Eliminate the length argument for retrieving the ByteBuffer.

api/src/main/java/io/grpc/HasByteBuffer.java

@@ -32,10 +32,13 @@
 public interface HasByteBuffer {
 
   /**
-   * Gets a {@link ByteBuffer} containing up to {@code length} bytes of the content, or {@code
-   * null} if has reached end of the content.
-   * @param length the maximum number of bytes to contain in returned {@link ByteBuffer}.
+   * Gets a {@link ByteBuffer} containing some bytes of the content next to be read, or {@code
+   * null} if has reached end of the content. The number of bytes contained in the returned buffer
+   * is implementation specific. Calling this method does not change the position of the input
+   * stream. The returned buffer's content should not be modified, but the position, limit, and
+   * mark may be changed. Operations for changing the position, limit, and mark of the returned
+   * buffer does not affect the position, limit, and mark of this input stream.
    */
   @Nullable
-  ByteBuffer getByteBuffer(int length);
+  ByteBuffer getByteBuffer();
 }

core/src/main/java/io/grpc/internal/AbstractReadableBuffer.java

@@ -61,7 +61,7 @@ public boolean canUseByteBuffer() {
   }
 
   @Override
-  public ByteBuffer getByteBuffer(int length) {
+  public ByteBuffer getByteBuffer() {
     throw new UnsupportedOperationException();
   }
 

core/src/main/java/io/grpc/internal/CompositeReadableBuffer.java

@@ -207,12 +207,11 @@ public boolean canUseByteBuffer() {
 
   @Nullable
   @Override
-  public ByteBuffer getByteBuffer(int length) {
+  public ByteBuffer getByteBuffer() {
     if (readableBuffers.isEmpty()) {
       return null;
     }
-    ReadableBuffer buffer = readableBuffers.peek();
-    return buffer.getByteBuffer(Math.min(length, buffer.readableBytes()));
+    return readableBuffers.peek().getByteBuffer();
   }
 
   @Override

core/src/main/java/io/grpc/internal/ForwardingReadableBuffer.java

@@ -114,8 +114,8 @@ public boolean canUseByteBuffer() {
 
   @Nullable
   @Override
-  public ByteBuffer getByteBuffer(int length) {
-    return buf.getByteBuffer(length);
+  public ByteBuffer getByteBuffer() {
+    return buf.getByteBuffer();
   }
 
   @Override

core/src/main/java/io/grpc/internal/ReadableBuffer.java

@@ -143,19 +143,19 @@ public interface ReadableBuffer extends Closeable {
   boolean canUseByteBuffer();
 
   /**
-   * Gets a {@link ByteBuffer} that contains up to {@code length} bytes of this buffer's content,
-   * or {@code null} if this buffer has been exhausted. The position of this buffer is unchanged
-   * after calling this method. The returned buffer's content should not be modified, but the
-   * position, limit, and mark may be changed. Operations for changing the position, limit, and
-   * mark of the returned {@link ByteBuffer} does not affect the position, limit, and mark of
-   * this buffer. {@link ByteBuffer}s returned by this method have independent position, limit
-   * and mark. This is an optional method, so callers should first check {@link #canUseByteBuffer}.
+   * Gets a {@link ByteBuffer} that contains some bytes of the content next to be read, or {@code
+   * null} if this buffer has been exhausted. The number of bytes contained in the returned buffer
+   * is implementation specific. The position of this buffer is unchanged after calling this
+   * method. The returned buffer's content should not be modified, but the position, limit, and
+   * mark may be changed. Operations for changing the position, limit, and mark of the returned
+   * buffer does not affect the position, limit, and mark of this buffer. Buffers returned by this
+   * method have independent position, limit and mark. This is an optional method, so callers
+   * should first check {@link #canUseByteBuffer}.
    *
-   * @param length the maximum number of bytes to contain in returned {@link ByteBuffer}.
    * @throws UnsupportedOperationException the buffer does not support this method.
    */
   @Nullable
-  ByteBuffer getByteBuffer(int length);
+  ByteBuffer getByteBuffer();
 
   /**
    * Closes this buffer and releases any resources.

core/src/main/java/io/grpc/internal/ReadableBuffers.java

@@ -319,6 +319,16 @@ public void mark() {
     public void reset() {
       bytes.reset();
     }
+
+    @Override
+    public boolean canUseByteBuffer() {
+      return true;
+    }
+
+    @Override
+    public ByteBuffer getByteBuffer() {
+      return (ByteBuffer) bytes;
+    }
   }
 
   /**
@@ -397,8 +407,8 @@ private static class ByteBufferInputStream extends BufferInputStream implements
 
     @Nullable
     @Override
-    public ByteBuffer getByteBuffer(int length) {
-      return buffer.getByteBuffer(length);
+    public ByteBuffer getByteBuffer() {
+      return buffer.getByteBuffer();
     }
   }
 

netty/src/main/java/io/grpc/netty/NettyReadableBuffer.java

@@ -110,8 +110,8 @@ public boolean canUseByteBuffer() {
   }
 
   @Override
-  public ByteBuffer getByteBuffer(int length) {
-    return buffer.nioBuffers(buffer.readerIndex(), length)[0];
+  public ByteBuffer getByteBuffer() {
+    return buffer.nioBuffers()[0];
   }
 
   /**

protobuf-lite/src/main/java/io/grpc/protobuf/lite/ProtoLiteUtils.java

@@ -287,11 +287,7 @@ public boolean hasNext() {
             if (buffer != null) {
               return true;
             }
-            try {
-              buffer = ((HasByteBuffer) stream).getByteBuffer(stream.available());
-            } catch (IOException e) {
-              throw new RuntimeException(e);
-            }
+            buffer = ((HasByteBuffer) stream).getByteBuffer();
             return buffer != null;
           }