/*
* Copyright 2016 the original author or authors.
*
* 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 ratpack.http.client.internal;
import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelPipeline;
import io.netty.channel.SimpleChannelInboundHandler;
import io.netty.handler.codec.http.*;
import io.netty.util.ReferenceCounted;
import org.reactivestreams.Subscriber;
import org.reactivestreams.Subscription;
import ratpack.exec.Downstream;
import ratpack.exec.Execution;
import ratpack.exec.Upstream;
import ratpack.func.Action;
import ratpack.http.Headers;
import ratpack.http.MutableHeaders;
import ratpack.http.Response;
import ratpack.http.Status;
import ratpack.http.client.RequestSpec;
import ratpack.http.client.StreamedResponse;
import ratpack.http.internal.DefaultStatus;
import ratpack.http.internal.NettyHeadersBackedHeaders;
import ratpack.stream.TransformablePublisher;
import ratpack.stream.internal.BufferedWriteStream;
import ratpack.stream.internal.BufferingPublisher;
import ratpack.util.Exceptions;
import java.net.URI;
import java.util.ArrayList;
import java.util.List;
public class ContentStreamingRequestAction extends RequestActionSupport<StreamedResponse> {
private static final String HANDLER_NAME = "streaming";
ContentStreamingRequestAction(URI uri, HttpClientInternal client, int redirectCount, Execution execution, Action<? super RequestSpec> requestConfigurer) throws Exception {
super(uri, client, redirectCount, execution, requestConfigurer);
}
@Override
protected void doDispose(ChannelPipeline channelPipeline, boolean forceClose) {
channelPipeline.remove(HANDLER_NAME);
super.doDispose(channelPipeline, forceClose);
}
@Override
protected void addResponseHandlers(ChannelPipeline p, Downstream<? super StreamedResponse> downstream) {
p.addLast(HANDLER_NAME, new Handler(p, downstream));
}
@Override
protected Upstream<StreamedResponse> onRedirect(URI locationUrl, int redirectCount, Action<? super RequestSpec> redirectRequestConfig) throws Exception {
return new ContentStreamingRequestAction(locationUrl, client, redirectCount, execution, redirectRequestConfig);
}
private class Handler extends SimpleChannelInboundHandler<HttpObject> {
private final ChannelPipeline channelPipeline;
private final Downstream<? super StreamedResponse> downstream;
private List<HttpContent> received;
private BufferedWriteStream<ByteBuf> write;
private HttpResponse response;
public Handler(ChannelPipeline channelPipeline, Downstream<? super StreamedResponse> downstream) {
super(false);
this.channelPipeline = channelPipeline;
this.downstream = downstream;
}
@Override
protected void channelRead0(ChannelHandlerContext ctx, HttpObject httpObject) throws Exception {
if (httpObject instanceof HttpResponse) {
this.response = (HttpResponse) httpObject;
int code = response.status().code();
if ((code >= 100 && code < 200) || code == 204) {
response.headers().remove(HttpHeaderNames.CONTENT_LENGTH);
}
// Switch auto reading off so we can control the flow of response content
channelPipeline.channel().config().setAutoRead(false);
execution.onComplete(() -> {
if (write == null) {
forceDispose(channelPipeline);
}
if (received != null) {
received.forEach(ReferenceCounted::release);
}
});
success(downstream, new DefaultStreamedResponse(channelPipeline));
} else if (httpObject instanceof HttpContent) {
HttpContent httpContent = ((HttpContent) httpObject).touch();
boolean hasContent = httpContent.content().readableBytes() > 0;
boolean isLast = httpObject instanceof LastHttpContent;
if (write == null) { // the stream has not yet been subscribed to
if (hasContent || isLast) {
if (received == null) {
received = new ArrayList<>();
}
received.add(httpContent.touch());
} else {
httpContent.release();
}
if (isLast) {
dispose(ctx.pipeline(), response);
}
} else { // the stream has been subscribed to
if (hasContent) {
write.item(httpContent.content().touch("emitting to user code"));
} else {
httpContent.release();
}
if (isLast) {
dispose(ctx.pipeline(), response);
write.complete();
} else {
if (write.getRequested() > 0) {
ctx.read();
}
}
}
}
}
@Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
cause = decorateException(cause);
if (write == null) {
error(downstream, cause);
} else {
write.error(cause);
}
forceDispose(ctx.pipeline());
}
class DefaultStreamedResponse implements StreamedResponse {
private final ChannelPipeline channelPipeline;
private final Status status;
private final Headers headers;
private DefaultStreamedResponse(ChannelPipeline channelPipeline) {
this.channelPipeline = channelPipeline;
this.headers = new NettyHeadersBackedHeaders(response.headers());
this.status = new DefaultStatus(response.status());
}
@Override
public Status getStatus() {
return status;
}
@Override
public int getStatusCode() {
return status.getCode();
}
@Override
public Headers getHeaders() {
return headers;
}
@Override
public TransformablePublisher<ByteBuf> getBody() {
return new BufferingPublisher<>(ByteBuf::release, write -> {
Handler.this.write = write;
if (received != null) {
for (HttpContent httpContent : received) {
if (httpContent.content().readableBytes() > 0) {
write.item(httpContent.content().touch("emitting to user code"));
} else {
httpContent.release();
}
if (httpContent instanceof LastHttpContent) {
dispose(channelPipeline, response);
write.complete();
}
}
received.clear();
}
return new Subscription() {
@Override
public void request(long n) {
channelPipeline.read();
}
@Override
public void cancel() {
forceDispose(channelPipeline);
}
};
});
}
@Override
public void forwardTo(Response response) {
forwardTo(response, Action.noop());
}
@Override
public void forwardTo(Response response, Action<? super MutableHeaders> headerMutator) {
MutableHeaders outgoingHeaders = response.getHeaders();
outgoingHeaders.copy(headers);
outgoingHeaders.remove(HttpHeaderNames.CONNECTION);
Exceptions.uncheck(() -> headerMutator.execute(outgoingHeaders));
response.status(status);
getBody().bindExec(ByteBuf::release).subscribe(new Subscriber<ByteBuf>() {
private Subscription subscription;
private Subscriber<? super ByteBuf> downstream;
@Override
public void onSubscribe(Subscription s) {
subscription = s;
subscription.request(1);
}
@Override
public void onNext(ByteBuf byteBuf) {
if (downstream == null) {
response.sendStream(s -> {
downstream = s;
downstream.onSubscribe(new Subscription() {
private ByteBuf initial = byteBuf;
@Override
public void request(long n) {
if (initial == null) {
subscription.request(n);
} else {
ByteBuf initialRef = this.initial;
this.initial = null;
downstream.onNext(initialRef);
n -= 1;
if (n > 0) {
subscription.request(1);
}
}
}
@Override
public void cancel() {
subscription.cancel();
if (initial != null) {
initial.release();
}
}
});
});
} else {
downstream.onNext(byteBuf);
}
}
@Override
public void onError(Throwable t) {
if (downstream == null) {
response.sendStream(s -> s.onError(t));
} else {
downstream.onError(t);
}
}
@Override
public void onComplete() {
if (downstream == null) {
response.send();
} else {
downstream.onComplete();
}
}
});
}
}
}
}