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