1 /**************************************************************** 2 * Licensed to the Apache Software Foundation (ASF) under one * 3 * or more contributor license agreements. See the NOTICE file * 4 * distributed with this work for additional information * 5 * regarding copyright ownership. The ASF licenses this file * 6 * to you under the Apache License, Version 2.0 (the * 7 * "License"); you may not use this file except in compliance * 8 * with the License. You may obtain a copy of the License at * 9 * * 10 * http://www.apache.org/licenses/LICENSE-2.0 * 11 * * 12 * Unless required by applicable law or agreed to in writing, * 13 * software distributed under the License is distributed on an * 14 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY * 15 * KIND, either express or implied. See the License for the * 16 * specific language governing permissions and limitations * 17 * under the License. * 18 ****************************************************************/ 19 20 21 22 package org.apache.james.util.scheduler; 23 24 import org.apache.avalon.cornerstone.services.scheduler.TimeScheduler; 25 26 import java.io.IOException; 27 import java.io.InputStream; 28 29 /** 30 * This will reset the scheduler each time a certain amount of data has 31 * been transfered. This allows us to keep the timeout settings low, while 32 * not timing out during large data transfers. 33 */ 34 public class SchedulerNotifyInputStream extends InputStream { 35 36 /** 37 * The wrapped InputStream 38 */ 39 InputStream in = null; 40 41 /** 42 * The scheduler managing the trigger to be reset by this stream 43 */ 44 TimeScheduler scheduler = null; 45 46 /** 47 * The name of the trigger 48 */ 49 String triggerName = null; 50 51 /** 52 * The number of bytes that need to be read before the counter is reset. 53 */ 54 int lengthReset = 0; 55 56 /** 57 * The number of bytes read since the counter was last reset 58 */ 59 int readCounter = 0; 60 61 /** 62 * @param in the InputStream to be wrapped by this stream 63 * @param scheduler the TimeScheduler managing the trigger to be reset by this stream 64 * @param triggerName the name of the particular trigger to be reset by this stream 65 * @param lengthReset the number of bytes to be read in between trigger resets 66 */ 67 public SchedulerNotifyInputStream(InputStream in, 68 TimeScheduler scheduler, String triggerName, int lengthReset) { 69 this.in = in; 70 this.scheduler = scheduler; 71 this.triggerName = triggerName; 72 this.lengthReset = lengthReset; 73 74 readCounter = 0; 75 } 76 77 /** 78 * Read an array of bytes from the stream 79 * 80 * @param b the array of bytes to read from the stream 81 * @param off the index in the array where we start writing 82 * @param len the number of bytes of the array to read 83 * 84 * @return the number of bytes read 85 * 86 * @throws IOException if an exception is encountered when reading 87 */ 88 public int read(byte[] b, int off, int len) throws IOException { 89 int l = in.read(b, off, len); 90 readCounter += l; 91 92 if (readCounter > lengthReset) { 93 readCounter -= lengthReset; 94 scheduler.resetTrigger(triggerName); 95 } 96 97 return l; 98 } 99 100 /** 101 * Read a byte from the stream 102 * 103 * @return the byte read from the stream 104 * @throws IOException if an exception is encountered when reading 105 */ 106 public int read() throws IOException { 107 int b = in.read(); 108 readCounter++; 109 110 if (readCounter > lengthReset) { 111 readCounter -= lengthReset; 112 scheduler.resetTrigger(triggerName); 113 } 114 115 return b; 116 } 117 118 /** 119 * Close the stream 120 * 121 * @throws IOException if an exception is encountered when closing 122 */ 123 public void close() throws IOException { 124 in.close(); 125 } 126 }