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