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    }