001    /*
002     * Sonar, open source software quality management tool.
003     * Copyright (C) 2008-2012 SonarSource
004     * mailto:contact AT sonarsource DOT com
005     *
006     * Sonar is free software; you can redistribute it and/or
007     * modify it under the terms of the GNU Lesser General Public
008     * License as published by the Free Software Foundation; either
009     * version 3 of the License, or (at your option) any later version.
010     *
011     * Sonar is distributed in the hope that it will be useful,
012     * but WITHOUT ANY WARRANTY; without even the implied warranty of
013     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014     * Lesser General Public License for more details.
015     *
016     * You should have received a copy of the GNU Lesser General Public
017     * License along with Sonar; if not, write to the Free Software
018     * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02
019     */
020    package org.sonar.channel;
021    
022    import java.io.IOException;
023    import java.io.Reader;
024    
025    /**
026     * This class is a special CodeReaderFilter that uses Channels to filter the character stream before it is passed to the main channels
027     * declared for the CodeReader.
028     * 
029     */
030    public final class ChannelCodeReaderFilter<OUTPUT> extends CodeReaderFilter<OUTPUT> {
031    
032      @SuppressWarnings("unchecked")
033      private Channel<OUTPUT>[] channels = new Channel[0];
034    
035      private CodeReader internalCodeReader;
036    
037      /**
038       * Creates a CodeReaderFilter that will use the provided Channels to filter the character stream it gets from its reader.
039       * 
040       * @param channels
041       *          the different channels
042       */
043      public ChannelCodeReaderFilter(Channel<OUTPUT>... channels) {
044        super();
045        this.channels = channels;
046      }
047    
048      /**
049       * Creates a CodeReaderFilter that will use the provided Channels to filter the character stream it gets from its reader. And optionally,
050       * it can push token to the provided output object.
051       * 
052       * @param output
053       *          the object that may accept tokens
054       * @param channels
055       *          the different channels
056       */
057      public ChannelCodeReaderFilter(OUTPUT output, Channel<OUTPUT>... channels) {
058        super(output);
059        this.channels = channels;
060      }
061    
062      /**
063       * {@inheritDoc}
064       */
065      @Override
066      public void setReader(Reader reader) {
067        super.setReader(reader);
068        internalCodeReader = new CodeReader(reader, getConfiguration());
069      }
070    
071      /**
072       * {@inheritDoc}
073       */
074      @Override
075      public int read(char[] filteredBuffer, int offset, int length) throws IOException {
076        if (internalCodeReader.peek() == -1) {
077          return -1;
078        }
079        int initialOffset = offset;
080        while (offset < filteredBuffer.length) {
081          if (internalCodeReader.peek() == -1) {
082            break;
083          }
084          boolean consumed = false;
085          for (Channel<OUTPUT> channel : channels) {
086            if (channel.consume(internalCodeReader, getOutput())) {
087              consumed = true;
088              break;
089            }
090          }
091          if ( !consumed) {
092            int charRead = internalCodeReader.pop();
093            filteredBuffer[offset++] = (char) charRead;
094          }
095        }
096        return offset - initialOffset;
097      }
098    
099    }