| // |
| // ======================================================================== |
| // Copyright (c) 1995-2016 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.ErrorCode; |
| 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 parentStreamId; |
| |
| public PriorityBodyParser(HeaderParser headerParser, Parser.Listener listener) |
| { |
| super(headerParser, listener); |
| } |
| |
| private void reset() |
| { |
| state = State.PREPARE; |
| cursor = 0; |
| exclusive = false; |
| parentStreamId = 0; |
| } |
| |
| @Override |
| public boolean parse(ByteBuffer buffer) |
| { |
| while (buffer.hasRemaining()) |
| { |
| switch (state) |
| { |
| case PREPARE: |
| { |
| // SPEC: wrong streamId is treated as connection error. |
| if (getStreamId() == 0) |
| return connectionFailure(buffer, ErrorCode.PROTOCOL_ERROR.code, "invalid_priority_frame"); |
| int length = getBodyLength(); |
| if (length != 5) |
| return connectionFailure(buffer, ErrorCode.FRAME_SIZE_ERROR.code, "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.PARENT_STREAM_ID; |
| break; |
| } |
| case PARENT_STREAM_ID: |
| { |
| if (buffer.remaining() >= 4) |
| { |
| parentStreamId = buffer.getInt(); |
| parentStreamId &= 0x7F_FF_FF_FF; |
| state = State.WEIGHT; |
| } |
| else |
| { |
| state = State.PARENT_STREAM_ID_BYTES; |
| cursor = 4; |
| } |
| break; |
| } |
| case PARENT_STREAM_ID_BYTES: |
| { |
| int currByte = buffer.get() & 0xFF; |
| --cursor; |
| parentStreamId += currByte << (8 * cursor); |
| if (cursor == 0) |
| { |
| parentStreamId &= 0x7F_FF_FF_FF; |
| state = State.WEIGHT; |
| } |
| break; |
| } |
| case WEIGHT: |
| { |
| // SPEC: stream cannot depend on itself. |
| if (getStreamId() == parentStreamId) |
| return connectionFailure(buffer, ErrorCode.PROTOCOL_ERROR.code, "invalid_priority_frame"); |
| |
| int weight = (buffer.get() & 0xFF) + 1; |
| return onPriority(parentStreamId, weight, exclusive); |
| } |
| default: |
| { |
| throw new IllegalStateException(); |
| } |
| } |
| } |
| return false; |
| } |
| |
| private boolean onPriority(int parentStreamId, int weight, boolean exclusive) |
| { |
| PriorityFrame frame = new PriorityFrame(getStreamId(), parentStreamId, weight, exclusive); |
| reset(); |
| notifyPriority(frame); |
| return true; |
| } |
| |
| private enum State |
| { |
| PREPARE, EXCLUSIVE, PARENT_STREAM_ID, PARENT_STREAM_ID_BYTES, WEIGHT |
| } |
| } |