/*
* 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.channel.ChannelHandlerContext;
import io.netty.handler.codec.MessageToMessageEncoder;
import io.netty.handler.codec.UnsupportedMessageTypeException;
import io.netty.handler.codec.http.FullHttpMessage;
import io.netty.handler.codec.http.HttpContent;
import io.netty.handler.codec.http.HttpHeaders;
import io.netty.handler.codec.http.HttpMessage;
import io.netty.handler.codec.http.HttpObject;
import io.netty.handler.codec.http.HttpRequest;
import io.netty.handler.codec.http.HttpResponse;
import io.netty.handler.codec.http.LastHttpContent;
import java.util.List;
import java.util.Map;
/**
* Encodes {@link HttpRequest}s, {@link HttpResponse}s, and {@link HttpContent}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 7 inclusive.
* 0 represents the highest priority and 7 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 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 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 initiated 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 7 inclusive.
* 0 represents the highest priority and 7 represents the lowest.
* This header is optional and defaults to 0.</td>
* </tr>
* </table>
*
* <h3>Required Annotations</h3>
*
* SPDY requires that all Requests and Pushed Resources contain
* an HTTP "Host" header.
*
* <h3>Optional Annotations</h3>
*
* Requests and Pushed Resources must contain a SPDY scheme header.
* This can be set via the {@code "X-SPDY-Scheme"} header but otherwise
* defaults to "https" as that is the most common SPDY deployment.
*
* <h3>Chunked Content</h3>
*
* This encoder associates all {@link HttpContent}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 extends MessageToMessageEncoder<HttpObject> {
private int currentStreamId;
/**
* Creates a new instance.
*
* @param version the protocol version
*/
public SpdyHttpEncoder(SpdyVersion version) {
if (version == null) {
throw new NullPointerException("version");
}
}
@Override
protected void encode(ChannelHandlerContext ctx, HttpObject msg, List<Object> out) throws Exception {
boolean valid = false;
boolean last = false;
if (msg instanceof HttpRequest) {
HttpRequest httpRequest = (HttpRequest) msg;
SpdySynStreamFrame spdySynStreamFrame = createSynStreamFrame(httpRequest);
out.add(spdySynStreamFrame);
last = spdySynStreamFrame.isLast() || spdySynStreamFrame.isUnidirectional();
valid = true;
}
if (msg instanceof HttpResponse) {
HttpResponse httpResponse = (HttpResponse) msg;
SpdyHeadersFrame spdyHeadersFrame = createHeadersFrame(httpResponse);
out.add(spdyHeadersFrame);
last = spdyHeadersFrame.isLast();
valid = true;
}
if (msg instanceof HttpContent && !last) {
HttpContent chunk = (HttpContent) msg;
chunk.content().retain();
SpdyDataFrame spdyDataFrame = new DefaultSpdyDataFrame(currentStreamId, chunk.content());
if (chunk instanceof LastHttpContent) {
LastHttpContent trailer = (LastHttpContent) chunk;
HttpHeaders trailers = trailer.trailingHeaders();
if (trailers.isEmpty()) {
spdyDataFrame.setLast(true);
out.add(spdyDataFrame);
} else {
// Create SPDY HEADERS frame out of trailers
SpdyHeadersFrame spdyHeadersFrame = new DefaultSpdyHeadersFrame(currentStreamId);
spdyHeadersFrame.setLast(true);
for (Map.Entry<String, String> entry: trailers) {
spdyHeadersFrame.headers().add(entry.getKey(), entry.getValue());
}
// Write DATA frame and append HEADERS frame
out.add(spdyDataFrame);
out.add(spdyHeadersFrame);
}
} else {
out.add(spdyDataFrame);
}
valid = true;
}
if (!valid) {
throw new UnsupportedMessageTypeException(msg);
}
}
@SuppressWarnings("deprecation")
private SpdySynStreamFrame createSynStreamFrame(HttpRequest httpRequest) throws Exception {
// Get the Stream-ID, Associated-To-Stream-ID, Priority, and scheme from the headers
final HttpHeaders httpHeaders = httpRequest.headers();
int streamId = SpdyHttpHeaders.getStreamId(httpRequest);
int associatedToStreamId = SpdyHttpHeaders.getAssociatedToStreamId(httpRequest);
byte priority = SpdyHttpHeaders.getPriority(httpRequest);
CharSequence scheme = httpHeaders.get(SpdyHttpHeaders.Names.SCHEME);
httpHeaders.remove(SpdyHttpHeaders.Names.STREAM_ID);
httpHeaders.remove(SpdyHttpHeaders.Names.ASSOCIATED_TO_STREAM_ID);
httpHeaders.remove(SpdyHttpHeaders.Names.PRIORITY);
httpHeaders.remove(SpdyHttpHeaders.Names.SCHEME);
// The Connection, Keep-Alive, Proxy-Connection, and Transfer-Encoding
// headers are not valid and MUST not be sent.
httpHeaders.remove(HttpHeaders.Names.CONNECTION);
httpHeaders.remove("Keep-Alive");
httpHeaders.remove("Proxy-Connection");
httpHeaders.remove(HttpHeaders.Names.TRANSFER_ENCODING);
SpdySynStreamFrame spdySynStreamFrame =
new DefaultSpdySynStreamFrame(streamId, associatedToStreamId, priority);
// Unfold the first line of the message into name/value pairs
SpdyHeaders frameHeaders = spdySynStreamFrame.headers();
frameHeaders.set(SpdyHeaders.HttpNames.METHOD, httpRequest.getMethod());
frameHeaders.set(SpdyHeaders.HttpNames.PATH, httpRequest.getUri());
frameHeaders.set(SpdyHeaders.HttpNames.VERSION, httpRequest.getProtocolVersion());
// Replace the HTTP host header with the SPDY host header
CharSequence host = httpHeaders.get(HttpHeaders.Names.HOST);
httpHeaders.remove(HttpHeaders.Names.HOST);
frameHeaders.set(SpdyHeaders.HttpNames.HOST, host);
// Set the SPDY scheme header
if (scheme == null) {
scheme = "https";
}
frameHeaders.set(SpdyHeaders.HttpNames.SCHEME, scheme);
// Transfer the remaining HTTP headers
for (Map.Entry<String, String> entry: httpHeaders) {
frameHeaders.add(entry.getKey(), entry.getValue());
}
currentStreamId = spdySynStreamFrame.streamId();
if (associatedToStreamId == 0) {
spdySynStreamFrame.setLast(isLast(httpRequest));
} else {
spdySynStreamFrame.setUnidirectional(true);
}
return spdySynStreamFrame;
}
@SuppressWarnings("deprecation")
private SpdyHeadersFrame createHeadersFrame(HttpResponse httpResponse) throws Exception {
// Get the Stream-ID from the headers
final HttpHeaders httpHeaders = httpResponse.headers();
int streamId = SpdyHttpHeaders.getStreamId(httpResponse);
httpHeaders.remove(SpdyHttpHeaders.Names.STREAM_ID);
// The Connection, Keep-Alive, Proxy-Connection, and Transfer-Encoding
// headers are not valid and MUST not be sent.
httpHeaders.remove(HttpHeaders.Names.CONNECTION);
httpHeaders.remove("Keep-Alive");
httpHeaders.remove("Proxy-Connection");
httpHeaders.remove(HttpHeaders.Names.TRANSFER_ENCODING);
SpdyHeadersFrame spdyHeadersFrame;
if (SpdyCodecUtil.isServerId(streamId)) {
spdyHeadersFrame = new DefaultSpdyHeadersFrame(streamId);
} else {
spdyHeadersFrame = new DefaultSpdySynReplyFrame(streamId);
}
SpdyHeaders frameHeaders = spdyHeadersFrame.headers();
// Unfold the first line of the response into name/value pairs
frameHeaders.set(SpdyHeaders.HttpNames.STATUS, httpResponse.getStatus().code());
frameHeaders.set(SpdyHeaders.HttpNames.VERSION, httpResponse.getProtocolVersion());
// Transfer the remaining HTTP headers
for (Map.Entry<String, String> entry: httpHeaders) {
spdyHeadersFrame.headers().add(entry.getKey(), entry.getValue());
}
currentStreamId = streamId;
spdyHeadersFrame.setLast(isLast(httpResponse));
return spdyHeadersFrame;
}
/**
* Checks if the given HTTP message should be considered as a last SPDY frame.
*
* @param httpMessage check this HTTP message
* @return whether the given HTTP message should generate a <em>last</em> SPDY frame.
*/
private static boolean isLast(HttpMessage httpMessage) {
if (httpMessage instanceof FullHttpMessage) {
FullHttpMessage fullMessage = (FullHttpMessage) httpMessage;
if (fullMessage.trailingHeaders().isEmpty() && !fullMessage.content().isReadable()) {
return true;
}
}
return false;
}
}