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 import java.util.Collections;
  28 import java.util.List;
  29
  30 import net.pterodactylus.sonitus.data.Controller;
  31 import net.pterodactylus.sonitus.data.Filter;
  32 import net.pterodactylus.sonitus.data.Metadata;
  33
  34 import com.google.common.io.Closeables;
  35
  36 /**
  37  * Dummy {@link Filter} implementation that pipes its input to its output.
  38  *
  39  * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
  40  */
  41 public class DummyFilter implements Filter {
  42
  43         /** The input stream from which to read. */
  44         private InputStream inputStream;
  45
  46         /** The output stream to which to write. */
  47         private OutputStream outputStream;
  48
  49         /** The current metadata. */
  50         private Metadata metadata;
  51
  52         //
  53         // CONTROLLED METHODS
  54         //
  55
  56         @Override
  57         public List<Controller<?>> controllers() {
  58                 return Collections.emptyList();
  59         }
  60
  61         //
  62         // FILTER METHODS
  63         //
  64
  65         @Override
  66         public void open(Metadata metadata) throws IOException {
  67                 this.metadata = metadata;
  68                 inputStream = createInputStream();
  69                 outputStream = createOutputStream();
  70         }
  71
  72         @Override
  73         public void close() {
  74                 try {
  75                         Closeables.close(outputStream, true);
  76                         Closeables.close(inputStream, true);
  77                 } catch (IOException e) {
  78                         /* won’t throw. */
  79                 }
  80         }
  81
  82         @Override
  83         public Metadata metadata() {
  84                 return metadata;
  85         }
  86
  87         @Override
  88         public void metadataUpdated(Metadata metadata) {
  89                 this.metadata = metadata;
  90         }
  91
  92         @Override
  93         public void process(byte[] buffer) throws IOException {
  94                 outputStream.write(buffer);
  95                 outputStream.flush();
  96         }
  97
  98         @Override
  99         public byte[] get(int bufferSize) throws IOException {
 100                 byte[] buffer = new byte[bufferSize];
 101                 int read = inputStream.read(buffer);
 102                 if (read == -1) {
 103                         throw new EOFException();
 104                 }
 105                 return Arrays.copyOf(buffer, read);
 106         }
 107
 108         //
 109         // SUBCLASS METHODS
 110         //
 111
 112         /**
 113          * Creates the input stream from which {@link net.pterodactylus.sonitus.data.Pipeline}
 114          * will read the audio data. If you override this, you have to override {@link
 115          * #createOutputStream()}, too!
 116          *
 117          * @return The input stream to read from
 118          * @throws IOException
 119          *              if an I/O error occurs
 120          */
 121         protected InputStream createInputStream() throws IOException {
 122                 return new PipedInputStream();
 123         }
 124
 125         /**
 126          * Creates the output stream to which {@link net.pterodactylus.sonitus.data.Pipeline}
 127          * will write the audio data. If you override this, you have to override {@link
 128          * #createInputStream()}, too!
 129          *
 130          * @return The output stream to write to
 131          * @throws IOException
 132          *              if an I/O error occurs
 133          */
 134         protected OutputStream createOutputStream() throws IOException {
 135                 return new PipedOutputStream((PipedInputStream) inputStream);
 136         }
 137
 138 }