lucene 4: optimize read/write BytesRef handling

src/main/java/org/elasticsearch/common/io/stream/BytesStreamInput.java

@@ -19,6 +19,7 @@
 
 package org.elasticsearch.common.io.stream;
 
+import org.apache.lucene.util.BytesRef;
 import org.elasticsearch.common.bytes.BytesArray;
 import org.elasticsearch.common.bytes.BytesReference;
 
@@ -69,6 +70,16 @@ public class BytesStreamInput extends StreamInput {
         return bytes;
     }
 
+    @Override
+    public BytesRef readBytesRef(int length) throws IOException {
+        if (unsafe) {
+            return super.readBytesRef(length);
+        }
+        BytesRef bytes = new BytesRef(buf, pos, length);
+        pos += length;
+        return bytes;
+    }
+
     @Override
     public long skip(long n) throws IOException {
         if (pos + n > count) {

src/main/java/org/elasticsearch/common/io/stream/StreamInput.java

@@ -87,10 +87,16 @@ public abstract class StreamInput extends InputStream {
 
     public BytesRef readBytesRef() throws IOException {
         int length = readVInt();
-        int offset = readVInt();
+        return readBytesRef(length);
+    }
+
+    public BytesRef readBytesRef(int length) throws IOException {
+        if (length == 0) {
+            return new BytesRef();
+        }
         byte[] bytes = new byte[length];
-        readBytes(bytes, offset, length);
-        return new BytesRef(bytes, offset, length);
+        readBytes(bytes, 0, length);
+        return new BytesRef(bytes, 0, length);
     }
 
     public void readFully(byte[] b) throws IOException {

src/main/java/org/elasticsearch/common/io/stream/StreamOutput.java

@@ -113,7 +113,6 @@ public abstract class StreamOutput extends OutputStream {
             return;
         }
         writeVInt(bytes.length);
-        writeVInt(bytes.offset);
         write(bytes.bytes, bytes.offset, bytes.length);
     }
 

src/main/java/org/elasticsearch/transport/netty/ChannelBufferStreamInput.java

@@ -19,6 +19,7 @@
 
 package org.elasticsearch.transport.netty;
 
+import org.apache.lucene.util.BytesRef;
 import org.elasticsearch.common.bytes.BytesReference;
 import org.elasticsearch.common.bytes.ChannelBufferBytesReference;
 import org.elasticsearch.common.io.stream.StreamInput;
@@ -57,6 +58,16 @@ public class ChannelBufferStreamInput extends StreamInput {
         return ref;
     }
 
+    @Override
+    public BytesRef readBytesRef(int length) throws IOException {
+        if (!buffer.hasArray()) {
+            return super.readBytesRef(length);
+        }
+        BytesRef bytesRef = new BytesRef(buffer.array(), buffer.arrayOffset() + buffer.readerIndex(), length);
+        buffer.skipBytes(length);
+        return bytesRef;
+    }
+
     @Override
     public int available() throws IOException {
         return endIndex - buffer.readerIndex();