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/*
 * ====================================================================
 * 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
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 * .
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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.annotation.ThreadingBehavior;
import org.apache.http.annotation.Contract;
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.CoreProtocolPNames;
import org.apache.http.params.DefaultedHttpParams;
import org.apache.http.params.HttpParams;
import org.apache.http.protocol.ExecutionContext;
import org.apache.http.protocol.HttpContext;
import org.apache.http.protocol.HttpProcessor;
import org.apache.http.util.Args;

/**
 * Client protocol handler implementation that provide compatibility with
 * the blocking I/O by utilizing shared content buffers and a fairly small pool
 * of worker threads. The throttling protocol handler allocates input / output
 * buffers of a constant length upon initialization and controls the rate of
 * I/O events in order to ensure those content buffers do not ever get
 * overflown. This helps ensure nearly constant memory footprint for HTTP
 * connections and avoid the out of memory condition while streaming content
 * in and out. The {@link HttpRequestExecutionHandler#handleResponse(HttpResponse, HttpContext)}
 * method will fire immediately when a message is received. The protocol handler
 * 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.
 * 

* Usually throttling protocol handlers need only a modest number of worker * threads, much fewer than the number of concurrent connections. If the length * of the message is smaller or about the size of the shared content buffer * worker thread will just store content in the buffer and terminate almost * immediately without blocking. The I/O dispatch thread in its turn will take * care of sending out the buffered content asynchronously. The worker thread * will have to block only when processing large messages and the shared buffer * fills up. It is generally advisable to allocate shared buffers of a size of * an average content body for optimal performance. *

* The following parameters can be used to customize the behavior of this * class: *

    *
  • {@link org.apache.http.nio.params.NIOReactorPNames#CONTENT_BUFFER_SIZE}
  • *
  • {@link org.apache.http.params.CoreProtocolPNames#WAIT_FOR_CONTINUE}
  • *
* * @since 4.0 * * @deprecated (4.2) use {@link HttpAsyncRequestExecutor} and {@link HttpAsyncRequester} */ @Deprecated @Contract(threading = ThreadingBehavior.SAFE_CONDITIONAL) public class ThrottlingHttpClientHandler extends NHttpHandlerBase implements NHttpClientHandler { protected HttpRequestExecutionHandler execHandler; protected final Executor executor; private final int bufsize; 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); Args.notNull(execHandler, "HTTP request execution handler"); Args.notNull(executor, "Executor"); this.execHandler = execHandler; this.executor = executor; this.bufsize = this.params.getIntParameter(NIOReactorPNames.CONTENT_BUFFER_SIZE, 20480); } public ThrottlingHttpClientHandler( final HttpProcessor httpProcessor, final HttpRequestExecutionHandler execHandler, final ConnectionReuseStrategy connStrategy, final Executor executor, final HttpParams params) { this(httpProcessor, execHandler, connStrategy, DirectByteBufferAllocator.INSTANCE, executor, params); } @Override public void connected(final NHttpClientConnection conn, final Object attachment) { final HttpContext context = conn.getContext(); initialize(conn, attachment); final ClientConnState connState = new ClientConnState(this.bufsize, conn, this.allocator); context.setAttribute(CONN_STATE, connState); if (this.eventListener != null) { this.eventListener.connectionOpen(conn); } requestReady(conn); } @Override public void closed(final NHttpClientConnection conn) { final HttpContext context = conn.getContext(); final ClientConnState connState = (ClientConnState) context.getAttribute(CONN_STATE); if (connState != null) { synchronized (connState) { connState.close(); connState.notifyAll(); } } this.execHandler.finalizeContext(context); if (this.eventListener != null) { this.eventListener.connectionClosed(conn); } } @Override public void exception(final NHttpClientConnection conn, final HttpException ex) { closeConnection(conn, ex); if (this.eventListener != null) { this.eventListener.fatalProtocolException(ex, conn); } } @Override public void exception(final NHttpClientConnection conn, final IOException ex) { shutdownConnection(conn, ex); if (this.eventListener != null) { this.eventListener.fatalIOException(ex, conn); } } @Override public void requestReady(final NHttpClientConnection conn) { final HttpContext context = conn.getContext(); final ClientConnState connState = (ClientConnState) context.getAttribute(CONN_STATE); try { synchronized (connState) { if (connState.getOutputState() != ClientConnState.READY) { return; } final 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 (final IOException ex) { shutdownConnection(conn, ex); if (this.eventListener != null) { this.eventListener.fatalIOException(ex, conn); } } catch (final HttpException ex) { closeConnection(conn, ex); if (this.eventListener != null) { this.eventListener.fatalProtocolException(ex, conn); } } } @Override public void outputReady(final NHttpClientConnection conn, final ContentEncoder encoder) { final HttpContext context = conn.getContext(); final ClientConnState connState = (ClientConnState) context.getAttribute(CONN_STATE); try { synchronized (connState) { if (connState.getOutputState() == ClientConnState.EXPECT_CONTINUE) { conn.suspendOutput(); return; } final 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 (final IOException ex) { shutdownConnection(conn, ex); if (this.eventListener != null) { this.eventListener.fatalIOException(ex, conn); } } } @Override public void responseReceived(final NHttpClientConnection conn) { final HttpContext context = conn.getContext(); final ClientConnState connState = (ClientConnState) context.getAttribute(CONN_STATE); try { synchronized (connState) { final HttpResponse response = conn.getHttpResponse(); response.setParams( new DefaultedHttpParams(response.getParams(), this.params)); final HttpRequest request = connState.getRequest(); final 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) { final 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 (final IOException ex) { shutdownConnection(conn, ex); if (this.eventListener != null) { this.eventListener.fatalIOException(ex, conn); } } catch (final HttpException ex) { closeConnection(conn, ex); if (this.eventListener != null) { this.eventListener.fatalProtocolException(ex, conn); } } } @Override public void inputReady(final NHttpClientConnection conn, final ContentDecoder decoder) { final HttpContext context = conn.getContext(); final ClientConnState connState = (ClientConnState) context.getAttribute(CONN_STATE); try { synchronized (connState) { final HttpResponse response = connState.getResponse(); final 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 (final IOException ex) { shutdownConnection(conn, ex); if (this.eventListener != null) { this.eventListener.fatalIOException(ex, conn); } } } @Override public void timeout(final NHttpClientConnection conn) { final HttpContext context = conn.getContext(); final 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 (final 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) { final 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 { final HttpRequest request = connState.getRequest(); final int timeout = connState.getTimeout(); conn.setSocketTimeout(timeout); sendRequestBody( (HttpEntityEnclosingRequest) request, connState, conn); } /** * @throws IOException - not thrown currently */ private void sendRequestBody( final HttpEntityEnclosingRequest request, final ClientConnState connState, final NHttpClientConnection conn) throws IOException { final HttpEntity entity = request.getEntity(); if (entity != null) { this.executor.execute(new Runnable() { @Override 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 (;;) { final int currentState = connState.getOutputState(); if (!connState.isWorkerRunning()) { break; } if (currentState == ServerConnState.SHUTDOWN) { return; } connState.wait(); } } catch (final InterruptedException ex) { connState.shutdown(); return; } connState.setWorkerRunning(true); } final OutputStream outstream = new ContentOutputStream( connState.getOutbuffer()); request.getEntity().writeTo(outstream); outstream.flush(); outstream.close(); synchronized (connState) { connState.setWorkerRunning(false); connState.notifyAll(); } } catch (final 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() { @Override 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 (;;) { final int currentState = connState.getOutputState(); if (!connState.isWorkerRunning()) { break; } if (currentState == ServerConnState.SHUTDOWN) { return; } connState.wait(); } } catch (final InterruptedException ex) { connState.shutdown(); return; } connState.setWorkerRunning(true); } execHandler.handleResponse(response, context); synchronized (connState) { try { for (;;) { final int currentState = connState.getInputState(); if (currentState == ClientConnState.RESPONSE_DONE) { break; } if (currentState == ServerConnState.SHUTDOWN) { return; } connState.wait(); } } catch (final InterruptedException ex) { connState.shutdown(); } connState.resetInput(); connState.resetOutput(); if (conn.isOpen()) { conn.requestOutput(); } connState.setWorkerRunning(false); connState.notifyAll(); } } catch (final 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( final 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(final int inputState) { this.inputState = inputState; } public int getOutputState() { return this.outputState; } public void setOutputState(final 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(final int timeout) { this.timeout = timeout; } public boolean isWorkerRunning() { return this.workerRunning; } public void setWorkerRunning(final 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; } } }




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