UniformStreamByteDistributor.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 java.util.ArrayDeque;
import java.util.Deque;

import static io.netty.handler.codec.http2.Http2CodecUtil.DEFAULT_MIN_ALLOCATION_CHUNK;
import static io.netty.handler.codec.http2.Http2CodecUtil.streamableBytes;
import static io.netty.handler.codec.http2.Http2Error.INTERNAL_ERROR;
import static io.netty.handler.codec.http2.Http2Exception.connectionError;
import static io.netty.util.internal.ObjectUtil.checkNotNull;
import static io.netty.util.internal.ObjectUtil.checkPositive;
import static java.lang.Math.max;
import static java.lang.Math.min;

/**
 * A {@link StreamByteDistributor} that ignores stream priority and uniformly allocates bytes to all
 * streams. This class uses a minimum chunk size that will be allocated to each stream. While
 * fewer streams may be written to in each call to {@link #distribute(int, Writer)}, doing this
 * should improve the goodput on each written stream.
 */
public final class UniformStreamByteDistributor implements StreamByteDistributor {
    private final Http2Connection.PropertyKey stateKey;
    private final Deque<State> queue = new ArrayDeque<State>(4);

    /**
     * The minimum number of bytes that we will attempt to allocate to a stream. This is to
     * help improve goodput on a per-stream basis.
     */
    private int minAllocationChunk = DEFAULT_MIN_ALLOCATION_CHUNK;
    private long totalStreamableBytes;

    public UniformStreamByteDistributor(Http2Connection connection) {
        // Add a state for the connection.
        stateKey = connection.newKey();
        Http2Stream connectionStream = connection.connectionStream();
        connectionStream.setProperty(stateKey, new State(connectionStream));

        // Register for notification of new streams.
        connection.addListener(new Http2ConnectionAdapter() {
            @Override
            public void onStreamAdded(Http2Stream stream) {
                stream.setProperty(stateKey, new State(stream));
            }

            @Override
            public void onStreamClosed(Http2Stream stream) {
// ... (143 more lines)