Method readProtobuf

src/HBaseRpc.java:1123–1145

De-serializes a protobuf from the given buffer. The protobuf is assumed to be prefixed by a varint indicating its size. @param buf The buffer to de-serialize the protobuf from. @param parser The protobuf parser to use for this type of protobuf. @return An instance of the de-serialized type. @thr

(final ChannelBuffer buf, final Parser<T> parser)

   * protobuf that couldn't be de-serialized.
   */
  static <T> T readProtobuf(final ChannelBuffer buf, final Parser<T> parser) {
    final int length = HBaseRpc.readProtoBufVarint(buf);
    HBaseRpc.checkArrayLength(buf, length);
    final byte[] payload;
    final int offset;
    if (buf.hasArray()) {  // Zero copy.
      payload = buf.array();
      offset = buf.arrayOffset() + buf.readerIndex();
      buf.readerIndex(buf.readerIndex() + length);
    } else {  // We have to copy the entire payload out of the buffer :(
      payload = new byte[length];
      buf.readBytes(payload);
      offset = 0;
    }
    try {
      return parser.parseFrom(payload, offset, length);
    } catch (InvalidProtocolBufferException e) {
      final String msg = "Invalid RPC response: length=" + length
        + ", payload=" + Bytes.pretty(payload);
      LOG.error("Invalid RPC from buffer: " + buf);
      throw new InvalidResponseException(msg, e);
    }
  }

  // -------------------------------------- //
  // Variable-length integer value encoding //