1 /* 2 * $HeadURL: http://svn.apache.org/repos/asf/httpcomponents/httpcore/trunk/module-main/src/main/java/org/apache/http/impl/io/SocketInputBuffer.java $ 3 * $Revision: 560358 $ 4 * $Date: 2007-07-27 12:30:42 -0700 (Fri, 27 Jul 2007) $ 5 * 6 * ==================================================================== 7 * Licensed to the Apache Software Foundation (ASF) under one 8 * or more contributor license agreements. See the NOTICE file 9 * distributed with this work for additional information 10 * regarding copyright ownership. The ASF licenses this file 11 * to you under the Apache License, Version 2.0 (the 12 * "License"); you may not use this file except in compliance 13 * with the License. You may obtain a copy of the License at 14 * 15 * http://www.apache.org/licenses/LICENSE-2.0 16 * 17 * Unless required by applicable law or agreed to in writing, 18 * software distributed under the License is distributed on an 19 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 20 * KIND, either express or implied. See the License for the 21 * specific language governing permissions and limitations 22 * under the License. 23 * ==================================================================== 24 * 25 * This software consists of voluntary contributions made by many 26 * individuals on behalf of the Apache Software Foundation. For more 27 * information on the Apache Software Foundation, please see 28 * <http://www.apache.org/>. 29 * 30 */ 31 32 package org.apache.http.impl.io; 33 34 import java.io.IOException; 35 import java.io.InterruptedIOException; 36 import java.net.Socket; 37 import java.net.SocketTimeoutException; 38 39 import java.net.SocketTimeoutException; 40 import org.apache.http.params.HttpParams; 41 42 43 /** 44 * {@link Socket} bound session input buffer. 45 * 46 * @author <a href="mailto:oleg at ural.ru">Oleg Kalnichevski</a> 47 * 48 * @version $Revision: 560358 $ 49 * 50 * @since 4.0 51 */ 52 public class SocketInputBuffer extends AbstractSessionInputBuffer { 53 54 private final Socket socket; 55 56 public SocketInputBuffer( 57 final Socket socket, 58 int buffersize, 59 final HttpParams params) throws IOException { 60 super(); 61 if (socket == null) { 62 throw new IllegalArgumentException("Socket may not be null"); 63 } 64 this.socket = socket; 65 // BEGIN android-changed 66 // Workaround for http://b/3514259. We take 'buffersize' as a hint in 67 // the weakest sense, and always use an 8KiB heap buffer and leave the 68 // kernel buffer size alone, trusting the system to have set a 69 // network-appropriate default. 70 init(socket.getInputStream(), 8192, params); 71 // END android-changed 72 } 73 74 public boolean isDataAvailable(int timeout) throws IOException { 75 boolean result = hasBufferedData(); 76 if (!result) { 77 int oldtimeout = this.socket.getSoTimeout(); 78 try { 79 this.socket.setSoTimeout(timeout); 80 fillBuffer(); 81 result = hasBufferedData(); 82 } catch (InterruptedIOException e) { 83 if (!(e instanceof SocketTimeoutException)) { 84 throw e; 85 } 86 } finally { 87 socket.setSoTimeout(oldtimeout); 88 } 89 } 90 return result; 91 } 92 93 // BEGIN android-added 94 /** 95 * Returns true if the connection is probably functional. It's insufficient 96 * to rely on isDataAvailable() returning normally; that approach cannot 97 * distinguish between an exhausted stream and a stream with zero bytes 98 * buffered. 99 * 100 * @hide 101 */ 102 public boolean isStale() throws IOException { 103 if (hasBufferedData()) { 104 return false; 105 } 106 int oldTimeout = this.socket.getSoTimeout(); 107 try { 108 this.socket.setSoTimeout(1); 109 return fillBuffer() == -1; 110 } catch (SocketTimeoutException e) { 111 return false; // the connection is not stale; hooray 112 } catch (IOException e) { 113 return true; // the connection is stale, the read or soTimeout failed. 114 } finally { 115 this.socket.setSoTimeout(oldTimeout); 116 } 117 } 118 // END android-added 119 } 120
