pass_by_value.diff

diff --git a/src/main/java/org/elasticsearch/index/translog/fs/FsChannelReader.java b/src/main/java/org/elasticsearch/index/translog/fs/FsChannelReader.java
index 295a4e8..eeb85cd 100644
--- a/src/main/java/org/elasticsearch/index/translog/fs/FsChannelReader.java
+++ b/src/main/java/org/elasticsearch/index/translog/fs/FsChannelReader.java
@@ -68,19 +68,7 @@ public abstract class FsChannelReader implements Closeable, Comparable<FsChannel
         return read(buffer, location.translogLocation, location.size);
     }
 
-    /**
-     * reads an operation from the given position and changes to point at the start of the next
-     * operation
-     */
-    public Translog.Operation readOpAndAdvancePosition(ByteBuffer reusableBuffer, AtomicLong position) throws IOException {
-        final long pos = position.get();
-        int opSize = readSize(reusableBuffer, pos);
-        Translog.Operation op = read(reusableBuffer, pos, opSize);
-        position.addAndGet(opSize);
-        return op;
-    }
-
-    protected int readSize(ByteBuffer reusableBuffer, long position) {
+    public int readSize(ByteBuffer reusableBuffer, long position) {
         // read op size from disk
         assert reusableBuffer.capacity() >= 4 : "reusable buffer must have capacity >=4 when reading opSize. got [" + reusableBuffer.capacity() + "]";
         try {
@@ -99,7 +87,7 @@ public abstract class FsChannelReader implements Closeable, Comparable<FsChannel
      * reads an operation at the given position and returns it. The buffer length is equal to the number
      * of bytes reads.
      */
-    protected Translog.Operation read(ByteBuffer reusableBuffer, long position, int opSize) throws IOException {
+    public Translog.Operation read(ByteBuffer reusableBuffer, long position, int opSize) throws IOException {
         final ByteBuffer buffer;
         if (reusableBuffer.capacity() >= opSize) {
             buffer = reusableBuffer;
diff --git a/src/main/java/org/elasticsearch/index/translog/fs/FsChannelSnapshot.java b/src/main/java/org/elasticsearch/index/translog/fs/FsChannelSnapshot.java
index 2e0d1d0..7364ccb 100644
--- a/src/main/java/org/elasticsearch/index/translog/fs/FsChannelSnapshot.java
+++ b/src/main/java/org/elasticsearch/index/translog/fs/FsChannelSnapshot.java
@@ -37,12 +37,11 @@ public class FsChannelSnapshot implements Closeable {
     protected final FsChannelReader reader;
     protected final AtomicBoolean closed = new AtomicBoolean(false);
 
-    // we use an atomic long to allow passing it by reference :(
-    protected final AtomicLong position;
+    protected long position;
 
     public FsChannelSnapshot(FsChannelReader reader) {
         this.reader = reader;
-        this.position = new AtomicLong(reader.firstPosition());
+        this.position = reader.firstPosition();
     }
 
     public long translogId() {
@@ -54,10 +53,13 @@ public class FsChannelSnapshot implements Closeable {
     }
 
     public Translog.Operation next(ByteBuffer reusableBuffer) throws IOException {
-        if (position.get() >= reader.sizeInBytes()) {
+        if (position >= reader.sizeInBytes()) {
             return null;
         }
-        return reader.readOpAndAdvancePosition(reusableBuffer, position);
+        int opSize = reader.readSize(reusableBuffer, position);
+        Translog.Operation op = reader.read(reusableBuffer, position, opSize);
+        position += opSize;
+        return op;
     }