[GitHub] [lucene-solr] jpountz commented on a change in pull request #1234: Add compression for Binary doc value fields

[GitBox <gi...@apache.org>]

jpountz commented on a change in pull request #1234: Add compression for Binary doc value fields
URL: https://github.com/apache/lucene-solr/pull/1234#discussion_r375273736
 
 

 ##########
 File path: lucene/core/src/java/org/apache/lucene/codecs/lucene80/Lucene80DocValuesConsumer.java
 ##########
 @@ -353,67 +360,168 @@ private void writeBlock(long[] values, int length, long gcd, ByteBuffersDataOutp
     }
   }
 
-  @Override
-  public void addBinaryField(FieldInfo field, DocValuesProducer valuesProducer) throws IOException {
-    meta.writeInt(field.number);
-    meta.writeByte(Lucene80DocValuesFormat.BINARY);
-
-    BinaryDocValues values = valuesProducer.getBinary(field);
-    long start = data.getFilePointer();
-    meta.writeLong(start); // dataOffset
-    int numDocsWithField = 0;
-    int minLength = Integer.MAX_VALUE;
-    int maxLength = 0;
-    for (int doc = values.nextDoc(); doc != DocIdSetIterator.NO_MORE_DOCS; doc = values.nextDoc()) {
-      numDocsWithField++;
-      BytesRef v = values.binaryValue();
-      int length = v.length;
-      data.writeBytes(v.bytes, v.offset, v.length);
-      minLength = Math.min(length, minLength);
-      maxLength = Math.max(length, maxLength);
+  class CompressedBinaryBlockWriter  implements Closeable {
+    FastCompressionHashTable ht = new LZ4.FastCompressionHashTable();    
+    int uncompressedBlockLength = 0;
+    int maxUncompressedBlockLength = 0;
+    int numDocsInCurrentBlock = 0;
+    int [] docLengths = new int[Lucene80DocValuesFormat.BINARY_DOCS_PER_COMPRESSED_BLOCK]; 
+    byte [] block = new byte [1024 * 16];
+    int totalChunks = 0;
+    long maxPointer = 0;
+    long blockAddressesStart = -1; 
+
+    private IndexOutput tempBinaryOffsets;
+    
+    
+    public CompressedBinaryBlockWriter() throws IOException {
+      tempBinaryOffsets = state.directory.createTempOutput(state.segmentInfo.name, "binary_pointers", state.context);
+      try {
+        CodecUtil.writeHeader(tempBinaryOffsets, Lucene80DocValuesFormat.META_CODEC + "FilePointers", Lucene80DocValuesFormat.VERSION_CURRENT);
+      } catch (Throwable exception) {
+        IOUtils.closeWhileHandlingException(this); //self-close because constructor caller can't 
+        throw exception;
+      }
     }
-    assert numDocsWithField <= maxDoc;
-    meta.writeLong(data.getFilePointer() - start); // dataLength
 
-    if (numDocsWithField == 0) {
-      meta.writeLong(-2); // docsWithFieldOffset
-      meta.writeLong(0L); // docsWithFieldLength
-      meta.writeShort((short) -1); // jumpTableEntryCount
-      meta.writeByte((byte) -1);   // denseRankPower
-    } else if (numDocsWithField == maxDoc) {
-      meta.writeLong(-1); // docsWithFieldOffset
-      meta.writeLong(0L); // docsWithFieldLength
-      meta.writeShort((short) -1); // jumpTableEntryCount
-      meta.writeByte((byte) -1);   // denseRankPower
-    } else {
-      long offset = data.getFilePointer();
-      meta.writeLong(offset); // docsWithFieldOffset
-      values = valuesProducer.getBinary(field);
-      final short jumpTableEntryCount = IndexedDISI.writeBitSet(values, data, IndexedDISI.DEFAULT_DENSE_RANK_POWER);
-      meta.writeLong(data.getFilePointer() - offset); // docsWithFieldLength
-      meta.writeShort(jumpTableEntryCount);
-      meta.writeByte(IndexedDISI.DEFAULT_DENSE_RANK_POWER);
+    void  addDoc(int doc, BytesRef v) throws IOException {
+      if (blockAddressesStart < 0) {
+        blockAddressesStart = data.getFilePointer();
+      }
+      docLengths[numDocsInCurrentBlock] = v.length;
+      block = ArrayUtil.grow(block, uncompressedBlockLength + v.length);
+      System.arraycopy(v.bytes, v.offset, block, uncompressedBlockLength, v.length);
+      uncompressedBlockLength += v.length;
+      numDocsInCurrentBlock++;
+      if (numDocsInCurrentBlock == Lucene80DocValuesFormat.BINARY_DOCS_PER_COMPRESSED_BLOCK) {
+        flushData();
+      }      
     }
 
-    meta.writeInt(numDocsWithField);
-    meta.writeInt(minLength);
-    meta.writeInt(maxLength);
-    if (maxLength > minLength) {
-      start = data.getFilePointer();
-      meta.writeLong(start);
+    private void flushData() throws IOException {
+      if(numDocsInCurrentBlock > 0) {
+        // Write offset to this block to temporary offsets file
+        totalChunks++;
+        long thisBlockStartPointer = data.getFilePointer();
+        data.writeVInt(numDocsInCurrentBlock);
+        for (int i = 0; i < numDocsInCurrentBlock; i++) {
 
 Review comment:
   +1

----------------------------------------------------------------
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
 
For queries about this service, please contact Infrastructure at:
users@infra.apache.org


With regards,
Apache Git Services

---------------------------------------------------------------------
To unsubscribe, e-mail: issues-unsubscribe@lucene.apache.org
For additional commands, e-mail: issues-help@lucene.apache.org