Merge pull request msgpack#459 from isopov/clear-position

add MessagePacker.clear() method to clear position

Author: xerial

msgpack-core/src/main/java/org/msgpack/core/MessageBufferPacker.java

@@ -56,11 +56,10 @@ private ArrayBufferOutput getArrayBufferOut()
         return (ArrayBufferOutput) out;
     }
 
-    /**
-     * Clears the written data.
-     */
+    @Override
     public void clear()
     {
+        super.clear();
         getArrayBufferOut().clear();
     }
 

msgpack-core/src/main/java/org/msgpack/core/MessagePacker.java

@@ -260,6 +260,14 @@ public long getTotalWrittenBytes()
         return totalFlushBytes + position;
     }
 
+    /**
+     * Clears the written data.
+     */
+    public void clear()
+    {
+        position = 0;
+    }
+
     /**
      * Flushes internal buffer to the underlying output.
      * <p>

msgpack-core/src/main/java/org/msgpack/core/buffer/ArrayBufferOutput.java

@@ -28,9 +28,9 @@
 public class ArrayBufferOutput
         implements MessageBufferOutput
 {
-    private List<MessageBuffer> list;
+    private final List<MessageBuffer> list;
+    private final int bufferSize;
     private MessageBuffer lastBuffer;
-    private int bufferSize;
 
     public ArrayBufferOutput()
     {

msgpack-core/src/test/scala/org/msgpack/core/MessageBufferPackerTest.scala

@@ -16,6 +16,7 @@
 package org.msgpack.core
 
 import java.io.ByteArrayOutputStream
+import java.util.Arrays
 
 import org.msgpack.value.ValueFactory._
 
@@ -32,5 +33,19 @@ class MessageBufferPackerTest extends MessagePackSpec {
 
       packer1.toByteArray shouldBe stream.toByteArray
     }
+
+    "clear unflushed" in {
+      val packer = MessagePack.newDefaultBufferPacker
+      packer.packInt(1);
+      packer.clear();
+      packer.packInt(2);
+
+      packer.toByteArray shouldBe Array(2)
+      val buffer = packer.toBufferList().get(0)
+      buffer.toByteArray() shouldBe Array(2)
+      val array = Arrays.copyOf(buffer.sliceAsByteBuffer().array(), buffer.size())
+      array shouldBe Array(2)
+    }
+
   }
 }