/*
* $HeadURL: https://svn.apache.org/repos/asf/httpcomponents/httpcore/tags/4.0-beta3/module-nio/src/main/java/org/apache/http/nio/protocol/ThrottlingHttpClientHandler.java $
* $Revision: 690361 $
* $Date: 2008-08-29 20:35:29 +0200 (Fri, 29 Aug 2008) $
*
* ====================================================================
* 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 java.util.concurrent.Executor;
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.HttpStatus;
import org.apache.http.nio.ContentDecoder;
import org.apache.http.nio.ContentEncoder;
import org.apache.http.nio.IOControl;
import org.apache.http.nio.NHttpClientConnection;
import org.apache.http.nio.NHttpClientHandler;
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.protocol.ThrottlingHttpServiceHandler.ServerConnState;
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.CoreProtocolPNames;
import org.apache.http.params.DefaultedHttpParams;
import org.apache.http.protocol.ExecutionContext;
import org.apache.http.protocol.HttpContext;
import org.apache.http.protocol.HttpProcessor;
/**
* HTTP client 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 client handler will delegate the tasks of sending entity enclosing
* HTTP requests and processing of HTTP responses 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 ThrottlingHttpClientHandler extends NHttpHandlerBase
implements NHttpClientHandler {
protected HttpRequestExecutionHandler execHandler;
protected final Executor executor;
public ThrottlingHttpClientHandler(
final HttpProcessor httpProcessor,
final HttpRequestExecutionHandler execHandler,
final ConnectionReuseStrategy connStrategy,
final ByteBufferAllocator allocator,
final Executor executor,
final HttpParams params) {
super(httpProcessor, connStrategy, allocator, params);
if (execHandler == null) {
throw new IllegalArgumentException("HTTP request execution handler may not be null.");
}
if (executor == null) {
throw new IllegalArgumentException("Executor may not be null");
}
this.execHandler = execHandler;
this.executor = executor;
}
public ThrottlingHttpClientHandler(
final HttpProcessor httpProcessor,
final HttpRequestExecutionHandler execHandler,
final ConnectionReuseStrategy connStrategy,
final Executor executor,
final HttpParams params) {
this(httpProcessor, execHandler, connStrategy,
new DirectByteBufferAllocator(), executor, params);
}
public void connected(final NHttpClientConnection conn, final Object attachment) {
HttpContext context = conn.getContext();
initialize(conn, attachment);
int bufsize = this.params.getIntParameter(
NIOReactorPNames.CONTENT_BUFFER_SIZE, 20480);
ClientConnState connState = new ClientConnState(bufsize, conn, this.allocator);
context.setAttribute(CONN_STATE, connState);
if (this.eventListener != null) {
this.eventListener.connectionOpen(conn);
}
requestReady(conn);
}
public void closed(final NHttpClientConnection conn) {
HttpContext context = conn.getContext();
ClientConnState connState = (ClientConnState) context.getAttribute(CONN_STATE);
if (connState != null) {
synchronized (connState) {
connState.close();
connState.notifyAll();
}
}
if (this.eventListener != null) {
this.eventListener.connectionClosed(conn);
}
this.execHandler.finalizeContext(context);
if (this.eventListener != null) {
this.eventListener.connectionClosed(conn);
}
}
public void exception(final NHttpClientConnection conn, final HttpException ex) {
closeConnection(conn, ex);
if (this.eventListener != null) {
this.eventListener.fatalProtocolException(ex, conn);
}
}
public void exception(final NHttpClientConnection conn, final IOException ex) {
shutdownConnection(conn, ex);
if (this.eventListener != null) {
this.eventListener.fatalIOException(ex, conn);
}
}
public void requestReady(final NHttpClientConnection conn) {
HttpContext context = conn.getContext();
ClientConnState connState = (ClientConnState) context.getAttribute(CONN_STATE);
try {
synchronized (connState) {
if (connState.getOutputState() != ClientConnState.READY) {
return;
}
HttpRequest request = this.execHandler.submitRequest(context);
if (request == null) {
return;
}
request.setParams(
new DefaultedHttpParams(request.getParams(), this.params));
context.setAttribute(ExecutionContext.HTTP_REQUEST, request);
this.httpProcessor.process(request, context);
connState.setRequest(request);
conn.submitRequest(request);
connState.setOutputState(ClientConnState.REQUEST_SENT);
conn.requestInput();
if (request instanceof HttpEntityEnclosingRequest) {
if (((HttpEntityEnclosingRequest) request).expectContinue()) {
int timeout = conn.getSocketTimeout();
connState.setTimeout(timeout);
timeout = this.params.getIntParameter(
CoreProtocolPNames.WAIT_FOR_CONTINUE, 3000);
conn.setSocketTimeout(timeout);
connState.setOutputState(ClientConnState.EXPECT_CONTINUE);
} else {
sendRequestBody(
(HttpEntityEnclosingRequest) request,
connState,
conn);
}
}
connState.notifyAll();
}
} catch (IOException ex) {
shutdownConnection(conn, ex);
if (this.eventListener != null) {
this.eventListener.fatalIOException(ex, conn);
}
} catch (HttpException ex) {
closeConnection(conn, ex);
if (this.eventListener != null) {
this.eventListener.fatalProtocolException(ex, conn);
}
}
}
public void outputReady(final NHttpClientConnection conn, final ContentEncoder encoder) {
HttpContext context = conn.getContext();
ClientConnState connState = (ClientConnState) context.getAttribute(CONN_STATE);
try {
synchronized (connState) {
if (connState.getOutputState() == ClientConnState.EXPECT_CONTINUE) {
conn.suspendOutput();
return;
}
ContentOutputBuffer buffer = connState.getOutbuffer();
buffer.produceContent(encoder);
if (encoder.isCompleted()) {
connState.setInputState(ClientConnState.REQUEST_BODY_DONE);
} else {
connState.setInputState(ClientConnState.REQUEST_BODY_STREAM);
}
connState.notifyAll();
}
} catch (IOException ex) {
shutdownConnection(conn, ex);
if (this.eventListener != null) {
this.eventListener.fatalIOException(ex, conn);
}
}
}
public void responseReceived(final NHttpClientConnection conn) {
HttpContext context = conn.getContext();
ClientConnState connState = (ClientConnState) context.getAttribute(CONN_STATE);
try {
synchronized (connState) {
HttpResponse response = conn.getHttpResponse();
response.setParams(
new DefaultedHttpParams(response.getParams(), this.params));
HttpRequest request = connState.getRequest();
int statusCode = response.getStatusLine().getStatusCode();
if (statusCode < HttpStatus.SC_OK) {
// 1xx intermediate response
if (statusCode == HttpStatus.SC_CONTINUE
&& connState.getOutputState() == ClientConnState.EXPECT_CONTINUE) {
connState.setOutputState(ClientConnState.REQUEST_SENT);
continueRequest(conn, connState);
}
return;
} else {
connState.setResponse(response);
connState.setInputState(ClientConnState.RESPONSE_RECEIVED);
if (connState.getOutputState() == ClientConnState.EXPECT_CONTINUE) {
int timeout = connState.getTimeout();
conn.setSocketTimeout(timeout);
conn.resetOutput();
}
}
if (!canResponseHaveBody(request, response)) {
conn.resetInput();
response.setEntity(null);
connState.setInputState(ClientConnState.RESPONSE_DONE);
if (!this.connStrategy.keepAlive(response, context)) {
conn.close();
}
}
if (response.getEntity() != null) {
response.setEntity(new ContentBufferEntity(
response.getEntity(),
connState.getInbuffer()));
}
context.setAttribute(ExecutionContext.HTTP_RESPONSE, response);
this.httpProcessor.process(response, context);
handleResponse(response, connState, conn);
connState.notifyAll();
}
} catch (IOException ex) {
shutdownConnection(conn, ex);
if (this.eventListener != null) {
this.eventListener.fatalIOException(ex, conn);
}
} catch (HttpException ex) {
closeConnection(conn, ex);
if (this.eventListener != null) {
this.eventListener.fatalProtocolException(ex, conn);
}
}
}
public void inputReady(final NHttpClientConnection conn, final ContentDecoder decoder) {
HttpContext context = conn.getContext();
ClientConnState connState = (ClientConnState) context.getAttribute(CONN_STATE);
try {
synchronized (connState) {
HttpResponse response = connState.getResponse();
ContentInputBuffer buffer = connState.getInbuffer();
buffer.consumeContent(decoder);
if (decoder.isCompleted()) {
connState.setInputState(ClientConnState.RESPONSE_BODY_DONE);
if (!this.connStrategy.keepAlive(response, context)) {
conn.close();
}
} else {
connState.setInputState(ClientConnState.RESPONSE_BODY_STREAM);
}
connState.notifyAll();
}
} catch (IOException ex) {
shutdownConnection(conn, ex);
if (this.eventListener != null) {
this.eventListener.fatalIOException(ex, conn);
}
}
}
public void timeout(final NHttpClientConnection conn) {
HttpContext context = conn.getContext();
ClientConnState connState = (ClientConnState) context.getAttribute(CONN_STATE);
try {
synchronized (connState) {
if (connState.getOutputState() == ClientConnState.EXPECT_CONTINUE) {
connState.setOutputState(ClientConnState.REQUEST_SENT);
continueRequest(conn, connState);
connState.notifyAll();
return;
}
}
} catch (IOException ex) {
shutdownConnection(conn, ex);
if (this.eventListener != null) {
this.eventListener.fatalIOException(ex, conn);
}
}
handleTimeout(conn);
}
private void initialize(
final NHttpClientConnection conn,
final Object attachment) {
HttpContext context = conn.getContext();
context.setAttribute(ExecutionContext.HTTP_CONNECTION, conn);
this.execHandler.initalizeContext(context, attachment);
}
private void continueRequest(
final NHttpClientConnection conn,
final ClientConnState connState) throws IOException {
HttpRequest request = connState.getRequest();
int timeout = connState.getTimeout();
conn.setSocketTimeout(timeout);
sendRequestBody(
(HttpEntityEnclosingRequest) request,
connState,
conn);
}
private void sendRequestBody(
final HttpEntityEnclosingRequest request,
final ClientConnState connState,
final NHttpClientConnection conn) throws IOException {
HttpEntity entity = request.getEntity();
if (entity != null) {
this.executor.execute(new Runnable() {
public void run() {
try {
// 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.setWorkerRunning(true);
}
HttpEntity entity = request.getEntity();
OutputStream outstream = new ContentOutputStream(
connState.getOutbuffer());
entity.writeTo(outstream);
outstream.flush();
outstream.close();
synchronized (connState) {
connState.setWorkerRunning(false);
connState.notifyAll();
}
} catch (IOException ex) {
shutdownConnection(conn, ex);
if (eventListener != null) {
eventListener.fatalIOException(ex, conn);
}
}
}
});
}
}
private void handleResponse(
final HttpResponse response,
final ClientConnState connState,
final NHttpClientConnection conn) {
final HttpContext context = conn.getContext();
this.executor.execute(new Runnable() {
public void run() {
try {
// 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.setWorkerRunning(true);
}
execHandler.handleResponse(response, context);
synchronized (connState) {
try {
for (;;) {
int currentState = connState.getInputState();
if (currentState == ClientConnState.RESPONSE_DONE) {
break;
}
if (currentState == ServerConnState.SHUTDOWN) {
return;
}
connState.wait();
}
} catch (InterruptedException ex) {
connState.shutdown();
}
connState.resetInput();
connState.resetOutput();
if (conn.isOpen()) {
conn.requestOutput();
}
connState.setWorkerRunning(false);
connState.notifyAll();
}
} catch (IOException ex) {
shutdownConnection(conn, ex);
if (eventListener != null) {
eventListener.fatalIOException(ex, conn);
}
}
}
});
}
static class ClientConnState {
public static final int SHUTDOWN = -1;
public static final int READY = 0;
public static final int REQUEST_SENT = 1;
public static final int EXPECT_CONTINUE = 2;
public static final int REQUEST_BODY_STREAM = 4;
public static final int REQUEST_BODY_DONE = 8;
public static final int RESPONSE_RECEIVED = 16;
public static final int RESPONSE_BODY_STREAM = 32;
public static final int RESPONSE_BODY_DONE = 64;
public static final int RESPONSE_DONE = 64;
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 int timeout;
private volatile boolean workerRunning;
public ClientConnState(
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 int getTimeout() {
return this.timeout;
}
public void setTimeout(int timeout) {
this.timeout = timeout;
}
public boolean isWorkerRunning() {
return this.workerRunning;
}
public void setWorkerRunning(boolean b) {
this.workerRunning = b;
}
public void close() {
this.inbuffer.close();
this.outbuffer.close();
this.inputState = SHUTDOWN;
this.outputState = SHUTDOWN;
}
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;
}
}
}