final SegmentWriteState state, Sorter.DocMap sortMap, NormsProducer norms) throws IOException {
+    super.flush(fieldsToFlush, state, sortMap, norms);
     if (tmpDirectory != null) {
       if (sortMap == null) {
         // we're lucky the index is already sorted, just rename the temporary file and return

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/core/src/java/org/apache/lucene/index/TermVectorsConsumer.java
----------------------------------------------------------------------
diff --git a/lucene/core/src/java/org/apache/lucene/index/TermVectorsConsumer.java b/lucene/core/src/java/org/apache/lucene/index/TermVectorsConsumer.java
index 46dc63c..1ac20dd 100644
--- a/lucene/core/src/java/org/apache/lucene/index/TermVectorsConsumer.java
+++ b/lucene/core/src/java/org/apache/lucene/index/TermVectorsConsumer.java
@@ -21,6 +21,7 @@ import java.io.IOException;
 import java.util.Arrays;
 import java.util.Map;
 
+import org.apache.lucene.codecs.NormsProducer;
 import org.apache.lucene.codecs.TermVectorsWriter;
 import org.apache.lucene.store.FlushInfo;
 import org.apache.lucene.store.IOContext;
@@ -53,7 +54,7 @@ class TermVectorsConsumer extends TermsHash {
   }
 
   @Override
-  void flush(Map<String, TermsHashPerField> fieldsToFlush, final SegmentWriteState state, Sorter.DocMap sortMap) throws IOException {
+  void flush(Map<String, TermsHashPerField> fieldsToFlush, final SegmentWriteState state, Sorter.DocMap sortMap, NormsProducer norms) throws IOException {
     if (writer != null) {
       int numDocs = state.segmentInfo.maxDoc();
       assert numDocs > 0;

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/core/src/java/org/apache/lucene/index/TermsEnum.java
----------------------------------------------------------------------
diff --git a/lucene/core/src/java/org/apache/lucene/index/TermsEnum.java b/lucene/core/src/java/org/apache/lucene/index/TermsEnum.java
index 4b5755a..7bbb3f7 100644
--- a/lucene/core/src/java/org/apache/lucene/index/TermsEnum.java
+++ b/lucene/core/src/java/org/apache/lucene/index/TermsEnum.java
@@ -19,6 +19,7 @@ package org.apache.lucene.index;
 
 import java.io.IOException;
 
+import org.apache.lucene.search.similarities.Similarity.SimScorer;
 import org.apache.lucene.util.AttributeSource;
 import org.apache.lucene.util.BytesRef;
 import org.apache.lucene.util.BytesRefIterator;
@@ -171,6 +172,12 @@ public abstract class TermsEnum implements BytesRefIterator {
   public abstract PostingsEnum postings(PostingsEnum reuse, int flags) throws IOException;
 
   /**
+   * Return a {@link ImpactsEnum} that computes impacts with {@code scorer}.
+   * @see #postings(PostingsEnum, int)
+   */
+  public abstract ImpactsEnum impacts(SimScorer scorer, int flags) throws IOException;
+  
+  /**
    * Expert: Returns the TermsEnums internal state to position the TermsEnum
    * without re-seeking the term dictionary.
    * <p>
@@ -228,7 +235,12 @@ public abstract class TermsEnum implements BytesRefIterator {
     public PostingsEnum postings(PostingsEnum reuse, int flags) {
       throw new IllegalStateException("this method should never be called");
     }
-      
+
+    @Override
+    public ImpactsEnum impacts(SimScorer scorer, int flags) throws IOException {
+      throw new IllegalStateException("this method should never be called");
+    }
+
     @Override
     public BytesRef next() {
       return null;

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/core/src/java/org/apache/lucene/index/TermsHash.java
----------------------------------------------------------------------
diff --git a/lucene/core/src/java/org/apache/lucene/index/TermsHash.java b/lucene/core/src/java/org/apache/lucene/index/TermsHash.java
index bede2f8..f420aca 100644
--- a/lucene/core/src/java/org/apache/lucene/index/TermsHash.java
+++ b/lucene/core/src/java/org/apache/lucene/index/TermsHash.java
@@ -21,6 +21,7 @@ import java.io.IOException;
 import java.util.HashMap;
 import java.util.Map;
 
+import org.apache.lucene.codecs.NormsProducer;
 import org.apache.lucene.util.ByteBlockPool;
 import org.apache.lucene.util.Counter;
 import org.apache.lucene.util.IntBlockPool;
@@ -76,13 +77,14 @@ abstract class TermsHash {
     bytePool.reset(false, false);
   }
 
-  void flush(Map<String,TermsHashPerField> fieldsToFlush, final SegmentWriteState state, Sorter.DocMap sortMap) throws IOException {
+  void flush(Map<String,TermsHashPerField> fieldsToFlush, final SegmentWriteState state,
+      Sorter.DocMap sortMap, NormsProducer norms) throws IOException {
     if (nextTermsHash != null) {
       Map<String,TermsHashPerField> nextChildFields = new HashMap<>();
       for (final Map.Entry<String,TermsHashPerField> entry : fieldsToFlush.entrySet()) {
         nextChildFields.put(entry.getKey(), entry.getValue().nextPerField);
       }
-      nextTermsHash.flush(nextChildFields, state, sortMap);
+      nextTermsHash.flush(nextChildFields, state, sortMap, norms);
     }
   }
 

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/core/src/java/org/apache/lucene/search/FuzzyTermsEnum.java
----------------------------------------------------------------------
diff --git a/lucene/core/src/java/org/apache/lucene/search/FuzzyTermsEnum.java b/lucene/core/src/java/org/apache/lucene/search/FuzzyTermsEnum.java
index 881c5dd..72f9473 100644
--- a/lucene/core/src/java/org/apache/lucene/search/FuzzyTermsEnum.java
+++ b/lucene/core/src/java/org/apache/lucene/search/FuzzyTermsEnum.java
@@ -17,11 +17,13 @@
 package org.apache.lucene.search;
 
 
+import org.apache.lucene.index.ImpactsEnum;
 import org.apache.lucene.index.PostingsEnum;
 import org.apache.lucene.index.Term;
 import org.apache.lucene.index.TermState;
 import org.apache.lucene.index.Terms;
 import org.apache.lucene.index.TermsEnum;
+import org.apache.lucene.search.similarities.Similarity.SimScorer;
 import org.apache.lucene.util.Attribute;
 import org.apache.lucene.util.AttributeImpl;
 import org.apache.lucene.util.AttributeReflector;
@@ -273,6 +275,11 @@ public final class FuzzyTermsEnum extends TermsEnum {
   }
   
   @Override
+  public ImpactsEnum impacts(SimScorer scorer, int flags) throws IOException {
+    return actualEnum.impacts(scorer, flags);
+  }
+  
+  @Override
   public void seekExact(BytesRef term, TermState state) throws IOException {
     actualEnum.seekExact(term, state);
   }

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/core/src/java/org/apache/lucene/search/LeafSimScorer.java
----------------------------------------------------------------------
diff --git a/lucene/core/src/java/org/apache/lucene/search/LeafSimScorer.java b/lucene/core/src/java/org/apache/lucene/search/LeafSimScorer.java
index 5de8295..f3dc5ea 100644
--- a/lucene/core/src/java/org/apache/lucene/search/LeafSimScorer.java
+++ b/lucene/core/src/java/org/apache/lucene/search/LeafSimScorer.java
@@ -40,6 +40,11 @@ public final class LeafSimScorer {
     maxScore = needsScores ? scorer.score(maxFreq, 1) : Float.MAX_VALUE;
   }
 
+  /** Return the wrapped {@link SimScorer}. */
+  public SimScorer getSimScorer() {
+    return scorer;
+  }
+
   private long getNormValue(int doc) throws IOException {
     if (norms != null) {
       boolean found = norms.advanceExact(doc);

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/core/src/java/org/apache/lucene/search/SynonymQuery.java
----------------------------------------------------------------------
diff --git a/lucene/core/src/java/org/apache/lucene/search/SynonymQuery.java b/lucene/core/src/java/org/apache/lucene/search/SynonymQuery.java
index d9335cf..1eba910 100644
--- a/lucene/core/src/java/org/apache/lucene/search/SynonymQuery.java
+++ b/lucene/core/src/java/org/apache/lucene/search/SynonymQuery.java
@@ -29,7 +29,6 @@ import org.apache.lucene.index.FieldInfo;
 import org.apache.lucene.index.IndexOptions;
 import org.apache.lucene.index.IndexReader;
 import org.apache.lucene.index.LeafReaderContext;
-import org.apache.lucene.index.PostingsEnum;
 import org.apache.lucene.index.Term;
 import org.apache.lucene.index.TermStates;
 import org.apache.lucene.index.TermState;
@@ -208,9 +207,8 @@ public final class SynonymQuery extends Query {
           termsEnum.seekExact(terms[i].bytes(), state);
           long termMaxFreq = getMaxFreq(indexOptions, termsEnum.totalTermFreq(), termsEnum.docFreq());
           totalMaxFreq += termMaxFreq;
-          PostingsEnum postings = termsEnum.postings(null, PostingsEnum.FREQS);
           LeafSimScorer simScorer = new LeafSimScorer(simWeight, context.reader(), true, termMaxFreq);
-          subScorers.add(new TermScorer(this, postings, simScorer));
+          subScorers.add(new TermScorer(this, termsEnum, ScoreMode.COMPLETE, simScorer));
         }
       }
       if (subScorers.isEmpty()) {

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/core/src/java/org/apache/lucene/search/TermQuery.java
----------------------------------------------------------------------
diff --git a/lucene/core/src/java/org/apache/lucene/search/TermQuery.java b/lucene/core/src/java/org/apache/lucene/search/TermQuery.java
index d629acd..f1f4415 100644
--- a/lucene/core/src/java/org/apache/lucene/search/TermQuery.java
+++ b/lucene/core/src/java/org/apache/lucene/search/TermQuery.java
@@ -25,7 +25,6 @@ import org.apache.lucene.index.IndexOptions;
 import org.apache.lucene.index.IndexReaderContext;
 import org.apache.lucene.index.LeafReader;
 import org.apache.lucene.index.LeafReaderContext;
-import org.apache.lucene.index.PostingsEnum;
 import org.apache.lucene.index.ReaderUtil;
 import org.apache.lucene.index.Term;
 import org.apache.lucene.index.TermStates;
@@ -46,21 +45,21 @@ public class TermQuery extends Query {
     private final Similarity similarity;
     private final Similarity.SimScorer simScorer;
     private final TermStates termStates;
-    private final boolean needsScores;
+    private final ScoreMode scoreMode;
 
-    public TermWeight(IndexSearcher searcher, boolean needsScores,
+    public TermWeight(IndexSearcher searcher, ScoreMode scoreMode,
         float boost, TermStates termStates) throws IOException {
       super(TermQuery.this);
-      if (needsScores && termStates == null) {
+      if (scoreMode.needsScores() && termStates == null) {
         throw new IllegalStateException("termStates are required when scores are needed");
       }
-      this.needsScores = needsScores;
+      this.scoreMode = scoreMode;
       this.termStates = termStates;
       this.similarity = searcher.getSimilarity();
 
       final CollectionStatistics collectionStats;
       final TermStatistics termStats;
-      if (needsScores) {
+      if (scoreMode.needsScores()) {
         collectionStats = searcher.collectionStatistics(term.field());
         termStats = searcher.termStatistics(term, termStates);
       } else {
@@ -97,10 +96,9 @@ public class TermQuery extends Query {
           .getFieldInfos()
           .fieldInfo(getTerm().field())
           .getIndexOptions();
-      PostingsEnum docs = termsEnum.postings(null, needsScores ? PostingsEnum.FREQS : PostingsEnum.NONE);
-      assert docs != null;
       float maxFreq = getMaxFreq(indexOptions, termsEnum.totalTermFreq(), termsEnum.docFreq());
-      return new TermScorer(this, docs, new LeafSimScorer(simScorer, context.reader(), needsScores, maxFreq));
+      LeafSimScorer scorer = new LeafSimScorer(simScorer, context.reader(), scoreMode.needsScores(), maxFreq);
+      return new TermScorer(this, termsEnum, scoreMode, scorer);
     }
 
     private long getMaxFreq(IndexOptions indexOptions, long ttf, long df) {
@@ -198,7 +196,7 @@ public class TermQuery extends Query {
       termState = this.perReaderTermState;
     }
 
-    return new TermWeight(searcher, scoreMode.needsScores(), boost, termState);
+    return new TermWeight(searcher, scoreMode, boost, termState);
   }
 
   /** Prints a user-readable version of this query. */

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/core/src/java/org/apache/lucene/search/TermScorer.java
----------------------------------------------------------------------
diff --git a/lucene/core/src/java/org/apache/lucene/search/TermScorer.java b/lucene/core/src/java/org/apache/lucene/search/TermScorer.java
index 653a60e..fc426da 100644
--- a/lucene/core/src/java/org/apache/lucene/search/TermScorer.java
+++ b/lucene/core/src/java/org/apache/lucene/search/TermScorer.java
@@ -19,29 +19,92 @@ package org.apache.lucene.search;
 
 import java.io.IOException;
 
+import org.apache.lucene.index.ImpactsEnum;
 import org.apache.lucene.index.PostingsEnum;
+import org.apache.lucene.index.TermsEnum;
 
 /** Expert: A <code>Scorer</code> for documents matching a <code>Term</code>.
  */
 final class TermScorer extends Scorer {
   private final PostingsEnum postingsEnum;
+  private final DocIdSetIterator iterator;
   private final LeafSimScorer docScorer;
+  private float minCompetitiveScore;
 
   /**
    * Construct a <code>TermScorer</code>.
    *
    * @param weight
    *          The weight of the <code>Term</code> in the query.
-   * @param td
-   *          An iterator over the documents matching the <code>Term</code>.
+   * @param te
+   *          A {@link TermsEnum} positioned on the expected term.
    * @param docScorer
-   *          The <code>Similarity.SimScorer</code> implementation
-   *          to be used for score computations.
+   *          A {@link LeafSimScorer} for the appropriate field.
    */
-  TermScorer(Weight weight, PostingsEnum td, LeafSimScorer docScorer) {
+  TermScorer(Weight weight, TermsEnum te, ScoreMode scoreMode, LeafSimScorer docScorer) throws IOException {
     super(weight);
     this.docScorer = docScorer;
-    this.postingsEnum = td;
+    if (scoreMode == ScoreMode.TOP_SCORES) {
+      ImpactsEnum impactsEnum = te.impacts(docScorer.getSimScorer(), PostingsEnum.FREQS);
+      postingsEnum = impactsEnum;
+      iterator = new DocIdSetIterator() {
+
+        int upTo = -1;
+        float maxScore;
+
+        private int advanceTarget(int target) throws IOException {
+          if (minCompetitiveScore == 0) {
+            // no potential for skipping
+            return target;
+          }
+
+          if (target > upTo) {
+            upTo = impactsEnum.advanceShallow(target);
+            maxScore = impactsEnum.getMaxScore(upTo);
+          }
+
+          while (true) {
+            assert upTo >= target;
+
+            if (maxScore >= minCompetitiveScore) {
+              return target;
+            }
+
+            if (upTo == NO_MORE_DOCS) {
+              return NO_MORE_DOCS;
+            }
+
+            target = upTo + 1;
+
+            upTo = impactsEnum.advanceShallow(target);
+            maxScore = impactsEnum.getMaxScore(upTo);
+          }
+        }
+
+        @Override
+        public int advance(int target) throws IOException {
+          return impactsEnum.advance(advanceTarget(target));
+        }
+
+        @Override
+        public int nextDoc() throws IOException {
+          return advance(impactsEnum.docID() + 1);
+        }
+
+        @Override
+        public int docID() {
+          return impactsEnum.docID();
+        }
+
+        @Override
+        public long cost() {
+          return impactsEnum.cost();
+        }
+      };
+    } else {
+      postingsEnum = te.postings(null, scoreMode.needsScores() ? PostingsEnum.FREQS : PostingsEnum.NONE);
+      iterator = postingsEnum;
+    }
   }
 
   @Override
@@ -55,7 +118,7 @@ final class TermScorer extends Scorer {
 
   @Override
   public DocIdSetIterator iterator() {
-    return postingsEnum;
+    return iterator;
   }
 
   @Override
@@ -69,6 +132,11 @@ final class TermScorer extends Scorer {
     return docScorer.maxScore();
   }
 
+  @Override
+  public void setMinCompetitiveScore(float minScore) {
+    this.minCompetitiveScore = minScore;
+  }
+
   /** Returns a string representation of this <code>TermScorer</code>. */
   @Override
   public String toString() { return "scorer(" + weight + ")[" + super.toString() + "]"; }

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/core/src/test/org/apache/lucene/codecs/TestCompetitiveFreqNormAccumulator.java
----------------------------------------------------------------------
diff --git a/lucene/core/src/test/org/apache/lucene/codecs/TestCompetitiveFreqNormAccumulator.java b/lucene/core/src/test/org/apache/lucene/codecs/TestCompetitiveFreqNormAccumulator.java
new file mode 100644
index 0000000..5743e64
--- /dev/null
+++ b/lucene/core/src/test/org/apache/lucene/codecs/TestCompetitiveFreqNormAccumulator.java
@@ -0,0 +1,104 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.lucene.codecs;
+
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.Set;
+
+import org.apache.lucene.codecs.CompetitiveFreqNormAccumulator.FreqAndNorm;
+import org.apache.lucene.util.LuceneTestCase;
+
+public class TestCompetitiveFreqNormAccumulator extends LuceneTestCase {
+
+  public void testBasics() {
+    CompetitiveFreqNormAccumulator acc = new CompetitiveFreqNormAccumulator();
+    Set<FreqAndNorm> expected = new HashSet<>();
+
+    acc.add(3, 5);
+    expected.add(new FreqAndNorm(3, 5));
+    assertEquals(expected, acc.getCompetitiveFreqNormPairs());
+
+    acc.add(6, 11);
+    expected.add(new FreqAndNorm(6, 11));
+    assertEquals(expected, acc.getCompetitiveFreqNormPairs());
+
+    acc.add(10, 13);
+    expected.add(new FreqAndNorm(10, 13));
+    assertEquals(expected, acc.getCompetitiveFreqNormPairs());
+    
+    acc.add(1, 2);
+    expected.add(new FreqAndNorm(1, 2));
+    assertEquals(expected, acc.getCompetitiveFreqNormPairs());
+
+    acc.add(7, 9);
+    expected.remove(new FreqAndNorm(6, 11));
+    expected.add(new FreqAndNorm(7, 9));
+    assertEquals(expected, acc.getCompetitiveFreqNormPairs());
+
+    acc.add(8, 2);
+    expected.clear();
+    expected.add(new FreqAndNorm(10, 13));
+    expected.add(new FreqAndNorm(8, 2));
+    assertEquals(expected, acc.getCompetitiveFreqNormPairs());
+  }
+
+  public void testExtremeNorms() {
+    CompetitiveFreqNormAccumulator acc = new CompetitiveFreqNormAccumulator();
+    Set<FreqAndNorm> expected = new HashSet<>();
+
+    acc.add(3, 5);
+    expected.add(new FreqAndNorm(3, 5));
+    assertEquals(expected, acc.getCompetitiveFreqNormPairs());
+
+    acc.add(10, 10000);
+    expected.add(new FreqAndNorm(10, 10000));
+    assertEquals(expected, acc.getCompetitiveFreqNormPairs());
+
+    acc.add(5, 200);
+    expected.add(new FreqAndNorm(5, 200));
+    assertEquals(expected, acc.getCompetitiveFreqNormPairs());
+
+    acc.add(20, -100);
+    expected.add(new FreqAndNorm(20, -100));
+    assertEquals(expected, acc.getCompetitiveFreqNormPairs());
+
+    acc.add(30, -3);
+    expected.add(new FreqAndNorm(30, -3));
+    assertEquals(expected, acc.getCompetitiveFreqNormPairs());
+  }
+
+  public void testOmitFreqs() {
+    CompetitiveFreqNormAccumulator acc = new CompetitiveFreqNormAccumulator();
+
+    acc.add(1, 5);
+    acc.add(1, 7);
+    acc.add(1, 4);
+
+    assertEquals(Collections.singleton(new FreqAndNorm(1, 4)), acc.getCompetitiveFreqNormPairs());
+  }
+
+  public void testOmitNorms() {
+    CompetitiveFreqNormAccumulator acc = new CompetitiveFreqNormAccumulator();
+
+    acc.add(5, 1);
+    acc.add(7, 1);
+    acc.add(4, 1);
+
+    assertEquals(Collections.singleton(new FreqAndNorm(7, 1)), acc.getCompetitiveFreqNormPairs());
+  }
+}

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/core/src/test/org/apache/lucene/codecs/lucene50/TestBlockPostingsFormat.java
----------------------------------------------------------------------
diff --git a/lucene/core/src/test/org/apache/lucene/codecs/lucene50/TestBlockPostingsFormat.java b/lucene/core/src/test/org/apache/lucene/codecs/lucene50/TestBlockPostingsFormat.java
index f2ed86c..d507b7b 100644
--- a/lucene/core/src/test/org/apache/lucene/codecs/lucene50/TestBlockPostingsFormat.java
+++ b/lucene/core/src/test/org/apache/lucene/codecs/lucene50/TestBlockPostingsFormat.java
@@ -17,8 +17,11 @@
 package org.apache.lucene.codecs.lucene50;
 
 
+import java.io.IOException;
+
 import org.apache.lucene.analysis.MockAnalyzer;
 import org.apache.lucene.codecs.Codec;
+import org.apache.lucene.codecs.CompetitiveFreqNormAccumulator;
 import org.apache.lucene.codecs.blocktree.FieldReader;
 import org.apache.lucene.codecs.blocktree.Stats;
 import org.apache.lucene.document.Document;
@@ -27,7 +30,12 @@ import org.apache.lucene.index.BasePostingsFormatTestCase;
 import org.apache.lucene.index.DirectoryReader;
 import org.apache.lucene.index.IndexWriter;
 import org.apache.lucene.index.IndexWriterConfig;
+import org.apache.lucene.search.similarities.Similarity.SimScorer;
+import org.apache.lucene.store.ByteArrayDataInput;
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
+import org.apache.lucene.store.IndexInput;
+import org.apache.lucene.store.IndexOutput;
 import org.apache.lucene.util.TestUtil;
 
 /**
@@ -78,4 +86,56 @@ public class TestBlockPostingsFormat extends BasePostingsFormatTestCase {
     shouldFail(10, -1);
     shouldFail(10, 12);
   }
+
+  public void testImpactSerialization() throws IOException {
+    // omit norms and omit freqs
+    doTestImpactSerialization(new int[] { 1 }, new long[] { 1L });
+
+    // omit freqs
+    doTestImpactSerialization(new int[] { 1 }, new long[] { 42L });
+    // omit freqs with very large norms
+    doTestImpactSerialization(new int[] { 1 }, new long[] { -100L });
+
+    // omit norms
+    doTestImpactSerialization(new int[] { 30 }, new long[] { 1L });
+    // omit norms with large freq
+    doTestImpactSerialization(new int[] { 500 }, new long[] { 1L });
+
+    // freqs and norms, basic
+    doTestImpactSerialization(
+        new int[] { 1, 3, 7, 15, 20, 28 },
+        new long[] { 7L, 9L, 10L, 11L, 13L, 14L });
+
+    // freqs and norms, high values
+    doTestImpactSerialization(
+        new int[] { 2, 10, 12, 50, 1000, 1005 },
+        new long[] { 2L, 10L, 50L, -100L, -80L, -3L });
+  }
+
+  private void doTestImpactSerialization(int[] freqs, long[] norms) throws IOException {
+    CompetitiveFreqNormAccumulator acc = new CompetitiveFreqNormAccumulator();
+    for (int i = 0; i < freqs.length; ++i) {
+      acc.add(freqs[i], norms[i]);
+    }
+    try(Directory dir = newDirectory()) {
+      try (IndexOutput out = dir.createOutput("foo", IOContext.DEFAULT)) {
+        Lucene50SkipWriter.writeImpacts(acc, out);
+      }
+      try (IndexInput in = dir.openInput("foo", IOContext.DEFAULT)) {
+        byte[] b = new byte[Math.toIntExact(in.length())];
+        in.readBytes(b, 0, b.length);
+        Lucene50ScoreSkipReader.readImpacts(new ByteArrayDataInput(b), new SimScorer("") {
+          int i = 0;
+
+          @Override
+          public float score(float freq, long norm) {
+            assert freq == freqs[i];
+            assert norm == norms[i];
+            i++;
+            return 0;
+          }
+        });
+      }
+    }
+  }
 }

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/core/src/test/org/apache/lucene/codecs/perfield/TestPerFieldPostingsFormat2.java
----------------------------------------------------------------------
diff --git a/lucene/core/src/test/org/apache/lucene/codecs/perfield/TestPerFieldPostingsFormat2.java b/lucene/core/src/test/org/apache/lucene/codecs/perfield/TestPerFieldPostingsFormat2.java
index 804f507..84544bc 100644
--- a/lucene/core/src/test/org/apache/lucene/codecs/perfield/TestPerFieldPostingsFormat2.java
+++ b/lucene/core/src/test/org/apache/lucene/codecs/perfield/TestPerFieldPostingsFormat2.java
@@ -28,6 +28,7 @@ import org.apache.lucene.analysis.MockAnalyzer;
 import org.apache.lucene.codecs.Codec;
 import org.apache.lucene.codecs.FieldsConsumer;
 import org.apache.lucene.codecs.FieldsProducer;
+import org.apache.lucene.codecs.NormsProducer;
 import org.apache.lucene.codecs.PostingsFormat;
 import org.apache.lucene.codecs.asserting.AssertingCodec;
 import org.apache.lucene.codecs.blockterms.LuceneVarGapFixedInterval;
@@ -407,17 +408,17 @@ public class TestPerFieldPostingsFormat2 extends LuceneTestCase {
       final FieldsConsumer consumer = delegate.fieldsConsumer(state);
       return new FieldsConsumer() {
         @Override
-        public void write(Fields fields) throws IOException {
-          consumer.write(fields);
+        public void write(Fields fields, NormsProducer norms) throws IOException {
+          consumer.write(fields, norms);
         }
 
         @Override
-        public void merge(MergeState mergeState) throws IOException {
+        public void merge(MergeState mergeState, NormsProducer norms) throws IOException {
           nbMergeCalls++;
           for (FieldInfo fi : mergeState.mergeFieldInfos) {
             fieldNames.add(fi.name);
           }
-          consumer.merge(mergeState);
+          consumer.merge(mergeState, norms);
         }
 
         @Override

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/core/src/test/org/apache/lucene/index/TestCodecs.java
----------------------------------------------------------------------
diff --git a/lucene/core/src/test/org/apache/lucene/index/TestCodecs.java b/lucene/core/src/test/org/apache/lucene/index/TestCodecs.java
index 4625f73..efe4587 100644
--- a/lucene/core/src/test/org/apache/lucene/index/TestCodecs.java
+++ b/lucene/core/src/test/org/apache/lucene/index/TestCodecs.java
@@ -17,6 +17,7 @@
 package org.apache.lucene.index;
 
 
+import java.io.IOException;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.HashMap;
@@ -28,10 +29,12 @@ import org.apache.lucene.analysis.MockAnalyzer;
 import org.apache.lucene.codecs.Codec;
 import org.apache.lucene.codecs.FieldsConsumer;
 import org.apache.lucene.codecs.FieldsProducer;
+import org.apache.lucene.codecs.NormsProducer;
 import org.apache.lucene.document.Document;
 import org.apache.lucene.document.Field.Store;
 import org.apache.lucene.document.StringField;
 import org.apache.lucene.search.DocIdSetIterator;
+import org.apache.lucene.search.similarities.Similarity.SimScorer;
 import org.apache.lucene.store.Directory;
 import org.apache.lucene.util.BytesRef;
 import org.apache.lucene.util.IOUtils;
@@ -676,6 +679,10 @@ public class TestCodecs extends LuceneTestCase {
       return new DataPostingsEnum(fieldData.terms[upto]);
     }
 
+    @Override
+    public ImpactsEnum impacts(SimScorer scorer, int flags) throws IOException {
+      throw new UnsupportedOperationException();
+    }
   }
 
   private static class DataPostingsEnum extends PostingsEnum {
@@ -752,9 +759,65 @@ public class TestCodecs extends LuceneTestCase {
 
     Arrays.sort(fields);
     FieldsConsumer consumer = codec.postingsFormat().fieldsConsumer(state);
+    NormsProducer fakeNorms = new NormsProducer() {
+      
+      @Override
+      public long ramBytesUsed() {
+        return 0;
+      }
+      
+      @Override
+      public void close() throws IOException {}
+      
+      @Override
+      public NumericDocValues getNorms(FieldInfo field) throws IOException {
+        return new NumericDocValues() {
+          
+          int doc = -1;
+          
+          @Override
+          public int nextDoc() throws IOException {
+            return advance(doc + 1);
+          }
+          
+          @Override
+          public int docID() {
+            return doc;
+          }
+          
+          @Override
+          public long cost() {
+            return si.maxDoc();
+          }
+          
+          @Override
+          public int advance(int target) throws IOException {
+            if (target >= si.maxDoc()) {
+              return doc = NO_MORE_DOCS;
+            } else {
+              return doc = target;
+            }
+          }
+          
+          @Override
+          public boolean advanceExact(int target) throws IOException {
+            doc = target;
+            return true;
+          }
+          
+          @Override
+          public long longValue() throws IOException {
+            return 1;
+          }
+        };
+      }
+      
+      @Override
+      public void checkIntegrity() throws IOException {}
+    };
     boolean success = false;
     try {
-      consumer.write(new DataFields(fields));
+      consumer.write(new DataFields(fields), fakeNorms);
       success = true;
     } finally {
       if (success) {

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/core/src/test/org/apache/lucene/search/TestTermScorer.java
----------------------------------------------------------------------
diff --git a/lucene/core/src/test/org/apache/lucene/search/TestTermScorer.java b/lucene/core/src/test/org/apache/lucene/search/TestTermScorer.java
index 2758c96..73d3e6a 100644
--- a/lucene/core/src/test/org/apache/lucene/search/TestTermScorer.java
+++ b/lucene/core/src/test/org/apache/lucene/search/TestTermScorer.java
@@ -24,12 +24,18 @@ import java.util.List;
 import org.apache.lucene.analysis.MockAnalyzer;
 import org.apache.lucene.document.Document;
 import org.apache.lucene.document.Field;
+import org.apache.lucene.document.StringField;
+import org.apache.lucene.document.Field.Store;
+import org.apache.lucene.index.DirectoryReader;
 import org.apache.lucene.index.FilterLeafReader;
+import org.apache.lucene.index.IndexReader;
+import org.apache.lucene.index.IndexWriter;
 import org.apache.lucene.index.LeafReader;
 import org.apache.lucene.index.LeafReaderContext;
 import org.apache.lucene.index.NumericDocValues;
 import org.apache.lucene.index.RandomIndexWriter;
 import org.apache.lucene.index.Term;
+import org.apache.lucene.search.BooleanClause.Occur;
 import org.apache.lucene.search.similarities.ClassicSimilarity;
 import org.apache.lucene.store.Directory;
 import org.apache.lucene.util.LuceneTestCase;
@@ -202,4 +208,57 @@ public class TestTermScorer extends LuceneTestCase {
     // should not fail this time since norms are not necessary
     weight2.scorer(forbiddenNorms.getContext()).iterator().nextDoc();
   }
+
+  public void testRandomTopDocs() throws IOException {
+    Directory dir = newDirectory();
+    IndexWriter w = new IndexWriter(dir, newIndexWriterConfig());
+    int numDocs = atLeast(128 * 8 * 8 * 3); // make sure some terms have skip data
+    for (int i = 0; i < numDocs; ++i) {
+      Document doc = new Document();
+      int numValues = random().nextInt(1 << random().nextInt(5));
+      int start = random().nextInt(10);
+      for (int j = 0; j < numValues; ++j) {
+        doc.add(new StringField("foo", Integer.toString(start + j), Store.NO));
+      }
+      w.addDocument(doc);
+    }
+    IndexReader reader = DirectoryReader.open(w);
+    w.close();
+    IndexSearcher searcher = newSearcher(reader);
+
+    for (int iter = 0; iter < 15; ++iter) {
+      Query query = new TermQuery(new Term("foo", Integer.toString(iter)));
+
+      TopScoreDocCollector collector1 = TopScoreDocCollector.create(10, null, true); // COMPLETE
+      TopScoreDocCollector collector2 = TopScoreDocCollector.create(10, null, false); // TOP_SCORES
+      
+      searcher.search(query, collector1);
+      searcher.search(query, collector2);
+      assertTopDocsEquals(collector1.topDocs(), collector2.topDocs());
+
+      int filterTerm = random().nextInt(15);
+      Query filteredQuery = new BooleanQuery.Builder()
+          .add(query, Occur.MUST)
+          .add(new TermQuery(new Term("foo", Integer.toString(filterTerm))), Occur.FILTER)
+          .build();
+
+      collector1 = TopScoreDocCollector.create(10, null, true); // COMPLETE
+      collector2 = TopScoreDocCollector.create(10, null, false); // TOP_SCORES
+      searcher.search(filteredQuery, collector1);
+      searcher.search(filteredQuery, collector2);
+      assertTopDocsEquals(collector1.topDocs(), collector2.topDocs());
+    }
+    reader.close();
+    dir.close();
+  }
+
+  private static void assertTopDocsEquals(TopDocs td1, TopDocs td2) {
+    assertEquals(td1.scoreDocs.length, td2.scoreDocs.length);
+    for (int i = 0; i < td1.scoreDocs.length; ++i) {
+      ScoreDoc sd1 = td1.scoreDocs[i];
+      ScoreDoc sd2 = td2.scoreDocs[i];
+      assertEquals(sd1.doc, sd2.doc);
+      assertEquals(sd1.score, sd2.score, 0f);
+    }
+  }
 }

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/memory/src/java/org/apache/lucene/index/memory/MemoryIndex.java
----------------------------------------------------------------------
diff --git a/lucene/memory/src/java/org/apache/lucene/index/memory/MemoryIndex.java b/lucene/memory/src/java/org/apache/lucene/index/memory/MemoryIndex.java
index 0d8d949..4014e8c 100644
--- a/lucene/memory/src/java/org/apache/lucene/index/memory/MemoryIndex.java
+++ b/lucene/memory/src/java/org/apache/lucene/index/memory/MemoryIndex.java
@@ -42,6 +42,7 @@ import org.apache.lucene.search.ScoreMode;
 import org.apache.lucene.search.Scorer;
 import org.apache.lucene.search.SimpleCollector;
 import org.apache.lucene.search.similarities.Similarity;
+import org.apache.lucene.search.similarities.Similarity.SimScorer;
 import org.apache.lucene.store.RAMDirectory;
 import org.apache.lucene.util.ArrayUtil;
 import org.apache.lucene.util.Bits;
@@ -1425,6 +1426,11 @@ public class MemoryIndex {
       }
 
       @Override
+      public ImpactsEnum impacts(SimScorer scorer, int flags) throws IOException {
+        return new SlowImpactsEnum(postings(null, flags), scorer.score(Float.MAX_VALUE, 1L));
+      }
+
+      @Override
       public void seekExact(BytesRef term, TermState state) throws IOException {
         assert state != null;
         this.seekExact(((OrdTermState)state).ord);

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/sandbox/src/java/org/apache/lucene/codecs/idversion/IDVersionPostingsReader.java
----------------------------------------------------------------------
diff --git a/lucene/sandbox/src/java/org/apache/lucene/codecs/idversion/IDVersionPostingsReader.java b/lucene/sandbox/src/java/org/apache/lucene/codecs/idversion/IDVersionPostingsReader.java
index 54f4aa4..4203e07 100644
--- a/lucene/sandbox/src/java/org/apache/lucene/codecs/idversion/IDVersionPostingsReader.java
+++ b/lucene/sandbox/src/java/org/apache/lucene/codecs/idversion/IDVersionPostingsReader.java
@@ -23,7 +23,9 @@ import org.apache.lucene.codecs.CodecUtil;
 import org.apache.lucene.codecs.PostingsReaderBase;
 import org.apache.lucene.index.PostingsEnum;
 import org.apache.lucene.index.FieldInfo;
+import org.apache.lucene.index.ImpactsEnum;
 import org.apache.lucene.index.SegmentReadState;
+import org.apache.lucene.search.similarities.Similarity.SimScorer;
 import org.apache.lucene.store.DataInput;
 import org.apache.lucene.store.IndexInput;
 
@@ -88,6 +90,11 @@ final class IDVersionPostingsReader extends PostingsReaderBase {
   }
 
   @Override
+  public ImpactsEnum impacts(FieldInfo fieldInfo, BlockTermState state, SimScorer scorer, int flags) throws IOException {
+    throw new UnsupportedOperationException("Should never be called, IDVersionSegmentTermsEnum implements impacts directly");
+  }
+
+  @Override
   public long ramBytesUsed() {
     return 0;
   }

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/sandbox/src/java/org/apache/lucene/codecs/idversion/IDVersionPostingsWriter.java
----------------------------------------------------------------------
diff --git a/lucene/sandbox/src/java/org/apache/lucene/codecs/idversion/IDVersionPostingsWriter.java b/lucene/sandbox/src/java/org/apache/lucene/codecs/idversion/IDVersionPostingsWriter.java
index fc643d2..30e1980 100644
--- a/lucene/sandbox/src/java/org/apache/lucene/codecs/idversion/IDVersionPostingsWriter.java
+++ b/lucene/sandbox/src/java/org/apache/lucene/codecs/idversion/IDVersionPostingsWriter.java
@@ -23,6 +23,7 @@ import org.apache.lucene.codecs.CodecUtil;
 import org.apache.lucene.codecs.PushPostingsWriterBase;
 import org.apache.lucene.index.FieldInfo;
 import org.apache.lucene.index.IndexOptions;
+import org.apache.lucene.index.NumericDocValues;
 import org.apache.lucene.index.SegmentWriteState;
 import org.apache.lucene.store.DataOutput;
 import org.apache.lucene.store.IndexOutput;
@@ -78,7 +79,7 @@ final class IDVersionPostingsWriter extends PushPostingsWriterBase {
   }
 
   @Override
-  public void startTerm() {
+  public void startTerm(NumericDocValues norms) {
     lastDocID = -1;
   }
 

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/sandbox/src/java/org/apache/lucene/codecs/idversion/IDVersionSegmentTermsEnum.java
----------------------------------------------------------------------
diff --git a/lucene/sandbox/src/java/org/apache/lucene/codecs/idversion/IDVersionSegmentTermsEnum.java b/lucene/sandbox/src/java/org/apache/lucene/codecs/idversion/IDVersionSegmentTermsEnum.java
index 0af64d9..d5f51e0 100644
--- a/lucene/sandbox/src/java/org/apache/lucene/codecs/idversion/IDVersionSegmentTermsEnum.java
+++ b/lucene/sandbox/src/java/org/apache/lucene/codecs/idversion/IDVersionSegmentTermsEnum.java
@@ -20,9 +20,12 @@ import java.io.IOException;
 import java.io.PrintStream;
 
 import org.apache.lucene.codecs.BlockTermState;
+import org.apache.lucene.index.ImpactsEnum;
 import org.apache.lucene.index.PostingsEnum;
+import org.apache.lucene.index.SlowImpactsEnum;
 import org.apache.lucene.index.TermState;
 import org.apache.lucene.index.TermsEnum;
+import org.apache.lucene.search.similarities.Similarity.SimScorer;
 import org.apache.lucene.store.ByteArrayDataInput;
 import org.apache.lucene.store.IndexInput;
 import org.apache.lucene.util.ArrayUtil;
@@ -1006,6 +1009,13 @@ public final class IDVersionSegmentTermsEnum extends TermsEnum {
   }
 
   @Override
+  public ImpactsEnum impacts(SimScorer scorer, int flags) throws IOException {
+    // Only one posting, the slow impl is fine
+    // We could make this throw UOE but then CheckIndex is angry
+    return new SlowImpactsEnum(postings(null, flags), scorer.score(Float.MAX_VALUE, 1));
+  }
+
+  @Override
   public void seekExact(BytesRef target, TermState otherState) {
     // if (DEBUG) {
     //   System.out.println("BTTR.seekExact termState seg=" + segment + " target=" + target.utf8ToString() + " " + target + " state=" + otherState);


[3/3] lucene-solr:master: LUCENE-4198: Give codecs the opportunity to index impacts.

Posted by jp...@apache.org.
LUCENE-4198: Give codecs the opportunity to index impacts.


Project: http://git-wip-us.apache.org/repos/asf/lucene-solr/repo
Commit: http://git-wip-us.apache.org/repos/asf/lucene-solr/commit/f410df81
Tree: http://git-wip-us.apache.org/repos/asf/lucene-solr/tree/f410df81
Diff: http://git-wip-us.apache.org/repos/asf/lucene-solr/diff/f410df81

Branch: refs/heads/master
Commit: f410df81136291f61b8deaace22bf4bb650de1ad
Parents: ebb346d
Author: Adrien Grand <jp...@gmail.com>
Authored: Wed Jan 31 13:16:06 2018 +0100
Committer: Adrien Grand <jp...@gmail.com>
Committed: Wed Jan 31 14:54:52 2018 +0100

----------------------------------------------------------------------
 lucene/CHANGES.txt                              |   3 +
 .../codecs/blockterms/BlockTermsReader.java     |   8 +
 .../codecs/blockterms/BlockTermsWriter.java     |   9 +-
 .../blocktreeords/OrdsBlockTreeTermsWriter.java |   9 +-
 .../blocktreeords/OrdsIntersectTermsEnum.java   |   8 +
 .../blocktreeords/OrdsSegmentTermsEnum.java     |  15 +
 .../bloom/BloomFilteringPostingsFormat.java     |  11 +-
 .../codecs/memory/DirectPostingsFormat.java     |  12 +
 .../lucene/codecs/memory/FSTOrdTermsReader.java |   8 +
 .../lucene/codecs/memory/FSTOrdTermsWriter.java |   5 +-
 .../lucene/codecs/memory/FSTTermsReader.java    |   8 +
 .../lucene/codecs/memory/FSTTermsWriter.java    |   5 +-
 .../codecs/memory/MemoryDocValuesProducer.java  |   6 +-
 .../codecs/memory/MemoryPostingsFormat.java     |  11 +-
 .../simpletext/SimpleTextFieldsReader.java      |   7 +
 .../simpletext/SimpleTextFieldsWriter.java      |   3 +-
 .../simpletext/SimpleTextTermVectorsReader.java |   7 +
 .../codecs/CompetitiveFreqNormAccumulator.java  | 163 +++++++
 .../apache/lucene/codecs/FieldsConsumer.java    |   8 +-
 .../lucene/codecs/MultiLevelSkipListReader.java |   4 +-
 .../lucene/codecs/MultiLevelSkipListWriter.java |   8 +-
 .../lucene/codecs/PostingsReaderBase.java       |  10 +-
 .../lucene/codecs/PostingsWriterBase.java       |   2 +-
 .../lucene/codecs/PushPostingsWriterBase.java   |  13 +-
 .../codecs/blocktree/BitSetTermsEnum.java       |   9 +
 .../codecs/blocktree/BlockTreeTermsWriter.java  |   9 +-
 .../codecs/blocktree/IntersectTermsEnum.java    |   8 +
 .../codecs/blocktree/SegmentTermsEnum.java      |  15 +
 .../CompressingTermVectorsReader.java           |  10 +
 .../codecs/lucene50/Lucene50PostingsFormat.java |   3 +-
 .../codecs/lucene50/Lucene50PostingsReader.java | 486 ++++++++++++++++++-
 .../codecs/lucene50/Lucene50PostingsWriter.java |  35 +-
 .../lucene50/Lucene50ScoreSkipReader.java       | 106 ++++
 .../codecs/lucene50/Lucene50SkipReader.java     |  19 +-
 .../codecs/lucene50/Lucene50SkipWriter.java     |  63 ++-
 .../lucene/codecs/lucene70/IndexedDISI.java     |   8 +-
 .../lucene70/Lucene70DocValuesProducer.java     |   7 +
 .../codecs/lucene70/Lucene70NormsProducer.java  |  56 ++-
 .../codecs/perfield/PerFieldPostingsFormat.java |   9 +-
 .../org/apache/lucene/index/CheckIndex.java     | 104 +++-
 .../lucene/index/DefaultIndexingChain.java      |  16 +-
 .../apache/lucene/index/FilterLeafReader.java   |   5 +
 .../apache/lucene/index/FilteredTermsEnum.java  |   8 +-
 .../org/apache/lucene/index/FreqProxFields.java |   6 +
 .../lucene/index/FreqProxTermsWriter.java       |   8 +-
 .../org/apache/lucene/index/ImpactsEnum.java    |  53 ++
 .../org/apache/lucene/index/MultiTermsEnum.java |   6 +
 .../org/apache/lucene/index/SegmentMerger.java  |  41 +-
 .../apache/lucene/index/SlowImpactsEnum.java    |  94 ++++
 .../lucene/index/SortedDocValuesTermsEnum.java  |   6 +
 .../index/SortedSetDocValuesTermsEnum.java      |   6 +
 .../index/SortingTermVectorsConsumer.java       |   5 +-
 .../lucene/index/TermVectorsConsumer.java       |   3 +-
 .../java/org/apache/lucene/index/TermsEnum.java |  14 +-
 .../java/org/apache/lucene/index/TermsHash.java |   6 +-
 .../apache/lucene/search/FuzzyTermsEnum.java    |   7 +
 .../org/apache/lucene/search/LeafSimScorer.java |   5 +
 .../org/apache/lucene/search/SynonymQuery.java  |   4 +-
 .../org/apache/lucene/search/TermQuery.java     |  18 +-
 .../org/apache/lucene/search/TermScorer.java    |  82 +++-
 .../TestCompetitiveFreqNormAccumulator.java     | 104 ++++
 .../lucene50/TestBlockPostingsFormat.java       |  60 +++
 .../perfield/TestPerFieldPostingsFormat2.java   |   9 +-
 .../org/apache/lucene/index/TestCodecs.java     |  65 ++-
 .../apache/lucene/search/TestTermScorer.java    |  59 +++
 .../apache/lucene/index/memory/MemoryIndex.java |   6 +
 .../idversion/IDVersionPostingsReader.java      |   7 +
 .../idversion/IDVersionPostingsWriter.java      |   3 +-
 .../idversion/IDVersionSegmentTermsEnum.java    |  10 +
 .../idversion/VersionBlockTreeTermsWriter.java  |   9 +-
 .../document/CompletionFieldsConsumer.java      |   7 +-
 .../asserting/AssertingPostingsFormat.java      |   5 +-
 .../codecs/cranky/CrankyPostingsFormat.java     |   5 +-
 .../codecs/ramonly/RAMOnlyPostingsFormat.java   |  10 +-
 .../lucene/index/AssertingLeafReader.java       |  88 ++++
 .../index/BaseIndexFileFormatTestCase.java      |  24 +-
 .../lucene/index/BaseNormsFormatTestCase.java   |  22 +-
 .../index/BasePostingsFormatTestCase.java       |   5 +-
 .../lucene/index/RandomPostingsTester.java      | 204 +++++++-
 .../org/apache/solr/query/SolrRangeQuery.java   |   7 +
 .../apache/solr/uninverting/DocTermOrds.java    |   7 +
 81 files changed, 2267 insertions(+), 132 deletions(-)
----------------------------------------------------------------------


http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/CHANGES.txt
----------------------------------------------------------------------
diff --git a/lucene/CHANGES.txt b/lucene/CHANGES.txt
index e95d066..8ad847a 100644
--- a/lucene/CHANGES.txt
+++ b/lucene/CHANGES.txt
@@ -65,6 +65,9 @@ Improvements
 * LUCENE-8011: Improved similarity explanations.
   (Mayya Sharipova via Adrien Grand)
 
+* LUCENE-4198: Codecs now have the ability to index score impacts.
+  (Adrien Grand)
+
 Optimizations
 
 * LUCENE-8040: Optimize IndexSearcher.collectionStatistics, avoiding MultiFields/MultiTerms

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/codecs/src/java/org/apache/lucene/codecs/blockterms/BlockTermsReader.java
----------------------------------------------------------------------
diff --git a/lucene/codecs/src/java/org/apache/lucene/codecs/blockterms/BlockTermsReader.java b/lucene/codecs/src/java/org/apache/lucene/codecs/blockterms/BlockTermsReader.java
index 17024d8..a405ccb 100644
--- a/lucene/codecs/src/java/org/apache/lucene/codecs/blockterms/BlockTermsReader.java
+++ b/lucene/codecs/src/java/org/apache/lucene/codecs/blockterms/BlockTermsReader.java
@@ -32,12 +32,14 @@ import org.apache.lucene.codecs.PostingsReaderBase;
 import org.apache.lucene.index.CorruptIndexException;
 import org.apache.lucene.index.PostingsEnum;
 import org.apache.lucene.index.FieldInfo;
+import org.apache.lucene.index.ImpactsEnum;
 import org.apache.lucene.index.IndexFileNames;
 import org.apache.lucene.index.IndexOptions;
 import org.apache.lucene.index.SegmentReadState;
 import org.apache.lucene.index.TermState;
 import org.apache.lucene.index.Terms;
 import org.apache.lucene.index.TermsEnum;
+import org.apache.lucene.search.similarities.Similarity.SimScorer;
 import org.apache.lucene.store.ByteArrayDataInput;
 import org.apache.lucene.store.IndexInput;
 import org.apache.lucene.util.Accountable;
@@ -659,6 +661,12 @@ public class BlockTermsReader extends FieldsProducer {
       }
 
       @Override
+      public ImpactsEnum impacts(SimScorer scorer, int flags) throws IOException {
+        decodeMetaData();
+        return postingsReader.impacts(fieldInfo, state, scorer, flags);
+      }
+
+      @Override
       public void seekExact(BytesRef target, TermState otherState) {
         //System.out.println("BTR.seekExact termState target=" + target.utf8ToString() + " " + target + " this=" + this);
         assert otherState != null && otherState instanceof BlockTermState;

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/codecs/src/java/org/apache/lucene/codecs/blockterms/BlockTermsWriter.java
----------------------------------------------------------------------
diff --git a/lucene/codecs/src/java/org/apache/lucene/codecs/blockterms/BlockTermsWriter.java b/lucene/codecs/src/java/org/apache/lucene/codecs/blockterms/BlockTermsWriter.java
index f19cd2c..9ed87b5 100644
--- a/lucene/codecs/src/java/org/apache/lucene/codecs/blockterms/BlockTermsWriter.java
+++ b/lucene/codecs/src/java/org/apache/lucene/codecs/blockterms/BlockTermsWriter.java
@@ -26,6 +26,7 @@ import java.util.List;
 import org.apache.lucene.codecs.BlockTermState;
 import org.apache.lucene.codecs.CodecUtil;
 import org.apache.lucene.codecs.FieldsConsumer;
+import org.apache.lucene.codecs.NormsProducer;
 import org.apache.lucene.codecs.PostingsWriterBase;
 import org.apache.lucene.codecs.TermStats;
 import org.apache.lucene.index.IndexOptions;
@@ -127,7 +128,7 @@ public class BlockTermsWriter extends FieldsConsumer implements Closeable {
   }
 
   @Override
-  public void write(Fields fields) throws IOException {
+  public void write(Fields fields, NormsProducer norms) throws IOException {
 
     for(String field : fields) {
 
@@ -146,7 +147,7 @@ public class BlockTermsWriter extends FieldsConsumer implements Closeable {
           break;
         }
 
-        termsWriter.write(term, termsEnum);
+        termsWriter.write(term, termsEnum, norms);
       }
 
       termsWriter.finish();
@@ -232,9 +233,9 @@ public class BlockTermsWriter extends FieldsConsumer implements Closeable {
     
     private final BytesRefBuilder lastPrevTerm = new BytesRefBuilder();
 
-    void write(BytesRef text, TermsEnum termsEnum) throws IOException {
+    void write(BytesRef text, TermsEnum termsEnum, NormsProducer norms) throws IOException {
 
-      BlockTermState state = postingsWriter.writeTerm(text, termsEnum, docsSeen);
+      BlockTermState state = postingsWriter.writeTerm(text, termsEnum, docsSeen, norms);
       if (state == null) {
         // No docs for this term:
         return;

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/codecs/src/java/org/apache/lucene/codecs/blocktreeords/OrdsBlockTreeTermsWriter.java
----------------------------------------------------------------------
diff --git a/lucene/codecs/src/java/org/apache/lucene/codecs/blocktreeords/OrdsBlockTreeTermsWriter.java b/lucene/codecs/src/java/org/apache/lucene/codecs/blocktreeords/OrdsBlockTreeTermsWriter.java
index b16bb15..bdc0738 100644
--- a/lucene/codecs/src/java/org/apache/lucene/codecs/blocktreeords/OrdsBlockTreeTermsWriter.java
+++ b/lucene/codecs/src/java/org/apache/lucene/codecs/blocktreeords/OrdsBlockTreeTermsWriter.java
@@ -24,6 +24,7 @@ import java.util.List;
 import org.apache.lucene.codecs.BlockTermState;
 import org.apache.lucene.codecs.CodecUtil;
 import org.apache.lucene.codecs.FieldsConsumer;
+import org.apache.lucene.codecs.NormsProducer;
 import org.apache.lucene.codecs.PostingsWriterBase;
 import org.apache.lucene.codecs.blocktree.BlockTreeTermsWriter; // javadocs
 import org.apache.lucene.codecs.blocktreeords.FSTOrdsOutputs.Output;
@@ -213,7 +214,7 @@ public final class OrdsBlockTreeTermsWriter extends FieldsConsumer {
   }
 
   @Override
-  public void write(Fields fields) throws IOException {
+  public void write(Fields fields, NormsProducer norms) throws IOException {
 
     String lastField = null;
     for(String field : fields) {
@@ -233,7 +234,7 @@ public final class OrdsBlockTreeTermsWriter extends FieldsConsumer {
         if (term == null) {
           break;
         }
-        termsWriter.write(term, termsEnum);
+        termsWriter.write(term, termsEnum, norms);
       }
 
       termsWriter.finish();
@@ -771,7 +772,7 @@ public final class OrdsBlockTreeTermsWriter extends FieldsConsumer {
     }
     
     /** Writes one term's worth of postings. */
-    public void write(BytesRef text, TermsEnum termsEnum) throws IOException {
+    public void write(BytesRef text, TermsEnum termsEnum, NormsProducer norms) throws IOException {
       /*
       if (DEBUG) {
         int[] tmp = new int[lastTerm.length];
@@ -780,7 +781,7 @@ public final class OrdsBlockTreeTermsWriter extends FieldsConsumer {
       }
       */
 
-      BlockTermState state = postingsWriter.writeTerm(text, termsEnum, docsSeen);
+      BlockTermState state = postingsWriter.writeTerm(text, termsEnum, docsSeen, norms);
       if (state != null) {
         assert state.docFreq != 0;
         assert fieldInfo.getIndexOptions() == IndexOptions.DOCS || state.totalTermFreq >= state.docFreq: "postingsWriter=" + postingsWriter;

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/codecs/src/java/org/apache/lucene/codecs/blocktreeords/OrdsIntersectTermsEnum.java
----------------------------------------------------------------------
diff --git a/lucene/codecs/src/java/org/apache/lucene/codecs/blocktreeords/OrdsIntersectTermsEnum.java b/lucene/codecs/src/java/org/apache/lucene/codecs/blocktreeords/OrdsIntersectTermsEnum.java
index 6c2d2bc..fdb54df 100644
--- a/lucene/codecs/src/java/org/apache/lucene/codecs/blocktreeords/OrdsIntersectTermsEnum.java
+++ b/lucene/codecs/src/java/org/apache/lucene/codecs/blocktreeords/OrdsIntersectTermsEnum.java
@@ -20,9 +20,11 @@ package org.apache.lucene.codecs.blocktreeords;
 import java.io.IOException;
 
 import org.apache.lucene.codecs.blocktreeords.FSTOrdsOutputs.Output;
+import org.apache.lucene.index.ImpactsEnum;
 import org.apache.lucene.index.PostingsEnum;
 import org.apache.lucene.index.TermState;
 import org.apache.lucene.index.TermsEnum;
+import org.apache.lucene.search.similarities.Similarity.SimScorer;
 import org.apache.lucene.store.IndexInput;
 import org.apache.lucene.util.ArrayUtil;
 import org.apache.lucene.util.BytesRef;
@@ -205,6 +207,12 @@ final class OrdsIntersectTermsEnum extends TermsEnum {
     return fr.parent.postingsReader.postings(fr.fieldInfo, currentFrame.termState, reuse, flags);
   }
 
+  @Override
+  public ImpactsEnum impacts(SimScorer scorer, int flags) throws IOException {
+    currentFrame.decodeMetaData();
+    return fr.parent.postingsReader.impacts(fr.fieldInfo, currentFrame.termState, scorer, flags);
+  }
+
   private int getState() {
     int state = currentFrame.state;
     for(int idx=0;idx<currentFrame.suffix;idx++) {

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/codecs/src/java/org/apache/lucene/codecs/blocktreeords/OrdsSegmentTermsEnum.java
----------------------------------------------------------------------
diff --git a/lucene/codecs/src/java/org/apache/lucene/codecs/blocktreeords/OrdsSegmentTermsEnum.java b/lucene/codecs/src/java/org/apache/lucene/codecs/blocktreeords/OrdsSegmentTermsEnum.java
index 9a9d871..8d55a1d 100644
--- a/lucene/codecs/src/java/org/apache/lucene/codecs/blocktreeords/OrdsSegmentTermsEnum.java
+++ b/lucene/codecs/src/java/org/apache/lucene/codecs/blocktreeords/OrdsSegmentTermsEnum.java
@@ -25,9 +25,11 @@ import java.io.PrintStream;
 
 import org.apache.lucene.codecs.BlockTermState;
 import org.apache.lucene.codecs.blocktreeords.FSTOrdsOutputs.Output;
+import org.apache.lucene.index.ImpactsEnum;
 import org.apache.lucene.index.PostingsEnum;
 import org.apache.lucene.index.TermState;
 import org.apache.lucene.index.TermsEnum;
+import org.apache.lucene.search.similarities.Similarity.SimScorer;
 import org.apache.lucene.store.ByteArrayDataInput;
 import org.apache.lucene.store.IndexInput;
 import org.apache.lucene.util.ArrayUtil;
@@ -934,6 +936,19 @@ public final class OrdsSegmentTermsEnum extends TermsEnum {
   }
 
   @Override
+  public ImpactsEnum impacts(SimScorer scorer, int flags) throws IOException {
+    assert !eof;
+    //if (DEBUG) {
+    //System.out.println("BTTR.docs seg=" + segment);
+    //}
+    currentFrame.decodeMetaData();
+    //if (DEBUG) {
+    //System.out.println("  state=" + currentFrame.state);
+    //}
+    return fr.parent.postingsReader.impacts(fr.fieldInfo, currentFrame.state, scorer, flags);
+  }
+
+  @Override
   public void seekExact(BytesRef target, TermState otherState) {
     // if (DEBUG) {
     //   System.out.println("BTTR.seekExact termState seg=" + segment + " target=" + target.utf8ToString() + " " + target + " state=" + otherState);

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/codecs/src/java/org/apache/lucene/codecs/bloom/BloomFilteringPostingsFormat.java
----------------------------------------------------------------------
diff --git a/lucene/codecs/src/java/org/apache/lucene/codecs/bloom/BloomFilteringPostingsFormat.java b/lucene/codecs/src/java/org/apache/lucene/codecs/bloom/BloomFilteringPostingsFormat.java
index b864bf0..b826102 100644
--- a/lucene/codecs/src/java/org/apache/lucene/codecs/bloom/BloomFilteringPostingsFormat.java
+++ b/lucene/codecs/src/java/org/apache/lucene/codecs/bloom/BloomFilteringPostingsFormat.java
@@ -29,16 +29,19 @@ import java.util.Map.Entry;
 import org.apache.lucene.codecs.CodecUtil;
 import org.apache.lucene.codecs.FieldsConsumer;
 import org.apache.lucene.codecs.FieldsProducer;
+import org.apache.lucene.codecs.NormsProducer;
 import org.apache.lucene.codecs.PostingsFormat;
 import org.apache.lucene.codecs.bloom.FuzzySet.ContainsResult;
 import org.apache.lucene.index.PostingsEnum;
 import org.apache.lucene.index.FieldInfo;
 import org.apache.lucene.index.Fields;
+import org.apache.lucene.index.ImpactsEnum;
 import org.apache.lucene.index.IndexFileNames;
 import org.apache.lucene.index.SegmentReadState;
 import org.apache.lucene.index.SegmentWriteState;
 import org.apache.lucene.index.Terms;
 import org.apache.lucene.index.TermsEnum;
+import org.apache.lucene.search.similarities.Similarity.SimScorer;
 import org.apache.lucene.store.ChecksumIndexInput;
 import org.apache.lucene.store.DataOutput;
 import org.apache.lucene.store.IndexOutput;
@@ -371,6 +374,10 @@ public final class BloomFilteringPostingsFormat extends PostingsFormat {
         return delegate().postings(reuse, flags);
       }
 
+      @Override
+      public ImpactsEnum impacts(SimScorer scorer, int flags) throws IOException {
+        return delegate().impacts(scorer, flags);
+      }
     }
 
     @Override
@@ -416,7 +423,7 @@ public final class BloomFilteringPostingsFormat extends PostingsFormat {
     }
 
     @Override
-    public void write(Fields fields) throws IOException {
+    public void write(Fields fields, NormsProducer norms) throws IOException {
 
       // Delegate must write first: it may have opened files
       // on creating the class
@@ -424,7 +431,7 @@ public final class BloomFilteringPostingsFormat extends PostingsFormat {
       // close them; alternatively, if we delayed pulling
       // the fields consumer until here, we could do it
       // afterwards:
-      delegateFieldsConsumer.write(fields);
+      delegateFieldsConsumer.write(fields, norms);
 
       for(String field : fields) {
         Terms terms = fields.terms(field);

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/codecs/src/java/org/apache/lucene/codecs/memory/DirectPostingsFormat.java
----------------------------------------------------------------------
diff --git a/lucene/codecs/src/java/org/apache/lucene/codecs/memory/DirectPostingsFormat.java b/lucene/codecs/src/java/org/apache/lucene/codecs/memory/DirectPostingsFormat.java
index 00f25cf..901e1ae 100644
--- a/lucene/codecs/src/java/org/apache/lucene/codecs/memory/DirectPostingsFormat.java
+++ b/lucene/codecs/src/java/org/apache/lucene/codecs/memory/DirectPostingsFormat.java
@@ -29,14 +29,17 @@ import org.apache.lucene.codecs.PostingsFormat;
 import org.apache.lucene.codecs.lucene50.Lucene50PostingsFormat;
 import org.apache.lucene.index.FieldInfo;
 import org.apache.lucene.index.Fields;
+import org.apache.lucene.index.ImpactsEnum;
 import org.apache.lucene.index.IndexOptions;
 import org.apache.lucene.index.OrdTermState;
 import org.apache.lucene.index.PostingsEnum;
 import org.apache.lucene.index.SegmentReadState;
 import org.apache.lucene.index.SegmentWriteState;
+import org.apache.lucene.index.SlowImpactsEnum;
 import org.apache.lucene.index.TermState;
 import org.apache.lucene.index.Terms;
 import org.apache.lucene.index.TermsEnum;
+import org.apache.lucene.search.similarities.Similarity.SimScorer;
 import org.apache.lucene.store.IOContext;
 import org.apache.lucene.store.RAMOutputStream;
 import org.apache.lucene.util.Accountable;
@@ -944,6 +947,10 @@ public final class DirectPostingsFormat extends PostingsFormat {
         }
       }
 
+      @Override
+      public ImpactsEnum impacts(SimScorer scorer, int flags) throws IOException {
+        return new SlowImpactsEnum(postings(null, flags), scorer.score(Float.MAX_VALUE, 1));
+      }
     }
 
     private final class DirectIntersectTermsEnum extends TermsEnum {
@@ -1496,6 +1503,11 @@ public final class DirectPostingsFormat extends PostingsFormat {
       }
 
       @Override
+      public ImpactsEnum impacts(SimScorer scorer, int flags) throws IOException {
+        return new SlowImpactsEnum(postings(null, flags), scorer.score(Float.MAX_VALUE, 1));
+      }
+
+      @Override
       public SeekStatus seekCeil(BytesRef term) {
         throw new UnsupportedOperationException();
       }

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/codecs/src/java/org/apache/lucene/codecs/memory/FSTOrdTermsReader.java
----------------------------------------------------------------------
diff --git a/lucene/codecs/src/java/org/apache/lucene/codecs/memory/FSTOrdTermsReader.java b/lucene/codecs/src/java/org/apache/lucene/codecs/memory/FSTOrdTermsReader.java
index 5ba4c5f..4ecf4d6 100644
--- a/lucene/codecs/src/java/org/apache/lucene/codecs/memory/FSTOrdTermsReader.java
+++ b/lucene/codecs/src/java/org/apache/lucene/codecs/memory/FSTOrdTermsReader.java
@@ -34,6 +34,7 @@ import org.apache.lucene.index.CorruptIndexException;
 import org.apache.lucene.index.PostingsEnum;
 import org.apache.lucene.index.FieldInfo;
 import org.apache.lucene.index.FieldInfos;
+import org.apache.lucene.index.ImpactsEnum;
 import org.apache.lucene.index.IndexFileNames;
 import org.apache.lucene.index.IndexOptions;
 import org.apache.lucene.index.SegmentInfo;
@@ -41,6 +42,7 @@ import org.apache.lucene.index.SegmentReadState;
 import org.apache.lucene.index.TermState;
 import org.apache.lucene.index.Terms;
 import org.apache.lucene.index.TermsEnum;
+import org.apache.lucene.search.similarities.Similarity.SimScorer;
 import org.apache.lucene.store.ByteArrayDataInput;
 import org.apache.lucene.store.ChecksumIndexInput;
 import org.apache.lucene.store.IndexInput;
@@ -432,6 +434,12 @@ public class FSTOrdTermsReader extends FieldsProducer {
         return postingsReader.postings(fieldInfo, state, reuse, flags);
       }
 
+      @Override
+      public ImpactsEnum impacts(SimScorer scorer, int flags) throws IOException {
+        decodeMetaData();
+        return postingsReader.impacts(fieldInfo, state, scorer, flags);
+      }
+
       // TODO: this can be achieved by making use of Util.getByOutput()
       //           and should have related tests
       @Override

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/codecs/src/java/org/apache/lucene/codecs/memory/FSTOrdTermsWriter.java
----------------------------------------------------------------------
diff --git a/lucene/codecs/src/java/org/apache/lucene/codecs/memory/FSTOrdTermsWriter.java b/lucene/codecs/src/java/org/apache/lucene/codecs/memory/FSTOrdTermsWriter.java
index cbe6583..b59d41d 100644
--- a/lucene/codecs/src/java/org/apache/lucene/codecs/memory/FSTOrdTermsWriter.java
+++ b/lucene/codecs/src/java/org/apache/lucene/codecs/memory/FSTOrdTermsWriter.java
@@ -24,6 +24,7 @@ import java.util.List;
 import org.apache.lucene.codecs.BlockTermState;
 import org.apache.lucene.codecs.CodecUtil;
 import org.apache.lucene.codecs.FieldsConsumer;
+import org.apache.lucene.codecs.NormsProducer;
 import org.apache.lucene.codecs.PostingsWriterBase;
 import org.apache.lucene.index.FieldInfo;
 import org.apache.lucene.index.FieldInfos;
@@ -186,7 +187,7 @@ public class FSTOrdTermsWriter extends FieldsConsumer {
   }
 
   @Override
-  public void write(Fields fields) throws IOException {
+  public void write(Fields fields, NormsProducer norms) throws IOException {
     for(String field : fields) {
       Terms terms = fields.terms(field);
       if (terms == null) {
@@ -205,7 +206,7 @@ public class FSTOrdTermsWriter extends FieldsConsumer {
         if (term == null) {
           break;
         }
-        BlockTermState termState = postingsWriter.writeTerm(term, termsEnum, docsSeen);
+        BlockTermState termState = postingsWriter.writeTerm(term, termsEnum, docsSeen, norms);
         if (termState != null) {
           termsWriter.finishTerm(term, termState);
           sumTotalTermFreq += termState.totalTermFreq;

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/codecs/src/java/org/apache/lucene/codecs/memory/FSTTermsReader.java
----------------------------------------------------------------------
diff --git a/lucene/codecs/src/java/org/apache/lucene/codecs/memory/FSTTermsReader.java b/lucene/codecs/src/java/org/apache/lucene/codecs/memory/FSTTermsReader.java
index 8dda05c..b1b61e1 100644
--- a/lucene/codecs/src/java/org/apache/lucene/codecs/memory/FSTTermsReader.java
+++ b/lucene/codecs/src/java/org/apache/lucene/codecs/memory/FSTTermsReader.java
@@ -34,6 +34,7 @@ import org.apache.lucene.index.CorruptIndexException;
 import org.apache.lucene.index.PostingsEnum;
 import org.apache.lucene.index.FieldInfo;
 import org.apache.lucene.index.FieldInfos;
+import org.apache.lucene.index.ImpactsEnum;
 import org.apache.lucene.index.IndexFileNames;
 import org.apache.lucene.index.IndexOptions;
 import org.apache.lucene.index.SegmentInfo;
@@ -41,6 +42,7 @@ import org.apache.lucene.index.SegmentReadState;
 import org.apache.lucene.index.TermState;
 import org.apache.lucene.index.Terms;
 import org.apache.lucene.index.TermsEnum;
+import org.apache.lucene.search.similarities.Similarity.SimScorer;
 import org.apache.lucene.store.ByteArrayDataInput;
 import org.apache.lucene.store.IndexInput;
 import org.apache.lucene.util.Accountable;
@@ -299,6 +301,12 @@ public class FSTTermsReader extends FieldsProducer {
       }
 
       @Override
+      public ImpactsEnum impacts(SimScorer scorer, int flags) throws IOException {
+        decodeMetaData();
+        return postingsReader.impacts(fieldInfo, state, scorer, flags);
+      }
+
+      @Override
       public void seekExact(long ord) throws IOException {
         throw new UnsupportedOperationException();
       }

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/codecs/src/java/org/apache/lucene/codecs/memory/FSTTermsWriter.java
----------------------------------------------------------------------
diff --git a/lucene/codecs/src/java/org/apache/lucene/codecs/memory/FSTTermsWriter.java b/lucene/codecs/src/java/org/apache/lucene/codecs/memory/FSTTermsWriter.java
index 8284d74..8e55d41 100644
--- a/lucene/codecs/src/java/org/apache/lucene/codecs/memory/FSTTermsWriter.java
+++ b/lucene/codecs/src/java/org/apache/lucene/codecs/memory/FSTTermsWriter.java
@@ -24,6 +24,7 @@ import java.util.List;
 import org.apache.lucene.codecs.BlockTermState;
 import org.apache.lucene.codecs.CodecUtil;
 import org.apache.lucene.codecs.FieldsConsumer;
+import org.apache.lucene.codecs.NormsProducer;
 import org.apache.lucene.codecs.PostingsWriterBase;
 import org.apache.lucene.index.IndexOptions;
 import org.apache.lucene.index.FieldInfo;
@@ -158,7 +159,7 @@ public class FSTTermsWriter extends FieldsConsumer {
   }
 
   @Override
-  public void write(Fields fields) throws IOException {
+  public void write(Fields fields, NormsProducer norms) throws IOException {
     for(String field : fields) {
       Terms terms = fields.terms(field);
       if (terms == null) {
@@ -179,7 +180,7 @@ public class FSTTermsWriter extends FieldsConsumer {
           break;
         }
             
-        BlockTermState termState = postingsWriter.writeTerm(term, termsEnum, docsSeen);
+        BlockTermState termState = postingsWriter.writeTerm(term, termsEnum, docsSeen, norms);
         if (termState != null) {
           termsWriter.finishTerm(term, termState);
           sumTotalTermFreq += termState.totalTermFreq;

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/codecs/src/java/org/apache/lucene/codecs/memory/MemoryDocValuesProducer.java
----------------------------------------------------------------------
diff --git a/lucene/codecs/src/java/org/apache/lucene/codecs/memory/MemoryDocValuesProducer.java b/lucene/codecs/src/java/org/apache/lucene/codecs/memory/MemoryDocValuesProducer.java
index b81e56e..855002c 100644
--- a/lucene/codecs/src/java/org/apache/lucene/codecs/memory/MemoryDocValuesProducer.java
+++ b/lucene/codecs/src/java/org/apache/lucene/codecs/memory/MemoryDocValuesProducer.java
@@ -29,7 +29,7 @@ import java.util.concurrent.atomic.AtomicLong;
 import org.apache.lucene.codecs.CodecUtil;
 import org.apache.lucene.codecs.DocValuesProducer;
 import org.apache.lucene.index.*;
-import org.apache.lucene.index.SortedDocValues;
+import org.apache.lucene.search.similarities.Similarity.SimScorer;
 import org.apache.lucene.store.ByteArrayDataInput;
 import org.apache.lucene.store.ChecksumIndexInput;
 import org.apache.lucene.store.IndexInput;
@@ -870,5 +870,9 @@ class MemoryDocValuesProducer extends DocValuesProducer {
       throw new UnsupportedOperationException();
     }
 
+    @Override
+    public ImpactsEnum impacts(SimScorer scorer, int flags) throws IOException {
+      throw new UnsupportedOperationException();
+    }
   }
 }

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/codecs/src/java/org/apache/lucene/codecs/memory/MemoryPostingsFormat.java
----------------------------------------------------------------------
diff --git a/lucene/codecs/src/java/org/apache/lucene/codecs/memory/MemoryPostingsFormat.java b/lucene/codecs/src/java/org/apache/lucene/codecs/memory/MemoryPostingsFormat.java
index 21983c6..0df7d92 100644
--- a/lucene/codecs/src/java/org/apache/lucene/codecs/memory/MemoryPostingsFormat.java
+++ b/lucene/codecs/src/java/org/apache/lucene/codecs/memory/MemoryPostingsFormat.java
@@ -27,6 +27,7 @@ import java.util.TreeMap;
 import org.apache.lucene.codecs.CodecUtil;
 import org.apache.lucene.codecs.FieldsConsumer;
 import org.apache.lucene.codecs.FieldsProducer;
+import org.apache.lucene.codecs.NormsProducer;
 import org.apache.lucene.codecs.PostingsFormat;
 import org.apache.lucene.codecs.TermStats;
 import org.apache.lucene.index.CorruptIndexException;
@@ -34,12 +35,15 @@ import org.apache.lucene.index.PostingsEnum;
 import org.apache.lucene.index.FieldInfo;
 import org.apache.lucene.index.FieldInfos;
 import org.apache.lucene.index.Fields;
+import org.apache.lucene.index.ImpactsEnum;
 import org.apache.lucene.index.IndexFileNames;
 import org.apache.lucene.index.IndexOptions;
 import org.apache.lucene.index.SegmentReadState;
 import org.apache.lucene.index.SegmentWriteState;
+import org.apache.lucene.index.SlowImpactsEnum;
 import org.apache.lucene.index.Terms;
 import org.apache.lucene.index.TermsEnum;
+import org.apache.lucene.search.similarities.Similarity.SimScorer;
 import org.apache.lucene.store.ByteArrayDataInput;
 import org.apache.lucene.store.ChecksumIndexInput;
 import org.apache.lucene.store.IOContext;
@@ -287,7 +291,7 @@ public final class MemoryPostingsFormat extends PostingsFormat {
     }
 
     @Override
-    public void write(Fields fields) throws IOException {
+    public void write(Fields fields, NormsProducer norms) throws IOException {
       for(String field : fields) {
 
         Terms terms = fields.terms(field);
@@ -815,6 +819,11 @@ public final class MemoryPostingsFormat extends PostingsFormat {
     }
 
     @Override
+    public ImpactsEnum impacts(SimScorer scorer, int flags) throws IOException {
+      return new SlowImpactsEnum(postings(null, flags), scorer.score(Float.MAX_VALUE, 1));
+    }
+
+    @Override
     public BytesRef term() {
       return current.input;
     }

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/codecs/src/java/org/apache/lucene/codecs/simpletext/SimpleTextFieldsReader.java
----------------------------------------------------------------------
diff --git a/lucene/codecs/src/java/org/apache/lucene/codecs/simpletext/SimpleTextFieldsReader.java b/lucene/codecs/src/java/org/apache/lucene/codecs/simpletext/SimpleTextFieldsReader.java
index f5504b3..22aeb5c 100644
--- a/lucene/codecs/src/java/org/apache/lucene/codecs/simpletext/SimpleTextFieldsReader.java
+++ b/lucene/codecs/src/java/org/apache/lucene/codecs/simpletext/SimpleTextFieldsReader.java
@@ -29,11 +29,14 @@ import java.util.TreeMap;
 import org.apache.lucene.codecs.FieldsProducer;
 import org.apache.lucene.index.FieldInfo;
 import org.apache.lucene.index.FieldInfos;
+import org.apache.lucene.index.ImpactsEnum;
 import org.apache.lucene.index.IndexOptions;
 import org.apache.lucene.index.PostingsEnum;
 import org.apache.lucene.index.SegmentReadState;
+import org.apache.lucene.index.SlowImpactsEnum;
 import org.apache.lucene.index.Terms;
 import org.apache.lucene.index.TermsEnum;
+import org.apache.lucene.search.similarities.Similarity.SimScorer;
 import org.apache.lucene.store.BufferedChecksumIndexInput;
 import org.apache.lucene.store.ChecksumIndexInput;
 import org.apache.lucene.store.IndexInput;
@@ -230,6 +233,10 @@ class SimpleTextFieldsReader extends FieldsProducer {
       return docsEnum.reset(docsStart, indexOptions == IndexOptions.DOCS, docFreq);
     }
 
+    @Override
+    public ImpactsEnum impacts(SimScorer scorer, int flags) throws IOException {
+      return new SlowImpactsEnum(postings(null, PostingsEnum.FREQS), scorer.score(Float.MAX_VALUE, 1));
+    }
   }
 
   private class SimpleTextDocsEnum extends PostingsEnum {

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/codecs/src/java/org/apache/lucene/codecs/simpletext/SimpleTextFieldsWriter.java
----------------------------------------------------------------------
diff --git a/lucene/codecs/src/java/org/apache/lucene/codecs/simpletext/SimpleTextFieldsWriter.java b/lucene/codecs/src/java/org/apache/lucene/codecs/simpletext/SimpleTextFieldsWriter.java
index 2023552..d8299b5 100644
--- a/lucene/codecs/src/java/org/apache/lucene/codecs/simpletext/SimpleTextFieldsWriter.java
+++ b/lucene/codecs/src/java/org/apache/lucene/codecs/simpletext/SimpleTextFieldsWriter.java
@@ -20,6 +20,7 @@ package org.apache.lucene.codecs.simpletext;
 import java.io.IOException;
 
 import org.apache.lucene.codecs.FieldsConsumer;
+import org.apache.lucene.codecs.NormsProducer;
 import org.apache.lucene.index.PostingsEnum;
 import org.apache.lucene.index.FieldInfo;
 import org.apache.lucene.index.FieldInfos;
@@ -56,7 +57,7 @@ class SimpleTextFieldsWriter extends FieldsConsumer {
   }
 
   @Override
-  public void write(Fields fields) throws IOException {
+  public void write(Fields fields, NormsProducer norms) throws IOException {
     write(writeState.fieldInfos, fields);
   }
 

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/codecs/src/java/org/apache/lucene/codecs/simpletext/SimpleTextTermVectorsReader.java
----------------------------------------------------------------------
diff --git a/lucene/codecs/src/java/org/apache/lucene/codecs/simpletext/SimpleTextTermVectorsReader.java b/lucene/codecs/src/java/org/apache/lucene/codecs/simpletext/SimpleTextTermVectorsReader.java
index 25f2a4d..ee0757d 100644
--- a/lucene/codecs/src/java/org/apache/lucene/codecs/simpletext/SimpleTextTermVectorsReader.java
+++ b/lucene/codecs/src/java/org/apache/lucene/codecs/simpletext/SimpleTextTermVectorsReader.java
@@ -27,10 +27,13 @@ import java.util.TreeMap;
 import org.apache.lucene.codecs.TermVectorsReader;
 import org.apache.lucene.index.PostingsEnum;
 import org.apache.lucene.index.Fields;
+import org.apache.lucene.index.ImpactsEnum;
 import org.apache.lucene.index.IndexFileNames;
 import org.apache.lucene.index.SegmentInfo;
+import org.apache.lucene.index.SlowImpactsEnum;
 import org.apache.lucene.index.Terms;
 import org.apache.lucene.index.TermsEnum;
+import org.apache.lucene.search.similarities.Similarity.SimScorer;
 import org.apache.lucene.store.AlreadyClosedException;
 import org.apache.lucene.store.BufferedChecksumIndexInput;
 import org.apache.lucene.store.ChecksumIndexInput;
@@ -410,6 +413,10 @@ public class SimpleTextTermVectorsReader extends TermVectorsReader {
       return e;
     }
 
+    @Override
+    public ImpactsEnum impacts(SimScorer scorer, int flags) throws IOException {
+      return new SlowImpactsEnum(postings(null, PostingsEnum.FREQS), scorer.score(Float.MAX_VALUE, 1));
+    }
   }
 
   // note: these two enum classes are exactly like the Default impl...

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/core/src/java/org/apache/lucene/codecs/CompetitiveFreqNormAccumulator.java
----------------------------------------------------------------------
diff --git a/lucene/core/src/java/org/apache/lucene/codecs/CompetitiveFreqNormAccumulator.java b/lucene/core/src/java/org/apache/lucene/codecs/CompetitiveFreqNormAccumulator.java
new file mode 100644
index 0000000..3dd9d35
--- /dev/null
+++ b/lucene/core/src/java/org/apache/lucene/codecs/CompetitiveFreqNormAccumulator.java
@@ -0,0 +1,163 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.lucene.codecs;
+
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.Comparator;
+import java.util.Iterator;
+import java.util.SortedSet;
+import java.util.TreeSet;
+
+/**
+ * This class accumulates the (freq, norm) pairs that may produce competitive scores.
+ */
+public final class CompetitiveFreqNormAccumulator {
+
+  // We speed up accumulation for common norm values by first computing
+  // the max freq for all norms in -128..127
+  private final int[] maxFreqs;
+  private boolean dirty;
+  private final TreeSet<FreqAndNorm> freqNormPairs;
+
+  /** Sole constructor. */
+  public CompetitiveFreqNormAccumulator() {
+    maxFreqs = new int[256];
+    Comparator<FreqAndNorm> comparator = new Comparator<CompetitiveFreqNormAccumulator.FreqAndNorm>() {
+      @Override
+      public int compare(FreqAndNorm o1, FreqAndNorm o2) {
+        // greater freqs compare greater
+        int cmp = Integer.compare(o1.freq, o2.freq);
+        if (cmp == 0) {
+          // greater norms compare lower
+          cmp = Long.compareUnsigned(o2.norm, o1.norm);
+        }
+        return cmp;
+      }
+    };
+    freqNormPairs = new TreeSet<>(comparator);
+  }
+
+  /** Reset to the same state it was in after creation. */
+  public void clear() {
+    Arrays.fill(maxFreqs, 0);
+    dirty = false;
+    freqNormPairs.clear();
+  }
+
+  /**
+   * A (freq, norm) pair.
+   */
+  public static class FreqAndNorm {
+    /** Doc-term frequency. */
+    public final int freq;
+    /** Normalization factor. */
+    public final long norm;
+
+    /** Sole constructor. */
+    public FreqAndNorm(int freq, long norm) {
+      this.freq = freq;
+      this.norm = norm;
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+      if (obj == null || obj instanceof FreqAndNorm == false) {
+        return false;
+      }
+      FreqAndNorm that = (FreqAndNorm) obj;
+      return freq == that.freq && norm == that.norm;
+    }
+
+    @Override
+    public int hashCode() {
+      int h = getClass().hashCode();
+      h = 31 * h + freq;
+      h = 31 * h + Long.hashCode(norm);
+      return h;
+    }
+
+    @Override
+    public String toString() {
+      return "{" + freq + "," + norm + "}";
+    }
+  }
+
+  /** Accumulate a (freq,norm) pair, updating this structure if there is no
+   *  equivalent or more competitive entry already. */
+  public void add(int freq, long norm) {
+    if (norm >= Byte.MIN_VALUE && norm <= Byte.MAX_VALUE) {
+      int index = Byte.toUnsignedInt((byte) norm);
+      maxFreqs[index] = Math.max(maxFreqs[index], freq); 
+      dirty = true;
+    } else {
+      add(new FreqAndNorm(freq, norm));
+    }
+  }
+
+  /** Merge {@code acc} into this. */
+  public void addAll(CompetitiveFreqNormAccumulator acc) {
+    for (FreqAndNorm entry : acc.getCompetitiveFreqNormPairs()) {
+      add(entry);
+    }
+  }
+
+  /** Get the set of competitive freq and norm pairs, orderer by increasing freq and norm. */
+  public SortedSet<FreqAndNorm> getCompetitiveFreqNormPairs() {
+    if (dirty) {
+      for (int i = 0; i < maxFreqs.length; ++i) {
+        if (maxFreqs[i] > 0) {
+          add(new FreqAndNorm(maxFreqs[i], (byte) i));
+          maxFreqs[i] = 0;
+        }
+      }
+      dirty = false;
+    }
+    return Collections.unmodifiableSortedSet(freqNormPairs);
+  }
+
+  private void add(FreqAndNorm newEntry) {
+    FreqAndNorm next = freqNormPairs.ceiling(newEntry);
+    if (next == null) {
+      // nothing is more competitive
+      freqNormPairs.add(newEntry);
+    } else if (Long.compareUnsigned(next.norm, newEntry.norm) <= 0) {
+      // we already have this entry or more competitive entries in the tree
+      return;
+    } else {
+      // some entries have a greater freq but a less competitive norm, so we
+      // don't know which one will trigger greater scores, still add to the tree
+      freqNormPairs.add(newEntry);
+    }
+
+    for (Iterator<FreqAndNorm> it = freqNormPairs.headSet(newEntry, false).descendingIterator(); it.hasNext(); ) {
+      FreqAndNorm entry = it.next();
+      if (Long.compareUnsigned(entry.norm, newEntry.norm) >= 0) {
+        // less competitive
+        it.remove();
+      } else {
+        // lesser freq but better norm, further entries are not comparable
+        break;
+      }
+    }
+  }
+
+  @Override
+  public String toString() {
+    return getCompetitiveFreqNormPairs().toString();
+  }
+}

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/core/src/java/org/apache/lucene/codecs/FieldsConsumer.java
----------------------------------------------------------------------
diff --git a/lucene/core/src/java/org/apache/lucene/codecs/FieldsConsumer.java b/lucene/core/src/java/org/apache/lucene/codecs/FieldsConsumer.java
index 28bae1d..f4fc9ac 100644
--- a/lucene/core/src/java/org/apache/lucene/codecs/FieldsConsumer.java
+++ b/lucene/core/src/java/org/apache/lucene/codecs/FieldsConsumer.java
@@ -76,14 +76,14 @@ public abstract class FieldsConsumer implements Closeable {
    *         live docs when pulling docs/positions enums.
    *  </ul>
    */
-  public abstract void write(Fields fields) throws IOException;
+  public abstract void write(Fields fields, NormsProducer norms) throws IOException;
   
   /** Merges in the fields from the readers in 
    *  <code>mergeState</code>. The default implementation skips
-   *  and maps around deleted documents, and calls {@link #write(Fields)}.
+   *  and maps around deleted documents, and calls {@link #write(Fields,NormsProducer)}.
    *  Implementations can override this method for more sophisticated
    *  merging (bulk-byte copying, etc). */
-  public void merge(MergeState mergeState) throws IOException {
+  public void merge(MergeState mergeState, NormsProducer norms) throws IOException {
     final List<Fields> fields = new ArrayList<>();
     final List<ReaderSlice> slices = new ArrayList<>();
 
@@ -102,7 +102,7 @@ public abstract class FieldsConsumer implements Closeable {
     Fields mergedFields = new MappedMultiFields(mergeState, 
                                                 new MultiFields(fields.toArray(Fields.EMPTY_ARRAY),
                                                                 slices.toArray(ReaderSlice.EMPTY_ARRAY)));
-    write(mergedFields);
+    write(mergedFields, norms);
   }
 
   // NOTE: strange but necessary so javadocs linting is happy:

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/core/src/java/org/apache/lucene/codecs/MultiLevelSkipListReader.java
----------------------------------------------------------------------
diff --git a/lucene/core/src/java/org/apache/lucene/codecs/MultiLevelSkipListReader.java b/lucene/core/src/java/org/apache/lucene/codecs/MultiLevelSkipListReader.java
index c937886..517c731 100644
--- a/lucene/core/src/java/org/apache/lucene/codecs/MultiLevelSkipListReader.java
+++ b/lucene/core/src/java/org/apache/lucene/codecs/MultiLevelSkipListReader.java
@@ -40,8 +40,8 @@ public abstract class MultiLevelSkipListReader implements Closeable {
   /** the maximum number of skip levels possible for this index */
   protected int maxNumberOfSkipLevels; 
   
-  // number of levels in this skip list
-  private int numberOfSkipLevels;
+  /** number of levels in this skip list */
+  protected int numberOfSkipLevels;
   
   // Expert: defines the number of top skip levels to buffer in memory.
   // Reducing this number results in less memory usage, but possibly

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/core/src/java/org/apache/lucene/codecs/MultiLevelSkipListWriter.java
----------------------------------------------------------------------
diff --git a/lucene/core/src/java/org/apache/lucene/codecs/MultiLevelSkipListWriter.java b/lucene/core/src/java/org/apache/lucene/codecs/MultiLevelSkipListWriter.java
index 207b324..8e090be 100644
--- a/lucene/core/src/java/org/apache/lucene/codecs/MultiLevelSkipListWriter.java
+++ b/lucene/core/src/java/org/apache/lucene/codecs/MultiLevelSkipListWriter.java
@@ -53,13 +53,13 @@ import org.apache.lucene.util.MathUtil;
 
 public abstract class MultiLevelSkipListWriter {
   /** number of levels in this skip list */
-  protected int numberOfSkipLevels;
+  protected final int numberOfSkipLevels;
   
   /** the skip interval in the list with level = 0 */
-  private int skipInterval;
+  private final int skipInterval;
 
   /** skipInterval used for level &gt; 0 */
-  private int skipMultiplier;
+  private final int skipMultiplier;
   
   /** for every skip level a different buffer is used  */
   private RAMOutputStream[] skipBuffer;
@@ -69,6 +69,7 @@ public abstract class MultiLevelSkipListWriter {
     this.skipInterval = skipInterval;
     this.skipMultiplier = skipMultiplier;
     
+    int numberOfSkipLevels;
     // calculate the maximum number of skip levels for this document frequency
     if (df <= skipInterval) {
       numberOfSkipLevels = 1;
@@ -80,6 +81,7 @@ public abstract class MultiLevelSkipListWriter {
     if (numberOfSkipLevels > maxSkipLevels) {
       numberOfSkipLevels = maxSkipLevels;
     }
+    this.numberOfSkipLevels = numberOfSkipLevels;
   }
   
   /** Creates a {@code MultiLevelSkipListWriter}, where

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/core/src/java/org/apache/lucene/codecs/PostingsReaderBase.java
----------------------------------------------------------------------
diff --git a/lucene/core/src/java/org/apache/lucene/codecs/PostingsReaderBase.java b/lucene/core/src/java/org/apache/lucene/codecs/PostingsReaderBase.java
index 56cbab5..ca403fa 100644
--- a/lucene/core/src/java/org/apache/lucene/codecs/PostingsReaderBase.java
+++ b/lucene/core/src/java/org/apache/lucene/codecs/PostingsReaderBase.java
@@ -22,7 +22,9 @@ import java.io.IOException;
 
 import org.apache.lucene.index.PostingsEnum;
 import org.apache.lucene.index.FieldInfo;
+import org.apache.lucene.index.ImpactsEnum;
 import org.apache.lucene.index.SegmentReadState;
+import org.apache.lucene.search.similarities.Similarity;
 import org.apache.lucene.store.DataInput;
 import org.apache.lucene.store.IndexInput;
 import org.apache.lucene.util.Accountable;
@@ -65,7 +67,13 @@ public abstract class PostingsReaderBase implements Closeable, Accountable {
   /** Must fully consume state, since after this call that
    *  TermState may be reused. */
   public abstract PostingsEnum postings(FieldInfo fieldInfo, BlockTermState state, PostingsEnum reuse, int flags) throws IOException;
-  
+
+  /**
+   * Return a {@link ImpactsEnum} that computes impacts with {@code scorer}.
+   * @see #postings(FieldInfo, BlockTermState, PostingsEnum, int)
+   */
+  public abstract ImpactsEnum impacts(FieldInfo fieldInfo, BlockTermState state, Similarity.SimScorer scorer, int flags) throws IOException;
+
   /** 
    * Checks consistency of this reader.
    * <p>

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/core/src/java/org/apache/lucene/codecs/PostingsWriterBase.java
----------------------------------------------------------------------
diff --git a/lucene/core/src/java/org/apache/lucene/codecs/PostingsWriterBase.java b/lucene/core/src/java/org/apache/lucene/codecs/PostingsWriterBase.java
index b4f2d4e..48c6027 100644
--- a/lucene/core/src/java/org/apache/lucene/codecs/PostingsWriterBase.java
+++ b/lucene/core/src/java/org/apache/lucene/codecs/PostingsWriterBase.java
@@ -60,7 +60,7 @@ public abstract class PostingsWriterBase implements Closeable {
    *  FixedBitSet} for every docID written.  If no docs
    *  were written, this method should return null, and the
    *  terms dict will skip the term. */
-  public abstract BlockTermState writeTerm(BytesRef term, TermsEnum termsEnum, FixedBitSet docsSeen) throws IOException;
+  public abstract BlockTermState writeTerm(BytesRef term, TermsEnum termsEnum, FixedBitSet docsSeen, NormsProducer norms) throws IOException;
 
   /**
    * Encode metadata as long[] and byte[]. {@code absolute} controls whether 

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/core/src/java/org/apache/lucene/codecs/PushPostingsWriterBase.java
----------------------------------------------------------------------
diff --git a/lucene/core/src/java/org/apache/lucene/codecs/PushPostingsWriterBase.java b/lucene/core/src/java/org/apache/lucene/codecs/PushPostingsWriterBase.java
index 1fb83b9..98bdd91 100644
--- a/lucene/core/src/java/org/apache/lucene/codecs/PushPostingsWriterBase.java
+++ b/lucene/core/src/java/org/apache/lucene/codecs/PushPostingsWriterBase.java
@@ -22,6 +22,7 @@ import java.io.IOException;
 import org.apache.lucene.index.PostingsEnum;
 import org.apache.lucene.index.FieldInfo;
 import org.apache.lucene.index.IndexOptions;
+import org.apache.lucene.index.NumericDocValues;
 import org.apache.lucene.index.TermsEnum;
 import org.apache.lucene.util.BytesRef;
 import org.apache.lucene.util.FixedBitSet;
@@ -74,7 +75,7 @@ public abstract class PushPostingsWriterBase extends PostingsWriterBase {
   /** Start a new term.  Note that a matching call to {@link
    *  #finishTerm(BlockTermState)} is done, only if the term has at least one
    *  document. */
-  public abstract void startTerm() throws IOException;
+  public abstract void startTerm(NumericDocValues norms) throws IOException;
 
   /** Finishes the current term.  The provided {@link
    *  BlockTermState} contains the term's summary statistics, 
@@ -117,8 +118,14 @@ public abstract class PushPostingsWriterBase extends PostingsWriterBase {
   }
 
   @Override
-  public final BlockTermState writeTerm(BytesRef term, TermsEnum termsEnum, FixedBitSet docsSeen) throws IOException {
-    startTerm();
+  public final BlockTermState writeTerm(BytesRef term, TermsEnum termsEnum, FixedBitSet docsSeen, NormsProducer norms) throws IOException {
+    NumericDocValues normValues;
+    if (fieldInfo.hasNorms() == false) {
+      normValues = null;
+    } else {
+      normValues = norms.getNorms(fieldInfo);
+    }
+    startTerm(normValues);
     postingsEnum = termsEnum.postings(postingsEnum, enumFlags);
     assert postingsEnum != null;
 

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/core/src/java/org/apache/lucene/codecs/blocktree/BitSetTermsEnum.java
----------------------------------------------------------------------
diff --git a/lucene/core/src/java/org/apache/lucene/codecs/blocktree/BitSetTermsEnum.java b/lucene/core/src/java/org/apache/lucene/codecs/blocktree/BitSetTermsEnum.java
index ffc182f..4305c46 100644
--- a/lucene/core/src/java/org/apache/lucene/codecs/blocktree/BitSetTermsEnum.java
+++ b/lucene/core/src/java/org/apache/lucene/codecs/blocktree/BitSetTermsEnum.java
@@ -17,9 +17,13 @@
 package org.apache.lucene.codecs.blocktree;
 
 
+import java.io.IOException;
+
 import org.apache.lucene.codecs.PostingsWriterBase;
+import org.apache.lucene.index.ImpactsEnum;
 import org.apache.lucene.index.PostingsEnum;
 import org.apache.lucene.index.TermsEnum;
+import org.apache.lucene.search.similarities.Similarity.SimScorer;
 import org.apache.lucene.util.BitSet;
 import org.apache.lucene.util.BytesRef;
 
@@ -80,4 +84,9 @@ class BitSetTermsEnum extends TermsEnum {
     postingsEnum.reset();
     return postingsEnum;
   }
+
+  @Override
+  public ImpactsEnum impacts(SimScorer scorer, int flags) throws IOException {
+    throw new UnsupportedOperationException();
+  }
 }

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/core/src/java/org/apache/lucene/codecs/blocktree/BlockTreeTermsWriter.java
----------------------------------------------------------------------
diff --git a/lucene/core/src/java/org/apache/lucene/codecs/blocktree/BlockTreeTermsWriter.java b/lucene/core/src/java/org/apache/lucene/codecs/blocktree/BlockTreeTermsWriter.java
index bdacc22..ec3f6e6 100644
--- a/lucene/core/src/java/org/apache/lucene/codecs/blocktree/BlockTreeTermsWriter.java
+++ b/lucene/core/src/java/org/apache/lucene/codecs/blocktree/BlockTreeTermsWriter.java
@@ -24,6 +24,7 @@ import java.util.List;
 import org.apache.lucene.codecs.BlockTermState;
 import org.apache.lucene.codecs.CodecUtil;
 import org.apache.lucene.codecs.FieldsConsumer;
+import org.apache.lucene.codecs.NormsProducer;
 import org.apache.lucene.codecs.PostingsWriterBase;
 import org.apache.lucene.index.FieldInfo;
 import org.apache.lucene.index.FieldInfos;
@@ -315,7 +316,7 @@ public final class BlockTreeTermsWriter extends FieldsConsumer {
   }
 
   @Override
-  public void write(Fields fields) throws IOException {
+  public void write(Fields fields, NormsProducer norms) throws IOException {
     //if (DEBUG) System.out.println("\nBTTW.write seg=" + segment);
 
     String lastField = null;
@@ -340,7 +341,7 @@ public final class BlockTreeTermsWriter extends FieldsConsumer {
         }
 
         //if (DEBUG) System.out.println("write field=" + fieldInfo.name + " term=" + brToString(term));
-        termsWriter.write(term, termsEnum);
+        termsWriter.write(term, termsEnum, norms);
       }
 
       termsWriter.finish();
@@ -852,7 +853,7 @@ public final class BlockTreeTermsWriter extends FieldsConsumer {
     }
     
     /** Writes one term's worth of postings. */
-    public void write(BytesRef text, TermsEnum termsEnum) throws IOException {
+    public void write(BytesRef text, TermsEnum termsEnum, NormsProducer norms) throws IOException {
       /*
       if (DEBUG) {
         int[] tmp = new int[lastTerm.length];
@@ -861,7 +862,7 @@ public final class BlockTreeTermsWriter extends FieldsConsumer {
       }
       */
 
-      BlockTermState state = postingsWriter.writeTerm(text, termsEnum, docsSeen);
+      BlockTermState state = postingsWriter.writeTerm(text, termsEnum, docsSeen, norms);
       if (state != null) {
 
         assert state.docFreq != 0;

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/core/src/java/org/apache/lucene/codecs/blocktree/IntersectTermsEnum.java
----------------------------------------------------------------------
diff --git a/lucene/core/src/java/org/apache/lucene/codecs/blocktree/IntersectTermsEnum.java b/lucene/core/src/java/org/apache/lucene/codecs/blocktree/IntersectTermsEnum.java
index 7521763..6bccddc 100644
--- a/lucene/core/src/java/org/apache/lucene/codecs/blocktree/IntersectTermsEnum.java
+++ b/lucene/core/src/java/org/apache/lucene/codecs/blocktree/IntersectTermsEnum.java
@@ -19,10 +19,12 @@ package org.apache.lucene.codecs.blocktree;
 
 import java.io.IOException;
 
+import org.apache.lucene.index.ImpactsEnum;
 import org.apache.lucene.index.PostingsEnum;
 import org.apache.lucene.index.TermState;
 import org.apache.lucene.index.Terms;
 import org.apache.lucene.index.TermsEnum;
+import org.apache.lucene.search.similarities.Similarity.SimScorer;
 import org.apache.lucene.store.IndexInput;
 import org.apache.lucene.util.ArrayUtil;
 import org.apache.lucene.util.BytesRef;
@@ -232,6 +234,12 @@ final class IntersectTermsEnum extends TermsEnum {
     return fr.parent.postingsReader.postings(fr.fieldInfo, currentFrame.termState, reuse, flags);
   }
 
+  @Override
+  public ImpactsEnum impacts(SimScorer scorer, int flags) throws IOException {
+    currentFrame.decodeMetaData();
+    return fr.parent.postingsReader.impacts(fr.fieldInfo, currentFrame.termState, scorer, flags);
+  }
+
   private int getState() {
     int state = currentFrame.state;
     for(int idx=0;idx<currentFrame.suffix;idx++) {

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/core/src/java/org/apache/lucene/codecs/blocktree/SegmentTermsEnum.java
----------------------------------------------------------------------
diff --git a/lucene/core/src/java/org/apache/lucene/codecs/blocktree/SegmentTermsEnum.java b/lucene/core/src/java/org/apache/lucene/codecs/blocktree/SegmentTermsEnum.java
index 73c32bb..ef83f49 100644
--- a/lucene/core/src/java/org/apache/lucene/codecs/blocktree/SegmentTermsEnum.java
+++ b/lucene/core/src/java/org/apache/lucene/codecs/blocktree/SegmentTermsEnum.java
@@ -21,9 +21,11 @@ import java.io.IOException;
 import java.io.PrintStream;
 
 import org.apache.lucene.codecs.BlockTermState;
+import org.apache.lucene.index.ImpactsEnum;
 import org.apache.lucene.index.PostingsEnum;
 import org.apache.lucene.index.TermState;
 import org.apache.lucene.index.TermsEnum;
+import org.apache.lucene.search.similarities.Similarity.SimScorer;
 import org.apache.lucene.store.ByteArrayDataInput;
 import org.apache.lucene.store.IndexInput;
 import org.apache.lucene.util.ArrayUtil;
@@ -1003,6 +1005,19 @@ final class SegmentTermsEnum extends TermsEnum {
   }
 
   @Override
+  public ImpactsEnum impacts(SimScorer scorer, int flags) throws IOException {
+    assert !eof;
+    //if (DEBUG) {
+    //System.out.println("BTTR.docs seg=" + segment);
+    //}
+    currentFrame.decodeMetaData();
+    //if (DEBUG) {
+    //System.out.println("  state=" + currentFrame.state);
+    //}
+    return fr.parent.postingsReader.impacts(fr.fieldInfo, currentFrame.state, scorer, flags);
+  }
+
+  @Override
   public void seekExact(BytesRef target, TermState otherState) {
     // if (DEBUG) {
     //   System.out.println("BTTR.seekExact termState seg=" + segment + " target=" + target.utf8ToString() + " " + target + " state=" + otherState);

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/core/src/java/org/apache/lucene/codecs/compressing/CompressingTermVectorsReader.java
----------------------------------------------------------------------
diff --git a/lucene/core/src/java/org/apache/lucene/codecs/compressing/CompressingTermVectorsReader.java b/lucene/core/src/java/org/apache/lucene/codecs/compressing/CompressingTermVectorsReader.java
index f5318ba..a0f5292 100644
--- a/lucene/core/src/java/org/apache/lucene/codecs/compressing/CompressingTermVectorsReader.java
+++ b/lucene/core/src/java/org/apache/lucene/codecs/compressing/CompressingTermVectorsReader.java
@@ -27,14 +27,17 @@ import java.util.NoSuchElementException;
 import org.apache.lucene.codecs.CodecUtil;
 import org.apache.lucene.codecs.TermVectorsReader;
 import org.apache.lucene.index.CorruptIndexException;
+import org.apache.lucene.index.SlowImpactsEnum;
 import org.apache.lucene.index.PostingsEnum;
 import org.apache.lucene.index.FieldInfo;
 import org.apache.lucene.index.FieldInfos;
 import org.apache.lucene.index.Fields;
+import org.apache.lucene.index.ImpactsEnum;
 import org.apache.lucene.index.IndexFileNames;
 import org.apache.lucene.index.SegmentInfo;
 import org.apache.lucene.index.Terms;
 import org.apache.lucene.index.TermsEnum;
+import org.apache.lucene.search.similarities.Similarity.SimScorer;
 import org.apache.lucene.store.AlreadyClosedException;
 import org.apache.lucene.store.ByteArrayDataInput;
 import org.apache.lucene.store.ChecksumIndexInput;
@@ -942,6 +945,13 @@ public final class CompressingTermVectorsReader extends TermVectorsReader implem
       return docsEnum;
     }
 
+    @Override
+    public ImpactsEnum impacts(SimScorer scorer, int flags) throws IOException {
+      final PostingsEnum delegate = postings(null, PostingsEnum.FREQS);
+      final float maxScore = scorer.score(Float.MAX_VALUE, 1);
+      return new SlowImpactsEnum(delegate, maxScore);
+    }
+
   }
 
   private static class TVPostingsEnum extends PostingsEnum {

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/core/src/java/org/apache/lucene/codecs/lucene50/Lucene50PostingsFormat.java
----------------------------------------------------------------------
diff --git a/lucene/core/src/java/org/apache/lucene/codecs/lucene50/Lucene50PostingsFormat.java b/lucene/core/src/java/org/apache/lucene/codecs/lucene50/Lucene50PostingsFormat.java
index 3b0d5c2..a99894a 100644
--- a/lucene/core/src/java/org/apache/lucene/codecs/lucene50/Lucene50PostingsFormat.java
+++ b/lucene/core/src/java/org/apache/lucene/codecs/lucene50/Lucene50PostingsFormat.java
@@ -384,7 +384,8 @@ public final class Lucene50PostingsFormat extends PostingsFormat {
 
   // Increment version to change it
   final static int VERSION_START = 0;
-  final static int VERSION_CURRENT = VERSION_START;
+  final static int VERSION_IMPACT_SKIP_DATA = 1;
+  final static int VERSION_CURRENT = VERSION_IMPACT_SKIP_DATA;
 
   private final int minTermBlockSize;
   private final int maxTermBlockSize;

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/core/src/java/org/apache/lucene/codecs/lucene50/Lucene50PostingsReader.java
----------------------------------------------------------------------
diff --git a/lucene/core/src/java/org/apache/lucene/codecs/lucene50/Lucene50PostingsReader.java b/lucene/core/src/java/org/apache/lucene/codecs/lucene50/Lucene50PostingsReader.java
index 0dde774..62c7f3f 100644
--- a/lucene/core/src/java/org/apache/lucene/codecs/lucene50/Lucene50PostingsReader.java
+++ b/lucene/core/src/java/org/apache/lucene/codecs/lucene50/Lucene50PostingsReader.java
@@ -19,16 +19,20 @@ package org.apache.lucene.codecs.lucene50;
 
 import java.io.IOException;
 import java.util.Arrays;
+import java.util.Objects;
 
 import org.apache.lucene.codecs.BlockTermState;
 import org.apache.lucene.codecs.CodecUtil;
 import org.apache.lucene.codecs.PostingsReaderBase;
 import org.apache.lucene.codecs.lucene50.Lucene50PostingsFormat.IntBlockTermState;
 import org.apache.lucene.index.FieldInfo;
+import org.apache.lucene.index.ImpactsEnum;
 import org.apache.lucene.index.IndexFileNames;
 import org.apache.lucene.index.IndexOptions;
 import org.apache.lucene.index.PostingsEnum;
 import org.apache.lucene.index.SegmentReadState;
+import org.apache.lucene.index.SlowImpactsEnum;
+import org.apache.lucene.search.similarities.Similarity.SimScorer;
 import org.apache.lucene.store.DataInput;
 import org.apache.lucene.store.IndexInput;
 import org.apache.lucene.util.ArrayUtil;
@@ -234,6 +238,16 @@ public final class Lucene50PostingsReader extends PostingsReaderBase {
     }
   }
 
+  @Override
+  public ImpactsEnum impacts(FieldInfo fieldInfo, BlockTermState state, SimScorer scorer, int flags) throws IOException {
+    Objects.requireNonNull(scorer);
+    if (state.docFreq <= BLOCK_SIZE || version < Lucene50PostingsFormat.VERSION_IMPACT_SKIP_DATA) {
+      // no skip data
+      return new SlowImpactsEnum(postings(fieldInfo, state, null, flags), scorer.score(Float.MAX_VALUE, 1));
+    }
+    return new BlockImpactsEverythingEnum(fieldInfo, (IntBlockTermState) state, scorer, flags);
+  }
+
   final class BlockDocsEnum extends PostingsEnum {
     private final byte[] encoded;
     
@@ -401,7 +415,8 @@ public final class Lucene50PostingsReader extends PostingsReaderBase {
 
         if (skipper == null) {
           // Lazy init: first time this enum has ever been used for skipping
-          skipper = new Lucene50SkipReader(docIn.clone(),
+          skipper = new Lucene50SkipReader(version,
+                                           docIn.clone(),
                                            MAX_SKIP_LEVELS,
                                            indexHasPos,
                                            indexHasOffsets,
@@ -666,7 +681,8 @@ public final class Lucene50PostingsReader extends PostingsReaderBase {
       if (target > nextSkipDoc) {
         if (skipper == null) {
           // Lazy init: first time this enum has ever been used for skipping
-          skipper = new Lucene50SkipReader(docIn.clone(),
+          skipper = new Lucene50SkipReader(version,
+                                           docIn.clone(),
                                            MAX_SKIP_LEVELS,
                                            true,
                                            indexHasOffsets,
@@ -1082,7 +1098,8 @@ public final class Lucene50PostingsReader extends PostingsReaderBase {
       if (target > nextSkipDoc) {
         if (skipper == null) {
           // Lazy init: first time this enum has ever been used for skipping
-          skipper = new Lucene50SkipReader(docIn.clone(),
+          skipper = new Lucene50SkipReader(version,
+                                        docIn.clone(),
                                         MAX_SKIP_LEVELS,
                                         true,
                                         indexHasOffsets,
@@ -1272,6 +1289,469 @@ public final class Lucene50PostingsReader extends PostingsReaderBase {
     }
   }
 
+  final class BlockImpactsEverythingEnum extends ImpactsEnum {
+    
+    private final byte[] encoded;
+
+    private final int[] docDeltaBuffer = new int[MAX_DATA_SIZE];
+    private final int[] freqBuffer = new int[MAX_DATA_SIZE];
+    private final int[] posDeltaBuffer = new int[MAX_DATA_SIZE];
+
+    private final int[] payloadLengthBuffer;
+    private final int[] offsetStartDeltaBuffer;
+    private final int[] offsetLengthBuffer;
+
+    private byte[] payloadBytes;
+    private int payloadByteUpto;
+    private int payloadLength;
+
+    private int lastStartOffset;
+    private int startOffset = -1;
+    private int endOffset = -1;
+
+    private int docBufferUpto;
+    private int posBufferUpto;
+
+    private final Lucene50ScoreSkipReader skipper;
+
+    final IndexInput docIn;
+    final IndexInput posIn;
+    final IndexInput payIn;
+    final BytesRef payload;
+
+    final boolean indexHasFreq;
+    final boolean indexHasPos;
+    final boolean indexHasOffsets;
+    final boolean indexHasPayloads;
+
+    private int docFreq;                              // number of docs in this posting list
+    private long totalTermFreq;                       // number of positions in this posting list
+    private int docUpto;                              // how many docs we've read
+    private int doc;                                  // doc we last read
+    private int accum;                                // accumulator for doc deltas
+    private int freq;                                 // freq we last read
+    private int position;                             // current position
+
+    // how many positions "behind" we are; nextPosition must
+    // skip these to "catch up":
+    private int posPendingCount;
+
+    // Lazy pos seek: if != -1 then we must seek to this FP
+    // before reading positions:
+    private long posPendingFP;
+
+    // Lazy pay seek: if != -1 then we must seek to this FP
+    // before reading payloads/offsets:
+    private long payPendingFP;
+
+    // Where this term's postings start in the .doc file:
+    private long docTermStartFP;
+
+    // Where this term's postings start in the .pos file:
+    private long posTermStartFP;
+
+    // Where this term's payloads/offsets start in the .pay
+    // file:
+    private long payTermStartFP;
+
+    // File pointer where the last (vInt encoded) pos delta
+    // block is.  We need this to know whether to bulk
+    // decode vs vInt decode the block:
+    private long lastPosBlockFP;
+
+    private int nextSkipDoc = -1;
+    
+    private final boolean needsPositions;
+    private final boolean needsOffsets; // true if we actually need offsets
+    private final boolean needsPayloads; // true if we actually need payloads
+    
+    private long seekTo = -1;
+    
+    public BlockImpactsEverythingEnum(FieldInfo fieldInfo, IntBlockTermState termState, SimScorer scorer, int flags) throws IOException {
+      indexHasFreq = fieldInfo.getIndexOptions().compareTo(IndexOptions.DOCS_AND_FREQS) >= 0;
+      indexHasPos = fieldInfo.getIndexOptions().compareTo(IndexOptions.DOCS_AND_FREQS_AND_POSITIONS) >= 0;
+      indexHasOffsets = fieldInfo.getIndexOptions().compareTo(IndexOptions.DOCS_AND_FREQS_AND_POSITIONS_AND_OFFSETS) >= 0;
+      indexHasPayloads = fieldInfo.hasPayloads();
+      
+      needsPositions = PostingsEnum.featureRequested(flags, PostingsEnum.POSITIONS);
+      needsOffsets = PostingsEnum.featureRequested(flags, PostingsEnum.OFFSETS);
+      needsPayloads = PostingsEnum.featureRequested(flags, PostingsEnum.PAYLOADS);
+      
+      this.docIn = Lucene50PostingsReader.this.docIn.clone();
+      
+      encoded = new byte[MAX_ENCODED_SIZE];
+
+      if (indexHasPos && needsPositions) {
+        this.posIn = Lucene50PostingsReader.this.posIn.clone();
+      } else {
+        this.posIn = null;
+      }
+      
+      if ((indexHasOffsets && needsOffsets) || (indexHasPayloads && needsPayloads)) {
+        this.payIn = Lucene50PostingsReader.this.payIn.clone();
+      } else {
+        this.payIn = null;
+      }
+      
+      if (indexHasOffsets) {
+        offsetStartDeltaBuffer = new int[MAX_DATA_SIZE];
+        offsetLengthBuffer = new int[MAX_DATA_SIZE];
+      } else {
+        offsetStartDeltaBuffer = null;
+        offsetLengthBuffer = null;
+        startOffset = -1;
+        endOffset = -1;
+      }
+
+      if (indexHasPayloads) {
+        payloadLengthBuffer = new int[MAX_DATA_SIZE];
+        payloadBytes = new byte[128];
+        payload = new BytesRef();
+      } else {
+        payloadLengthBuffer = null;
+        payloadBytes = null;
+        payload = null;
+      }
+
+      docFreq = termState.docFreq;
+      docTermStartFP = termState.docStartFP;
+      posTermStartFP = termState.posStartFP;
+      payTermStartFP = termState.payStartFP;
+      totalTermFreq = termState.totalTermFreq;
+      docIn.seek(docTermStartFP);
+      posPendingFP = posTermStartFP;
+      payPendingFP = payTermStartFP;
+      posPendingCount = 0;
+      if (termState.totalTermFreq < BLOCK_SIZE) {
+        lastPosBlockFP = posTermStartFP;
+      } else if (termState.totalTermFreq == BLOCK_SIZE) {
+        lastPosBlockFP = -1;
+      } else {
+        lastPosBlockFP = posTermStartFP + termState.lastPosBlockOffset;
+      }
+
+      doc = -1;
+      accum = 0;
+      docUpto = 0;
+      docBufferUpto = BLOCK_SIZE;
+
+      skipper = new Lucene50ScoreSkipReader(version,
+          docIn.clone(),
+          MAX_SKIP_LEVELS,
+          indexHasPos,
+          indexHasOffsets,
+          indexHasPayloads,
+          scorer);
+      skipper.init(docTermStartFP+termState.skipOffset, docTermStartFP, posTermStartFP, payTermStartFP, docFreq);
+
+      if (indexHasFreq == false) {
+        Arrays.fill(freqBuffer, 1);
+      }
+    }
+    
+    @Override
+    public int freq() throws IOException {
+      return freq;
+    }
+
+    @Override
+    public int docID() {
+      return doc;
+    }
+
+    private void refillDocs() throws IOException {
+      final int left = docFreq - docUpto;
+      assert left > 0;
+
+      if (left >= BLOCK_SIZE) {
+        forUtil.readBlock(docIn, encoded, docDeltaBuffer);
+        if (indexHasFreq) {
+          forUtil.readBlock(docIn, encoded, freqBuffer);
+        }
+      } else {
+        readVIntBlock(docIn, docDeltaBuffer, freqBuffer, left, indexHasFreq);
+      }
+      docBufferUpto = 0;
+    }
+    
+    private void refillPositions() throws IOException {
+      if (posIn.getFilePointer() == lastPosBlockFP) {
+        final int count = (int) (totalTermFreq % BLOCK_SIZE);
+        int payloadLength = 0;
+        int offsetLength = 0;
+        payloadByteUpto = 0;
+        for(int i=0;i<count;i++) {
+          int code = posIn.readVInt();
+          if (indexHasPayloads) {
+            if ((code & 1) != 0) {
+              payloadLength = posIn.readVInt();
+            }
+            payloadLengthBuffer[i] = payloadLength;
+            posDeltaBuffer[i] = code >>> 1;
+            if (payloadLength != 0) {
+              if (payloadByteUpto + payloadLength > payloadBytes.length) {
+                payloadBytes = ArrayUtil.grow(payloadBytes, payloadByteUpto + payloadLength);
+              }
+              posIn.readBytes(payloadBytes, payloadByteUpto, payloadLength);
+              payloadByteUpto += payloadLength;
+            }
+          } else {
+            posDeltaBuffer[i] = code;
+          }
+
+          if (indexHasOffsets) {
+            int deltaCode = posIn.readVInt();
+            if ((deltaCode & 1) != 0) {
+              offsetLength = posIn.readVInt();
+            }
+            offsetStartDeltaBuffer[i] = deltaCode >>> 1;
+            offsetLengthBuffer[i] = offsetLength;
+          }
+        }
+        payloadByteUpto = 0;
+      } else {
+        forUtil.readBlock(posIn, encoded, posDeltaBuffer);
+
+        if (indexHasPayloads && payIn != null) {
+          if (needsPayloads) {
+            forUtil.readBlock(payIn, encoded, payloadLengthBuffer);
+            int numBytes = payIn.readVInt();
+
+            if (numBytes > payloadBytes.length) {
+              payloadBytes = ArrayUtil.grow(payloadBytes, numBytes);
+            }
+            payIn.readBytes(payloadBytes, 0, numBytes);
+          } else {
+            // this works, because when writing a vint block we always force the first length to be written
+            forUtil.skipBlock(payIn); // skip over lengths
+            int numBytes = payIn.readVInt(); // read length of payloadBytes
+            payIn.seek(payIn.getFilePointer() + numBytes); // skip over payloadBytes
+          }
+          payloadByteUpto = 0;
+        }
+
+        if (indexHasOffsets && payIn != null) {
+          if (needsOffsets) {
+            forUtil.readBlock(payIn, encoded, offsetStartDeltaBuffer);
+            forUtil.readBlock(payIn, encoded, offsetLengthBuffer);
+          } else {
+            // this works, because when writing a vint block we always force the first length to be written
+            forUtil.skipBlock(payIn); // skip over starts
+            forUtil.skipBlock(payIn); // skip over lengths
+          }
+        }
+      }
+    }
+
+    @Override
+    public int nextDoc() throws IOException {
+      return advance(doc + 1);
+    }
+
+    @Override
+    public float getMaxScore(int upTo) throws IOException {
+      return skipper.getMaxScore(upTo);
+    }
+
+    @Override
+    public int advanceShallow(int target) throws IOException {
+      if (target > nextSkipDoc) {
+        // always plus one to fix the result, since skip position in Lucene50SkipReader 
+        // is a little different from MultiLevelSkipListReader
+        final int newDocUpto = skipper.skipTo(target) + 1; 
+  
+        if (newDocUpto > docUpto) {
+          // Skipper moved
+          assert newDocUpto % BLOCK_SIZE == 0 : "got " + newDocUpto;
+          docUpto = newDocUpto;
+
+          // Force to read next block
+          docBufferUpto = BLOCK_SIZE;
+          accum = skipper.getDoc();
+          posPendingFP = skipper.getPosPointer();
+          payPendingFP = skipper.getPayPointer();
+          posPendingCount = skipper.getPosBufferUpto();
+          lastStartOffset = 0; // new document
+          payloadByteUpto = skipper.getPayloadByteUpto();             // actually, this is just lastSkipEntry
+          seekTo = skipper.getDocPointer();       // delay the seek
+        }
+        // next time we call advance, this is used to 
+        // foresee whether skipper is necessary.
+        nextSkipDoc = skipper.getNextSkipDoc();
+      }
+      assert nextSkipDoc >= target;
+      return nextSkipDoc;
+    }
+
+    @Override
+    public int advance(int target) throws IOException {
+      if (target > nextSkipDoc) {
+        advanceShallow(target);
+      }
+      if (docUpto == docFreq) {
+        return doc = NO_MORE_DOCS;
+      }
+      if (docBufferUpto == BLOCK_SIZE) {
+        if (seekTo >= 0) {
+          docIn.seek(seekTo);
+          seekTo = -1;
+        }
+        refillDocs();
+      }
+
+      // Now scan:
+      while (true) {
+        accum += docDeltaBuffer[docBufferUpto];
+        freq = freqBuffer[docBufferUpto];
+        posPendingCount += freq;
+        docBufferUpto++;
+        docUpto++;
+
+        if (accum >= target) {
+          break;
+        }
+        if (docUpto == docFreq) {
+          return doc = NO_MORE_DOCS;
+        }
+      }
+      position = 0;
+      lastStartOffset = 0;
+
+      return doc = accum;
+    }
+
+    // TODO: in theory we could avoid loading frq block
+    // when not needed, ie, use skip data to load how far to
+    // seek the pos pointer ... instead of having to load frq
+    // blocks only to sum up how many positions to skip
+    private void skipPositions() throws IOException {
+      // Skip positions now:
+      int toSkip = posPendingCount - freq;
+      // if (DEBUG) {
+      //   System.out.println("      FPR.skipPositions: toSkip=" + toSkip);
+      // }
+
+      final int leftInBlock = BLOCK_SIZE - posBufferUpto;
+      if (toSkip < leftInBlock) {
+        int end = posBufferUpto + toSkip;
+        while(posBufferUpto < end) {
+          if (indexHasPayloads) {
+            payloadByteUpto += payloadLengthBuffer[posBufferUpto];
+          }
+          posBufferUpto++;
+        }
+      } else {
+        toSkip -= leftInBlock;
+        while(toSkip >= BLOCK_SIZE) {
+          assert posIn.getFilePointer() != lastPosBlockFP;
+          forUtil.skipBlock(posIn);
+  
+          if (indexHasPayloads && payIn != null) {
+            // Skip payloadLength block:
+            forUtil.skipBlock(payIn);
+
+            // Skip payloadBytes block:
+            int numBytes = payIn.readVInt();
+            payIn.seek(payIn.getFilePointer() + numBytes);
+          }
+
+          if (indexHasOffsets && payIn != null) {
+            forUtil.skipBlock(payIn);
+            forUtil.skipBlock(payIn);
+          }
+          toSkip -= BLOCK_SIZE;
+        }
+        refillPositions();
+        payloadByteUpto = 0;
+        posBufferUpto = 0;
+        while(posBufferUpto < toSkip) {
+          if (indexHasPayloads) {
+            payloadByteUpto += payloadLengthBuffer[posBufferUpto];
+          }
+          posBufferUpto++;
+        }
+      }
+
+      position = 0;
+      lastStartOffset = 0;
+    }
+
+    @Override
+    public int nextPosition() throws IOException {
+      if (indexHasPos == false || needsPositions == false) {
+        return -1;
+      }
+      assert posPendingCount > 0;
+      
+      if (posPendingFP != -1) {
+        posIn.seek(posPendingFP);
+        posPendingFP = -1;
+
+        if (payPendingFP != -1 && payIn != null) {
+          payIn.seek(payPendingFP);
+          payPendingFP = -1;
+        }
+
+        // Force buffer refill:
+        posBufferUpto = BLOCK_SIZE;
+      }
+
+      if (posPendingCount > freq) {
+        skipPositions();
+        posPendingCount = freq;
+      }
+
+      if (posBufferUpto == BLOCK_SIZE) {
+        refillPositions();
+        posBufferUpto = 0;
+      }
+      position += posDeltaBuffer[posBufferUpto];
+
+      if (indexHasPayloads) {
+        payloadLength = payloadLengthBuffer[posBufferUpto];
+        payload.bytes = payloadBytes;
+        payload.offset = payloadByteUpto;
+        payload.length = payloadLength;
+        payloadByteUpto += payloadLength;
+      }
+
+      if (indexHasOffsets && needsOffsets) {
+        startOffset = lastStartOffset + offsetStartDeltaBuffer[posBufferUpto];
+        endOffset = startOffset + offsetLengthBuffer[posBufferUpto];
+        lastStartOffset = startOffset;
+      }
+
+      posBufferUpto++;
+      posPendingCount--;
+      return position;
+    }
+
+    @Override
+    public int startOffset() {
+      return startOffset;
+    }
+  
+    @Override
+    public int endOffset() {
+      return endOffset;
+    }
+  
+    @Override
+    public BytesRef getPayload() {
+      if (payloadLength == 0) {
+        return null;
+      } else {
+        return payload;
+      }
+    }
+    
+    @Override
+    public long cost() {
+      return docFreq;
+    }
+
+  }
+
   @Override
   public long ramBytesUsed() {
     return BASE_RAM_BYTES_USED;

http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/f410df81/lucene/core/src/java/org/apache/lucene/codecs/lucene50/Lucene50PostingsWriter.java
----------------------------------------------------------------------
diff --git a/lucene/core/src/java/org/apache/lucene/codecs/lucene50/Lucene50PostingsWriter.java b/lucene/core/src/java/org/apache/lucene/codecs/lucene50/Lucene50PostingsWriter.java
index 6d24a4c..06b9a0c 100644
--- a/lucene/core/src/java/org/apache/lucene/codecs/lucene50/Lucene50PostingsWriter.java
+++ b/lucene/core/src/java/org/apache/lucene/codecs/lucene50/Lucene50PostingsWriter.java
@@ -31,12 +31,14 @@ import java.io.IOException;
 
 import org.apache.lucene.codecs.BlockTermState;
 import org.apache.lucene.codecs.CodecUtil;
+import org.apache.lucene.codecs.CompetitiveFreqNormAccumulator;
 import org.apache.lucene.codecs.PushPostingsWriterBase;
 import org.apache.lucene.codecs.lucene50.Lucene50PostingsFormat.IntBlockTermState;
 import org.apache.lucene.index.CorruptIndexException;
 import org.apache.lucene.index.FieldInfo;
 import org.apache.lucene.index.IndexFileNames;
 import org.apache.lucene.index.IndexWriter;
+import org.apache.lucene.index.NumericDocValues;
 import org.apache.lucene.index.SegmentWriteState;
 import org.apache.lucene.store.DataOutput;
 import org.apache.lucene.store.IndexOutput;
@@ -96,7 +98,11 @@ public final class Lucene50PostingsWriter extends PushPostingsWriterBase {
 
   private final ForUtil forUtil;
   private final Lucene50SkipWriter skipWriter;
-  
+
+  private boolean fieldHasNorms;
+  private NumericDocValues norms;
+  private final CompetitiveFreqNormAccumulator competitiveFreqNormAccumulator = new CompetitiveFreqNormAccumulator();
+
   /** Creates a postings writer */
   public Lucene50PostingsWriter(SegmentWriteState state) throws IOException {
     final float acceptableOverheadRatio = PackedInts.COMPACT;
@@ -185,6 +191,7 @@ public final class Lucene50PostingsWriter extends PushPostingsWriterBase {
     super.setField(fieldInfo);
     skipWriter.setField(writePositions, writeOffsets, writePayloads);
     lastState = emptyState;
+    fieldHasNorms = fieldInfo.hasNorms();
     if (writePositions) {
       if (writePayloads || writeOffsets) {
         return 3;  // doc + pos + pay FP
@@ -197,7 +204,7 @@ public final class Lucene50PostingsWriter extends PushPostingsWriterBase {
   }
 
   @Override
-  public void startTerm() {
+  public void startTerm(NumericDocValues norms) {
     docStartFP = docOut.getFilePointer();
     if (writePositions) {
       posStartFP = posOut.getFilePointer();
@@ -208,6 +215,8 @@ public final class Lucene50PostingsWriter extends PushPostingsWriterBase {
     lastDocID = 0;
     lastBlockDocID = -1;
     skipWriter.resetSkip();
+    this.norms = norms;
+    competitiveFreqNormAccumulator.clear();
   }
 
   @Override
@@ -216,7 +225,9 @@ public final class Lucene50PostingsWriter extends PushPostingsWriterBase {
     // Should write skip data as well as postings list for
     // current block.
     if (lastBlockDocID != -1 && docBufferUpto == 0) {
-      skipWriter.bufferSkip(lastBlockDocID, docCount, lastBlockPosFP, lastBlockPayFP, lastBlockPosBufferUpto, lastBlockPayloadByteUpto);
+      skipWriter.bufferSkip(lastBlockDocID, competitiveFreqNormAccumulator, docCount,
+          lastBlockPosFP, lastBlockPayFP, lastBlockPosBufferUpto, lastBlockPayloadByteUpto);
+      competitiveFreqNormAccumulator.clear();
     }
 
     final int docDelta = docID - lastDocID;
@@ -247,6 +258,24 @@ public final class Lucene50PostingsWriter extends PushPostingsWriterBase {
     lastDocID = docID;
     lastPosition = 0;
     lastStartOffset = 0;
+
+    long norm;
+    if (fieldHasNorms) {
+      boolean found = norms.advanceExact(docID);
+      if (found == false) {
+        // This can happen if indexing hits a problem after adding a doc to the
+        // postings but before buffering the norm. Such documents are written
+        // deleted and will go away on the first merge.
+        norm = 1L;
+      } else {
+        norm = norms.longValue();
+        assert norm != 0 : docID;
+      }
+    } else {
+      norm = 1L;
+    }
+
+    competitiveFreqNormAccumulator.add(writeFreqs ? termDocFreq : 1, norm);
   }
 
   @Override