/*
* $HeadURL: http://svn.apache.org/repos/asf/jakarta/httpcomponents/httpcore/tags/4.0-alpha6/module-nio/src/main/java/org/apache/http/nio/protocol/ThrottlingHttpServiceHandler.java $
* $Revision: 576088 $
* $Date: 2007-09-16 14:30:34 +0200 (Sun, 16 Sep 2007) $
*
* ====================================================================
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF 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.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*
*/
package org.apache.http.nio.protocol;
import java.io.IOException;
import java.io.OutputStream;
import org.apache.http.ConnectionReuseStrategy;
import org.apache.http.HttpEntity;
import org.apache.http.HttpEntityEnclosingRequest;
import org.apache.http.HttpException;
import org.apache.http.HttpRequest;
import org.apache.http.HttpResponse;
import org.apache.http.HttpResponseFactory;
import org.apache.http.HttpStatus;
import org.apache.http.HttpVersion;
import org.apache.http.MethodNotSupportedException;
import org.apache.http.ProtocolVersion;
import org.apache.http.ProtocolException;
import org.apache.http.UnsupportedHttpVersionException;
import org.apache.http.entity.ByteArrayEntity;
import org.apache.http.nio.ContentDecoder;
import org.apache.http.nio.ContentEncoder;
import org.apache.http.nio.IOControl;
import org.apache.http.nio.NHttpConnection;
import org.apache.http.nio.NHttpServerConnection;
import org.apache.http.nio.entity.ContentBufferEntity;
import org.apache.http.nio.entity.ContentOutputStream;
import org.apache.http.nio.params.NIOReactorPNames;
import org.apache.http.nio.util.ByteBufferAllocator;
import org.apache.http.nio.util.ContentInputBuffer;
import org.apache.http.nio.util.ContentOutputBuffer;
import org.apache.http.nio.util.DirectByteBufferAllocator;
import org.apache.http.nio.util.SharedInputBuffer;
import org.apache.http.nio.util.SharedOutputBuffer;
import org.apache.http.params.HttpParams;
import org.apache.http.params.HttpParamsLinker;
import org.apache.http.protocol.HttpContext;
import org.apache.http.protocol.ExecutionContext;
import org.apache.http.protocol.HttpProcessor;
import org.apache.http.protocol.HttpRequestHandler;
import org.apache.http.util.EncodingUtils;
import org.apache.http.util.concurrent.Executor;
/**
* HTTP service handler implementation that allocates content buffers of limited
* size upon initialization and is capable of controlling the frequency of I/O
* events in order to guarantee those content buffers do not ever get overflown.
* This helps ensure near constant memory footprint of HTTP connections and to
* avoid the 'out of memory' condition while streaming out response content.
*
* <p>The service handler will delegate the task of processing requests and
* generating response content to an {@link Executor}, which is expected to
* perform those tasks using dedicated worker threads in order to avoid
* blocking the I/O thread.</p>
*
* @see NIOReactorPNames#CONTENT_BUFFER_SIZE
*
* @author <a href="mailto:oleg at ural.ru">Oleg Kalnichevski</a>
*
*/
public class ThrottlingHttpServiceHandler extends NHttpServiceHandlerBase {
protected final Executor executor;
public ThrottlingHttpServiceHandler(
final HttpProcessor httpProcessor,
final HttpResponseFactory responseFactory,
final ConnectionReuseStrategy connStrategy,
final ByteBufferAllocator allocator,
final Executor executor,
final HttpParams params) {
super(httpProcessor, responseFactory, connStrategy, allocator, params);
this.executor = executor;
}
public ThrottlingHttpServiceHandler(
final HttpProcessor httpProcessor,
final HttpResponseFactory responseFactory,
final ConnectionReuseStrategy connStrategy,
final Executor executor,
final HttpParams params) {
this(httpProcessor, responseFactory, connStrategy,
new DirectByteBufferAllocator(), executor, params);
}
public void connected(final NHttpServerConnection conn) {
HttpContext context = conn.getContext();
int bufsize = this.params.getIntParameter(
NIOReactorPNames.CONTENT_BUFFER_SIZE, 20480);
ServerConnState connState = new ServerConnState(bufsize, conn, allocator);
context.setAttribute(CONN_STATE, connState);
if (this.eventListener != null) {
this.eventListener.connectionOpen(conn);
}
}
public void closed(final NHttpServerConnection conn) {
if (this.eventListener != null) {
this.eventListener.connectionClosed(conn);
}
}
public void exception(final NHttpServerConnection conn, final HttpException httpex) {
HttpContext context = conn.getContext();
ServerConnState connState = (ServerConnState) context.getAttribute(CONN_STATE);
try {
HttpResponse response = this.responseFactory.newHttpResponse(
HttpVersion.HTTP_1_0,
HttpStatus.SC_INTERNAL_SERVER_ERROR,
context);
HttpParamsLinker.link(response, this.params);
handleException(httpex, response);
response.setEntity(null);
this.httpProcessor.process(response, context);
synchronized (connState) {
connState.setResponse(response);
// Response is ready to be committed
conn.requestOutput();
}
} catch (IOException ex) {
shutdownConnection(conn, ex);
if (eventListener != null) {
eventListener.fatalIOException(ex, conn);
}
} catch (HttpException ex) {
closeConnection(conn, ex);
if (eventListener != null) {
eventListener.fatalProtocolException(ex, conn);
}
}
}
public void requestReceived(final NHttpServerConnection conn) {
HttpContext context = conn.getContext();
final HttpRequest request = conn.getHttpRequest();
final ServerConnState connState = (ServerConnState) context.getAttribute(CONN_STATE);
synchronized (connState) {
boolean contentExpected = false;
if (request instanceof HttpEntityEnclosingRequest) {
HttpEntity entity = ((HttpEntityEnclosingRequest) request).getEntity();
if (entity != null) {
contentExpected = true;
}
}
if (!contentExpected) {
conn.suspendInput();
}
this.executor.execute(new Runnable() {
public void run() {
try {
handleRequest(request, connState, conn);
} catch (IOException ex) {
shutdownConnection(conn, ex);
if (eventListener != null) {
eventListener.fatalIOException(ex, conn);
}
} catch (HttpException ex) {
shutdownConnection(conn, ex);
if (eventListener != null) {
eventListener.fatalProtocolException(ex, conn);
}
}
}
});
connState.notifyAll();
}
}
public void inputReady(final NHttpServerConnection conn, final ContentDecoder decoder) {
HttpContext context = conn.getContext();
ServerConnState connState = (ServerConnState) context.getAttribute(CONN_STATE);
try {
synchronized (connState) {
ContentInputBuffer buffer = connState.getInbuffer();
buffer.consumeContent(decoder);
if (decoder.isCompleted()) {
connState.setInputState(ServerConnState.REQUEST_BODY_DONE);
} else {
connState.setInputState(ServerConnState.REQUEST_BODY_STREAM);
}
connState.notifyAll();
}
} catch (IOException ex) {
shutdownConnection(conn, ex);
if (this.eventListener != null) {
this.eventListener.fatalIOException(ex, conn);
}
}
}
public void responseReady(final NHttpServerConnection conn) {
HttpContext context = conn.getContext();
ServerConnState connState = (ServerConnState) context.getAttribute(CONN_STATE);
try {
synchronized (connState) {
HttpResponse response = connState.getResponse();
if (connState.getOutputState() == ServerConnState.READY
&& response != null
&& !conn.isResponseSubmitted()) {
conn.submitResponse(response);
int statusCode = response.getStatusLine().getStatusCode();
HttpEntity entity = response.getEntity();
if (statusCode >= 200 && entity == null) {
connState.setOutputState(ServerConnState.RESPONSE_DONE);
if (!connState.isWorkerRunning()) {
connState.resetOutput();
connState.resetInput();
conn.requestInput();
}
if (!this.connStrategy.keepAlive(response, context)) {
conn.close();
}
} else {
connState.setOutputState(ServerConnState.RESPONSE_SENT);
}
}
connState.notifyAll();
}
} catch (IOException ex) {
shutdownConnection(conn, ex);
if (eventListener != null) {
eventListener.fatalIOException(ex, conn);
}
} catch (HttpException ex) {
closeConnection(conn, ex);
if (eventListener != null) {
eventListener.fatalProtocolException(ex, conn);
}
}
}
public void outputReady(final NHttpServerConnection conn, final ContentEncoder encoder) {
HttpContext context = conn.getContext();
ServerConnState connState = (ServerConnState) context.getAttribute(CONN_STATE);
try {
synchronized (connState) {
HttpResponse response = connState.getResponse();
ContentOutputBuffer buffer = connState.getOutbuffer();
buffer.produceContent(encoder);
if (encoder.isCompleted()) {
connState.setOutputState(ServerConnState.RESPONSE_BODY_DONE);
if (!connState.isWorkerRunning()) {
connState.resetOutput();
connState.resetInput();
conn.requestInput();
}
if (!this.connStrategy.keepAlive(response, context)) {
conn.close();
}
} else {
connState.setOutputState(ServerConnState.RESPONSE_BODY_STREAM);
}
connState.notifyAll();
}
} catch (IOException ex) {
shutdownConnection(conn, ex);
if (this.eventListener != null) {
this.eventListener.fatalIOException(ex, conn);
}
}
}
private void handleException(final HttpException ex, final HttpResponse response) {
if (ex instanceof MethodNotSupportedException) {
response.setStatusCode(HttpStatus.SC_NOT_IMPLEMENTED);
} else if (ex instanceof UnsupportedHttpVersionException) {
response.setStatusCode(HttpStatus.SC_HTTP_VERSION_NOT_SUPPORTED);
} else if (ex instanceof ProtocolException) {
response.setStatusCode(HttpStatus.SC_BAD_REQUEST);
} else {
response.setStatusCode(HttpStatus.SC_INTERNAL_SERVER_ERROR);
}
byte[] msg = EncodingUtils.getAsciiBytes(ex.getMessage());
ByteArrayEntity entity = new ByteArrayEntity(msg);
entity.setContentType("text/plain; charset=US-ASCII");
response.setEntity(entity);
}
private void handleRequest(
final HttpRequest request,
final ServerConnState connState,
final NHttpServerConnection conn) throws HttpException, IOException {
HttpContext context = conn.getContext();
// Block until previous request is fully processed and
// the worker thread no longer holds the shared buffer
synchronized (connState) {
try {
for (;;) {
int currentState = connState.getOutputState();
if (!connState.isWorkerRunning()) {
break;
}
if (currentState == ServerConnState.SHUTDOWN) {
return;
}
connState.wait();
}
} catch (InterruptedException ex) {
connState.shutdown();
return;
}
connState.setInputState(ServerConnState.REQUEST_RECEIVED);
connState.setRequest(request);
connState.setWorkerRunning(true);
}
HttpParamsLinker.link(request, this.params);
context.setAttribute(ExecutionContext.HTTP_CONNECTION, conn);
context.setAttribute(ExecutionContext.HTTP_REQUEST, request);
ProtocolVersion ver = request.getRequestLine().getProtocolVersion();
if (!ver.lessEquals(HttpVersion.HTTP_1_1)) {
// Downgrade protocol version if greater than HTTP/1.1
ver = HttpVersion.HTTP_1_1;
}
HttpResponse response = null;
if (request instanceof HttpEntityEnclosingRequest) {
HttpEntityEnclosingRequest eeRequest = (HttpEntityEnclosingRequest) request;
if (eeRequest.expectContinue()) {
response = this.responseFactory.newHttpResponse(
ver,
HttpStatus.SC_CONTINUE,
context);
HttpParamsLinker.link(response, this.params);
if (this.expectationVerifier != null) {
try {
this.expectationVerifier.verify(request, response, context);
} catch (HttpException ex) {
response = this.responseFactory.newHttpResponse(HttpVersion.HTTP_1_0,
HttpStatus.SC_INTERNAL_SERVER_ERROR, context);
HttpParamsLinker.link(request, this.params);
handleException(ex, response);
}
}
if (response.getStatusLine().getStatusCode() < 200) {
// Send 1xx response indicating the server expections
// have been met
synchronized (connState) {
connState.setResponse(response);
conn.requestOutput();
// Block until 1xx response is sent to the client
try {
for (;;) {
int currentState = connState.getOutputState();
if (currentState == ServerConnState.RESPONSE_SENT) {
break;
}
if (currentState == ServerConnState.SHUTDOWN) {
return;
}
connState.wait();
}
} catch (InterruptedException ex) {
connState.shutdown();
return;
}
connState.resetOutput();
response = null;
}
} else {
// Discard request entity
conn.resetInput();
eeRequest.setEntity(null);
}
}
// Create a wrapper entity instead of the original one
if (eeRequest.getEntity() != null) {
eeRequest.setEntity(new ContentBufferEntity(
eeRequest.getEntity(),
connState.getInbuffer()));
}
}
if (response == null) {
response = this.responseFactory.newHttpResponse(
ver,
HttpStatus.SC_OK,
context);
HttpParamsLinker.link(response, this.params);
context.setAttribute(ExecutionContext.HTTP_RESPONSE, response);
try {
this.httpProcessor.process(request, context);
HttpRequestHandler handler = null;
if (this.handlerResolver != null) {
String requestURI = request.getRequestLine().getUri();
handler = this.handlerResolver.lookup(requestURI);
}
if (handler != null) {
handler.handle(request, response, context);
} else {
response.setStatusCode(HttpStatus.SC_NOT_IMPLEMENTED);
}
} catch (HttpException ex) {
response = this.responseFactory.newHttpResponse(HttpVersion.HTTP_1_0,
HttpStatus.SC_INTERNAL_SERVER_ERROR, context);
HttpParamsLinker.link(response, this.params);
handleException(ex, response);
}
}
this.httpProcessor.process(response, context);
if (!canResponseHaveBody(request, response)) {
response.setEntity(null);
}
connState.setResponse(response);
// Response is ready to be committed
conn.requestOutput();
if (response.getEntity() != null) {
ContentOutputBuffer buffer = connState.getOutbuffer();
OutputStream outstream = new ContentOutputStream(buffer);
HttpEntity entity = response.getEntity();
entity.writeTo(outstream);
outstream.flush();
outstream.close();
}
synchronized (connState) {
if (connState.getOutputState() == ServerConnState.RESPONSE_DONE
&& conn.isOpen()) {
connState.resetInput();
connState.resetOutput();
conn.requestInput();
}
connState.setWorkerRunning(false);
connState.notifyAll();
}
}
protected void shutdownConnection(final NHttpConnection conn, final Throwable cause) {
HttpContext context = conn.getContext();
ServerConnState connState = (ServerConnState) context.getAttribute(CONN_STATE);
super.shutdownConnection(conn, cause);
if (connState != null) {
connState.shutdown();
}
}
static class ServerConnState {
public static final int SHUTDOWN = -1;
public static final int READY = 0;
public static final int REQUEST_RECEIVED = 1;
public static final int REQUEST_BODY_STREAM = 2;
public static final int REQUEST_BODY_DONE = 4;
public static final int RESPONSE_SENT = 8;
public static final int RESPONSE_BODY_STREAM = 16;
public static final int RESPONSE_BODY_DONE = 32;
public static final int RESPONSE_DONE = 32;
private final SharedInputBuffer inbuffer;
private final SharedOutputBuffer outbuffer;
private volatile int inputState;
private volatile int outputState;
private volatile HttpRequest request;
private volatile HttpResponse response;
private volatile boolean workerRunning;
public ServerConnState(
int bufsize,
final IOControl ioControl,
final ByteBufferAllocator allocator) {
super();
this.inbuffer = new SharedInputBuffer(bufsize, ioControl, allocator);
this.outbuffer = new SharedOutputBuffer(bufsize, ioControl, allocator);
this.inputState = READY;
this.outputState = READY;
}
public ContentInputBuffer getInbuffer() {
return this.inbuffer;
}
public ContentOutputBuffer getOutbuffer() {
return this.outbuffer;
}
public int getInputState() {
return this.inputState;
}
public void setInputState(int inputState) {
this.inputState = inputState;
}
public int getOutputState() {
return this.outputState;
}
public void setOutputState(int outputState) {
this.outputState = outputState;
}
public HttpRequest getRequest() {
return this.request;
}
public void setRequest(final HttpRequest request) {
this.request = request;
}
public HttpResponse getResponse() {
return this.response;
}
public void setResponse(final HttpResponse response) {
this.response = response;
}
public boolean isWorkerRunning() {
return this.workerRunning;
}
public void setWorkerRunning(boolean b) {
this.workerRunning = b;
}
public void shutdown() {
this.inbuffer.shutdown();
this.outbuffer.shutdown();
this.inputState = SHUTDOWN;
this.outputState = SHUTDOWN;
}
public void resetInput() {
this.inbuffer.reset();
this.request = null;
this.inputState = READY;
}
public void resetOutput() {
this.outbuffer.reset();
this.response = null;
this.outputState = READY;
}
}
}