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io.netty.handler.codec.spdy.SpdySessionHandler Maven / Gradle / Ivy
/*
* Copyright 2012 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.spdy;
import io.netty.buffer.MessageBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelDuplexHandler;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelFutureListener;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundMessageHandler;
import io.netty.channel.ChannelOutboundMessageHandler;
import io.netty.channel.ChannelPromise;
import java.util.concurrent.atomic.AtomicInteger;
/**
* Manages streams within a SPDY session.
*/
public class SpdySessionHandler
extends ChannelDuplexHandler
implements ChannelInboundMessageHandler, ChannelOutboundMessageHandler {
private static final SpdyProtocolException PROTOCOL_EXCEPTION = new SpdyProtocolException();
private static final SpdyProtocolException STREAM_CLOSED = new SpdyProtocolException("Stream closed");
static {
@SuppressWarnings("ZeroLengthArrayAllocation")
StackTraceElement[] emptyTrace = new StackTraceElement[0];
PROTOCOL_EXCEPTION.setStackTrace(emptyTrace);
STREAM_CLOSED.setStackTrace(emptyTrace);
}
private final SpdySession spdySession = new SpdySession();
private volatile int lastGoodStreamId;
private volatile int remoteConcurrentStreams;
private volatile int localConcurrentStreams;
private volatile int maxConcurrentStreams;
private static final int DEFAULT_WINDOW_SIZE = 64 * 1024; // 64 KB default initial window size
private volatile int initialSendWindowSize = DEFAULT_WINDOW_SIZE;
private volatile int initialReceiveWindowSize = DEFAULT_WINDOW_SIZE;
private final Object flowControlLock = new Object();
private final AtomicInteger pings = new AtomicInteger();
private volatile boolean sentGoAwayFrame;
private volatile boolean receivedGoAwayFrame;
private volatile ChannelPromise closeSessionFuture;
private final boolean server;
private final boolean flowControl;
/**
* Creates a new session handler.
*
* @param version the protocol version
* @param server {@code true} if and only if this session handler should
* handle the server endpoint of the connection.
* {@code false} if and only if this session handler should
* handle the client endpoint of the connection.
*/
public SpdySessionHandler(int version, boolean server) {
if (version < SpdyConstants.SPDY_MIN_VERSION || version > SpdyConstants.SPDY_MAX_VERSION) {
throw new IllegalArgumentException(
"unsupported version: " + version);
}
this.server = server;
flowControl = version >= 3;
}
@Override
public MessageBuf newInboundBuffer(ChannelHandlerContext ctx) throws Exception {
return Unpooled.messageBuffer();
}
@Override
public void freeInboundBuffer(ChannelHandlerContext ctx) throws Exception {
ctx.inboundMessageBuffer().release();
}
@Override
public MessageBuf newOutboundBuffer(ChannelHandlerContext ctx) throws Exception {
return Unpooled.messageBuffer();
}
@Override
public void freeOutboundBuffer(ChannelHandlerContext ctx) throws Exception {
ctx.outboundMessageBuffer().release();
}
@Override
public void inboundBufferUpdated(ChannelHandlerContext ctx) throws Exception {
MessageBuf in = ctx.inboundMessageBuffer();
boolean handled = false;
for (;;) {
Object msg = in.poll();
if (msg == null) {
break;
}
if (msg instanceof SpdySynStreamFrame) {
// Let the next handlers handle the buffered messages before SYN_STREAM message updates the
// lastGoodStreamId.
if (handled) {
ctx.fireInboundBufferUpdated();
}
}
handleInboundMessage(ctx, msg);
handled = true;
}
ctx.fireInboundBufferUpdated();
}
private void handleInboundMessage(ChannelHandlerContext ctx, Object msg) throws Exception {
if (msg instanceof SpdyDataFrame) {
/*
* SPDY Data frame processing requirements:
*
* If an endpoint receives a data frame for a Stream-ID which is not open
* and the endpoint has not sent a GOAWAY frame, it must issue a stream error
* with the error code INVALID_STREAM for the Stream-ID.
*
* If an endpoint which created the stream receives a data frame before receiving
* a SYN_REPLY on that stream, it is a protocol error, and the recipient must
* issue a stream error with the getStatus code PROTOCOL_ERROR for the Stream-ID.
*
* If an endpoint receives multiple data frames for invalid Stream-IDs,
* it may close the session.
*
* If an endpoint refuses a stream it must ignore any data frames for that stream.
*
* If an endpoint receives a data frame after the stream is half-closed from the
* sender, it must send a RST_STREAM frame with the getStatus STREAM_ALREADY_CLOSED.
*
* If an endpoint receives a data frame after the stream is closed, it must send
* a RST_STREAM frame with the getStatus PROTOCOL_ERROR.
*/
SpdyDataFrame spdyDataFrame = (SpdyDataFrame) msg;
int streamID = spdyDataFrame.getStreamId();
// Check if we received a data frame for a Stream-ID which is not open
if (!spdySession.isActiveStream(streamID)) {
if (streamID <= lastGoodStreamId) {
issueStreamError(ctx, streamID, SpdyStreamStatus.PROTOCOL_ERROR);
} else if (!sentGoAwayFrame) {
issueStreamError(ctx, streamID, SpdyStreamStatus.INVALID_STREAM);
}
return;
}
// Check if we received a data frame for a stream which is half-closed
if (spdySession.isRemoteSideClosed(streamID)) {
issueStreamError(ctx, streamID, SpdyStreamStatus.STREAM_ALREADY_CLOSED);
return;
}
// Check if we received a data frame before receiving a SYN_REPLY
if (!isRemoteInitiatedID(streamID) && !spdySession.hasReceivedReply(streamID)) {
issueStreamError(ctx, streamID, SpdyStreamStatus.PROTOCOL_ERROR);
return;
}
/*
* SPDY Data frame flow control processing requirements:
*
* Recipient should not send a WINDOW_UPDATE frame as it consumes the last data frame.
*/
if (flowControl) {
// Update receive window size
int deltaWindowSize = -1 * spdyDataFrame.data().readableBytes();
int newWindowSize = spdySession.updateReceiveWindowSize(streamID, deltaWindowSize);
// Window size can become negative if we sent a SETTINGS frame that reduces the
// size of the transfer window after the peer has written data frames.
// The value is bounded by the length that SETTINGS frame decrease the window.
// This difference is stored for the session when writing the SETTINGS frame
// and is cleared once we send a WINDOW_UPDATE frame.
if (newWindowSize < spdySession.getReceiveWindowSizeLowerBound(streamID)) {
issueStreamError(ctx, streamID, SpdyStreamStatus.FLOW_CONTROL_ERROR);
return;
}
// Window size became negative due to sender writing frame before receiving SETTINGS
// Send data frames upstream in initialReceiveWindowSize chunks
if (newWindowSize < 0) {
while (spdyDataFrame.data().readableBytes() > initialReceiveWindowSize) {
SpdyDataFrame partialDataFrame = new DefaultSpdyDataFrame(streamID,
spdyDataFrame.data().readSlice(initialReceiveWindowSize));
ctx.nextOutboundMessageBuffer().add(partialDataFrame);
ctx.flush();
}
}
// Send a WINDOW_UPDATE frame if less than half the window size remains
if (newWindowSize <= initialReceiveWindowSize / 2 && !spdyDataFrame.isLast()) {
deltaWindowSize = initialReceiveWindowSize - newWindowSize;
spdySession.updateReceiveWindowSize(streamID, deltaWindowSize);
SpdyWindowUpdateFrame spdyWindowUpdateFrame =
new DefaultSpdyWindowUpdateFrame(streamID, deltaWindowSize);
ctx.write(spdyWindowUpdateFrame);
}
}
// Close the remote side of the stream if this is the last frame
if (spdyDataFrame.isLast()) {
halfCloseStream(streamID, true);
}
} else if (msg instanceof SpdySynStreamFrame) {
/*
* SPDY SYN_STREAM frame processing requirements:
*
* If an endpoint receives a SYN_STREAM with a Stream-ID that is less than
* any previously received SYN_STREAM, it must issue a session error with
* the getStatus PROTOCOL_ERROR.
*
* If an endpoint receives multiple SYN_STREAM frames with the same active
* Stream-ID, it must issue a stream error with the getStatus code PROTOCOL_ERROR.
*
* The recipient can reject a stream by sending a stream error with the
* getStatus code REFUSED_STREAM.
*/
SpdySynStreamFrame spdySynStreamFrame = (SpdySynStreamFrame) msg;
int streamID = spdySynStreamFrame.getStreamId();
// Check if we received a valid SYN_STREAM frame
if (spdySynStreamFrame.isInvalid() ||
!isRemoteInitiatedID(streamID) ||
spdySession.isActiveStream(streamID)) {
issueStreamError(ctx, streamID, SpdyStreamStatus.PROTOCOL_ERROR);
return;
}
// Stream-IDs must be monotonically increasing
if (streamID <= lastGoodStreamId) {
issueSessionError(ctx, SpdySessionStatus.PROTOCOL_ERROR);
return;
}
// Try to accept the stream
byte priority = spdySynStreamFrame.getPriority();
boolean remoteSideClosed = spdySynStreamFrame.isLast();
boolean localSideClosed = spdySynStreamFrame.isUnidirectional();
if (!acceptStream(streamID, priority, remoteSideClosed, localSideClosed)) {
issueStreamError(ctx, streamID, SpdyStreamStatus.REFUSED_STREAM);
return;
}
} else if (msg instanceof SpdySynReplyFrame) {
/*
* SPDY SYN_REPLY frame processing requirements:
*
* If an endpoint receives multiple SYN_REPLY frames for the same active Stream-ID
* it must issue a stream error with the getStatus code STREAM_IN_USE.
*/
SpdySynReplyFrame spdySynReplyFrame = (SpdySynReplyFrame) msg;
int streamID = spdySynReplyFrame.getStreamId();
// Check if we received a valid SYN_REPLY frame
if (spdySynReplyFrame.isInvalid() ||
isRemoteInitiatedID(streamID) ||
spdySession.isRemoteSideClosed(streamID)) {
issueStreamError(ctx, streamID, SpdyStreamStatus.INVALID_STREAM);
return;
}
// Check if we have received multiple frames for the same Stream-ID
if (spdySession.hasReceivedReply(streamID)) {
issueStreamError(ctx, streamID, SpdyStreamStatus.STREAM_IN_USE);
return;
}
spdySession.receivedReply(streamID);
// Close the remote side of the stream if this is the last frame
if (spdySynReplyFrame.isLast()) {
halfCloseStream(streamID, true);
}
} else if (msg instanceof SpdyRstStreamFrame) {
/*
* SPDY RST_STREAM frame processing requirements:
*
* After receiving a RST_STREAM on a stream, the receiver must not send
* additional frames on that stream.
*
* An endpoint must not send a RST_STREAM in response to a RST_STREAM.
*/
SpdyRstStreamFrame spdyRstStreamFrame = (SpdyRstStreamFrame) msg;
removeStream(ctx, spdyRstStreamFrame.getStreamId());
} else if (msg instanceof SpdySettingsFrame) {
SpdySettingsFrame spdySettingsFrame = (SpdySettingsFrame) msg;
int newConcurrentStreams =
spdySettingsFrame.getValue(SpdySettingsFrame.SETTINGS_MAX_CONCURRENT_STREAMS);
if (newConcurrentStreams >= 0) {
updateConcurrentStreams(newConcurrentStreams, true);
}
// Persistence flag are inconsistent with the use of SETTINGS to communicate
// the initial window size. Remove flags from the sender requesting that the
// value be persisted. Remove values that the sender indicates are persisted.
if (spdySettingsFrame.isPersisted(SpdySettingsFrame.SETTINGS_INITIAL_WINDOW_SIZE)) {
spdySettingsFrame.removeValue(SpdySettingsFrame.SETTINGS_INITIAL_WINDOW_SIZE);
}
spdySettingsFrame.setPersistValue(SpdySettingsFrame.SETTINGS_INITIAL_WINDOW_SIZE, false);
if (flowControl) {
int newInitialWindowSize =
spdySettingsFrame.getValue(SpdySettingsFrame.SETTINGS_INITIAL_WINDOW_SIZE);
if (newInitialWindowSize >= 0) {
updateInitialSendWindowSize(newInitialWindowSize);
}
}
} else if (msg instanceof SpdyPingFrame) {
/*
* SPDY PING frame processing requirements:
*
* Receivers of a PING frame should send an identical frame to the sender
* as soon as possible.
*
* Receivers of a PING frame must ignore frames that it did not initiate
*/
SpdyPingFrame spdyPingFrame = (SpdyPingFrame) msg;
if (isRemoteInitiatedID(spdyPingFrame.getId())) {
ctx.write(spdyPingFrame);
return;
}
// Note: only checks that there are outstanding pings since uniqueness is not enforced
if (pings.get() == 0) {
return;
}
pings.getAndDecrement();
} else if (msg instanceof SpdyGoAwayFrame) {
receivedGoAwayFrame = true;
} else if (msg instanceof SpdyHeadersFrame) {
SpdyHeadersFrame spdyHeadersFrame = (SpdyHeadersFrame) msg;
int streamID = spdyHeadersFrame.getStreamId();
// Check if we received a valid HEADERS frame
if (spdyHeadersFrame.isInvalid()) {
issueStreamError(ctx, streamID, SpdyStreamStatus.PROTOCOL_ERROR);
return;
}
if (spdySession.isRemoteSideClosed(streamID)) {
issueStreamError(ctx, streamID, SpdyStreamStatus.INVALID_STREAM);
return;
}
// Close the remote side of the stream if this is the last frame
if (spdyHeadersFrame.isLast()) {
halfCloseStream(streamID, true);
}
} else if (msg instanceof SpdyWindowUpdateFrame) {
/*
* SPDY WINDOW_UPDATE frame processing requirements:
*
* Receivers of a WINDOW_UPDATE that cause the window size to exceed 2^31
* must send a RST_STREAM with the getStatus code FLOW_CONTROL_ERROR.
*
* Sender should ignore all WINDOW_UPDATE frames associated with a stream
* after sending the last frame for the stream.
*/
if (flowControl) {
SpdyWindowUpdateFrame spdyWindowUpdateFrame = (SpdyWindowUpdateFrame) msg;
int streamID = spdyWindowUpdateFrame.getStreamId();
int deltaWindowSize = spdyWindowUpdateFrame.getDeltaWindowSize();
// Ignore frames for half-closed streams
if (spdySession.isLocalSideClosed(streamID)) {
return;
}
// Check for numerical overflow
if (spdySession.getSendWindowSize(streamID) > Integer.MAX_VALUE - deltaWindowSize) {
issueStreamError(ctx, streamID, SpdyStreamStatus.FLOW_CONTROL_ERROR);
return;
}
updateSendWindowSize(ctx, streamID, deltaWindowSize);
}
}
ctx.nextInboundMessageBuffer().add(msg);
}
@Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
if (cause instanceof SpdyProtocolException) {
issueSessionError(ctx, SpdySessionStatus.PROTOCOL_ERROR);
}
super.exceptionCaught(ctx, cause);
}
@Override
public void close(ChannelHandlerContext ctx, ChannelPromise promise) throws Exception {
sendGoAwayFrame(ctx, promise);
}
@Override
public void flush(ChannelHandlerContext ctx, ChannelPromise promise) throws Exception {
MessageBuf in = ctx.outboundMessageBuffer();
for (;;) {
Object msg = in.poll();
if (msg == null) {
break;
}
if (msg instanceof SpdyDataFrame ||
msg instanceof SpdySynStreamFrame ||
msg instanceof SpdySynReplyFrame ||
msg instanceof SpdyRstStreamFrame ||
msg instanceof SpdySettingsFrame ||
msg instanceof SpdyPingFrame ||
msg instanceof SpdyGoAwayFrame ||
msg instanceof SpdyHeadersFrame ||
msg instanceof SpdyWindowUpdateFrame) {
handleOutboundMessage(ctx, msg);
} else {
ctx.nextOutboundMessageBuffer().add(msg);
}
}
ctx.flush(promise);
}
private void handleOutboundMessage(ChannelHandlerContext ctx, Object msg)
throws Exception {
if (msg instanceof SpdyDataFrame) {
SpdyDataFrame spdyDataFrame = (SpdyDataFrame) msg;
final int streamID = spdyDataFrame.getStreamId();
// Frames must not be sent on half-closed streams
if (spdySession.isLocalSideClosed(streamID)) {
ctx.fireExceptionCaught(PROTOCOL_EXCEPTION);
return;
}
/*
* SPDY Data frame flow control processing requirements:
*
* Sender must not send a data frame with data length greater
* than the transfer window size.
*
* After sending each data frame, the sender decrements its
* transfer window size by the amount of data transmitted.
*
* When the window size becomes less than or equal to 0, the
* sender must pause transmitting data frames.
*/
if (flowControl) {
synchronized (flowControlLock) {
int dataLength = spdyDataFrame.data().readableBytes();
int sendWindowSize = spdySession.getSendWindowSize(streamID);
if (sendWindowSize >= dataLength) {
// Window size is large enough to send entire data frame
spdySession.updateSendWindowSize(streamID, -1 * dataLength);
// The transfer window size is pre-decremented when sending a data frame downstream.
// Close the stream on write failures that leaves the transfer window in a corrupt state.
//
// This is never sent because on write failure the connection will be closed
// immediately. Commenting out just in case I misunderstood it - T
//
//final ChannelHandlerContext context = ctx;
//e.getFuture().addListener(new ChannelFutureListener() {
// @Override
// public void operationComplete(ChannelFuture future) throws Exception {
// if (!future.isSuccess()) {
// issueStreamError(context, streamID, SpdyStreamStatus.INTERNAL_ERROR);
// }
// }
//});
} else if (sendWindowSize > 0) {
// Stream is not stalled but we cannot send the entire frame
spdySession.updateSendWindowSize(streamID, -1 * sendWindowSize);
// Create a partial data frame whose length is the current window size
SpdyDataFrame partialDataFrame = new DefaultSpdyDataFrame(streamID,
spdyDataFrame.data().readSlice(sendWindowSize));
// Enqueue the remaining data (will be the first frame queued)
spdySession.putPendingWrite(streamID, spdyDataFrame);
// The transfer window size is pre-decremented when sending a data frame downstream.
// Close the stream on write failures that leaves the transfer window in a corrupt state.
//
// This is never sent because on write failure the connection will be closed
// immediately. Commenting out just in case I misunderstood it - T
//
//final SocketAddress remoteAddress = e.getRemoteAddress();
//final ChannelHandlerContext context = ctx;
//e.getFuture().addListener(new ChannelFutureListener() {
// @Override
// public void operationComplete(ChannelFuture future) throws Exception {
// if (!future.isSuccess()) {
// issueStreamError(context, streamID, SpdyStreamStatus.INTERNAL_ERROR);
// }
// }
//});
ctx.nextOutboundMessageBuffer().add(partialDataFrame);
return;
} else {
// Stream is stalled -- enqueue Data frame and return
spdySession.putPendingWrite(streamID, spdyDataFrame);
return;
}
}
}
// Close the local side of the stream if this is the last frame
if (spdyDataFrame.isLast()) {
halfCloseStream(streamID, false);
}
} else if (msg instanceof SpdySynStreamFrame) {
SpdySynStreamFrame spdySynStreamFrame = (SpdySynStreamFrame) msg;
int streamID = spdySynStreamFrame.getStreamId();
if (isRemoteInitiatedID(streamID)) {
ctx.fireExceptionCaught(PROTOCOL_EXCEPTION);
return;
}
byte priority = spdySynStreamFrame.getPriority();
boolean remoteSideClosed = spdySynStreamFrame.isUnidirectional();
boolean localSideClosed = spdySynStreamFrame.isLast();
if (!acceptStream(streamID, priority, remoteSideClosed, localSideClosed)) {
ctx.fireExceptionCaught(PROTOCOL_EXCEPTION);
return;
}
} else if (msg instanceof SpdySynReplyFrame) {
SpdySynReplyFrame spdySynReplyFrame = (SpdySynReplyFrame) msg;
int streamID = spdySynReplyFrame.getStreamId();
// Frames must not be sent on half-closed streams
if (!isRemoteInitiatedID(streamID) || spdySession.isLocalSideClosed(streamID)) {
ctx.fireExceptionCaught(PROTOCOL_EXCEPTION);
return;
}
// Close the local side of the stream if this is the last frame
if (spdySynReplyFrame.isLast()) {
halfCloseStream(streamID, false);
}
} else if (msg instanceof SpdyRstStreamFrame) {
SpdyRstStreamFrame spdyRstStreamFrame = (SpdyRstStreamFrame) msg;
removeStream(ctx, spdyRstStreamFrame.getStreamId());
} else if (msg instanceof SpdySettingsFrame) {
SpdySettingsFrame spdySettingsFrame = (SpdySettingsFrame) msg;
int newConcurrentStreams =
spdySettingsFrame.getValue(SpdySettingsFrame.SETTINGS_MAX_CONCURRENT_STREAMS);
if (newConcurrentStreams >= 0) {
updateConcurrentStreams(newConcurrentStreams, false);
}
// Persistence flag are inconsistent with the use of SETTINGS to communicate
// the initial window size. Remove flags from the sender requesting that the
// value be persisted. Remove values that the sender indicates are persisted.
if (spdySettingsFrame.isPersisted(SpdySettingsFrame.SETTINGS_INITIAL_WINDOW_SIZE)) {
spdySettingsFrame.removeValue(SpdySettingsFrame.SETTINGS_INITIAL_WINDOW_SIZE);
}
spdySettingsFrame.setPersistValue(SpdySettingsFrame.SETTINGS_INITIAL_WINDOW_SIZE, false);
if (flowControl) {
int newInitialWindowSize =
spdySettingsFrame.getValue(SpdySettingsFrame.SETTINGS_INITIAL_WINDOW_SIZE);
if (newInitialWindowSize >= 0) {
updateInitialReceiveWindowSize(newInitialWindowSize);
}
}
} else if (msg instanceof SpdyPingFrame) {
SpdyPingFrame spdyPingFrame = (SpdyPingFrame) msg;
if (isRemoteInitiatedID(spdyPingFrame.getId())) {
ctx.fireExceptionCaught(new IllegalArgumentException(
"invalid PING ID: " + spdyPingFrame.getId()));
return;
}
pings.getAndIncrement();
} else if (msg instanceof SpdyGoAwayFrame) {
// Why is this being sent? Intercept it and fail the write.
// Should have sent a CLOSE ChannelStateEvent
ctx.fireExceptionCaught(PROTOCOL_EXCEPTION);
return;
} else if (msg instanceof SpdyHeadersFrame) {
SpdyHeadersFrame spdyHeadersFrame = (SpdyHeadersFrame) msg;
int streamID = spdyHeadersFrame.getStreamId();
// Frames must not be sent on half-closed streams
if (spdySession.isLocalSideClosed(streamID)) {
ctx.fireExceptionCaught(PROTOCOL_EXCEPTION);
return;
}
// Close the local side of the stream if this is the last frame
if (spdyHeadersFrame.isLast()) {
halfCloseStream(streamID, false);
}
} else if (msg instanceof SpdyWindowUpdateFrame) {
// Why is this being sent? Intercept it and fail the write.
ctx.fireExceptionCaught(PROTOCOL_EXCEPTION);
}
ctx.nextOutboundMessageBuffer().add(msg);
}
/*
* SPDY Session Error Handling:
*
* When a session error occurs, the endpoint encountering the error must first
* send a GOAWAY frame with the Stream-ID of the most recently received stream
* from the remote endpoint, and the error code for why the session is terminating.
*
* After sending the GOAWAY frame, the endpoint must close the TCP connection.
*/
private void issueSessionError(
ChannelHandlerContext ctx, SpdySessionStatus status) {
sendGoAwayFrame(ctx, status);
ctx.flush().addListener(ChannelFutureListener.CLOSE);
}
/*
* SPDY Stream Error Handling:
*
* Upon a stream error, the endpoint must send a RST_STREAM frame which contains
* the Stream-ID for the stream where the error occurred and the error getStatus which
* caused the error.
*
* After sending the RST_STREAM, the stream is closed to the sending endpoint.
*
* Note: this is only called by the worker thread
*/
private void issueStreamError(
ChannelHandlerContext ctx, int streamID, SpdyStreamStatus status) {
boolean fireMessageReceived = !spdySession.isRemoteSideClosed(streamID);
removeStream(ctx, streamID);
SpdyRstStreamFrame spdyRstStreamFrame = new DefaultSpdyRstStreamFrame(streamID, status);
ctx.write(spdyRstStreamFrame);
if (fireMessageReceived) {
ctx.nextInboundMessageBuffer().add(spdyRstStreamFrame);
ctx.fireInboundBufferUpdated();
}
}
/*
* Helper functions
*/
private boolean isRemoteInitiatedID(int id) {
boolean serverID = SpdyCodecUtil.isServerId(id);
return server && !serverID || !server && serverID;
}
private void updateConcurrentStreams(int newConcurrentStreams, boolean remote) {
if (remote) {
remoteConcurrentStreams = newConcurrentStreams;
} else {
localConcurrentStreams = newConcurrentStreams;
}
if (localConcurrentStreams == remoteConcurrentStreams) {
maxConcurrentStreams = localConcurrentStreams;
return;
}
if (localConcurrentStreams == 0) {
maxConcurrentStreams = remoteConcurrentStreams;
return;
}
if (remoteConcurrentStreams == 0) {
maxConcurrentStreams = localConcurrentStreams;
return;
}
if (localConcurrentStreams > remoteConcurrentStreams) {
maxConcurrentStreams = remoteConcurrentStreams;
} else {
maxConcurrentStreams = localConcurrentStreams;
}
}
// need to synchronize to prevent new streams from being created while updating active streams
private synchronized void updateInitialSendWindowSize(int newInitialWindowSize) {
int deltaWindowSize = newInitialWindowSize - initialSendWindowSize;
initialSendWindowSize = newInitialWindowSize;
for (Integer streamId: spdySession.getActiveStreams()) {
spdySession.updateSendWindowSize(streamId.intValue(), deltaWindowSize);
}
}
// need to synchronize to prevent new streams from being created while updating active streams
private synchronized void updateInitialReceiveWindowSize(int newInitialWindowSize) {
int deltaWindowSize = newInitialWindowSize - initialReceiveWindowSize;
initialReceiveWindowSize = newInitialWindowSize;
spdySession.updateAllReceiveWindowSizes(deltaWindowSize);
}
// need to synchronize accesses to sentGoAwayFrame, lastGoodStreamId, and initial window sizes
private synchronized boolean acceptStream(
int streamID, byte priority, boolean remoteSideClosed, boolean localSideClosed) {
// Cannot initiate any new streams after receiving or sending GOAWAY
if (receivedGoAwayFrame || sentGoAwayFrame) {
return false;
}
int maxConcurrentStreams = this.maxConcurrentStreams; // read volatile once
if (maxConcurrentStreams != 0 &&
spdySession.numActiveStreams() >= maxConcurrentStreams) {
return false;
}
spdySession.acceptStream(
streamID, priority, remoteSideClosed, localSideClosed,
initialSendWindowSize, initialReceiveWindowSize);
if (isRemoteInitiatedID(streamID)) {
lastGoodStreamId = streamID;
}
return true;
}
private void halfCloseStream(int streamID, boolean remote) {
if (remote) {
spdySession.closeRemoteSide(streamID);
} else {
spdySession.closeLocalSide(streamID);
}
if (closeSessionFuture != null && spdySession.noActiveStreams()) {
closeSessionFuture.setSuccess();
}
}
private void removeStream(ChannelHandlerContext ctx, int streamID) {
if (spdySession.removeStream(streamID)) {
ctx.fireExceptionCaught(STREAM_CLOSED);
}
if (closeSessionFuture != null && spdySession.noActiveStreams()) {
closeSessionFuture.setSuccess();
}
}
private void updateSendWindowSize(ChannelHandlerContext ctx, final int streamID, int deltaWindowSize) {
synchronized (flowControlLock) {
int newWindowSize = spdySession.updateSendWindowSize(streamID, deltaWindowSize);
while (newWindowSize > 0) {
// Check if we have unblocked a stalled stream
SpdyDataFrame spdyDataFrame = (SpdyDataFrame) spdySession.getPendingWrite(streamID);
if (spdyDataFrame == null) {
break;
}
int dataFrameSize = spdyDataFrame.data().readableBytes();
if (newWindowSize >= dataFrameSize) {
// Window size is large enough to send entire data frame
spdySession.removePendingWrite(streamID);
newWindowSize = spdySession.updateSendWindowSize(streamID, -1 * dataFrameSize);
// The transfer window size is pre-decremented when sending a data frame downstream.
// Close the stream on write failures that leaves the transfer window in a corrupt state.
//
// This is never sent because on write failure the connection will be closed
// immediately. Commenting out just in case I misunderstood it - T
//
//final ChannelHandlerContext context = ctx;
//e.getFuture().addListener(new ChannelFutureListener() {
// @Override
// public void operationComplete(ChannelFuture future) throws Exception {
// if (!future.isSuccess()) {
// issueStreamError(context, streamID, SpdyStreamStatus.INTERNAL_ERROR);
// }
// }
//});
// Close the local side of the stream if this is the last frame
if (spdyDataFrame.isLast()) {
halfCloseStream(streamID, false);
}
ctx.nextOutboundMessageBuffer().add(spdyDataFrame);
} else {
// We can send a partial frame
spdySession.updateSendWindowSize(streamID, -1 * newWindowSize);
// Create a partial data frame whose length is the current window size
SpdyDataFrame partialDataFrame = new DefaultSpdyDataFrame(streamID,
spdyDataFrame.data().readSlice(newWindowSize));
// The transfer window size is pre-decremented when sending a data frame downstream.
// Close the stream on write failures that leaves the transfer window in a corrupt state.
//
// This is never sent because on write failure the connection will be closed
// immediately. Commenting out just in case I misunderstood it - T
//
//final SocketAddress remoteAddress = e.getRemoteAddress();
//final ChannelHandlerContext context = ctx;
//e.getFuture().addListener(new ChannelFutureListener() {
// @Override
// public void operationComplete(ChannelFuture future) throws Exception {
// if (!future.isSuccess()) {
// issueStreamError(context, streamID, SpdyStreamStatus.INTERNAL_ERROR);
// }
// }
//});
ctx.nextOutboundMessageBuffer().add(partialDataFrame);
newWindowSize = 0;
}
}
}
}
private void sendGoAwayFrame(ChannelHandlerContext ctx, ChannelPromise future) {
// Avoid NotYetConnectedException
if (!ctx.channel().isActive()) {
ctx.close(future);
return;
}
sendGoAwayFrame(ctx, SpdySessionStatus.OK);
ChannelFuture f = ctx.flush();
if (spdySession.noActiveStreams()) {
f.addListener(new ClosingChannelFutureListener(ctx, future));
} else {
closeSessionFuture = ctx.newPromise();
closeSessionFuture.addListener(new ClosingChannelFutureListener(ctx, future));
}
// FIXME: Close the connection forcibly after timeout.
}
private synchronized void sendGoAwayFrame(
ChannelHandlerContext ctx, SpdySessionStatus status) {
if (!sentGoAwayFrame) {
sentGoAwayFrame = true;
SpdyGoAwayFrame spdyGoAwayFrame = new DefaultSpdyGoAwayFrame(lastGoodStreamId, status);
ctx.nextOutboundMessageBuffer().add(spdyGoAwayFrame);
}
}
private static final class ClosingChannelFutureListener implements ChannelFutureListener {
private final ChannelHandlerContext ctx;
private final ChannelPromise promise;
ClosingChannelFutureListener(ChannelHandlerContext ctx, ChannelPromise promise) {
this.ctx = ctx;
this.promise = promise;
}
@Override
public void operationComplete(ChannelFuture sentGoAwayFuture) throws Exception {
ctx.close(promise);
}
}
}
