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 * Copyright 2014 Red Hat, Inc., and individual contributors
 * as indicated by the @author tags.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
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package io.undertow.protocols.http2;

import java.util.Deque;
import java.util.Iterator;
import java.util.List;

import io.undertow.UndertowLogger;
import io.undertow.server.protocol.framed.FramePriority;
import io.undertow.server.protocol.framed.SendFrameHeader;

TODO: real priority
Author:Stuart Douglas
/** * TODO: real priority * * @author Stuart Douglas */
class Http2FramePriority implements FramePriority<Http2Channel, AbstractHttp2StreamSourceChannel, AbstractHttp2StreamSinkChannel> { private int nextId; Http2FramePriority(int nextId) { this.nextId = nextId; } @Override public boolean insertFrame(AbstractHttp2StreamSinkChannel newFrame, List<AbstractHttp2StreamSinkChannel> pendingFrames) { //we need to deal with out of order streams //if multiple threads are creating streams they may not end up here in the correct order boolean incrementIfAccepted = false; if ((newFrame.getChannel().isClient() && newFrame instanceof Http2HeadersStreamSinkChannel) || newFrame instanceof Http2PushPromiseStreamSinkChannel) { if (newFrame instanceof Http2PushPromiseStreamSinkChannel) { int streamId = ((Http2PushPromiseStreamSinkChannel) newFrame).getStreamId(); if (streamId > nextId) { return false; } else if (streamId == nextId) { incrementIfAccepted = true; } } else { int streamId = ((Http2HeadersStreamSinkChannel) newFrame).getStreamId(); if (streamId > nextId) { return false; } else if (streamId == nextId) { incrementIfAccepted = true; } } } //first deal with flow control if (newFrame instanceof Http2StreamSinkChannel) { if (newFrame.isBroken() || !newFrame.isOpen()) { return true; //just quietly drop the frame } try { SendFrameHeader header = ((Http2StreamSinkChannel) newFrame).generateSendFrameHeader(); //if no header is generated then flow control means we can't send anything if (header.getByteBuffer() == null) { //we clear the header, as we want to generate a new real header when the flow control window is updated ((Http2StreamSinkChannel) newFrame).clearHeader(); return false; } } catch (Exception e) { UndertowLogger.REQUEST_LOGGER.debugf("Failed to generate header %s", newFrame); } } pendingFrames.add(newFrame); if (incrementIfAccepted) { nextId += 2; } return true; } @Override public void frameAdded(AbstractHttp2StreamSinkChannel addedFrame, List<AbstractHttp2StreamSinkChannel> pendingFrames, Deque<AbstractHttp2StreamSinkChannel> holdFrames) { Iterator<AbstractHttp2StreamSinkChannel> it = holdFrames.iterator(); while (it.hasNext()) { AbstractHttp2StreamSinkChannel pending = it.next(); boolean incrementNextId = false; if ((pending.getChannel().isClient() && pending instanceof Http2HeadersStreamSinkChannel) || pending instanceof Http2PushPromiseStreamSinkChannel) { if (pending instanceof Http2PushPromiseStreamSinkChannel) { int streamId = ((Http2PushPromiseStreamSinkChannel) pending).getStreamId(); if (streamId > nextId) { continue; } else if (streamId == nextId) { incrementNextId = true; } } else { int streamId = ((Http2HeadersStreamSinkChannel) pending).getStreamId(); if (streamId > nextId) { continue; } else if (streamId == nextId) { incrementNextId = true; } } } if (pending instanceof Http2StreamSinkChannel) { SendFrameHeader header = ((Http2StreamSinkChannel) pending).generateSendFrameHeader(); if (header.getByteBuffer() != null) { pendingFrames.add(pending); it.remove(); it = holdFrames.iterator(); if (incrementNextId) { nextId += 2; } } else { //we clear the header, as we want to generate a new real header when the flow control window is updated ((Http2StreamSinkChannel) pending).clearHeader(); } } } } }