//
// ========================================================================
// Copyright (c) 1995-2014 Mort Bay Consulting Pty. Ltd.
// ------------------------------------------------------------------------
// All rights reserved. This program and the accompanying materials
// are made available under the terms of the Eclipse Public License v1.0
// and Apache License v2.0 which accompanies this distribution.
//
// The Eclipse Public License is available at
// http://www.eclipse.org/legal/epl-v10.html
//
// The Apache License v2.0 is available at
// http://www.opensource.org/licenses/apache2.0.php
//
// You may elect to redistribute this code under either of these licenses.
// ========================================================================
//
package org.eclipse.jetty.http2.parser;
import java.nio.ByteBuffer;
import org.eclipse.jetty.http2.ErrorCodes;
import org.eclipse.jetty.http2.frames.PriorityFrame;
public class PriorityBodyParser extends BodyParser
{
private State state = State.PREPARE;
private int cursor;
private boolean exclusive;
private int streamId;
public PriorityBodyParser(HeaderParser headerParser, Parser.Listener listener)
{
super(headerParser, listener);
}
private void reset()
{
state = State.PREPARE;
cursor = 0;
exclusive = false;
streamId = 0;
}
@Override
public Result parse(ByteBuffer buffer)
{
while (buffer.hasRemaining())
{
switch (state)
{
case PREPARE:
{
// SPEC: wrong streamId is treated as connection error.
if (getStreamId() == 0)
{
return notifyConnectionFailure(ErrorCodes.PROTOCOL_ERROR, "invalid_priority_frame");
}
int length = getBodyLength();
if (length != 5)
{
return notifyConnectionFailure(ErrorCodes.FRAME_SIZE_ERROR, "invalid_priority_frame");
}
state = State.EXCLUSIVE;
break;
}
case EXCLUSIVE:
{
// We must only peek the first byte and not advance the buffer
// because the 31 least significant bits represent the stream id.
int currByte = buffer.get(buffer.position());
exclusive = (currByte & 0x80) == 0x80;
state = State.STREAM_ID;
break;
}
case STREAM_ID:
{
if (buffer.remaining() >= 4)
{
streamId = buffer.getInt();
streamId &= 0x7F_FF_FF_FF;
state = State.WEIGHT;
}
else
{
state = State.STREAM_ID_BYTES;
cursor = 4;
}
break;
}
case STREAM_ID_BYTES:
{
int currByte = buffer.get() & 0xFF;
--cursor;
streamId += currByte << (8 * cursor);
if (cursor == 0)
{
streamId &= 0x7F_FF_FF_FF;
state = State.WEIGHT;
}
break;
}
case WEIGHT:
{
int weight = buffer.get() & 0xFF;
return onPriority(streamId, weight, exclusive);
}
default:
{
throw new IllegalStateException();
}
}
}
return Result.PENDING;
}
private Result onPriority(int streamId, int weight, boolean exclusive)
{
PriorityFrame frame = new PriorityFrame(streamId, getStreamId(), weight, exclusive);
reset();
return notifyPriority(frame) ? Result.ASYNC : Result.COMPLETE;
}
private enum State
{
PREPARE, EXCLUSIVE, STREAM_ID, STREAM_ID_BYTES, WEIGHT
}
}