Improved V2Batch: iterators don't change V2Batch internal state any more. It now implement Closable, for auto-release.

Author: fbacchella

src/main/java/org/logstash/beats/V2Batch.java

@@ -1,17 +1,18 @@
 package org.logstash.beats;
 
+import java.io.Closeable;
+import java.util.Iterator;
+import java.util.NoSuchElementException;
+
 import io.netty.buffer.ByteBuf;
 import io.netty.buffer.PooledByteBufAllocator;
 
-import java.util.Iterator;
-
 /**
  * Implementation of {@link Batch} for the v2 protocol backed by ByteBuf. *must* be released after use.
  */
-public class V2Batch implements Batch {
+public class V2Batch implements Batch, Closeable {
     private ByteBuf internalBuffer = PooledByteBufAllocator.DEFAULT.buffer();
     private int written = 0;
-    private int read = 0;
     private static final int SIZE_OF_INT = 4;
     private int batchSize;
     private int highestSequence = -1;
@@ -27,20 +28,27 @@ public byte getProtocol() {
         return Protocol.VERSION_2;
     }
 
-    public Iterator<Message> iterator(){
-        internalBuffer.resetReaderIndex();
+    public Iterator<Message> iterator() {
         return new Iterator<Message>() {
+            private int read = 0;
+            private ByteBuf readerBuffer = internalBuffer.asReadOnly();
+            {
+                readerBuffer.resetReaderIndex();
+            }
             @Override
             public boolean hasNext() {
                 return read < written;
             }
 
             @Override
             public Message next() {
-                int sequenceNumber = internalBuffer.readInt();
-                int readableBytes = internalBuffer.readInt();
-                Message message = new Message(sequenceNumber, internalBuffer.slice(internalBuffer.readerIndex(), readableBytes));
-                internalBuffer.readerIndex(internalBuffer.readerIndex() + readableBytes);
+                if (read >= written) {
+                    throw new NoSuchElementException();
+                }
+                int sequenceNumber = readerBuffer.readInt();
+                int readableBytes = readerBuffer.readInt();
+                Message message = new Message(sequenceNumber, readerBuffer.slice(readerBuffer.readerIndex(), readableBytes));
+                readerBuffer.readerIndex(readerBuffer.readerIndex() + readableBytes);
                 message.setBatch(V2Batch.this);
                 read++;
                 return message;
@@ -101,4 +109,10 @@ void addMessage(int sequenceNumber, ByteBuf buffer, int size) {
     public void release() {
         internalBuffer.release();
     }
+
+    @Override
+    public void close() {
+        release();
+    }
+
 }

src/test/java/org/logstash/beats/V2BatchTest.java

@@ -20,48 +20,49 @@ public class V2BatchTest {
 
     @Test
     public void testIsEmpty() {
-        V2Batch batch = new V2Batch();
-        assertTrue(batch.isEmpty());
-        ByteBuf content = messageContents();
-        batch.addMessage(1, content, content.readableBytes());
-        assertFalse(batch.isEmpty());
+        try (V2Batch batch = new V2Batch()){
+            assertTrue(batch.isEmpty());
+            ByteBuf content = messageContents();
+            batch.addMessage(1, content, content.readableBytes());
+            assertFalse(batch.isEmpty());
+        }
     }
 
     @Test
     public void testSize() {
-        V2Batch batch = new V2Batch();
-        assertEquals(0, batch.size());
-        ByteBuf content = messageContents();
-        batch.addMessage(1, content, content.readableBytes());
-        assertEquals(1, batch.size());
+        try (V2Batch batch = new V2Batch()) {
+            assertEquals(0, batch.size());
+            ByteBuf content = messageContents();
+            batch.addMessage(1, content, content.readableBytes());
+            assertEquals(1, batch.size());
+        }
     }
 
     @Test
-    public void TestGetProtocol() {
-        assertEquals(Protocol.VERSION_2, new V2Batch().getProtocol());
+    public void testGetProtocol() {
+        try (V2Batch batch = new V2Batch()) {
+            assertEquals(Protocol.VERSION_2, batch.getProtocol());
+        }
     }
 
     @Test
-    public void TestCompleteReturnTrueWhenIReceiveTheSameAmountOfEvent() {
-        V2Batch batch = new V2Batch();
-        int numberOfEvent = 2;
-
-        batch.setBatchSize(numberOfEvent);
-
-        for(int i = 1; i <= numberOfEvent; i++) {
-            ByteBuf content = messageContents();
-            batch.addMessage(i, content, content.readableBytes());
+    public void testCompleteReturnTrueWhenIReceiveTheSameAmountOfEvent() {
+        try (V2Batch batch = new V2Batch()) {
+            int numberOfEvent = 2;
+            batch.setBatchSize(numberOfEvent);
+            for (int i = 1; i <= numberOfEvent; i++) {
+                ByteBuf content = messageContents();
+                batch.addMessage(i, content, content.readableBytes());
+            }
+            assertTrue(batch.isComplete());
         }
-
-        assertTrue(batch.isComplete());
     }
 
     @Test
     public void testBigBatch() {
-        V2Batch batch = new V2Batch();
-        int size = 4096;
-        assertEquals(0, batch.size());
-        try {
+        try (V2Batch batch = new V2Batch()) {
+            int size = 4096;
+            assertEquals(0, batch.size());
             ByteBuf content = messageContents();
             for (int i = 0; i < size; i++) {
                 batch.addMessage(i, content, content.readableBytes());
@@ -71,8 +72,6 @@ public void testBigBatch() {
             for (Message message : batch) {
                 assertEquals(message.getSequence(), i++);
             }
-        }finally {
-            batch.release();
         }
     }
 
@@ -91,17 +90,15 @@ public void testHighSequence(){
         assertEquals(startSequenceNumber + numberOfEvent, batch.getHighestSequence());
     }
 
-
     @Test
-    public void TestCompleteReturnWhenTheNumberOfEventDoesntMatchBatchSize() {
-        V2Batch batch = new V2Batch();
-        int numberOfEvent = 2;
-
-        batch.setBatchSize(numberOfEvent);
-        ByteBuf content = messageContents();
-        batch.addMessage(1, content, content.readableBytes());
-
-        assertFalse(batch.isComplete());
+    public void testCompleteReturnWhenTheNumberOfEventDoesntMatchBatchSize() {
+        try (V2Batch batch = new V2Batch()) {
+            int numberOfEvent = 2;
+            batch.setBatchSize(numberOfEvent);
+            ByteBuf content = messageContents();
+            batch.addMessage(1, content, content.readableBytes());
+            assertFalse(batch.isComplete());
+        }
     }
 
     public static ByteBuf messageContents() {
@@ -114,4 +111,4 @@ public static ByteBuf messageContents() {
             throw new RuntimeException(e);
         }
     }
-}
+}