Expose the DataOutput

Author: dungba88

lucene/core/src/java/org/apache/lucene/util/fst/BytesStore.java

@@ -370,18 +370,6 @@ public void truncate(long newLen) {
     assert newLen == getPosition();
   }
 
-  /** Writes all of our bytes to the target {@link FSTDataOutputWriter}. */
-  public void writeTo(FSTDataOutputWriter out) throws IOException {
-    reverse(0, getPosition() - 1);
-    for (byte[] block : blocks) {
-      if (block == current) { // last block
-        out.writeBytes(block, 0, nextWrite);
-      } else {
-        out.writeBytes(block, 0, block.length);
-      }
-    }
-  }
-
   /** Writes all of our bytes to the target {@link DataOutput}. */
   @Override
   public void writeTo(DataOutput out) throws IOException {

lucene/core/src/java/org/apache/lucene/util/fst/FSTCompiler.java

@@ -119,8 +119,8 @@ public class FSTCompiler<T> {
   final float directAddressingMaxOversizingFactor;
   long directAddressingExpansionCredit;
 
-  // writer for frozen nodes
-  final FSTDataOutputWriter fstWriter;
+  // the DataOutput to write the FST to
+  final DataOutput dataOutput;
 
   // The number of bits for scratch area when adding a node
   private static final int SCRATCH_PAGE_BITS = 8;
@@ -160,12 +160,12 @@ private FSTCompiler(
     // pad: ensure no node gets address 0 which is reserved to mean
     // the stop state w/ no arcs
     try {
-      fstWriter.writeByte((byte) 0);
+      fstWriter.getDataOutput().writeByte((byte) 0);
       numBytesWritten++;
     } catch (IOException e) {
       throw new RuntimeException(e);
     }
-    this.fstWriter = fstWriter;
+    this.dataOutput = fstWriter.getDataOutput();
     fst =
         new FST<>(
             new FST.FSTMetadata<>(inputType, null, -1, VERSION_CURRENT, 0),
@@ -513,7 +513,7 @@ long addNode(FSTCompiler.UnCompiledNode<T> nodeIn) throws IOException {
       }
     }
 
-    scratchBytes.writeTo(fstWriter);
+    scratchBytes.writeTo(dataOutput);
     numBytesWritten += scratchBytes.getPosition();
 
     nodeCount++;

lucene/core/src/java/org/apache/lucene/util/fst/FSTDataOutputWriter.java

@@ -35,8 +35,6 @@ final class FSTDataOutputWriter {
   /** the main DataOutput to store the FST bytes */
   private final DataOutput dataOutput;
 
-  private long size;
-
   /**
    * ctor
    *
@@ -46,26 +44,8 @@ public FSTDataOutputWriter(DataOutput dataOutput) {
     this.dataOutput = dataOutput;
   }
 
-  /**
-   * Write a single byte to the end of the DataOutput
-   *
-   * @param b the byte to write
-   */
-  public void writeByte(byte b) throws IOException {
-    size++;
-    dataOutput.writeByte(b);
-  }
-
-  /**
-   * Write a byte array to the end of the DataOutput
-   *
-   * @param b the byte array to write
-   * @param offset the offset of the array
-   * @param length the number of bytes to write
-   */
-  public void writeBytes(byte[] b, int offset, int length) throws IOException {
-    size += length;
-    dataOutput.writeBytes(b, offset, length);
+  public DataOutput getDataOutput() {
+    return dataOutput;
   }
 
   /**
@@ -78,7 +58,8 @@ public FSTReader getReader() {
     return new FSTReader() {
       @Override
       public long size() {
-        return size;
+        // the FSTReader#size() method was no longer being used, hence just outputs 0 here
+        return 0;
       }
 
       @Override