/*
* Copyright 2014 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:
*
* 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 limitations under
* the License.
*/
package io.netty.handler.codec.http2;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelFutureListener;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelPromise;
import io.netty.channel.CoalescingBufferQueue;
import io.netty.util.internal.UnstableApi;
import java.util.ArrayDeque;
import static io.netty.handler.codec.http2.Http2CodecUtil.DEFAULT_PRIORITY_WEIGHT;
import static io.netty.handler.codec.http2.Http2Error.PROTOCOL_ERROR;
import static io.netty.handler.codec.http2.Http2Exception.connectionError;
import static io.netty.util.internal.ObjectUtil.checkNotNull;
import static java.lang.Integer.MAX_VALUE;
import static java.lang.Math.min;
/**
* Default implementation of {@link Http2ConnectionEncoder}.
*/
@UnstableApi
public class DefaultHttp2ConnectionEncoder implements Http2ConnectionEncoder {
private final Http2FrameWriter frameWriter;
private final Http2Connection connection;
private Http2LifecycleManager lifecycleManager;
// We prefer ArrayDeque to LinkedList because later will produce more GC.
// This initial capacity is plenty for SETTINGS traffic.
private final ArrayDeque<Http2Settings> outstandingLocalSettingsQueue = new ArrayDeque<Http2Settings>(4);
public DefaultHttp2ConnectionEncoder(Http2Connection connection, Http2FrameWriter frameWriter) {
this.connection = checkNotNull(connection, "connection");
this.frameWriter = checkNotNull(frameWriter, "frameWriter");
if (connection.remote().flowController() == null) {
connection.remote().flowController(new DefaultHttp2RemoteFlowController(connection));
}
}
@Override
public void lifecycleManager(Http2LifecycleManager lifecycleManager) {
this.lifecycleManager = checkNotNull(lifecycleManager, "lifecycleManager");
}
@Override
public Http2FrameWriter frameWriter() {
return frameWriter;
}
@Override
public Http2Connection connection() {
return connection;
}
@Override
public final Http2RemoteFlowController flowController() {
return connection().remote().flowController();
}
@Override
public void remoteSettings(Http2Settings settings) throws Http2Exception {
Boolean pushEnabled = settings.pushEnabled();
Http2FrameWriter.Configuration config = configuration();
Http2HeadersEncoder.Configuration outboundHeaderConfig = config.headersConfiguration();
Http2FrameSizePolicy outboundFrameSizePolicy = config.frameSizePolicy();
if (pushEnabled != null) {
if (!connection.isServer() && pushEnabled) {
throw connectionError(PROTOCOL_ERROR,
"Client received a value of ENABLE_PUSH specified to other than 0");
}
connection.remote().allowPushTo(pushEnabled);
}
Long maxConcurrentStreams = settings.maxConcurrentStreams();
if (maxConcurrentStreams != null) {
connection.local().maxActiveStreams((int) min(maxConcurrentStreams, MAX_VALUE));
}
Long headerTableSize = settings.headerTableSize();
if (headerTableSize != null) {
outboundHeaderConfig.maxHeaderTableSize((int) min(headerTableSize, MAX_VALUE));
}
Long maxHeaderListSize = settings.maxHeaderListSize();
if (maxHeaderListSize != null) {
outboundHeaderConfig.maxHeaderListSize(maxHeaderListSize);
}
Integer maxFrameSize = settings.maxFrameSize();
if (maxFrameSize != null) {
outboundFrameSizePolicy.maxFrameSize(maxFrameSize);
}
Integer initialWindowSize = settings.initialWindowSize();
if (initialWindowSize != null) {
flowController().initialWindowSize(initialWindowSize);
}
}
@Override
public ChannelFuture writeData(final ChannelHandlerContext ctx, final int streamId, ByteBuf data, int padding,
final boolean endOfStream, ChannelPromise promise) {
final Http2Stream stream;
try {
stream = requireStream(streamId);
// Verify that the stream is in the appropriate state for sending DATA frames.
switch (stream.state()) {
case OPEN:
case HALF_CLOSED_REMOTE:
// Allowed sending DATA frames in these states.
break;
default:
throw new IllegalStateException(String.format(
"Stream %d in unexpected state: %s", stream.id(), stream.state()));
}
} catch (Throwable e) {
data.release();
return promise.setFailure(e);
}
// Hand control of the frame to the flow controller.
flowController().addFlowControlled(stream,
new FlowControlledData(stream, data, padding, endOfStream, promise));
return promise;
}
@Override
public ChannelFuture writeHeaders(ChannelHandlerContext ctx, int streamId, Http2Headers headers, int padding,
boolean endStream, ChannelPromise promise) {
return writeHeaders(ctx, streamId, headers, 0, DEFAULT_PRIORITY_WEIGHT, false, padding, endStream, promise);
}
@Override
public ChannelFuture writeHeaders(final ChannelHandlerContext ctx, final int streamId,
final Http2Headers headers, final int streamDependency, final short weight,
final boolean exclusive, final int padding, final boolean endOfStream, ChannelPromise promise) {
try {
Http2Stream stream = connection.stream(streamId);
if (stream == null) {
stream = connection.local().createStream(streamId, endOfStream);
} else {
switch (stream.state()) {
case RESERVED_LOCAL:
stream.open(endOfStream);
break;
case OPEN:
case HALF_CLOSED_REMOTE:
// Allowed sending headers in these states.
break;
default:
throw new IllegalStateException(String.format(
"Stream %d in unexpected state: %s", stream.id(), stream.state()));
}
}
// Trailing headers must go through flow control if there are other frames queued in flow control
// for this stream.
Http2RemoteFlowController flowController = flowController();
if (!endOfStream || !flowController.hasFlowControlled(stream)) {
if (endOfStream) {
final Http2Stream finalStream = stream;
final ChannelFutureListener closeStreamLocalListener = new ChannelFutureListener() {
@Override
public void operationComplete(ChannelFuture future) throws Exception {
lifecycleManager.closeStreamLocal(finalStream, future);
}
};
promise = promise.unvoid().addListener(closeStreamLocalListener);
}
ChannelFuture future = frameWriter.writeHeaders(ctx, streamId, headers, streamDependency,
weight, exclusive, padding, endOfStream, promise);
// Writing headers may fail during the encode state if they violate HPACK limits.
Throwable failureCause = future.cause();
if (failureCause == null) {
// Synchronously set the headersSent flag to ensure that we do not subsequently write
// other headers containing pseudo-header fields.
stream.headersSent();
} else {
lifecycleManager.onError(ctx, failureCause);
}
return future;
} else {
// Pass headers to the flow-controller so it can maintain their sequence relative to DATA frames.
flowController.addFlowControlled(stream,
new FlowControlledHeaders(stream, headers, streamDependency, weight, exclusive, padding,
true, promise));
return promise;
}
} catch (Throwable t) {
lifecycleManager.onError(ctx, t);
promise.tryFailure(t);
return promise;
}
}
@Override
public ChannelFuture writePriority(ChannelHandlerContext ctx, int streamId, int streamDependency, short weight,
boolean exclusive, ChannelPromise promise) {
return frameWriter.writePriority(ctx, streamId, streamDependency, weight, exclusive, promise);
}
@Override
public ChannelFuture writeRstStream(ChannelHandlerContext ctx, int streamId, long errorCode,
ChannelPromise promise) {
// Delegate to the lifecycle manager for proper updating of connection state.
return lifecycleManager.resetStream(ctx, streamId, errorCode, promise);
}
@Override
public ChannelFuture writeSettings(ChannelHandlerContext ctx, Http2Settings settings,
ChannelPromise promise) {
outstandingLocalSettingsQueue.add(settings);
try {
Boolean pushEnabled = settings.pushEnabled();
if (pushEnabled != null && connection.isServer()) {
throw connectionError(PROTOCOL_ERROR, "Server sending SETTINGS frame with ENABLE_PUSH specified");
}
} catch (Throwable e) {
return promise.setFailure(e);
}
return frameWriter.writeSettings(ctx, settings, promise);
}
@Override
public ChannelFuture writeSettingsAck(ChannelHandlerContext ctx, ChannelPromise promise) {
return frameWriter.writeSettingsAck(ctx, promise);
}
@Override
public ChannelFuture writePing(ChannelHandlerContext ctx, boolean ack, ByteBuf data, ChannelPromise promise) {
return frameWriter.writePing(ctx, ack, data, promise);
}
@Override
public ChannelFuture writePushPromise(ChannelHandlerContext ctx, int streamId, int promisedStreamId,
Http2Headers headers, int padding, ChannelPromise promise) {
try {
if (connection.goAwayReceived()) {
throw connectionError(PROTOCOL_ERROR, "Sending PUSH_PROMISE after GO_AWAY received.");
}
Http2Stream stream = requireStream(streamId);
// Reserve the promised stream.
connection.local().reservePushStream(promisedStreamId, stream);
ChannelFuture future = frameWriter.writePushPromise(ctx, streamId, promisedStreamId, headers, padding,
promise);
// Writing headers may fail during the encode state if they violate HPACK limits.
Throwable failureCause = future.cause();
if (failureCause == null) {
stream.pushPromiseSent();
} else {
lifecycleManager.onError(ctx, failureCause);
}
return future;
} catch (Throwable t) {
lifecycleManager.onError(ctx, t);
promise.tryFailure(t);
return promise;
}
}
@Override
public ChannelFuture writeGoAway(ChannelHandlerContext ctx, int lastStreamId, long errorCode, ByteBuf debugData,
ChannelPromise promise) {
return lifecycleManager.goAway(ctx, lastStreamId, errorCode, debugData, promise);
}
@Override
public ChannelFuture writeWindowUpdate(ChannelHandlerContext ctx, int streamId, int windowSizeIncrement,
ChannelPromise promise) {
return promise.setFailure(new UnsupportedOperationException("Use the Http2[Inbound|Outbound]FlowController" +
" objects to control window sizes"));
}
@Override
public ChannelFuture writeFrame(ChannelHandlerContext ctx, byte frameType, int streamId, Http2Flags flags,
ByteBuf payload, ChannelPromise promise) {
return frameWriter.writeFrame(ctx, frameType, streamId, flags, payload, promise);
}
@Override
public void close() {
frameWriter.close();
}
@Override
public Http2Settings pollSentSettings() {
return outstandingLocalSettingsQueue.poll();
}
@Override
public Configuration configuration() {
return frameWriter.configuration();
}
private Http2Stream requireStream(int streamId) {
Http2Stream stream = connection.stream(streamId);
if (stream == null) {
final String message;
if (connection.streamMayHaveExisted(streamId)) {
message = "Stream no longer exists: " + streamId;
} else {
message = "Stream does not exist: " + streamId;
}
throw new IllegalArgumentException(message);
}
return stream;
}
/**
* Wrap a DATA frame so it can be written subject to flow-control. Note that this implementation assumes it
* only writes padding once for the entire payload as opposed to writing it once per-frame. This makes the
* {@link #size} calculation deterministic thereby greatly simplifying the implementation.
* <p>
* If frame-splitting is required to fit within max-frame-size and flow-control constraints we ensure that
* the passed promise is not completed until last frame write.
* </p>
*/
private final class FlowControlledData extends FlowControlledBase {
private final CoalescingBufferQueue queue;
private int dataSize;
FlowControlledData(Http2Stream stream, ByteBuf buf, int padding, boolean endOfStream,
ChannelPromise promise) {
super(stream, padding, endOfStream, promise);
queue = new CoalescingBufferQueue(promise.channel());
queue.add(buf, promise);
dataSize = queue.readableBytes();
}
@Override
public int size() {
return dataSize + padding;
}
@Override
public void error(ChannelHandlerContext ctx, Throwable cause) {
queue.releaseAndFailAll(cause);
// Don't update dataSize because we need to ensure the size() method returns a consistent size even after
// error so we don't invalidate flow control when returning bytes to flow control.
lifecycleManager.onError(ctx, cause);
}
@Override
public void write(ChannelHandlerContext ctx, int allowedBytes) {
int queuedData = queue.readableBytes();
if (!endOfStream) {
if (queuedData == 0) {
// There's no need to write any data frames because there are only empty data frames in the queue
// and it is not end of stream yet. Just complete their promises by writing an empty buffer.
ChannelPromise writePromise = ctx.newPromise().addListener(this);
queue.remove(0, writePromise).release();
ctx.write(Unpooled.EMPTY_BUFFER, writePromise);
return;
}
if (allowedBytes == 0) {
return;
}
}
// Determine how much data to write.
int writableData = min(queuedData, allowedBytes);
ChannelPromise writePromise = ctx.newPromise().addListener(this);
ByteBuf toWrite = queue.remove(writableData, writePromise);
dataSize = queue.readableBytes();
// Determine how much padding to write.
int writablePadding = min(allowedBytes - writableData, padding);
padding -= writablePadding;
// Write the frame(s).
frameWriter().writeData(ctx, stream.id(), toWrite, writablePadding,
endOfStream && size() == 0, writePromise);
}
@Override
public boolean merge(ChannelHandlerContext ctx, Http2RemoteFlowController.FlowControlled next) {
FlowControlledData nextData;
if (FlowControlledData.class != next.getClass() ||
MAX_VALUE - (nextData = (FlowControlledData) next).size() < size()) {
return false;
}
nextData.queue.copyTo(queue);
dataSize = queue.readableBytes();
// Given that we're merging data into a frame it doesn't really make sense to accumulate padding.
padding = Math.max(padding, nextData.padding);
endOfStream = nextData.endOfStream;
return true;
}
}
/**
* Wrap headers so they can be written subject to flow-control. While headers do not have cost against the
* flow-control window their order with respect to other frames must be maintained, hence if a DATA frame is
* blocked on flow-control a HEADER frame must wait until this frame has been written.
*/
private final class FlowControlledHeaders extends FlowControlledBase {
private final Http2Headers headers;
private final int streamDependency;
private final short weight;
private final boolean exclusive;
FlowControlledHeaders(Http2Stream stream, Http2Headers headers, int streamDependency, short weight,
boolean exclusive, int padding, boolean endOfStream, ChannelPromise promise) {
super(stream, padding, endOfStream, promise);
this.headers = headers;
this.streamDependency = streamDependency;
this.weight = weight;
this.exclusive = exclusive;
}
@Override
public int size() {
return 0;
}
@Override
public void error(ChannelHandlerContext ctx, Throwable cause) {
if (ctx != null) {
lifecycleManager.onError(ctx, cause);
}
promise.tryFailure(cause);
}
@Override
public void write(ChannelHandlerContext ctx, int allowedBytes) {
if (promise.isVoid()) {
promise = ctx.newPromise();
}
promise.addListener(this);
ChannelFuture f = frameWriter.writeHeaders(ctx, stream.id(), headers, streamDependency, weight, exclusive,
padding, endOfStream, promise);
// Writing headers may fail during the encode state if they violate HPACK limits.
Throwable failureCause = f.cause();
if (failureCause == null) {
stream.headersSent();
} else {
lifecycleManager.onError(ctx, failureCause);
}
}
@Override
public boolean merge(ChannelHandlerContext ctx, Http2RemoteFlowController.FlowControlled next) {
return false;
}
}
/**
* Common base type for payloads to deliver via flow-control.
*/
public abstract class FlowControlledBase implements Http2RemoteFlowController.FlowControlled,
ChannelFutureListener {
protected final Http2Stream stream;
protected ChannelPromise promise;
protected boolean endOfStream;
protected int padding;
FlowControlledBase(final Http2Stream stream, int padding, boolean endOfStream,
final ChannelPromise promise) {
if (padding < 0) {
throw new IllegalArgumentException("padding must be >= 0");
}
this.padding = padding;
this.endOfStream = endOfStream;
this.stream = stream;
this.promise = promise;
}
@Override
public void writeComplete() {
if (endOfStream) {
lifecycleManager.closeStreamLocal(stream, promise);
}
}
@Override
public void operationComplete(ChannelFuture future) throws Exception {
if (!future.isSuccess()) {
error(flowController().channelHandlerContext(), future.cause());
}
}
}
}