StreamBufferingEncoder.java — netty Source File

Source Code

/*
 * Copyright 2015 The Netty Project
 *
 * The Netty Project licenses this file to you 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:
 *
 * https://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 limitations under
 * the License.
 */

package io.netty.handler.codec.http2;

import io.netty.buffer.ByteBuf;
import io.netty.buffer.ByteBufUtil;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelPromise;
import io.netty.util.ReferenceCountUtil;

import java.util.ArrayDeque;
import java.util.Iterator;
import java.util.Map;
import java.util.Queue;
import java.util.TreeMap;

import static io.netty.handler.codec.http2.Http2CodecUtil.SMALLEST_MAX_CONCURRENT_STREAMS;
import static io.netty.handler.codec.http2.Http2Error.PROTOCOL_ERROR;
import static io.netty.handler.codec.http2.Http2Exception.connectionError;

/**
 * Implementation of a {@link Http2ConnectionEncoder} that dispatches all method call to another
 * {@link Http2ConnectionEncoder}, until {@code SETTINGS_MAX_CONCURRENT_STREAMS} is reached.
 * <p/>
 * <p>When this limit is hit, instead of rejecting any new streams this implementation buffers newly
 * created streams and their corresponding frames. Once an active stream gets closed or the maximum
 * number of concurrent streams is increased, this encoder will automatically try to empty its
 * buffer and create as many new streams as possible.
 * <p/>
 * <p>
 * If a {@code GOAWAY} frame is received from the remote endpoint, all buffered writes for streams
 * with an ID less than the specified {@code lastStreamId} will immediately fail with a
 * {@link Http2GoAwayException}.
 * <p/>
 * <p>
 * If the channel/encoder gets closed, all new and buffered writes will immediately fail with a
 * {@link Http2ChannelClosedException}.
 * </p>
 * <p>This implementation makes the buffering mostly transparent and is expected to be used as a
 * drop-in decorator of {@link DefaultHttp2ConnectionEncoder}.
 * </p>
 */
public class StreamBufferingEncoder extends DecoratingHttp2ConnectionEncoder {

    /**
     * Thrown if buffered streams are terminated due to this encoder being closed.
// ... (347 more lines)