src/main/java/net/pterodactylus/sonitus/data/filter/DummyFilter.java

   1 /*
   2  * Sonitus - AbstractFilter.java - Copyright © 2013 David Roden
   3  *
   4  * This program is free software: you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation, either version 3 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 package net.pterodactylus.sonitus.data.filter;
  19
  20 import java.io.EOFException;
  21 import java.io.IOException;
  22 import java.io.InputStream;
  23 import java.io.OutputStream;
  24 import java.io.PipedInputStream;
  25 import java.io.PipedOutputStream;
  26 import java.util.Arrays;
  27
  28 import net.pterodactylus.sonitus.data.Filter;
  29 import net.pterodactylus.sonitus.data.Metadata;
  30
  31 import com.google.common.io.Closeables;
  32
  33 /**
  34  * Dummy {@link Filter} implementation that pipes its input to its output.
  35  *
  36  * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
  37  */
  38 public class DummyFilter implements Filter {
  39
  40         /** The input stream from which to read. */
  41         private InputStream inputStream;
  42
  43         /** The output stream to which to write. */
  44         private OutputStream outputStream;
  45
  46         /** The current metadata. */
  47         private Metadata metadata;
  48
  49         //
  50         // FILTER METHODS
  51         //
  52
  53         @Override
  54         public void open(Metadata metadata) throws IOException {
  55                 this.metadata = metadata;
  56                 inputStream = createInputStream();
  57                 outputStream = createOutputStream();
  58         }
  59
  60         @Override
  61         public void close() {
  62                 try {
  63                         Closeables.close(outputStream, true);
  64                         Closeables.close(inputStream, true);
  65                 } catch (IOException e) {
  66                         /* won’t throw. */
  67                 }
  68         }
  69
  70         @Override
  71         public Metadata metadata() {
  72                 return metadata;
  73         }
  74
  75         @Override
  76         public void metadataUpdated(Metadata metadata) {
  77                 this.metadata = metadata;
  78         }
  79
  80         @Override
  81         public void process(byte[] buffer) throws IOException {
  82                 outputStream.write(buffer);
  83                 outputStream.flush();
  84         }
  85
  86         @Override
  87         public byte[] get(int bufferSize) throws IOException {
  88                 byte[] buffer = new byte[bufferSize];
  89                 int read = inputStream.read(buffer);
  90                 if (read == -1) {
  91                         throw new EOFException();
  92                 }
  93                 return Arrays.copyOf(buffer, read);
  94         }
  95
  96         //
  97         // SUBCLASS METHODS
  98         //
  99
 100         /**
 101          * Creates the input stream from which {@link net.pterodactylus.sonitus.data.Pipeline}
 102          * will read the audio data. If you override this, you have to override {@link
 103          * #createOutputStream()}, too!
 104          *
 105          * @return The input stream to read from
 106          * @throws IOException
 107          *              if an I/O error occurs
 108          */
 109         protected InputStream createInputStream() throws IOException {
 110                 return new PipedInputStream();
 111         }
 112
 113         /**
 114          * Creates the output stream to which {@link net.pterodactylus.sonitus.data.Pipeline}
 115          * will write the audio data. If you override this, you have to override {@link
 116          * #createInputStream()}, too!
 117          *
 118          * @return The output stream to write to
 119          * @throws IOException
 120          *              if an I/O error occurs
 121          */
 122         protected OutputStream createOutputStream() throws IOException {
 123                 return new PipedOutputStream((PipedInputStream) inputStream);
 124         }
 125
 126 }