bulk load dense binary doc values.

Author: martijnvg

server/src/main/java/org/elasticsearch/index/codec/tsdb/es819/ES819TSDBDocValuesProducer.java

@@ -208,6 +208,26 @@ public BytesRef binaryValue() throws IOException {
                         bytesSlice.readBytes((long) doc * length, bytes.bytes, 0, length);
                         return bytes;
                     }
+
+                    @Override
+                    public BlockLoader.Block tryRead(
+                        BlockLoader.BlockFactory factory,
+                        BlockLoader.Docs docs,
+                        int offset,
+                        boolean nullsFiltered,
+                        BlockDocValuesReader.ToDouble toDouble,
+                        boolean toInt
+                    ) throws IOException {
+                        int count = docs.count() - offset;
+                        try (var builder = factory.bytesRefs(count)) {
+                            for (int i = offset; i < docs.count(); i++) {
+                                doc = docs.get(i);
+                                bytesSlice.readBytes((long) doc * length, bytes.bytes, 0, length);
+                                builder.appendBytesRef(bytes);
+                            }
+                            return builder.build();
+                        }
+                    }
                 };
             } else {
                 // variable length
@@ -223,6 +243,28 @@ public BytesRef binaryValue() throws IOException {
                         bytesSlice.readBytes(startOffset, bytes.bytes, 0, bytes.length);
                         return bytes;
                     }
+
+                    @Override
+                    public BlockLoader.Block tryRead(
+                        BlockLoader.BlockFactory factory,
+                        BlockLoader.Docs docs,
+                        int offset,
+                        boolean nullsFiltered,
+                        BlockDocValuesReader.ToDouble toDouble,
+                        boolean toInt
+                    ) throws IOException {
+                        int count = docs.count() - offset;
+                        try (var builder = factory.bytesRefs(count)) {
+                            for (int i = offset; i < docs.count(); i++) {
+                                doc = docs.get(i);
+                                long startOffset = addresses.get(doc);
+                                bytes.length = (int) (addresses.get(doc + 1L) - startOffset);
+                                bytesSlice.readBytes(startOffset, bytes.bytes, 0, bytes.length);
+                                builder.appendBytesRef(bytes);
+                            }
+                            return builder.build();
+                        }
+                    }
                 };
             }
         } else {
@@ -267,7 +309,7 @@ public BytesRef binaryValue() throws IOException {
         }
     }
 
-    private abstract static class DenseBinaryDocValues extends BinaryDocValues {
+    private abstract static class DenseBinaryDocValues extends BinaryDocValues implements BlockLoader.OptionalColumnAtATimeReader {
 
         final int maxDoc;
         int doc = -1;

server/src/main/java/org/elasticsearch/index/mapper/BlockDocValuesReader.java

@@ -1032,6 +1032,17 @@ public BytesRefsFromBinary(BinaryDocValues docValues) {
             super(docValues);
         }
 
+        @Override
+        public BlockLoader.Block read(BlockFactory factory, Docs docs, int offset, boolean nullsFiltered) throws IOException {
+            if (docValues instanceof BlockLoader.OptionalColumnAtATimeReader direct) {
+                BlockLoader.Block block = direct.tryRead(factory, docs, offset, nullsFiltered, null, false);
+                if (block != null) {
+                    return block;
+                }
+            }
+            return super.read(factory, docs, offset, nullsFiltered);
+        }
+
         @Override
         void read(int doc, BytesRefBuilder builder) throws IOException {
             if (false == docValues.advanceExact(doc)) {