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Posted to commits@maven.apache.org by cs...@apache.org on 2015/11/03 12:29:20 UTC

[2/2] maven-indexer git commit: Added index writer, that writes single chunk for now

Added index writer, that writes single chunk for now


Project: http://git-wip-us.apache.org/repos/asf/maven-indexer/repo
Commit: http://git-wip-us.apache.org/repos/asf/maven-indexer/commit/b9c4d908
Tree: http://git-wip-us.apache.org/repos/asf/maven-indexer/tree/b9c4d908
Diff: http://git-wip-us.apache.org/repos/asf/maven-indexer/diff/b9c4d908

Branch: refs/heads/maven-indexer-5.x
Commit: b9c4d90810b6174a1851c179ffebf2c3456c4c66
Parents: af8783d
Author: Tamas Cservenak <ta...@cservenak.net>
Authored: Tue Nov 3 12:28:41 2015 +0100
Committer: Tamas Cservenak <ta...@cservenak.net>
Committed: Tue Nov 3 12:28:41 2015 +0100

----------------------------------------------------------------------
 .../apache/maven/index/reader/ChunkReader.java  | 423 +++++--------------
 .../apache/maven/index/reader/ChunkWriter.java  | 177 ++++++++
 .../apache/maven/index/reader/IndexReader.java  |  59 +--
 .../apache/maven/index/reader/IndexWriter.java  | 196 +++++++++
 .../apache/maven/index/reader/Iterables.java    | 204 +++++++++
 .../org/apache/maven/index/reader/Record.java   | 215 ++++++++--
 .../maven/index/reader/RecordCompactor.java     | 205 +++++++++
 .../maven/index/reader/RecordExpander.java      | 228 ++++++++++
 .../maven/index/reader/ResourceHandler.java     |   2 +-
 .../org/apache/maven/index/reader/Utils.java    |  98 +++++
 .../index/reader/WritableResourceHandler.java   |  11 +-
 .../index/reader/CachingResourceHandler.java    |  22 +-
 .../maven/index/reader/ChunkReaderTest.java     |  71 +++-
 .../index/reader/DirectoryResourceHandler.java  |  26 +-
 .../maven/index/reader/IndexReaderTest.java     |  66 ++-
 .../maven/index/reader/IndexWriterTest.java     |  91 ++++
 .../maven/index/reader/IterablesTest.java       |  92 ++++
 .../apache/maven/index/reader/TestSupport.java  | 163 +++++++
 .../resources/nexus-maven-repository-index.gz   | Bin 319 -> 0 bytes
 .../nexus-maven-repository-index.properties     |   6 -
 .../simple/nexus-maven-repository-index.gz      | Bin 0 -> 319 bytes
 .../nexus-maven-repository-index.properties     |   6 +
 pom.xml                                         |   2 +-
 23 files changed, 1919 insertions(+), 444 deletions(-)
----------------------------------------------------------------------


http://git-wip-us.apache.org/repos/asf/maven-indexer/blob/b9c4d908/indexer-reader/src/main/java/org/apache/maven/index/reader/ChunkReader.java
----------------------------------------------------------------------
diff --git a/indexer-reader/src/main/java/org/apache/maven/index/reader/ChunkReader.java b/indexer-reader/src/main/java/org/apache/maven/index/reader/ChunkReader.java
index 89434fd..dc6ee79 100644
--- a/indexer-reader/src/main/java/org/apache/maven/index/reader/ChunkReader.java
+++ b/indexer-reader/src/main/java/org/apache/maven/index/reader/ChunkReader.java
@@ -20,40 +20,27 @@ package org.apache.maven.index.reader;
  */
 
 import java.io.Closeable;
+import java.io.DataInput;
 import java.io.DataInputStream;
 import java.io.EOFException;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.UTFDataFormatException;
-import java.util.Arrays;
 import java.util.Date;
 import java.util.HashMap;
 import java.util.Iterator;
 import java.util.Map;
 import java.util.NoSuchElementException;
-import java.util.regex.Pattern;
 import java.util.zip.GZIPInputStream;
 
-import org.apache.maven.index.reader.Record.Type;
-
 /**
- * Maven 2 Index published binary chunk reader.
+ * Maven 2 Index published binary chunk reader, it reads raw Maven Indexer records from the transport binary format.
  *
  * @since 5.1.2
  */
 public class ChunkReader
-    implements Closeable, Iterable<Record>
+    implements Closeable, Iterable<Map<String, String>>
 {
-  private static final String FIELD_SEPARATOR = "|";
-
-  private static final String NOT_AVAILABLE = "NA";
-
-  private static final String UINFO = "u";
-
-  private static final String INFO = "i";
-
-  private static final Pattern FS_PATTERN = Pattern.compile(Pattern.quote(FIELD_SEPARATOR));
-
   private final String chunkName;
 
   private final DataInputStream dataInputStream;
@@ -78,14 +65,14 @@ public class ChunkReader
   }
 
   /**
-   * Returns index getVersion. All releases so far always returned {@code 1}.
+   * Returns index version. All releases so far always returned {@code 1}.
    */
   public int getVersion() {
     return version;
   }
 
   /**
-   * Returns the getTimestamp of last update of the index.
+   * Returns the index timestamp of last update of the index.
    */
   public Date getTimestamp() {
     return timestamp;
@@ -94,7 +81,7 @@ public class ChunkReader
   /**
    * Returns the {@link Record} iterator.
    */
-  public Iterator<Record> iterator() {
+  public Iterator<Map<String, String>> iterator() {
     try {
       return new IndexIterator(dataInputStream);
     }
@@ -114,341 +101,155 @@ public class ChunkReader
    * Low memory footprint index iterator that incrementally parses the underlying stream.
    */
   private static class IndexIterator
-      implements Iterator<Record>
+      implements Iterator<Map<String, String>>
   {
     private final DataInputStream dataInputStream;
 
-    private Record nextRecord;
+    private Map<String, String> nextRecord;
 
     public IndexIterator(final DataInputStream dataInputStream) throws IOException {
       this.dataInputStream = dataInputStream;
-      this.nextRecord = readRecord();
+      this.nextRecord = nextRecord();
     }
 
     public boolean hasNext() {
       return nextRecord != null;
     }
 
-    public Record next() {
+    public Map<String, String> next() {
       if (nextRecord == null) {
         throw new NoSuchElementException("chunk depleted");
       }
-      Record result = nextRecord;
+      Map<String, String> result = nextRecord;
+      nextRecord = nextRecord();
+      return result;
+    }
+
+    private Map<String, String> nextRecord() {
       try {
-        nextRecord = readRecord();
-        return result;
+        return readRecord(dataInputStream);
       }
       catch (IOException e) {
         throw new RuntimeException("read error", e);
       }
     }
+  }
 
-    /**
-     * Reads and returns next record from the underlying stream, or {@code null} if no more records.
-     */
-    private Record readRecord()
-        throws IOException
-    {
-      int fieldCount;
-      try {
-        fieldCount = dataInputStream.readInt();
-      }
-      catch (EOFException ex) {
-        return null; // no more documents
-      }
-
-      Map<String, String> recordMap = new HashMap<String, String>();
-      for (int i = 0; i < fieldCount; i++) {
-        readField(recordMap);
-      }
-
-      if (recordMap.containsKey("DESCRIPTOR")) {
-        return new Record(Type.DESCRIPTOR, recordMap, expandDescriptor(recordMap));
-      }
-      else if (recordMap.containsKey("allGroups")) {
-        return new Record(Type.ALL_GROUPS, recordMap, expandAllGroups(recordMap));
-      }
-      else if (recordMap.containsKey("rootGroups")) {
-        return new Record(Type.ROOT_GROUPS, recordMap, expandRootGroups(recordMap));
-      }
-      else if (recordMap.containsKey("del")) {
-        return new Record(Type.ARTIFACT_REMOVE, recordMap, expandDeletedArtifact(recordMap));
-      }
-      else {
-        // Fix up UINFO field wrt MINDEXER-41
-        final String uinfo = recordMap.get(UINFO);
-        final String info = recordMap.get(INFO);
-        if (uinfo != null && !(info == null || info.trim().length() == 0)) {
-          final String[] splitInfo = FS_PATTERN.split(info);
-          if (splitInfo.length > 6) {
-            final String extension = splitInfo[6];
-            if (uinfo.endsWith(FIELD_SEPARATOR + NOT_AVAILABLE)) {
-              recordMap.put(UINFO, uinfo + FIELD_SEPARATOR + extension);
-            }
-          }
-        }
-        return new Record(Type.ARTIFACT_ADD, recordMap, expandAddedArtifact(recordMap));
-      }
+  /**
+   * Reads and returns next record from the underlying stream, or {@code null} if no more records.
+   */
+  private static Map<String, String> readRecord(final DataInput dataInput)
+      throws IOException
+  {
+    int fieldCount;
+    try {
+      fieldCount = dataInput.readInt();
     }
-
-    private void readField(final Map<String, String> record)
-        throws IOException
-    {
-      dataInputStream.read(); // flags: neglect them
-      String name = dataInputStream.readUTF();
-      String value = readUTF();
-      record.put(name, value);
+    catch (EOFException ex) {
+      return null; // no more documents
     }
 
-    private String readUTF()
-        throws IOException
-    {
-      int utflen = dataInputStream.readInt();
-
-      byte[] bytearr;
-      char[] chararr;
-
-      try {
-        bytearr = new byte[utflen];
-        chararr = new char[utflen];
-      }
-      catch (OutOfMemoryError e) {
-        IOException ioex = new IOException("Index data content is corrupt");
-        ioex.initCause(e);
-        throw ioex;
-      }
-
-      int c, char2, char3;
-      int count = 0;
-      int chararr_count = 0;
+    Map<String, String> recordMap = new HashMap<String, String>();
+    for (int i = 0; i < fieldCount; i++) {
+      readField(recordMap, dataInput);
+    }
+    return recordMap;
+  }
 
-      dataInputStream.readFully(bytearr, 0, utflen);
+  private static void readField(final Map<String, String> record, final DataInput dataInput)
+      throws IOException
+  {
+    dataInput.readByte(); // flags: neglect them
+    String name = dataInput.readUTF();
+    String value = readUTF(dataInput);
+    record.put(name, value);
+  }
 
-      while (count < utflen) {
-        c = bytearr[count] & 0xff;
-        if (c > 127) {
-          break;
-        }
-        count++;
-        chararr[chararr_count++] = (char) c;
-      }
+  private static String readUTF(final DataInput dataInput)
+      throws IOException
+  {
+    int utflen = dataInput.readInt();
 
-      while (count < utflen) {
-        c = bytearr[count] & 0xff;
-        switch (c >> 4) {
-          case 0:
-          case 1:
-          case 2:
-          case 3:
-          case 4:
-          case 5:
-          case 6:
-          case 7:
-                    /* 0xxxxxxx */
-            count++;
-            chararr[chararr_count++] = (char) c;
-            break;
+    byte[] bytearr;
+    char[] chararr;
 
-          case 12:
-          case 13:
-                    /* 110x xxxx 10xx xxxx */
-            count += 2;
-            if (count > utflen) {
-              throw new UTFDataFormatException("malformed input: partial character at end");
-            }
-            char2 = bytearr[count - 1];
-            if ((char2 & 0xC0) != 0x80) {
-              throw new UTFDataFormatException("malformed input around byte " + count);
-            }
-            chararr[chararr_count++] = (char) (((c & 0x1F) << 6) | (char2 & 0x3F));
-            break;
-
-          case 14:
-                    /* 1110 xxxx 10xx xxxx 10xx xxxx */
-            count += 3;
-            if (count > utflen) {
-              throw new UTFDataFormatException("malformed input: partial character at end");
-            }
-            char2 = bytearr[count - 2];
-            char3 = bytearr[count - 1];
-            if (((char2 & 0xC0) != 0x80) || ((char3 & 0xC0) != 0x80)) {
-              throw new UTFDataFormatException("malformed input around byte " + (count - 1));
-            }
-            chararr[chararr_count++] =
-                (char) (((c & 0x0F) << 12) | ((char2 & 0x3F) << 6) | (char3 & 0x3F));
-            break;
-
-          default:
-                    /* 10xx xxxx, 1111 xxxx */
-            throw new UTFDataFormatException("malformed input around byte " + count);
-        }
-      }
-
-      // The number of chars produced may be less than utflen
-      return new String(chararr, 0, chararr_count);
+    try {
+      bytearr = new byte[utflen];
+      chararr = new char[utflen];
     }
-
-    private Map<String, Object> expandDescriptor(final Map<String, String> raw) {
-      final Map<String, Object> result = new HashMap<String, Object>();
-      String[] r = FS_PATTERN.split(raw.get("IDXINFO"));
-      result.put(Record.REPOSITORY_ID, r[1]);
-      return result;
+    catch (OutOfMemoryError e) {
+      IOException ioex = new IOException("Index data content is corrupt");
+      ioex.initCause(e);
+      throw ioex;
     }
 
-    private Map<String, Object> expandAllGroups(final Map<String, String> raw) {
-      final Map<String, Object> result = new HashMap<String, Object>();
-      putIfNotNullAsList(raw, Record.ALL_GROUPS_LIST, result, "allGroups");
-      return result;
-    }
+    int c, char2, char3;
+    int count = 0;
+    int chararr_count = 0;
 
-    private Map<String, Object> expandRootGroups(final Map<String, String> raw) {
-      final Map<String, Object> result = new HashMap<String, Object>();
-      putIfNotNullAsList(raw, Record.ROOT_GROUPS_LIST, result, "rootGroups");
-      return result;
-    }
+    dataInput.readFully(bytearr, 0, utflen);
 
-    private Map<String, Object> expandDeletedArtifact(final Map<String, String> raw) {
-      final Map<String, Object> result = new HashMap<String, Object>();
-      putIfNotNullTS(raw, "m", result, Record.REC_MODIFIED);
-      if (raw.containsKey("del")) {
-        expandUinfo(raw.get("del"), result);
+    while (count < utflen) {
+      c = bytearr[count] & 0xff;
+      if (c > 127) {
+        break;
       }
-      return result;
+      count++;
+      chararr[chararr_count++] = (char) c;
     }
 
-    /**
-     * Expands the "encoded" Maven Indexer record by splitting the synthetic fields and applying expanded field naming.
-     */
-    private Map<String, Object> expandAddedArtifact(final Map<String, String> raw) {
-      final Map<String, Object> result = new HashMap<String, Object>();
-
-      // Minimal
-      expandUinfo(raw.get(UINFO), result);
-      final String info = raw.get(INFO);
-      if (info != null) {
-        String[] r = FS_PATTERN.split(info);
-        result.put(Record.PACKAGING, renvl(r[0]));
-        result.put(Record.FILE_MODIFIED, Long.valueOf(r[1]));
-        result.put(Record.FILE_SIZE, Long.valueOf(r[2]));
-        result.put(Record.HAS_SOURCES, "1".equals(r[3]) ? Boolean.TRUE.toString() : Boolean.FALSE.toString());
-        result.put(Record.HAS_JAVADOC, "1".equals(r[4]) ? Boolean.TRUE.toString() : Boolean.FALSE.toString());
-        result.put(Record.HAS_SIGNATURE, "1".equals(r[5]) ? Boolean.TRUE.toString() : Boolean.FALSE.toString());
-        if (r.length > 6) {
-          result.put(Record.FILE_EXTENSION, r[6]);
-        }
-        else {
-          final String packaging = raw.get(Record.PACKAGING);
-          if (raw.get(Record.CLASSIFIER) != null
-              || "pom".equals(packaging)
-              || "war".equals(packaging)
-              || "ear".equals(packaging)) {
-            result.put(Record.FILE_EXTENSION, packaging);
+    while (count < utflen) {
+      c = bytearr[count] & 0xff;
+      switch (c >> 4) {
+        case 0:
+        case 1:
+        case 2:
+        case 3:
+        case 4:
+        case 5:
+        case 6:
+        case 7:
+                    /* 0xxxxxxx */
+          count++;
+          chararr[chararr_count++] = (char) c;
+          break;
+
+        case 12:
+        case 13:
+                    /* 110x xxxx 10xx xxxx */
+          count += 2;
+          if (count > utflen) {
+            throw new UTFDataFormatException("malformed input: partial character at end");
           }
-          else {
-            result.put(Record.FILE_EXTENSION, "jar"); // best guess
+          char2 = bytearr[count - 1];
+          if ((char2 & 0xC0) != 0x80) {
+            throw new UTFDataFormatException("malformed input around byte " + count);
           }
-        }
-      }
-      putIfNotNullTS(raw, "m", result, Record.REC_MODIFIED);
-      putIfNotNull(raw, "n", result, Record.NAME);
-      putIfNotNull(raw, "d", result, Record.DESCRIPTION);
-      putIfNotNull(raw, "1", result, Record.SHA1);
-
-      // Jar file contents (optional)
-      putIfNotNullAsList(raw, "classnames", result, Record.CLASSNAMES);
-
-      // Maven Plugin (optional)
-      putIfNotNull(raw, "px", result, Record.PLUGIN_PREFIX);
-      putIfNotNullAsList(raw, "gx", result, Record.PLUGIN_GOALS);
-
-      // OSGi (optional)
-      putIfNotNull(raw, "Bundle-SymbolicName", result, "Bundle-SymbolicName");
-      putIfNotNull(raw, "Bundle-Version", result, "Bundle-Version");
-      putIfNotNull(raw, "Export-Package", result, "Export-Package");
-      putIfNotNull(raw, "Export-Service", result, "Export-Service");
-      putIfNotNull(raw, "Bundle-Description", result, "Bundle-Description");
-      putIfNotNull(raw, "Bundle-Name", result, "Bundle-Name");
-      putIfNotNull(raw, "Bundle-License", result, "Bundle-License");
-      putIfNotNull(raw, "Bundle-DocURL", result, "Bundle-DocURL");
-      putIfNotNull(raw, "Import-Package", result, "Import-Package");
-      putIfNotNull(raw, "Require-Bundle", result, "Require-Bundle");
-      putIfNotNull(raw, "Bundle-Version", result, "Bundle-Version");
-
-      return result;
-    }
+          chararr[chararr_count++] = (char) (((c & 0x1F) << 6) | (char2 & 0x3F));
+          break;
 
-    /**
-     * Expands UINFO synthetic field. Handles {@code null} String inputs.
-     */
-    private void expandUinfo(final String uinfo, final Map<String, Object> result) {
-      if (uinfo != null) {
-        String[] r = FS_PATTERN.split(uinfo);
-        result.put(Record.GROUP_ID, r[0]);
-        result.put(Record.ARTIFACT_ID, r[1]);
-        result.put(Record.VERSION, r[2]);
-        String classifier = renvl(r[3]);
-        if (classifier != null) {
-          result.put(Record.CLASSIFIER, classifier);
-          if (r.length > 4) {
-            result.put(Record.FILE_EXTENSION, r[4]);
+        case 14:
+                    /* 1110 xxxx 10xx xxxx 10xx xxxx */
+          count += 3;
+          if (count > utflen) {
+            throw new UTFDataFormatException("malformed input: partial character at end");
           }
-        }
-        else if (r.length > 4) {
-          result.put(Record.PACKAGING, r[4]);
-        }
-      }
-    }
-  }
-
-  /**
-   * Helper to put a value from source map into target map, if not null.
-   */
-  private static void putIfNotNull(
-      final Map<String, String> source,
-      final String sourceName,
-      final Map<String, Object> target,
-      final String targetName)
-  {
-    String value = source.get(sourceName);
-    if (value != null && value.trim().length() != 0) {
-      target.put(targetName, value);
-    }
-  }
-
-  /**
-   * Helper to put a {@link Long} value from source map into target map, if not null.
-   */
-  private static void putIfNotNullTS(
-      final Map<String, String> source,
-      final String sourceName,
-      final Map<String, Object> target,
-      final String targetName)
-  {
-    String value = source.get(sourceName);
-    if (value != null && value.trim().length() != 0) {
-      target.put(targetName, Long.valueOf(value));
-    }
-  }
+          char2 = bytearr[count - 2];
+          char3 = bytearr[count - 1];
+          if (((char2 & 0xC0) != 0x80) || ((char3 & 0xC0) != 0x80)) {
+            throw new UTFDataFormatException("malformed input around byte " + (count - 1));
+          }
+          chararr[chararr_count++] =
+              (char) (((c & 0x0F) << 12) | ((char2 & 0x3F) << 6) | (char3 & 0x3F));
+          break;
 
-  /**
-   * Helper to put a collection value from source map into target map as {@link java.util.List}, if not null.
-   */
-  private static void putIfNotNullAsList(
-      final Map<String, String> source,
-      final String sourceName,
-      final Map<String, Object> target,
-      final String targetName)
-  {
-    String value = source.get(sourceName);
-    if (value != null && value.trim().length() != 0) {
-      target.put(targetName, Arrays.asList(FS_PATTERN.split(value)));
+        default:
+                    /* 10xx xxxx, 1111 xxxx */
+          throw new UTFDataFormatException("malformed input around byte " + count);
+      }
     }
-  }
 
-  /**
-   * Helper to translate the "NA" (not available) input into {@code null} value.
-   */
-  private static String renvl(final String v) {
-    return NOT_AVAILABLE.equals(v) ? null : v;
+    // The number of chars produced may be less than utflen
+    return new String(chararr, 0, chararr_count);
   }
 }

http://git-wip-us.apache.org/repos/asf/maven-indexer/blob/b9c4d908/indexer-reader/src/main/java/org/apache/maven/index/reader/ChunkWriter.java
----------------------------------------------------------------------
diff --git a/indexer-reader/src/main/java/org/apache/maven/index/reader/ChunkWriter.java b/indexer-reader/src/main/java/org/apache/maven/index/reader/ChunkWriter.java
new file mode 100644
index 0000000..24e4701
--- /dev/null
+++ b/indexer-reader/src/main/java/org/apache/maven/index/reader/ChunkWriter.java
@@ -0,0 +1,177 @@
+package org.apache.maven.index.reader;
+
+/*
+ * 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.
+ */
+
+import java.io.Closeable;
+import java.io.DataOutput;
+import java.io.DataOutputStream;
+import java.io.IOException;
+import java.io.OutputStream;
+import java.util.Date;
+import java.util.Iterator;
+import java.util.Map;
+import java.util.zip.GZIPOutputStream;
+
+/**
+ * Maven 2 Index published binary chunk writer, it writes raw Maven Indexer records to the transport binary format.
+ *
+ * @since 5.1.2
+ */
+public class ChunkWriter
+    implements Closeable
+{
+  private static final int F_INDEXED = 1;
+
+  private static final int F_TOKENIZED = 2;
+
+  private static final int F_STORED = 4;
+
+  private final String chunkName;
+
+  private final DataOutputStream dataOutputStream;
+
+  private final int version;
+
+  private final Date timestamp;
+
+  public ChunkWriter(final String chunkName, final OutputStream outputStream, final int version, final Date timestamp)
+      throws IOException
+  {
+    this.chunkName = chunkName.trim();
+    this.dataOutputStream = new DataOutputStream(new GZIPOutputStream(outputStream, 2 * 1024));
+    this.version = version;
+    this.timestamp = timestamp;
+
+    dataOutputStream.writeByte(version);
+    dataOutputStream.writeLong(timestamp == null ? -1 : timestamp.getTime());
+  }
+
+  /**
+   * Returns the chunk name.
+   */
+  public String getName() {
+    return chunkName;
+  }
+
+  /**
+   * Returns index version. All releases so far always returned {@code 1}.
+   */
+  public int getVersion() {
+    return version;
+  }
+
+  /**
+   * Returns the index timestamp of last update of the index.
+   */
+  public Date getTimestamp() {
+    return timestamp;
+  }
+
+  /**
+   * Writes out the record iterator and returns the written record count.
+   */
+  public int writeChunk(final Iterator<Map<String, String>> iterator) throws IOException {
+    int written = 0;
+    while (iterator.hasNext()) {
+      writeRecord(iterator.next(), dataOutputStream);
+      written++;
+    }
+    return written;
+  }
+
+  /**
+   * Closes this reader and it's underlying input.
+   */
+  public void close() throws IOException {
+    dataOutputStream.close();
+  }
+
+  private static void writeRecord(final Map<String, String> record, final DataOutput dataOutput)
+      throws IOException
+  {
+    dataOutput.writeInt(record.size());
+    for (Map.Entry<String, String> entry : record.entrySet()) {
+      writeField(entry.getKey(), entry.getValue(), dataOutput);
+    }
+  }
+
+  private static void writeField(final String fieldName, final String fieldValue, final DataOutput dataOutput)
+      throws IOException
+  {
+    boolean isIndexed = !(fieldName.equals("i") || fieldName.equals("m"));
+    boolean isTokenized = !(fieldName.equals("i")
+        || fieldName.equals("m")
+        || fieldName.equals("1")
+        || fieldName.equals("px"));
+    int flags = (isIndexed ? F_INDEXED : 0) + (isTokenized ? F_TOKENIZED : 0) + F_STORED;
+    dataOutput.writeByte(flags);
+    dataOutput.writeUTF(fieldName);
+    writeUTF(fieldValue, dataOutput);
+  }
+
+  private static void writeUTF(final String str, final DataOutput dataOutput)
+      throws IOException
+  {
+    int strlen = str.length();
+    int utflen = 0;
+    int c;
+    // use charAt instead of copying String to char array
+    for (int i = 0; i < strlen; i++) {
+      c = str.charAt(i);
+      if ((c >= 0x0001) && (c <= 0x007F)) {
+        utflen++;
+      }
+      else if (c > 0x07FF) {
+        utflen += 3;
+      }
+      else {
+        utflen += 2;
+      }
+    }
+    dataOutput.writeInt(utflen);
+    byte[] bytearr = new byte[utflen];
+    int count = 0;
+    int i = 0;
+    for (; i < strlen; i++) {
+      c = str.charAt(i);
+      if (!((c >= 0x0001) && (c <= 0x007F))) {
+        break;
+      }
+      bytearr[count++] = (byte) c;
+    }
+    for (; i < strlen; i++) {
+      c = str.charAt(i);
+      if ((c >= 0x0001) && (c <= 0x007F)) {
+        bytearr[count++] = (byte) c;
+
+      }
+      else if (c > 0x07FF) {
+        bytearr[count++] = (byte) (0xE0 | ((c >> 12) & 0x0F));
+        bytearr[count++] = (byte) (0x80 | ((c >> 6) & 0x3F));
+        bytearr[count++] = (byte) (0x80 | ((c >> 0) & 0x3F));
+      }
+      else {
+        bytearr[count++] = (byte) (0xC0 | ((c >> 6) & 0x1F));
+        bytearr[count++] = (byte) (0x80 | ((c >> 0) & 0x3F));
+      }
+    }
+    dataOutput.write(bytearr, 0, utflen);
+  }
+}

http://git-wip-us.apache.org/repos/asf/maven-indexer/blob/b9c4d908/indexer-reader/src/main/java/org/apache/maven/index/reader/IndexReader.java
----------------------------------------------------------------------
diff --git a/indexer-reader/src/main/java/org/apache/maven/index/reader/IndexReader.java b/indexer-reader/src/main/java/org/apache/maven/index/reader/IndexReader.java
index 45514b9..d74c366 100644
--- a/indexer-reader/src/main/java/org/apache/maven/index/reader/IndexReader.java
+++ b/indexer-reader/src/main/java/org/apache/maven/index/reader/IndexReader.java
@@ -19,39 +19,28 @@ package org.apache.maven.index.reader;
  * under the License.
  */
 
-import java.io.ByteArrayInputStream;
-import java.io.ByteArrayOutputStream;
 import java.io.Closeable;
 import java.io.IOException;
-import java.io.InputStream;
-import java.text.DateFormat;
+import java.io.OutputStream;
 import java.text.ParseException;
-import java.text.SimpleDateFormat;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.Date;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Properties;
-import java.util.TimeZone;
+
+import static org.apache.maven.index.reader.Utils.loadProperties;
 
 /**
- * Maven 2 Index reader that handles incremental updates if possible.
+ * Maven 2 Index reader that handles incremental updates if possible and provides one or more {@link ChunkReader}s, to
+ * read all the required records.
  *
  * @since 5.1.2
  */
 public class IndexReader
     implements Iterable<ChunkReader>, Closeable
 {
-  private static final String INDEX_FILE_PREFIX = "nexus-maven-repository-index";
-
-  private static final DateFormat INDEX_DATE_FORMAT;
-
-  static {
-    INDEX_DATE_FORMAT = new SimpleDateFormat("yyyyMMddHHmmss.SSS Z");
-    INDEX_DATE_FORMAT.setTimeZone(TimeZone.getTimeZone("GMT"));
-  }
-
   private final WritableResourceHandler local;
 
   private final ResourceHandler remote;
@@ -74,10 +63,10 @@ public class IndexReader
     }
     this.local = local;
     this.remote = remote;
-    remoteIndexProperties = loadProperties(remote.open(INDEX_FILE_PREFIX + ".properties"));
+    remoteIndexProperties = loadProperties(remote.open(Utils.INDEX_FILE_PREFIX + ".properties"));
     try {
       if (local != null) {
-        localIndexProperties = loadProperties(local.open(INDEX_FILE_PREFIX + ".properties"));
+        localIndexProperties = loadProperties(local.open(Utils.INDEX_FILE_PREFIX + ".properties"));
         String remoteIndexId = remoteIndexProperties.getProperty("nexus.index.id");
         String localIndexId = localIndexProperties.getProperty("nexus.index.id");
         if (remoteIndexId == null || localIndexId == null || !remoteIndexId.equals(localIndexId)) {
@@ -86,14 +75,16 @@ public class IndexReader
                   remoteIndexId);
         }
         this.indexId = localIndexId;
-        this.publishedTimestamp = INDEX_DATE_FORMAT.parse(localIndexProperties.getProperty("nexus.index.timestamp"));
+        this.publishedTimestamp = Utils.INDEX_DATE_FORMAT
+            .parse(localIndexProperties.getProperty("nexus.index.timestamp"));
         this.incremental = canRetrieveAllChunks();
         this.chunkNames = calculateChunkNames();
       }
       else {
         localIndexProperties = null;
         this.indexId = remoteIndexProperties.getProperty("nexus.index.id");
-        this.publishedTimestamp = INDEX_DATE_FORMAT.parse(remoteIndexProperties.getProperty("nexus.index.timestamp"));
+        this.publishedTimestamp = Utils.INDEX_DATE_FORMAT
+            .parse(remoteIndexProperties.getProperty("nexus.index.timestamp"));
         this.incremental = false;
         this.chunkNames = calculateChunkNames();
       }
@@ -170,9 +161,13 @@ public class IndexReader
    * for future incremental updates.
    */
   private void syncLocalWithRemote() throws IOException {
-    final ByteArrayOutputStream bos = new ByteArrayOutputStream();
-    remoteIndexProperties.store(bos, "Maven Indexer Reader");
-    local.save(INDEX_FILE_PREFIX + ".properties", new ByteArrayInputStream(bos.toByteArray()));
+    final OutputStream outputStream = local.openWrite(Utils.INDEX_FILE_PREFIX + ".properties");
+    try {
+      remoteIndexProperties.store(outputStream, "Maven Indexer Reader");
+    }
+    finally {
+      outputStream.close();
+    }
   }
 
   /**
@@ -185,12 +180,12 @@ public class IndexReader
       int currentCounter = Integer.parseInt(localIndexProperties.getProperty("nexus.index.last-incremental"));
       currentCounter++;
       while (currentCounter <= maxCounter) {
-        chunkNames.add(INDEX_FILE_PREFIX + "." + currentCounter++ + ".gz");
+        chunkNames.add(Utils.INDEX_FILE_PREFIX + "." + currentCounter++ + ".gz");
       }
       return Collections.unmodifiableList(chunkNames);
     }
     else {
-      return Collections.singletonList(INDEX_FILE_PREFIX + ".gz");
+      return Collections.singletonList(Utils.INDEX_FILE_PREFIX + ".gz");
     }
   }
 
@@ -264,18 +259,4 @@ public class IndexReader
       }
     }
   }
-
-  /**
-   * Creates and loads {@link Properties} from provided {@link InputStream} and closes the stream.
-   */
-  private static Properties loadProperties(final InputStream inputStream) throws IOException {
-    try {
-      final Properties properties = new Properties();
-      properties.load(inputStream);
-      return properties;
-    }
-    finally {
-      inputStream.close();
-    }
-  }
 }

http://git-wip-us.apache.org/repos/asf/maven-indexer/blob/b9c4d908/indexer-reader/src/main/java/org/apache/maven/index/reader/IndexWriter.java
----------------------------------------------------------------------
diff --git a/indexer-reader/src/main/java/org/apache/maven/index/reader/IndexWriter.java b/indexer-reader/src/main/java/org/apache/maven/index/reader/IndexWriter.java
new file mode 100644
index 0000000..f52cb29
--- /dev/null
+++ b/indexer-reader/src/main/java/org/apache/maven/index/reader/IndexWriter.java
@@ -0,0 +1,196 @@
+package org.apache.maven.index.reader;
+
+/*
+ * 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.
+ */
+
+import java.io.Closeable;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.text.ParseException;
+import java.util.Date;
+import java.util.Iterator;
+import java.util.Map;
+import java.util.Properties;
+import java.util.UUID;
+
+import static org.apache.maven.index.reader.Utils.loadProperties;
+
+/**
+ * Maven 2 Index writer that writes chunk and maintains published property file.
+ * <p/>
+ * <strong>Currently no incremental update is supported, as the deleteion states should be maintained by
+ * caller</strong>. Hence, this writer will always produce the "main" chunk only.
+ *
+ * @since 5.1.2
+ */
+public class IndexWriter
+    implements Closeable
+{
+  private static final int INDEX_V1 = 1;
+
+  private final WritableResourceHandler local;
+
+  private final Properties localIndexProperties;
+
+  private final boolean incremental;
+
+  private final String nextChunkCounter;
+
+  private final String nextChunkName;
+
+  public IndexWriter(final WritableResourceHandler local, final String indexId, final boolean incrementalSupported)
+      throws IOException
+  {
+    if (local == null) {
+      throw new NullPointerException("local resource handler null");
+    }
+    if (indexId == null) {
+      throw new NullPointerException("indexId null");
+    }
+    this.local = local;
+    InputStream localIndexPropertiesInputStream = local.open(Utils.INDEX_FILE_PREFIX + ".properties");
+    if (incrementalSupported && localIndexPropertiesInputStream != null) {
+      // existing index, this is incremental publish, and we will add new chunk
+      this.localIndexProperties = loadProperties(local.open(Utils.INDEX_FILE_PREFIX + ".properties"));
+      String localIndexId = localIndexProperties.getProperty("nexus.index.id");
+      if (localIndexId == null || !localIndexId.equals(indexId)) {
+        throw new IllegalArgumentException(
+            "index already exists and indexId mismatch or unreadable: " + localIndexId + ", " +
+                indexId);
+      }
+      this.incremental = true;
+      this.nextChunkCounter = calculateNextChunkCounter();
+      this.nextChunkName = Utils.INDEX_FILE_PREFIX + "." + nextChunkCounter + ".gz";
+    }
+    else {
+      // non-existing index, create published index from scratch
+      this.localIndexProperties = new Properties();
+      this.localIndexProperties.setProperty("nexus.index.id", indexId);
+      this.localIndexProperties.setProperty("nexus.index.chain-id", UUID.randomUUID().toString());
+      this.incremental = false;
+      this.nextChunkCounter = null;
+      this.nextChunkName = Utils.INDEX_FILE_PREFIX + ".gz";
+    }
+  }
+
+  /**
+   * Returns the index context ID that published index has set.
+   */
+  public String getIndexId() {
+    return localIndexProperties.getProperty("nexus.index.id");
+  }
+
+  /**
+   * Returns the {@link Date} when index was last published or {@code null} if this is first publishing. In other
+   * words,returns {@code null} when {@link #isIncremental()} returns {@code false}. After this writer is closed, the
+   * return value is updated to "now" (in {@link #close() method}.
+   */
+  public Date getPublishedTimestamp() {
+    try {
+      String timestamp = localIndexProperties.getProperty("nexus.index.timestamp");
+      if (timestamp != null) {
+        return Utils.INDEX_DATE_FORMAT.parse(timestamp);
+      }
+      return null;
+    }
+    catch (ParseException e) {
+      throw new RuntimeException("Corrupt date", e);
+    }
+  }
+
+  /**
+   * Returns {@code true} if incremental publish is about to happen.
+   */
+  public boolean isIncremental() {
+    return incremental;
+  }
+
+  /**
+   * Returns the chain id of published index. If {@link #isIncremental()} is {@code false}, this is the newly generated
+   * chain ID.
+   */
+  public String getChainId() {
+    return localIndexProperties.getProperty("nexus.index.chain-id");
+  }
+
+  /**
+   * Returns the next chunk name about to be published.
+   */
+  public String getNextChunkName() {
+    return nextChunkName;
+  }
+
+  /**
+   * Writes out the record iterator and returns the written record count.
+   */
+  public int writeChunk(final Iterator<Map<String, String>> iterator) throws IOException {
+    int written;
+    final ChunkWriter chunkWriter = new ChunkWriter(nextChunkName, local.openWrite(nextChunkName), INDEX_V1, new Date());
+    try {
+      written = chunkWriter.writeChunk(iterator);
+    }
+    finally {
+      chunkWriter.close();
+    }
+    if (incremental) {
+      // TODO: update main gz file
+    }
+    return written;
+  }
+
+  /**
+   * Closes the underlying {@link ResourceHandler} and synchronizes published index properties, so remote clients
+   * becomes able to consume newly published index. If sync is not desired (ie. due to aborted publish), then this
+   * method should NOT be invoked, but rather the {@link ResourceHandler} that caller provided in constructor of
+   * this class should be closed manually.
+   */
+  public void close() throws IOException {
+    try {
+      if (incremental) {
+        localIndexProperties.setProperty("nexus.index.last-incremental", nextChunkCounter);
+      }
+      localIndexProperties.setProperty("nexus.index.timestamp", Utils.INDEX_DATE_FORMAT.format(new Date()));
+
+      final OutputStream outputStream = local.openWrite(Utils.INDEX_FILE_PREFIX + ".properties");
+      try {
+        localIndexProperties.store(outputStream, "Maven Indexer Writer");
+      }
+      finally {
+        outputStream.close();
+      }
+    }
+    finally {
+      local.close();
+    }
+  }
+
+  /**
+   * Calculates the chunk names that needs to be fetched.
+   */
+  private String calculateNextChunkCounter() {
+    String lastChunkCounter = localIndexProperties.getProperty("nexus.index.last-incremental");
+    if (lastChunkCounter != null) {
+      return String.valueOf(Integer.parseInt(lastChunkCounter) + 1);
+    }
+    else {
+      return "1";
+    }
+  }
+}

http://git-wip-us.apache.org/repos/asf/maven-indexer/blob/b9c4d908/indexer-reader/src/main/java/org/apache/maven/index/reader/Iterables.java
----------------------------------------------------------------------
diff --git a/indexer-reader/src/main/java/org/apache/maven/index/reader/Iterables.java b/indexer-reader/src/main/java/org/apache/maven/index/reader/Iterables.java
new file mode 100644
index 0000000..78941dc
--- /dev/null
+++ b/indexer-reader/src/main/java/org/apache/maven/index/reader/Iterables.java
@@ -0,0 +1,204 @@
+package org.apache.maven.index.reader;
+
+/*
+ * 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.
+ */
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Map;
+import java.util.NoSuchElementException;
+import java.util.TreeSet;
+
+import org.apache.maven.index.reader.Record.EntryKey;
+import org.apache.maven.index.reader.Record.Type;
+
+/**
+ * Helpers to transform {@link Iterable}.
+ *
+ * @since 5.1.2
+ */
+public final class Iterables
+{
+  private Iterables() {
+    // nothing
+  }
+
+  /**
+   * Transforming function.
+   */
+  public interface Function<I, O>
+  {
+    O apply(I rec);
+  }
+
+  /**
+   * Applies {@link Function} to an {@link Iterable} on the fly.
+   */
+  public static <I, O> Iterable<O> transform(final Iterable<I> iterable, final Function<I, O> function) {
+    return new Iterable<O>()
+    {
+      public Iterator<O> iterator() {
+        return new TransformIterator<I, O>(iterable.iterator(), function);
+      }
+    };
+  }
+
+  /**
+   * Helper method, that "decorates" the stream of records to be written out with "special" Maven Indexer records, so
+   * all the caller is needed to provide {@Link Iterable} or {@link Record}s <strong>to be</strong> on the index, with
+   * record type {@link Record.Type#ARTIFACT_ADD}. This method will create the output as "proper" Maven Indexer record
+   * streeam, by adding the {@link Type#DESCRIPTOR}, {@link Type#ROOT_GROUPS} and {@link Type#ALL_GROUPS} special
+   * records.
+   */
+  public static Iterable<Map<String, String>> decorateAndTransform(final Iterable<Record> iterable,
+                                                                   final String repoId)
+  {
+    final RecordCompactor recordCompactor = new RecordCompactor();
+    final TreeSet<String> allGroups = new TreeSet<String>();
+    final TreeSet<String> rootGroups = new TreeSet<String>();
+    final ArrayList<Iterator<Record>> iterators = new ArrayList<Iterator<Record>>();
+    iterators.add(Collections.singletonList(descriptor(repoId)).iterator());
+    iterators.add(iterable.iterator());
+    iterators.add(Collections.singletonList(allGroups(allGroups)).iterator());
+    iterators.add(Collections.singletonList(rootGroups(rootGroups)).iterator());
+    return transform(
+        new Iterable<Record>()
+        {
+          public Iterator<Record> iterator() {
+            return new ConcatIterator<Record>(iterators.iterator());
+          }
+        },
+        new Function<Record, Map<String, String>>()
+        {
+          public Map<String, String> apply(final Record rec) {
+            if (Type.DESCRIPTOR == rec.getType()) {
+              return recordCompactor.apply(descriptor(repoId));
+            }
+            else if (Type.ALL_GROUPS == rec.getType()) {
+              return recordCompactor.apply(allGroups(allGroups));
+            }
+            else if (Type.ROOT_GROUPS == rec.getType()) {
+              return recordCompactor.apply(rootGroups(rootGroups));
+            }
+            else {
+              final String groupId = rec.get(Record.GROUP_ID);
+              if (groupId != null) {
+                allGroups.add(groupId);
+                rootGroups.add(Utils.rootGroup(groupId));
+              }
+              return recordCompactor.apply(rec);
+            }
+          }
+        }
+    );
+  }
+
+  private static Record descriptor(final String repoId) {
+    HashMap<EntryKey, Object> entries = new HashMap<EntryKey, Object>();
+    entries.put(Record.REPOSITORY_ID, repoId);
+    return new Record(Type.DESCRIPTOR, entries);
+  }
+
+  private static Record allGroups(final Collection<String> allGroups) {
+    HashMap<EntryKey, Object> entries = new HashMap<EntryKey, Object>();
+    entries.put(Record.ALL_GROUPS, allGroups.toArray(new String[allGroups.size()]));
+    return new Record(Type.ALL_GROUPS, entries);
+  }
+
+  private static Record rootGroups(final Collection<String> rootGroups) {
+    HashMap<EntryKey, Object> entries = new HashMap<EntryKey, Object>();
+    entries.put(Record.ROOT_GROUPS, rootGroups.toArray(new String[rootGroups.size()]));
+    return new Record(Type.ROOT_GROUPS, entries);
+  }
+
+  // ==
+
+  private static final class TransformIterator<I, O>
+      implements Iterator<O>
+  {
+    private final Iterator<I> iterator;
+
+    private final Function<I, O> function;
+
+    private TransformIterator(final Iterator<I> iterator, final Function<I, O> function) {
+      this.iterator = iterator;
+      this.function = function;
+    }
+
+    public boolean hasNext() {
+      return iterator.hasNext();
+    }
+
+    public O next() {
+      return function.apply(iterator.next());
+    }
+  }
+
+  private static final class ConcatIterator<T>
+      implements Iterator<T>
+  {
+    private final Iterator<Iterator<T>> iterators;
+
+    private Iterator<T> current;
+
+    private T nextElement;
+
+    private ConcatIterator(final Iterator<Iterator<T>> iterators) {
+      this.iterators = iterators;
+      this.nextElement = getNextElement();
+    }
+
+    public boolean hasNext() {
+      return nextElement != null;
+    }
+
+    public T next() {
+      if (nextElement == null) {
+        throw new NoSuchElementException();
+      }
+      T result = nextElement;
+      nextElement = getNextElement();
+      return result;
+    }
+
+    protected T getNextElement() {
+      if ((current == null || !current.hasNext()) && iterators.hasNext()) {
+        current = iterators.next();
+      }
+      while (current != null && !current.hasNext()) {
+        if (!iterators.hasNext()) {
+          current = null;
+          break;
+        }
+        current = iterators.next();
+      }
+      if (current != null) {
+        return current.next();
+      }
+      else {
+        return null;
+      }
+    }
+  }
+}

http://git-wip-us.apache.org/repos/asf/maven-indexer/blob/b9c4d908/indexer-reader/src/main/java/org/apache/maven/index/reader/Record.java
----------------------------------------------------------------------
diff --git a/indexer-reader/src/main/java/org/apache/maven/index/reader/Record.java b/indexer-reader/src/main/java/org/apache/maven/index/reader/Record.java
index 3354008..1746845 100644
--- a/indexer-reader/src/main/java/org/apache/maven/index/reader/Record.java
+++ b/indexer-reader/src/main/java/org/apache/maven/index/reader/Record.java
@@ -26,113 +26,225 @@ import java.util.Map;
  *
  * @since 5.1.2
  */
-public class Record
+public final class Record
 {
+  public static final class EntryKey<T>
+  {
+    private final String name;
+
+    private final Class<T> proto;
+
+    public EntryKey(final String name, final Class<T> proto) {
+      if (name == null) {
+        throw new NullPointerException("name is null");
+      }
+      if (proto == null) {
+        throw new NullPointerException("proto is null");
+      }
+      this.name = name;
+      this.proto = proto;
+    }
+
+    public T coerce(final Object object) {
+      return (T) proto.cast(object);
+    }
+
+    @Override
+    public boolean equals(final Object o) {
+      if (this == o) {
+        return true;
+      }
+      if (!(o instanceof EntryKey)) {
+        return false;
+      }
+      EntryKey entryKey = (EntryKey) o;
+      return name.equals(entryKey.name);
+    }
+
+    @Override
+    public int hashCode() {
+      return name.hashCode();
+    }
+
+    @Override
+    public String toString() {
+      return "Key{" +
+          "name='" + name + '\'' +
+          ", type=" + proto.getSimpleName() +
+          '}';
+    }
+  }
+
   /**
    * Key of repository ID entry, that contains {@link String}.
    */
-  public static final String REPOSITORY_ID = "repositoryId";
+  public static final EntryKey<String> REPOSITORY_ID = new EntryKey<String>("repositoryId", String.class);
 
   /**
    * Key of all groups list entry, that contains {@link java.util.List<String>}.
    */
-  public static final String ALL_GROUPS_LIST = "allGroupsList";
+  public static final EntryKey<String[]> ALL_GROUPS = new EntryKey<String[]>("allGroups", String[].class);
 
   /**
    * Key of root groups list entry, that contains {@link java.util.List<String>}.
    */
-  public static final String ROOT_GROUPS_LIST = "rootGroupsList";
+  public static final EntryKey<String[]> ROOT_GROUPS = new EntryKey<String[]>("rootGroups", String[].class);
 
   /**
    * Key of index record modification (added to index or removed from index) timestamp entry, that contains {@link
    * Long}.
    */
-  public static final String REC_MODIFIED = "recordModified";
+  public static final EntryKey<Long> REC_MODIFIED = new EntryKey<Long>("recordModified", Long.class);
 
   /**
    * Key of artifact groupId entry, that contains {@link String}.
    */
-  public static final String GROUP_ID = "groupId";
+  public static final EntryKey<String> GROUP_ID = new EntryKey<String>("groupId", String.class);
 
   /**
    * Key of artifact artifactId entry, that contains {@link String}.
    */
-  public static final String ARTIFACT_ID = "artifactId";
+  public static final EntryKey<String> ARTIFACT_ID = new EntryKey<String>("artifactId", String.class);
 
   /**
    * Key of artifact version entry, that contains {@link String}.
    */
-  public static final String VERSION = "version";
+  public static final EntryKey<String> VERSION = new EntryKey<String>("version", String.class);
 
   /**
    * Key of artifact classifier entry, that contains {@link String}.
    */
-  public static final String CLASSIFIER = "classifier";
+  public static final EntryKey<String> CLASSIFIER = new EntryKey<String>("classifier", String.class);
 
   /**
    * Key of artifact packaging entry, that contains {@link String}.
    */
-  public static final String PACKAGING = "packaging";
+  public static final EntryKey<String> PACKAGING = new EntryKey<String>("packaging", String.class);
 
   /**
    * Key of artifact file extension, that contains {@link String}.
    */
-  public static final String FILE_EXTENSION = "fileExtension";
+  public static final EntryKey<String> FILE_EXTENSION = new EntryKey<String>("fileExtension", String.class);
 
   /**
    * Key of artifact file last modified timestamp, that contains {@link Long}.
    */
-  public static final String FILE_MODIFIED = "fileModified";
+  public static final EntryKey<Long> FILE_MODIFIED = new EntryKey<Long>("fileModified", Long.class);
 
   /**
    * Key of artifact file size in bytes, that contains {@link Long}.
    */
-  public static final String FILE_SIZE = "fileSize";
+  public static final EntryKey<Long> FILE_SIZE = new EntryKey<Long>("fileSize", Long.class);
 
   /**
    * Key of artifact Sources presence flag, that contains {@link Boolean}.
    */
-  public static final String HAS_SOURCES = "hasSources";
+  public static final EntryKey<Boolean> HAS_SOURCES = new EntryKey<Boolean>("hasSources", Boolean.class);
 
   /**
    * Key of artifact Javadoc presence flag, that contains {@link Boolean}.
    */
-  public static final String HAS_JAVADOC = "hasJavadoc";
+  public static final EntryKey<Boolean> HAS_JAVADOC = new EntryKey<Boolean>("hasJavadoc", Boolean.class);
 
   /**
    * Key of artifact signature presence flag, that contains {@link Boolean}.
    */
-  public static final String HAS_SIGNATURE = "hasSignature";
+  public static final EntryKey<Boolean> HAS_SIGNATURE = new EntryKey<Boolean>("hasSignature", Boolean.class);
 
   /**
    * Key of artifact name (as set in POM), that contains {@link String}.
    */
-  public static final String NAME = "name";
+  public static final EntryKey<String> NAME = new EntryKey<String>("name", String.class);
 
   /**
    * Key of artifact description (as set in POM), that contains {@link String}.
    */
-  public static final String DESCRIPTION = "description";
+  public static final EntryKey<String> DESCRIPTION = new EntryKey<String>("description", String.class);
 
   /**
    * Key of artifact SHA1 digest, that contains {@link String}.
    */
-  public static final String SHA1 = "sha1";
+  public static final EntryKey<String> SHA1 = new EntryKey<String>("sha1", String.class);
+
+  /**
+   * Key of artifact contained class names, that contains {@link java.util.List<String>}. Extracted by {@code
+   * JarFileContentsIndexCreator}.
+   */
+  public static final EntryKey<String[]> CLASSNAMES = new EntryKey<String[]>("classNames", String[].class);
+
+  /**
+   * Key of plugin artifact prefix, that contains {@link String}. Extracted by {@code
+   * MavenPluginArtifactInfoIndexCreator}.
+   */
+  public static final EntryKey<String> PLUGIN_PREFIX = new EntryKey<String>("pluginPrefix", String.class);
+
+  /**
+   * Key of plugin artifact goals, that contains {@link java.util.List<String>}. Extracted by {@code
+   * MavenPluginArtifactInfoIndexCreator}.
+   */
+  public static final EntryKey<String[]> PLUGIN_GOALS = new EntryKey<String[]>("pluginGoals", String[].class);
+
+  /**
+   * Key of OSGi "Bundle-SymbolicName" manifest entry, that contains {@link String}. Extracted by {@code
+   * OsgiArtifactIndexCreator}.
+   */
+  public static final EntryKey<String> OSGI_BUNDLE_SYMBOLIC_NAME = new EntryKey<String>("Bundle-SymbolicName",
+      String.class);
+
+  /**
+   * Key of OSGi "Bundle-Version" manifest entry, that contains {@link String}. Extracted by {@code
+   * OsgiArtifactIndexCreator}.
+   */
+  public static final EntryKey<String> OSGI_BUNDLE_VERSION = new EntryKey<String>("Bundle-Version", String.class);
+
+  /**
+   * Key of OSGi "Export-Package" manifest entry, that contains {@link String}. Extracted by {@code
+   * OsgiArtifactIndexCreator}.
+   */
+  public static final EntryKey<String> OSGI_EXPORT_PACKAGE = new EntryKey<String>("Export-Package", String.class);
+
+  /**
+   * Key of OSGi "Export-Service" manifest entry, that contains {@link String}. Extracted by {@code
+   * OsgiArtifactIndexCreator}.
+   */
+  public static final EntryKey<String> OSGI_EXPORT_SERVICE = new EntryKey<String>("Export-Service", String.class);
 
   /**
-   * Key of artifact contained class names, that contains {@link java.util.List<String>}.
+   * Key of OSGi "Bundle-Description" manifest entry, that contains {@link String}. Extracted by {@code
+   * OsgiArtifactIndexCreator}.
    */
-  public static final String CLASSNAMES = "classNames";
+  public static final EntryKey<String> OSGI_BUNDLE_DESCRIPTION = new EntryKey<String>("Bundle-Description",
+      String.class);
 
   /**
-   * Key of plugin artifact prefix, that contains {@link String}.
+   * Key of OSGi "Bundle-Name" manifest entry, that contains {@link String}. Extracted by {@code
+   * OsgiArtifactIndexCreator}.
    */
-  public static final String PLUGIN_PREFIX = "pluginPrefix";
+  public static final EntryKey<String> OSGI_BUNDLE_NAME = new EntryKey<String>("Bundle-Name", String.class);
 
   /**
-   * Key of plugin artifact goals, that contains {@link java.util.List<String>}.
+   * Key of OSGi "Bundle-License" manifest entry, that contains {@link String}. Extracted by {@code
+   * OsgiArtifactIndexCreator}.
    */
-  public static final String PLUGIN_GOALS = "pluginGoals";
+  public static final EntryKey<String> OSGI_BUNDLE_LICENSE = new EntryKey<String>("Bundle-License", String.class);
+
+  /**
+   * Key of OSGi "Bundle-DocURL" manifest entry, that contains {@link String}. Extracted by {@code
+   * OsgiArtifactIndexCreator}.
+   */
+  public static final EntryKey<String> OSGI_EXPORT_DOCURL = new EntryKey<String>("Bundle-DocURL", String.class);
+
+  /**
+   * Key of OSGi "Import-Package" manifest entry, that contains {@link String}. Extracted by {@code
+   * OsgiArtifactIndexCreator}.
+   */
+  public static final EntryKey<String> OSGI_IMPORT_PACKAGE = new EntryKey<String>("Import-Package", String.class);
+
+  /**
+   * Key of OSGi "Require-Bundle" manifest entry, that contains {@link String}. Extracted by {@code
+   * OsgiArtifactIndexCreator}.
+   */
+  public static final EntryKey<String> OSGI_REQUIRE_BUNDLE = new EntryKey<String>("Require-Bundle", String.class);
 
   /**
    * Types of returned records returned from index.
@@ -175,7 +287,7 @@ public class Record
     ARTIFACT_ADD,
 
     /**
-     * Artifact REMOTE record. In case of incremental updates, notes that this artifact was removed. Records of this
+     * Artifact REMOVE record. In case of incremental updates, signals that this artifact was removed. Records of this
      * type should be removed from your indexing system.
      * Contains following entries:
      * <ul>
@@ -194,7 +306,7 @@ public class Record
      * Special record, containing all the Maven "groupId"s that are enlisted on the index. Can be safely ignored.
      * Contains following entries:
      * <ul>
-     * <li>{@link #ALL_GROUPS_LIST}</li>
+     * <li>{@link #ALL_GROUPS}</li>
      * </ul>
      */
     ALL_GROUPS,
@@ -204,7 +316,7 @@ public class Record
      * ignored.
      * Contains following entries:
      * <ul>
-     * <li>{@link #ROOT_GROUPS_LIST}</li>
+     * <li>{@link #ROOT_GROUPS}</li>
      * </ul>
      */
     ROOT_GROUPS
@@ -212,13 +324,10 @@ public class Record
 
   private final Type type;
 
-  private final Map<String, String> raw;
+  private final Map<EntryKey, Object> expanded;
 
-  private final Map<String, Object> expanded;
-
-  public Record(final Type type, final Map<String, String> raw, final Map<String, Object> expanded) {
+  public Record(final Type type, final Map<EntryKey, Object> expanded) {
     this.type = type;
-    this.raw = raw;
     this.expanded = expanded;
   }
 
@@ -232,16 +341,44 @@ public class Record
   }
 
   /**
-   * Returns the "raw", Maven Indexer specific record as a {@link Map}.
+   * Returns the expanded (processed and expanded synthetic fields) record as {@link Map} ready for consumption.
    */
-  public Map<String, String> getRaw() {
-    return raw;
+  public Map<EntryKey, Object> getExpanded() {
+    return expanded;
   }
 
   /**
-   * Returns the expanded (processed and expanded synthetic fields) record as {@link Map} ready for consumption.
+   * Returns {@code true} if this record contains given {@link EntryKey}.
    */
-  public Map<String, Object> getExpanded() {
-    return expanded;
+  boolean containsKey(final EntryKey<?> entryKey) { return expanded.containsKey(entryKey); }
+
+  /**
+   * Type safe handy method to get value from expanded map.
+   */
+  public <T> T get(final EntryKey<T> entryKey) {
+    return entryKey.coerce(expanded.get(entryKey));
+  }
+
+  /**
+   * Type safe handy method to put value to expanded map. Accepts {@code null} values, that removes the mapping.
+   */
+  public <T> T put(final EntryKey<T> entryKey, final T value) {
+    if (value == null) {
+      return entryKey.coerce(expanded.remove(entryKey));
+    }
+    else {
+      if (!entryKey.proto.isAssignableFrom(value.getClass())) {
+        throw new IllegalArgumentException("Key " + entryKey + " does not accepts value " + value);
+      }
+      return entryKey.coerce(expanded.put(entryKey, value));
+    }
+  }
+
+  @Override
+  public String toString() {
+    return "Record{" +
+        "type=" + type +
+        ", expanded=" + expanded +
+        '}';
   }
 }

http://git-wip-us.apache.org/repos/asf/maven-indexer/blob/b9c4d908/indexer-reader/src/main/java/org/apache/maven/index/reader/RecordCompactor.java
----------------------------------------------------------------------
diff --git a/indexer-reader/src/main/java/org/apache/maven/index/reader/RecordCompactor.java b/indexer-reader/src/main/java/org/apache/maven/index/reader/RecordCompactor.java
new file mode 100644
index 0000000..3fcfd25
--- /dev/null
+++ b/indexer-reader/src/main/java/org/apache/maven/index/reader/RecordCompactor.java
@@ -0,0 +1,205 @@
+package org.apache.maven.index.reader;
+
+/*
+ * 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.
+ */
+
+import java.util.HashMap;
+import java.util.Map;
+
+import org.apache.maven.index.reader.Iterables.Function;
+import org.apache.maven.index.reader.Record.Type;
+
+import static org.apache.maven.index.reader.Utils.FIELD_SEPARATOR;
+import static org.apache.maven.index.reader.Utils.INFO;
+import static org.apache.maven.index.reader.Utils.UINFO;
+import static org.apache.maven.index.reader.Utils.nvl;
+
+/**
+ * Maven 2 Index record transformer, that transforms {@link Record}s into "native" Maven Indexer records.
+ *
+ * @since 5.1.2
+ */
+public class RecordCompactor
+    implements Function<Record, Map<String, String>>
+{
+  public Map<String, String> apply(final Record record) {
+    if (Type.DESCRIPTOR == record.getType()) {
+      return compactDescriptor(record);
+    }
+    else if (Type.ALL_GROUPS == record.getType()) {
+      return compactAllGroups(record);
+    }
+    else if (Type.ROOT_GROUPS == record.getType()) {
+      return compactRootGroups(record);
+    }
+    else if (Type.ARTIFACT_REMOVE == record.getType()) {
+      return compactDeletedArtifact(record);
+    }
+    else if (Type.ARTIFACT_ADD == record.getType()) {
+      return compactAddedArtifact(record);
+    }
+    else {
+      throw new IllegalArgumentException("Unknown record: " + record);
+    }
+  }
+
+  private static Map<String, String> compactDescriptor(final Record record) {
+    final Map<String, String> result = new HashMap<String, String>();
+    result.put("DESCRIPTOR", "NexusIndex");
+    result.put("IDXINFO", "1.0|" + record.get(Record.REPOSITORY_ID));
+    return result;
+  }
+
+  private static Map<String, String> compactAllGroups(final Record record) {
+    final Map<String, String> result = new HashMap<String, String>();
+    result.put("allGroups", "allGroups");
+    putIfNotNullAsStringArray(record.get(Record.ALL_GROUPS), result, "allGroupsList");
+    return result;
+  }
+
+  private static Map<String, String> compactRootGroups(final Record record) {
+    final Map<String, String> result = new HashMap<String, String>();
+    result.put("rootGroups", "allGroups");
+    putIfNotNullAsStringArray(record.get(Record.ROOT_GROUPS), result, "rootGroupsList");
+    return result;
+  }
+
+  private static Map<String, String> compactDeletedArtifact(final Record record) {
+    final Map<String, String> result = new HashMap<String, String>();
+    putIfNotNullTS(record.get(Record.REC_MODIFIED), result, "m");
+    result.put("del", compactUinfo(record));
+    return result;
+  }
+
+  /**
+   * Expands the "encoded" Maven Indexer record by splitting the synthetic fields and applying expanded field naming.
+   */
+  private static Map<String, String> compactAddedArtifact(final Record record) {
+    final Map<String, String> result = new HashMap<String, String>();
+
+    // Minimal
+    result.put(UINFO, compactUinfo(record));
+
+    StringBuilder info = new StringBuilder();
+    info.append(nvl(record.get(Record.PACKAGING)));
+    info.append(FIELD_SEPARATOR);
+    info.append(record.get(Record.FILE_MODIFIED));
+    info.append(FIELD_SEPARATOR);
+    info.append(record.get(Record.FILE_SIZE));
+    info.append(FIELD_SEPARATOR);
+    info.append(record.get(Record.HAS_SOURCES) ? "1" : "0");
+    info.append(FIELD_SEPARATOR);
+    info.append(record.get(Record.HAS_JAVADOC) ? "1" : "0");
+    info.append(FIELD_SEPARATOR);
+    info.append(record.get(Record.HAS_SIGNATURE) ? "1" : "0");
+    info.append(FIELD_SEPARATOR);
+    info.append(nvl(record.get(Record.FILE_EXTENSION)));
+    result.put(INFO, info.toString());
+
+    putIfNotNullTS(record.get(Record.REC_MODIFIED), result, "m");
+    putIfNotNull(record.get(Record.NAME), result, "n");
+    putIfNotNull(record.get(Record.DESCRIPTION), result, "d");
+    putIfNotNull(record.get(Record.SHA1), result, "1");
+
+    // Jar file contents (optional)
+    putIfNotNullAsStringArray(record.get(Record.CLASSNAMES), result, "classnames");
+
+    // Maven Plugin (optional)
+    putIfNotNull(record.get(Record.PLUGIN_PREFIX), result, "px");
+    putIfNotNullAsStringArray(record.get(Record.PLUGIN_GOALS), result, "gx");
+
+    // OSGi (optional)
+    putIfNotNull(record.get(Record.OSGI_BUNDLE_SYMBOLIC_NAME), result, "Bundle-SymbolicName");
+    putIfNotNull(record.get(Record.OSGI_BUNDLE_VERSION), result, "Bundle-Version");
+    putIfNotNull(record.get(Record.OSGI_EXPORT_PACKAGE), result, "Export-Package");
+    putIfNotNull(record.get(Record.OSGI_EXPORT_SERVICE), result, "Export-Service");
+    putIfNotNull(record.get(Record.OSGI_BUNDLE_DESCRIPTION), result, "Bundle-Description");
+    putIfNotNull(record.get(Record.OSGI_BUNDLE_NAME), result, "Bundle-Name");
+    putIfNotNull(record.get(Record.OSGI_BUNDLE_LICENSE), result, "Bundle-License");
+    putIfNotNull(record.get(Record.OSGI_EXPORT_DOCURL), result, "Bundle-DocURL");
+    putIfNotNull(record.get(Record.OSGI_IMPORT_PACKAGE), result, "Import-Package");
+    putIfNotNull(record.get(Record.OSGI_REQUIRE_BUNDLE), result, "Require-Bundle");
+
+    return result;
+  }
+
+  /**
+   * Creates UINFO synthetic field.
+   */
+  private static String compactUinfo(final Record record) {
+    final String classifier = record.get(Record.CLASSIFIER);
+    StringBuilder sb = new StringBuilder();
+    sb.append(record.get(Record.GROUP_ID))
+        .append(FIELD_SEPARATOR)
+        .append(record.get(Record.ARTIFACT_ID))
+        .append(FIELD_SEPARATOR)
+        .append(record.get(Record.VERSION))
+        .append(FIELD_SEPARATOR)
+        .append(nvl(classifier));
+    if (classifier != null) {
+      sb.append(record.get(Record.FILE_EXTENSION));
+    }
+    return sb.toString();
+  }
+
+  /**
+   * Helper to put a value from source map into target map, if not null.
+   */
+  private static void putIfNotNull(
+      final String source,
+      final Map<String, String> target,
+      final String targetName)
+  {
+    if (source != null) {
+      target.put(targetName, source);
+    }
+  }
+
+  /**
+   * Helper to put a {@link Long} value from source map into target map, if not null.
+   */
+  private static void putIfNotNullTS(
+      final Long source,
+      final Map<String, String> target,
+      final String targetName)
+  {
+    if (source != null) {
+      target.put(targetName, String.valueOf(source));
+    }
+  }
+
+  /**
+   * Helper to put a array value from source map into target map joined with {@link Utils#FIELD_SEPARATOR}, if not
+   * null.
+   */
+  private static void putIfNotNullAsStringArray(
+      final String[] source,
+      final Map<String, String> target,
+      final String targetName)
+  {
+    if (source != null && source.length > 0) {
+      StringBuilder sb = new StringBuilder();
+      sb.append(source[0]);
+      for (int i = 1; i < source.length; i++) {
+        sb.append(FIELD_SEPARATOR).append(source[i]);
+      }
+      target.put(targetName, sb.toString());
+    }
+  }
+}

http://git-wip-us.apache.org/repos/asf/maven-indexer/blob/b9c4d908/indexer-reader/src/main/java/org/apache/maven/index/reader/RecordExpander.java
----------------------------------------------------------------------
diff --git a/indexer-reader/src/main/java/org/apache/maven/index/reader/RecordExpander.java b/indexer-reader/src/main/java/org/apache/maven/index/reader/RecordExpander.java
new file mode 100644
index 0000000..83f6ca7
--- /dev/null
+++ b/indexer-reader/src/main/java/org/apache/maven/index/reader/RecordExpander.java
@@ -0,0 +1,228 @@
+package org.apache.maven.index.reader;
+
+/*
+ * 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.
+ */
+
+import java.util.HashMap;
+import java.util.Map;
+
+import org.apache.maven.index.reader.Iterables.Function;
+import org.apache.maven.index.reader.Record.EntryKey;
+import org.apache.maven.index.reader.Record.Type;
+
+import static org.apache.maven.index.reader.Utils.FIELD_SEPARATOR;
+import static org.apache.maven.index.reader.Utils.FS_PATTERN;
+import static org.apache.maven.index.reader.Utils.INFO;
+import static org.apache.maven.index.reader.Utils.NOT_AVAILABLE;
+import static org.apache.maven.index.reader.Utils.UINFO;
+import static org.apache.maven.index.reader.Utils.renvl;
+
+/**
+ * Maven 2 Index record transformer, that transforms "native" Maven Indexer records into {@link Record}s.
+ *
+ * @since 5.1.2
+ */
+public class RecordExpander
+    implements Function<Map<String, String>, Record>
+{
+  public Record apply(final Map<String, String> recordMap) {
+    if (recordMap.containsKey("DESCRIPTOR")) {
+      return expandDescriptor(recordMap);
+    }
+    else if (recordMap.containsKey("allGroups")) {
+      return expandAllGroups(recordMap);
+    }
+    else if (recordMap.containsKey("rootGroups")) {
+      return expandRootGroups(recordMap);
+    }
+    else if (recordMap.containsKey("del")) {
+      return expandDeletedArtifact(recordMap);
+    }
+    else {
+      // Fix up UINFO field wrt MINDEXER-41
+      final String uinfo = recordMap.get(UINFO);
+      final String info = recordMap.get(INFO);
+      if (uinfo != null && !(info == null || info.trim().length() == 0)) {
+        final String[] splitInfo = FS_PATTERN.split(info);
+        if (splitInfo.length > 6) {
+          final String extension = splitInfo[6];
+          if (uinfo.endsWith(FIELD_SEPARATOR + NOT_AVAILABLE)) {
+            recordMap.put(UINFO, uinfo + FIELD_SEPARATOR + extension);
+          }
+        }
+      }
+      return expandAddedArtifact(recordMap);
+    }
+  }
+
+  private static Record expandDescriptor(final Map<String, String> raw) {
+    final Record result = new Record(Type.DESCRIPTOR, new HashMap<EntryKey, Object>());
+    String[] r = FS_PATTERN.split(raw.get("IDXINFO"));
+    result.put(Record.REPOSITORY_ID, r[1]);
+    return result;
+  }
+
+  private static Record expandAllGroups(final Map<String, String> raw) {
+    final Record result = new Record(Type.ALL_GROUPS, new HashMap<EntryKey, Object>());
+    putIfNotNullAsStringArray(raw, "allGroupsList", result, Record.ALL_GROUPS);
+    return result;
+  }
+
+  private static Record expandRootGroups(final Map<String, String> raw) {
+    final Record result = new Record(Type.ROOT_GROUPS, new HashMap<EntryKey, Object>());
+    putIfNotNullAsStringArray(raw, "rootGroupsList", result, Record.ROOT_GROUPS);
+    return result;
+  }
+
+  private static Record expandDeletedArtifact(final Map<String, String> raw) {
+    final Record result = new Record(Type.ARTIFACT_REMOVE, new HashMap<EntryKey, Object>());
+    putIfNotNullTS(raw, "m", result, Record.REC_MODIFIED);
+    if (raw.containsKey("del")) {
+      expandUinfo(raw.get("del"), result);
+    }
+    return result;
+  }
+
+  /**
+   * Expands the "encoded" Maven Indexer record by splitting the synthetic fields and applying expanded field naming.
+   */
+  private static Record expandAddedArtifact(final Map<String, String> raw) {
+    final Record result = new Record(Type.ARTIFACT_ADD, new HashMap<EntryKey, Object>());
+
+    // Minimal
+    expandUinfo(raw.get(UINFO), result);
+    final String info = raw.get(INFO);
+    if (info != null) {
+      String[] r = FS_PATTERN.split(info);
+      result.put(Record.PACKAGING, renvl(r[0]));
+      result.put(Record.FILE_MODIFIED, Long.valueOf(r[1]));
+      result.put(Record.FILE_SIZE, Long.valueOf(r[2]));
+      result.put(Record.HAS_SOURCES, "1".equals(r[3]) ? Boolean.TRUE : Boolean.FALSE);
+      result.put(Record.HAS_JAVADOC, "1".equals(r[4]) ? Boolean.TRUE : Boolean.FALSE);
+      result.put(Record.HAS_SIGNATURE, "1".equals(r[5]) ? Boolean.TRUE : Boolean.FALSE);
+      if (r.length > 6) {
+        result.put(Record.FILE_EXTENSION, r[6]);
+      }
+      else {
+        final String packaging = Record.PACKAGING.coerce(result.get(Record.PACKAGING));
+        if (result.containsKey(Record.CLASSIFIER)
+            || "pom".equals(packaging)
+            || "war".equals(packaging)
+            || "ear".equals(packaging)) {
+          result.put(Record.FILE_EXTENSION, packaging);
+        }
+        else {
+          result.put(Record.FILE_EXTENSION, "jar"); // best guess
+        }
+      }
+    }
+    putIfNotNullTS(raw, "m", result, Record.REC_MODIFIED);
+    putIfNotNull(raw, "n", result, Record.NAME);
+    putIfNotNull(raw, "d", result, Record.DESCRIPTION);
+    putIfNotNull(raw, "1", result, Record.SHA1);
+
+    // Jar file contents (optional)
+    putIfNotNullAsStringArray(raw, "classnames", result, Record.CLASSNAMES);
+
+    // Maven Plugin (optional)
+    putIfNotNull(raw, "px", result, Record.PLUGIN_PREFIX);
+    putIfNotNullAsStringArray(raw, "gx", result, Record.PLUGIN_GOALS);
+
+    // OSGi (optional)
+    putIfNotNull(raw, "Bundle-SymbolicName", result, Record.OSGI_BUNDLE_SYMBOLIC_NAME);
+    putIfNotNull(raw, "Bundle-Version", result, Record.OSGI_BUNDLE_VERSION);
+    putIfNotNull(raw, "Export-Package", result, Record.OSGI_EXPORT_PACKAGE);
+    putIfNotNull(raw, "Export-Service", result, Record.OSGI_EXPORT_SERVICE);
+    putIfNotNull(raw, "Bundle-Description", result, Record.OSGI_BUNDLE_DESCRIPTION);
+    putIfNotNull(raw, "Bundle-Name", result, Record.OSGI_BUNDLE_NAME);
+    putIfNotNull(raw, "Bundle-License", result, Record.OSGI_BUNDLE_LICENSE);
+    putIfNotNull(raw, "Bundle-DocURL", result, Record.OSGI_EXPORT_DOCURL);
+    putIfNotNull(raw, "Import-Package", result, Record.OSGI_IMPORT_PACKAGE);
+    putIfNotNull(raw, "Require-Bundle", result, Record.OSGI_REQUIRE_BUNDLE);
+
+    return result;
+  }
+
+  /**
+   * Expands UINFO synthetic field. Handles {@code null} String inputs.
+   */
+  private static void expandUinfo(final String uinfo, final Record result) {
+    if (uinfo != null) {
+      String[] r = FS_PATTERN.split(uinfo);
+      result.put(Record.GROUP_ID, r[0]);
+      result.put(Record.ARTIFACT_ID, r[1]);
+      result.put(Record.VERSION, r[2]);
+      String classifier = renvl(r[3]);
+      if (classifier != null) {
+        result.put(Record.CLASSIFIER, classifier);
+        if (r.length > 4) {
+          result.put(Record.FILE_EXTENSION, r[4]);
+        }
+      }
+      else if (r.length > 4) {
+        result.put(Record.PACKAGING, r[4]);
+      }
+    }
+  }
+
+  /**
+   * Helper to put a value from source map into target map, if not null.
+   */
+  private static void putIfNotNull(
+      final Map<String, String> source,
+      final String sourceName,
+      final Record target,
+      final EntryKey targetName)
+  {
+    String value = source.get(sourceName);
+    if (value != null && value.trim().length() != 0) {
+      target.put(targetName, value);
+    }
+  }
+
+  /**
+   * Helper to put a {@link Long} value from source map into target map, if not null.
+   */
+  private static void putIfNotNullTS(
+      final Map<String, String> source,
+      final String sourceName,
+      final Record target,
+      final EntryKey targetName)
+  {
+    String value = source.get(sourceName);
+    if (value != null && value.trim().length() != 0) {
+      target.put(targetName, Long.valueOf(value));
+    }
+  }
+
+  /**
+   * Helper to put a collection value from source map into target map as {@link java.util.List}, if not null.
+   */
+  private static void putIfNotNullAsStringArray(
+      final Map<String, String> source,
+      final String sourceName,
+      final Record target,
+      final EntryKey targetName)
+  {
+    String value = source.get(sourceName);
+    if (value != null && value.trim().length() != 0) {
+      target.put(targetName, FS_PATTERN.split(value));
+    }
+  }
+}

http://git-wip-us.apache.org/repos/asf/maven-indexer/blob/b9c4d908/indexer-reader/src/main/java/org/apache/maven/index/reader/ResourceHandler.java
----------------------------------------------------------------------
diff --git a/indexer-reader/src/main/java/org/apache/maven/index/reader/ResourceHandler.java b/indexer-reader/src/main/java/org/apache/maven/index/reader/ResourceHandler.java
index 9780067..fa6b6a7 100644
--- a/indexer-reader/src/main/java/org/apache/maven/index/reader/ResourceHandler.java
+++ b/indexer-reader/src/main/java/org/apache/maven/index/reader/ResourceHandler.java
@@ -37,7 +37,7 @@ public interface ResourceHandler
 {
   /**
    * Returns the {@link InputStream} of resource with {@code name} or {@code null} if no such resource. Closing the
-   * stream is the responsibility of the caller.
+   * stream is the responsibility of the caller. The stream should be buffered if possible.
    *
    * @param name Resource name, guaranteed to be non-{@code null} and is FS name and URL safe string.
    */

http://git-wip-us.apache.org/repos/asf/maven-indexer/blob/b9c4d908/indexer-reader/src/main/java/org/apache/maven/index/reader/Utils.java
----------------------------------------------------------------------
diff --git a/indexer-reader/src/main/java/org/apache/maven/index/reader/Utils.java b/indexer-reader/src/main/java/org/apache/maven/index/reader/Utils.java
new file mode 100644
index 0000000..798c7a1
--- /dev/null
+++ b/indexer-reader/src/main/java/org/apache/maven/index/reader/Utils.java
@@ -0,0 +1,98 @@
+package org.apache.maven.index.reader;
+
+/*
+ * 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.
+ */
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.text.DateFormat;
+import java.text.SimpleDateFormat;
+import java.util.Properties;
+import java.util.TimeZone;
+import java.util.regex.Pattern;
+
+/**
+ * Reusable code snippets and constants.
+ *
+ * @since 5.1.2
+ */
+public final class Utils
+{
+  private Utils() {
+    // nothing
+  }
+
+  static final String INDEX_FILE_PREFIX = "nexus-maven-repository-index";
+
+  static final DateFormat INDEX_DATE_FORMAT;
+
+  static {
+    INDEX_DATE_FORMAT = new SimpleDateFormat("yyyyMMddHHmmss.SSS Z");
+    INDEX_DATE_FORMAT.setTimeZone(TimeZone.getTimeZone("GMT"));
+  }
+
+  static final String FIELD_SEPARATOR = "|";
+
+  static final String NOT_AVAILABLE = "NA";
+
+  static final String UINFO = "u";
+
+  static final String INFO = "i";
+
+  static final Pattern FS_PATTERN = Pattern.compile(Pattern.quote(FIELD_SEPARATOR));
+
+  /**
+   * Creates and loads {@link Properties} from provided {@link InputStream} and closes the stream.
+   */
+  static Properties loadProperties(final InputStream inputStream) throws IOException {
+    try {
+      final Properties properties = new Properties();
+      properties.load(inputStream);
+      return properties;
+    }
+    finally {
+      inputStream.close();
+    }
+  }
+
+  /**
+   * Helper to translate the "NA" (not available) input into {@code null} value.
+   */
+  static String renvl(final String v) {
+    return NOT_AVAILABLE.equals(v) ? null : v;
+  }
+
+  /**
+   * Helper to translate {@code null} into "NA" (not available) value.
+   */
+  static String nvl(final String v) {
+    return v == null ? NOT_AVAILABLE : v;
+  }
+
+  /**
+   * Returns the "root group" of given groupId.
+   */
+  static String rootGroup(final String groupId) {
+    int n = groupId.indexOf('.');
+    if (n > -1) {
+      return groupId.substring(0, n);
+    }
+    return groupId;
+  }
+}

http://git-wip-us.apache.org/repos/asf/maven-indexer/blob/b9c4d908/indexer-reader/src/main/java/org/apache/maven/index/reader/WritableResourceHandler.java
----------------------------------------------------------------------
diff --git a/indexer-reader/src/main/java/org/apache/maven/index/reader/WritableResourceHandler.java b/indexer-reader/src/main/java/org/apache/maven/index/reader/WritableResourceHandler.java
index 7fe3896..7d1ff03 100644
--- a/indexer-reader/src/main/java/org/apache/maven/index/reader/WritableResourceHandler.java
+++ b/indexer-reader/src/main/java/org/apache/maven/index/reader/WritableResourceHandler.java
@@ -20,7 +20,7 @@ package org.apache.maven.index.reader;
  */
 
 import java.io.IOException;
-import java.io.InputStream;
+import java.io.OutputStream;
 
 /**
  * Maven 2 Index writable {@link ResourceHandler}, is capable of saving resources too. Needed only if incremental index
@@ -34,11 +34,10 @@ public interface WritableResourceHandler
     extends ResourceHandler
 {
   /**
-   * Stores (creates or overwrites if resource with name exists) the resource under {@code name} with content provided
-   * by the stream. The {@link InputStream} should be closed when method returns.
+   * Returns the {@link OutputStream} of resource with {@code name}, never {@code null}. Closing the stream is the
+   * responsibility of the caller. The stream should be buffered if possible.
    *
-   * @param name        Resource name, guaranteed to be non-{@code null} and is FS name and URL safe string.
-   * @param inputStream the content of the resource, guaranteed to be non-{@code null}.
+   * @param name Resource name, guaranteed to be non-{@code null} and is FS name and URL safe string.
    */
-  void save(final String name, final InputStream inputStream) throws IOException;
+  OutputStream openWrite(final String name) throws IOException;
 }

http://git-wip-us.apache.org/repos/asf/maven-indexer/blob/b9c4d908/indexer-reader/src/test/java/org/apache/maven/index/reader/CachingResourceHandler.java
----------------------------------------------------------------------
diff --git a/indexer-reader/src/test/java/org/apache/maven/index/reader/CachingResourceHandler.java b/indexer-reader/src/test/java/org/apache/maven/index/reader/CachingResourceHandler.java
index 6afe222..d1f7a64 100644
--- a/indexer-reader/src/test/java/org/apache/maven/index/reader/CachingResourceHandler.java
+++ b/indexer-reader/src/test/java/org/apache/maven/index/reader/CachingResourceHandler.java
@@ -21,6 +21,7 @@ package org.apache.maven.index.reader;
 
 import java.io.IOException;
 import java.io.InputStream;
+import java.io.OutputStream;
 
 /**
  * A trivial caching {@link ResourceHandler} that caches forever during single session (existence of the instance).
@@ -49,7 +50,7 @@ public class CachingResourceHandler
     if (inputStream == null) {
       return null;
     }
-    local.save(name, inputStream);
+    writeLocal(name, inputStream);
     return local.open(name);
   }
 
@@ -57,4 +58,23 @@ public class CachingResourceHandler
     remote.close();
     local.close();
   }
+
+  private void writeLocal(final String name, final InputStream inputStream) throws IOException {
+    try {
+      final OutputStream outputStream = local.openWrite(name);
+      try {
+        int read;
+        byte[] bytes = new byte[8192];
+        while ((read = inputStream.read(bytes)) != -1) {
+          outputStream.write(bytes, 0, read);
+        }
+      }
+      finally {
+        outputStream.close();
+      }
+    }
+    finally {
+      inputStream.close();
+    }
+  }
 }

http://git-wip-us.apache.org/repos/asf/maven-indexer/blob/b9c4d908/indexer-reader/src/test/java/org/apache/maven/index/reader/ChunkReaderTest.java
----------------------------------------------------------------------
diff --git a/indexer-reader/src/test/java/org/apache/maven/index/reader/ChunkReaderTest.java b/indexer-reader/src/test/java/org/apache/maven/index/reader/ChunkReaderTest.java
index 0d1915d..097d44d 100644
--- a/indexer-reader/src/test/java/org/apache/maven/index/reader/ChunkReaderTest.java
+++ b/indexer-reader/src/test/java/org/apache/maven/index/reader/ChunkReaderTest.java
@@ -19,14 +19,18 @@ package org.apache.maven.index.reader;
  * under the License.
  */
 
+import java.io.File;
 import java.io.FileInputStream;
+import java.io.FileOutputStream;
 import java.io.IOException;
-import java.util.HashMap;
+import java.util.Date;
+import java.util.List;
 import java.util.Map;
 
 import org.apache.maven.index.reader.Record.Type;
 import org.junit.Test;
 
+import static org.hamcrest.CoreMatchers.nullValue;
 import static org.hamcrest.core.IsEqual.equalTo;
 import static org.junit.Assert.assertThat;
 
@@ -34,33 +38,56 @@ import static org.junit.Assert.assertThat;
  * UT for {@link ChunkReader}
  */
 public class ChunkReaderTest
+    extends TestSupport
 {
   @Test
   public void simple() throws IOException {
-    final Map<Type, Integer> recordTypes = new HashMap<Type, Integer>();
-    recordTypes.put(Type.DESCRIPTOR, 0);
-    recordTypes.put(Type.ROOT_GROUPS, 0);
-    recordTypes.put(Type.ALL_GROUPS, 0);
-    recordTypes.put(Type.ARTIFACT_ADD, 0);
-    recordTypes.put(Type.ARTIFACT_REMOVE, 0);
+    final ChunkReader chunkReader = new ChunkReader(
+        "full",
+        testResourceHandler("simple").open("nexus-maven-repository-index.gz")
+    );
+    final Map<Type, List<Record>> recordTypes = countRecordTypes(chunkReader);
+    assertThat(recordTypes.get(Type.DESCRIPTOR).size(), equalTo(1));
+    assertThat(recordTypes.get(Type.ROOT_GROUPS).size(), equalTo(1));
+    assertThat(recordTypes.get(Type.ALL_GROUPS).size(), equalTo(1));
+    assertThat(recordTypes.get(Type.ARTIFACT_ADD).size(), equalTo(2));
+    assertThat(recordTypes.get(Type.ARTIFACT_REMOVE), nullValue());
+  }
 
-    final ChunkReader chunkReader = new ChunkReader("full",
-        new FileInputStream("src/test/resources/nexus-maven-repository-index.gz"));
-    try {
-      assertThat(chunkReader.getVersion(), equalTo(1));
-      assertThat(chunkReader.getTimestamp().getTime(), equalTo(1243533418015L));
-      for (Record record : chunkReader) {
-        recordTypes.put(record.getType(), recordTypes.get(record.getType()) + 1);
+  @Test
+  public void roundtrip() throws IOException {
+    final Date published;
+    File tempChunkFile = createTempFile("nexus-maven-repository-index.gz");
+    {
+      final ChunkReader chunkReader = new ChunkReader(
+          "full",
+          testResourceHandler("simple").open("nexus-maven-repository-index.gz")
+      );
+      final ChunkWriter chunkWriter = new ChunkWriter(
+          chunkReader.getName(),
+          new FileOutputStream(tempChunkFile), 1, new Date()
+      );
+      try {
+        chunkWriter.writeChunk(chunkReader.iterator());
       }
-    }
-    finally {
-      chunkReader.close();
+      finally {
+        chunkWriter.close();
+        chunkReader.close();
+      }
+      published = chunkWriter.getTimestamp();
     }
 
-    assertThat(recordTypes.get(Type.DESCRIPTOR), equalTo(1));
-    assertThat(recordTypes.get(Type.ROOT_GROUPS), equalTo(1));
-    assertThat(recordTypes.get(Type.ALL_GROUPS), equalTo(1));
-    assertThat(recordTypes.get(Type.ARTIFACT_ADD), equalTo(2));
-    assertThat(recordTypes.get(Type.ARTIFACT_REMOVE), equalTo(0));
+    final ChunkReader chunkReader = new ChunkReader(
+        "full",
+        new FileInputStream(tempChunkFile)
+    );
+    assertThat(chunkReader.getVersion(), equalTo(1));
+    assertThat(chunkReader.getTimestamp().getTime(), equalTo(published.getTime()));
+    final Map<Type, List<Record>> recordTypes = countRecordTypes(chunkReader);
+    assertThat(recordTypes.get(Type.DESCRIPTOR).size(), equalTo(1));
+    assertThat(recordTypes.get(Type.ROOT_GROUPS).size(), equalTo(1));
+    assertThat(recordTypes.get(Type.ALL_GROUPS).size(), equalTo(1));
+    assertThat(recordTypes.get(Type.ARTIFACT_ADD).size(), equalTo(2));
+    assertThat(recordTypes.get(Type.ARTIFACT_REMOVE), nullValue());
   }
 }