001 /* 002 * Licensed to the Apache Software Foundation (ASF) under one 003 * or more contributor license agreements. See the NOTICE file 004 * distributed with this work for additional information 005 * regarding copyright ownership. The ASF licenses this file 006 * to you under the Apache License, Version 2.0 (the 007 * "License"); you may not use this file except in compliance 008 * with the License. You may obtain a copy of the License at 009 * 010 * http://www.apache.org/licenses/LICENSE-2.0 011 * 012 * Unless required by applicable law or agreed to in writing, 013 * software distributed under the License is distributed on an 014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 015 * KIND, either express or implied. See the License for the 016 * specific language governing permissions and limitations 017 * under the License. 018 */ 019 020 package org.apache.myfaces.tobago.util; 021 022 import org.apache.commons.logging.Log; 023 import org.apache.commons.logging.LogFactory; 024 025 import java.io.IOException; 026 import java.io.Writer; 027 028 // 029 // Buffering scheme: we use a tremendously simple buffering 030 // scheme that greatly reduces the number of calls into the 031 // Writer/PrintWriter. In practice this has produced significant 032 // measured performance gains (at least in JDK 1.3.1). We only 033 // support adding single characters to the buffer, so anytime 034 // multiple characters need to be written out, the entire buffer 035 // gets flushed. In practice, this is good enough, and keeps 036 // the core simple. 037 // 038 039 /** 040 * User: lofwyr 041 * Date: 07.05.2007 12:03:26 042 */ 043 public class ResponseWriterBuffer { 044 045 private static final Log LOG = LogFactory.getLog(ResponseWriterBuffer.class); 046 047 private static final int BUFFER_SIZE = 64; 048 049 private final char[] buff = new char[BUFFER_SIZE]; 050 051 private int bufferIndex; 052 053 private final Writer writer; 054 055 public ResponseWriterBuffer(final Writer writer) { 056 this.writer = writer; 057 } 058 059 /** 060 * Add a character to the buffer, flushing the buffer if the buffer is 061 * full 062 */ 063 public void addToBuffer(final char ch) throws IOException { 064 if (bufferIndex >= BUFFER_SIZE) { 065 writer.write(buff, 0, bufferIndex); 066 bufferIndex = 0; 067 } 068 069 buff[bufferIndex++] = ch; 070 } 071 072 public void addToBuffer(final char[] ch) throws IOException { 073 if (bufferIndex + ch.length >= BUFFER_SIZE) { 074 writer.write(buff, 0, bufferIndex); 075 bufferIndex = 0; 076 } 077 078 System.arraycopy(ch, 0, buff, bufferIndex, ch.length); 079 bufferIndex += ch.length; 080 } 081 082 /** 083 * Flush the contents of the buffer to the output stream 084 * and return the reset buffer index 085 */ 086 public void flushBuffer() throws IOException { 087 if (bufferIndex > 0) { 088 writer.write(buff, 0, bufferIndex); 089 } 090 bufferIndex = 0; 091 } 092 }