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/*
* 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:
*
* 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.example.http2.tiles;
import static io.netty.buffer.Unpooled.EMPTY_BUFFER;
import static io.netty.example.http2.Http2ExampleUtil.firstValue;
import static io.netty.example.http2.Http2ExampleUtil.toInt;
import static io.netty.handler.codec.http.HttpHeaderNames.CONTENT_TYPE;
import static io.netty.handler.codec.http.HttpUtil.setContentLength;
import static io.netty.handler.codec.http.HttpResponseStatus.BAD_REQUEST;
import static io.netty.handler.codec.http.HttpResponseStatus.OK;
import static io.netty.handler.codec.http.HttpVersion.HTTP_1_1;
import static java.lang.Integer.parseInt;
import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.SimpleChannelInboundHandler;
import io.netty.handler.codec.http.DefaultFullHttpResponse;
import io.netty.handler.codec.http.FullHttpRequest;
import io.netty.handler.codec.http.FullHttpResponse;
import io.netty.handler.codec.http.QueryStringDecoder;
import io.netty.handler.codec.http2.HttpConversionUtil;
import io.netty.handler.codec.http2.InboundHttp2ToHttpAdapter;
import java.util.concurrent.TimeUnit;
/**
* Handles all the requests for data. It receives a {@link FullHttpRequest},
* which has been converted by a {@link InboundHttp2ToHttpAdapter} before it
* arrived here. For further details, check {@link Http2OrHttpHandler} where the
* pipeline is setup.
*/
public class Http2RequestHandler extends SimpleChannelInboundHandler {
private static final String LATENCY_FIELD_NAME = "latency";
private static final int MIN_LATENCY = 0;
private static final int MAX_LATENCY = 1000;
private static final String IMAGE_COORDINATE_Y = "y";
private static final String IMAGE_COORDINATE_X = "x";
@Override
protected void channelRead0(ChannelHandlerContext ctx, FullHttpRequest request) throws Exception {
QueryStringDecoder queryString = new QueryStringDecoder(request.uri());
String streamId = streamId(request);
int latency = toInt(firstValue(queryString, LATENCY_FIELD_NAME), 0);
if (latency < MIN_LATENCY || latency > MAX_LATENCY) {
sendBadRequest(ctx, streamId);
return;
}
String x = firstValue(queryString, IMAGE_COORDINATE_X);
String y = firstValue(queryString, IMAGE_COORDINATE_Y);
if (x == null || y == null) {
handlePage(ctx, streamId, latency, request);
} else {
handleImage(x, y, ctx, streamId, latency, request);
}
}
private static void sendBadRequest(ChannelHandlerContext ctx, String streamId) {
FullHttpResponse response = new DefaultFullHttpResponse(HTTP_1_1, BAD_REQUEST, EMPTY_BUFFER);
streamId(response, streamId);
ctx.writeAndFlush(response);
}
private void handleImage(String x, String y, ChannelHandlerContext ctx, String streamId, int latency,
FullHttpRequest request) {
ByteBuf image = ImageCache.INSTANCE.image(parseInt(x), parseInt(y));
FullHttpResponse response = new DefaultFullHttpResponse(HTTP_1_1, OK, image.duplicate());
response.headers().set(CONTENT_TYPE, "image/jpeg");
sendResponse(ctx, streamId, latency, response, request);
}
private void handlePage(ChannelHandlerContext ctx, String streamId, int latency, FullHttpRequest request) {
byte[] body = Html.body(latency);
ByteBuf content = ctx.alloc().buffer(Html.HEADER.length + body.length + Html.FOOTER.length);
content.writeBytes(Html.HEADER);
content.writeBytes(body);
content.writeBytes(Html.FOOTER);
FullHttpResponse response = new DefaultFullHttpResponse(HTTP_1_1, OK, content);
response.headers().set(CONTENT_TYPE, "text/html; charset=UTF-8");
sendResponse(ctx, streamId, latency, response, request);
}
protected void sendResponse(final ChannelHandlerContext ctx, String streamId, int latency,
final FullHttpResponse response, final FullHttpRequest request) {
setContentLength(response, response.content().readableBytes());
streamId(response, streamId);
ctx.executor().schedule(new Runnable() {
@Override
public void run() {
ctx.writeAndFlush(response);
}
}, latency, TimeUnit.MILLISECONDS);
}
private static String streamId(FullHttpRequest request) {
return request.headers().get(HttpConversionUtil.ExtensionHeaderNames.STREAM_ID.text());
}
private static void streamId(FullHttpResponse response, String streamId) {
response.headers().set(HttpConversionUtil.ExtensionHeaderNames.STREAM_ID.text(), streamId);
}
@Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
cause.printStackTrace();
ctx.close();
}
}