Remove Unused ByteBufferReference (#61116) (#61250)

We only work with heap byte buffers at this point and those we can and do unwrap the
`byte[]` ourselves and use `BytesArray` instead of a needless level of indirection via `ByteBuffer`.

server/src/main/java/org/elasticsearch/common/bytes/ByteBufferReference.java

@@ -1,109 +0,0 @@
-/*
- * Licensed to Elasticsearch under one or more contributor
- * license agreements. See the NOTICE file distributed with
- * this work for additional information regarding copyright
- * ownership. Elasticsearch licenses this file to you under
- * the Apache License, Version 2.0 (the "License"); you may
- * not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *    http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing,
- * software distributed under the License is distributed on an
- * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
- * KIND, either express or implied.  See the License for the
- * specific language governing permissions and limitations
- * under the License.
- */
-
-package org.elasticsearch.common.bytes;
-
-import org.apache.lucene.util.BytesRef;
-import org.apache.lucene.util.FutureObjects;
-
-import java.nio.ByteBuffer;
-
-/**
- * This is a {@link BytesReference} backed by a {@link ByteBuffer}. The byte buffer can either be a heap or
- * direct byte buffer. The reference is composed of the space between the {@link ByteBuffer#position()} and
- * {@link ByteBuffer#limit()} at construction time. If the position or limit of the underlying byte buffer is
- * changed, those changes will not be reflected in this reference. Any changes to the underlying data in the
- * byte buffer will be reflected in this reference.
- */
-public class ByteBufferReference extends AbstractBytesReference {
-
-    private final ByteBuffer buffer;
-    private final int length;
-
-    ByteBufferReference(ByteBuffer buffer) {
-        this.buffer = buffer.slice();
-        this.length = buffer.remaining();
-    }
-
-    @Override
-    public byte get(int index) {
-        return buffer.get(index);
-    }
-
-    @Override
-    public int getInt(int index) {
-        return buffer.getInt(index);
-    }
-
-    @Override
-    public int indexOf(byte marker, int from) {
-        final int remainingBytes = Math.max(length - from, 0);
-        FutureObjects.checkFromIndexSize(from, remainingBytes, length);
-        if (buffer.hasArray()) {
-            int startIndex = from + buffer.arrayOffset();
-            int endIndex = startIndex + remainingBytes;
-            final byte[] array = buffer.array();
-            for (int i = startIndex; i < endIndex; i++) {
-                if (array[i] == marker) {
-                    return (i - buffer.arrayOffset());
-                }
-            }
-            return -1;
-        } else {
-            return super.indexOf(marker, from);
-        }
-    }
-
-    @Override
-    public int length() {
-        return length;
-    }
-
-    @Override
-    public BytesReference slice(int from, int length) {
-        FutureObjects.checkFromIndexSize(from, length, this.length);
-        buffer.position(from);
-        buffer.limit(from + length);
-        ByteBufferReference newByteBuffer = new ByteBufferReference(buffer);
-        buffer.position(0);
-        buffer.limit(this.length);
-        return newByteBuffer;
-    }
-
-    /**
-     * This will return a bytes ref composed of the bytes. If this is a direct byte buffer, the bytes will
-     * have to be copied.
-     *
-     * @return the bytes ref
-     */
-    @Override
-    public BytesRef toBytesRef() {
-        if (buffer.hasArray()) {
-            return new BytesRef(buffer.array(), buffer.arrayOffset(), length);
-        }
-        final byte[] copy = new byte[length];
-        buffer.get(copy, 0, length);
-        return new BytesRef(copy);
-    }
-
-    @Override
-    public long ramBytesUsed() {
-        return buffer.capacity();
-    }
-}

server/src/main/java/org/elasticsearch/common/bytes/BytesReference.java

@@ -107,11 +107,9 @@ public interface BytesReference extends Comparable<BytesReference>, ToXContentFr
      * Returns BytesReference composed of the provided ByteBuffer.
      */
     static BytesReference fromByteBuffer(ByteBuffer buffer) {
-        if (buffer.hasArray()) {
+        assert buffer.hasArray();
         return new BytesArray(buffer.array(), buffer.arrayOffset() + buffer.position(), buffer.remaining());
     }
-        return new ByteBufferReference(buffer);
-    }
 
     /**
      * Returns the byte at the specified index. Need to be between 0 and length.

server/src/test/java/org/elasticsearch/common/bytes/ByteBufferReferenceTests.java

@@ -1,44 +0,0 @@
-/*
- * Licensed to Elasticsearch under one or more contributor
- * license agreements. See the NOTICE file distributed with
- * this work for additional information regarding copyright
- * ownership. Elasticsearch licenses this file to you under
- * the Apache License, Version 2.0 (the "License"); you may
- * not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *    http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing,
- * software distributed under the License is distributed on an
- * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
- * KIND, either express or implied.  See the License for the
- * specific language governing permissions and limitations
- * under the License.
- */
-
-package org.elasticsearch.common.bytes;
-
-import java.io.IOException;
-import java.nio.ByteBuffer;
-
-public class ByteBufferReferenceTests extends AbstractBytesReferenceTestCase {
-
-    private void initializeBytes(byte[] bytes) {
-        for (int i = 0 ; i < bytes.length; ++i) {
-            bytes[i] = (byte) i;
-        }
-    }
-
-    @Override
-    protected BytesReference newBytesReference(int length) throws IOException {
-        return newBytesReferenceWithOffsetOfZero(length);
-    }
-
-    @Override
-    protected BytesReference newBytesReferenceWithOffsetOfZero(int length) throws IOException {
-        byte[] bytes = new byte[length];
-        initializeBytes(bytes);
-        return new ByteBufferReference(ByteBuffer.wrap(bytes));
-    }
-}