/*
* 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.
*/
/*
* Copyright 2012 Twitter, Inc.
*
* 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
* limitations under the License.
*/
package io.netty.handler.codec.spdy;
import java.util.List;
import java.util.Map;
import io.netty.channel.ChannelDownstreamHandler;
import io.netty.channel.ChannelEvent;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelFutureListener;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.Channels;
import io.netty.channel.MessageEvent;
import io.netty.handler.codec.http.HttpChunk;
import io.netty.handler.codec.http.HttpChunkTrailer;
import io.netty.handler.codec.http.HttpHeaders;
import io.netty.handler.codec.http.HttpMessage;
import io.netty.handler.codec.http.HttpRequest;
import io.netty.handler.codec.http.HttpResponse;
/**
* Encodes {@link HttpRequest}s, {@link HttpResponse}s, and {@link HttpChunk}s
* into {@link SpdySynStreamFrame}s and {@link SpdySynReplyFrame}s.
*
* <h3>Request Annotations</h3>
*
* SPDY specific headers must be added to {@link HttpRequest}s:
* <table border=1>
* <tr>
* <th>Header Name</th><th>Header Value</th>
* </tr>
* <tr>
* <td>{@code "X-SPDY-Stream-ID"}</td>
* <td>The Stream-ID for this request.
* Stream-IDs must be odd, positive integers, and must increase monotonically.</td>
* </tr>
* <tr>
* <td>{@code "X-SPDY-Priority"}</td>
* <td>The priority value for this request.
* The priority should be between 0 and 3 inclusive.
* 0 represents the highest priority and 3 represents the lowest.
* This header is optional and defaults to 0.</td>
* </tr>
* </table>
*
* <h3>Response Annotations</h3>
*
* SPDY specific headers must be added to {@link HttpResponse}s:
* <table border=1>
* <tr>
* <th>Header Name</th><th>Header Value</th>
* </tr>
* <tr>
* <td>{@code "X-SPDY-Stream-ID"}</td>
* <td>The Stream-ID of the request corresponding to this response.</td>
* </tr>
* </table>
*
* <h3>Pushed Resource Annotations</h3>
*
* SPDY specific headers must be added to pushed {@link HttpResponse}s:
* <table border=1>
* <tr>
* <th>Header Name</th><th>Header Value</th>
* </tr>
* <tr>
* <td>{@code "X-SPDY-Stream-ID"}</td>
* <td>The Stream-ID for this resource.
* Stream-IDs must be even, positive integers, and must increase monotonically.</td>
* </tr>
* <tr>
* <td>{@code "X-SPDY-Associated-To-Stream-ID"}</td>
* <td>The Stream-ID of the request that inititated this pushed resource.</td>
* </tr>
* <tr>
* <td>{@code "X-SPDY-Priority"}</td>
* <td>The priority value for this resource.
* The priority should be between 0 and 3 inclusive.
* 0 represents the highest priority and 3 represents the lowest.
* This header is optional and defaults to 0.</td>
* </tr>
* <tr>
* <td>{@code "X-SPDY-URL"}</td>
* <td>The full URL for the resource being pushed.</td>
* </tr>
* </table>
*
* <h3>Chunked Content</h3>
*
* This encoder associates all {@link HttpChunk}s that it receives
* with the most recently received 'chunked' {@link HttpRequest}
* or {@link HttpResponse}.
*
* <h3>Pushed Resources</h3>
*
* All pushed resources should be sent before sending the response
* that corresponds to the initial request.
*/
public class SpdyHttpEncoder implements ChannelDownstreamHandler {
private volatile int currentStreamID;
public SpdyHttpEncoder() {
}
public void handleDownstream(ChannelHandlerContext ctx, ChannelEvent evt)
throws Exception {
if (!(evt instanceof MessageEvent)) {
ctx.sendDownstream(evt);
return;
}
MessageEvent e = (MessageEvent) evt;
Object msg = e.getMessage();
if (msg instanceof HttpRequest) {
HttpRequest httpRequest = (HttpRequest) msg;
SpdySynStreamFrame spdySynStreamFrame = createSynStreamFrame(httpRequest);
int streamID = spdySynStreamFrame.getStreamID();
ChannelFuture future = getContentFuture(ctx, e, streamID, httpRequest);
Channels.write(ctx, future, spdySynStreamFrame, e.getRemoteAddress());
} else if (msg instanceof HttpResponse) {
HttpResponse httpResponse = (HttpResponse) msg;
if (httpResponse.containsHeader(SpdyHttpHeaders.Names.ASSOCIATED_TO_STREAM_ID)) {
SpdySynStreamFrame spdySynStreamFrame = createSynStreamFrame(httpResponse);
int streamID = spdySynStreamFrame.getStreamID();
ChannelFuture future = getContentFuture(ctx, e, streamID, httpResponse);
Channels.write(ctx, future, spdySynStreamFrame, e.getRemoteAddress());
} else {
SpdySynReplyFrame spdySynReplyFrame = createSynReplyFrame(httpResponse);
int streamID = spdySynReplyFrame.getStreamID();
ChannelFuture future = getContentFuture(ctx, e, streamID, httpResponse);
Channels.write(ctx, future, spdySynReplyFrame, e.getRemoteAddress());
}
} else if (msg instanceof HttpChunk) {
HttpChunk chunk = (HttpChunk) msg;
SpdyDataFrame spdyDataFrame = new DefaultSpdyDataFrame(currentStreamID);
spdyDataFrame.setData(chunk.getContent());
spdyDataFrame.setLast(chunk.isLast());
if (chunk instanceof HttpChunkTrailer) {
HttpChunkTrailer trailer = (HttpChunkTrailer) chunk;
List<Map.Entry<String, String>> trailers = trailer.getHeaders();
if (trailers.isEmpty()) {
Channels.write(ctx, e.getFuture(), spdyDataFrame, e.getRemoteAddress());
} else {
// Create SPDY HEADERS frame out of trailers
SpdyHeadersFrame spdyHeadersFrame = new DefaultSpdyHeadersFrame(currentStreamID);
for (Map.Entry<String, String> entry: trailers) {
spdyHeadersFrame.addHeader(entry.getKey(), entry.getValue());
}
// Write HEADERS frame and append Data Frame
ChannelFuture future = Channels.future(e.getChannel());
future.addListener(new SpdyFrameWriter(ctx, e, spdyDataFrame));
Channels.write(ctx, future, spdyHeadersFrame, e.getRemoteAddress());
}
} else {
Channels.write(ctx, e.getFuture(), spdyDataFrame, e.getRemoteAddress());
}
} else {
// Unknown message type
ctx.sendDownstream(evt);
}
}
private ChannelFuture getContentFuture(
ChannelHandlerContext ctx, MessageEvent e, int streamID, HttpMessage httpMessage) {
if (httpMessage.getContent().readableBytes() == 0) {
return e.getFuture();
}
// Create SPDY Data Frame out of message content
SpdyDataFrame spdyDataFrame = new DefaultSpdyDataFrame(streamID);
spdyDataFrame.setData(httpMessage.getContent());
spdyDataFrame.setLast(true);
// Create new future and add listener
ChannelFuture future = Channels.future(e.getChannel());
future.addListener(new SpdyFrameWriter(ctx, e, spdyDataFrame));
return future;
}
private class SpdyFrameWriter implements ChannelFutureListener {
private final ChannelHandlerContext ctx;
private final MessageEvent e;
private final Object spdyFrame;
SpdyFrameWriter(ChannelHandlerContext ctx, MessageEvent e, Object spdyFrame) {
this.ctx = ctx;
this.e = e;
this.spdyFrame = spdyFrame;
}
public void operationComplete(ChannelFuture future) throws Exception {
if (future.isSuccess()) {
Channels.write(ctx, e.getFuture(), spdyFrame, e.getRemoteAddress());
} else if (future.isCancelled()) {
e.getFuture().cancel();
} else {
e.getFuture().setFailure(future.getCause());
}
}
}
private SpdySynStreamFrame createSynStreamFrame(HttpMessage httpMessage)
throws Exception {
boolean chunked = httpMessage.isChunked();
// Get the Stream-ID, Associated-To-Stream-ID, Priority, and URL from the headers
int streamID = SpdyHttpHeaders.getStreamID(httpMessage);
int associatedToStreamID = SpdyHttpHeaders.getAssociatedToStreamID(httpMessage);
byte priority = SpdyHttpHeaders.getPriority(httpMessage);
String URL = SpdyHttpHeaders.getUrl(httpMessage);
SpdyHttpHeaders.removeStreamID(httpMessage);
SpdyHttpHeaders.removeAssociatedToStreamID(httpMessage);
SpdyHttpHeaders.removePriority(httpMessage);
SpdyHttpHeaders.removeUrl(httpMessage);
// The Connection, Keep-Alive, Proxy-Connection, and Transfer-Encoding
// headers are not valid and MUST not be sent.
httpMessage.removeHeader(HttpHeaders.Names.CONNECTION);
httpMessage.removeHeader("Keep-Alive");
httpMessage.removeHeader("Proxy-Connection");
httpMessage.removeHeader(HttpHeaders.Names.TRANSFER_ENCODING);
SpdySynStreamFrame spdySynStreamFrame = new DefaultSpdySynStreamFrame(streamID, associatedToStreamID, priority);
for (Map.Entry<String, String> entry: httpMessage.getHeaders()) {
spdySynStreamFrame.addHeader(entry.getKey(), entry.getValue());
}
// Unfold the first line of the message into name/value pairs
SpdyHeaders.setVersion(spdySynStreamFrame, httpMessage.getProtocolVersion());
if (httpMessage instanceof HttpRequest) {
HttpRequest httpRequest = (HttpRequest) httpMessage;
SpdyHeaders.setMethod(spdySynStreamFrame, httpRequest.getMethod());
SpdyHeaders.setUrl(spdySynStreamFrame, httpRequest.getUri());
}
if (httpMessage instanceof HttpResponse) {
HttpResponse httpResponse = (HttpResponse) httpMessage;
SpdyHeaders.setStatus(spdySynStreamFrame, httpResponse.getStatus());
SpdyHeaders.setUrl(spdySynStreamFrame, URL);
spdySynStreamFrame.setUnidirectional(true);
}
if (chunked) {
currentStreamID = streamID;
spdySynStreamFrame.setLast(false);
} else {
spdySynStreamFrame.setLast(httpMessage.getContent().readableBytes() == 0);
}
return spdySynStreamFrame;
}
private SpdySynReplyFrame createSynReplyFrame(HttpResponse httpResponse)
throws Exception {
boolean chunked = httpResponse.isChunked();
// Get the Stream-ID from the headers
int streamID = SpdyHttpHeaders.getStreamID(httpResponse);
SpdyHttpHeaders.removeStreamID(httpResponse);
// The Connection, Keep-Alive, Proxy-Connection, and Transfer-ENcoding
// headers are not valid and MUST not be sent.
httpResponse.removeHeader(HttpHeaders.Names.CONNECTION);
httpResponse.removeHeader("Keep-Alive");
httpResponse.removeHeader("Proxy-Connection");
httpResponse.removeHeader(HttpHeaders.Names.TRANSFER_ENCODING);
SpdySynReplyFrame spdySynReplyFrame = new DefaultSpdySynReplyFrame(streamID);
for (Map.Entry<String, String> entry: httpResponse.getHeaders()) {
spdySynReplyFrame.addHeader(entry.getKey(), entry.getValue());
}
// Unfold the first line of the repsonse into name/value pairs
SpdyHeaders.setStatus(spdySynReplyFrame, httpResponse.getStatus());
SpdyHeaders.setVersion(spdySynReplyFrame, httpResponse.getProtocolVersion());
if (chunked) {
currentStreamID = streamID;
spdySynReplyFrame.setLast(false);
} else {
spdySynReplyFrame.setLast(httpResponse.getContent().readableBytes() == 0);
}
return spdySynReplyFrame;
}
}