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

   1 /*
   2  * Sonitus - ExternalFilter.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.PipedOutputStream;
  25 import java.util.Arrays;
  26 import java.util.logging.Logger;
  27
  28 import net.pterodactylus.sonitus.data.ConnectException;
  29 import net.pterodactylus.sonitus.data.Connection;
  30 import net.pterodactylus.sonitus.data.Filter;
  31 import net.pterodactylus.sonitus.data.Metadata;
  32 import net.pterodactylus.sonitus.data.Source;
  33 import net.pterodactylus.sonitus.io.InputStreamDrainer;
  34
  35 import com.google.common.base.Preconditions;
  36 import com.google.common.collect.ImmutableList;
  37 import com.google.common.collect.Iterables;
  38
  39 /**
  40  * {@link Filter} implementation that runs its {@link Source} through an
  41  * external program.
  42  *
  43  * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
  44  */
  45 public abstract class ExternalFilter implements Filter {
  46
  47         /** The logger. */
  48         private final Logger logger = Logger.getLogger(getClass().getName());
  49
  50         /** The source. */
  51         private Source source;
  52
  53         private InputStream processInputStream;
  54
  55         //
  56         // FILTER METHODS
  57         //
  58
  59         @Override
  60         public Metadata metadata() {
  61                 return source.metadata();
  62         }
  63
  64         @Override
  65         public byte[] get(int bufferSize) throws EOFException, IOException {
  66                 byte[] buffer = new byte[bufferSize];
  67                 int read = processInputStream.read(buffer);
  68                 if (read == -1) {
  69                         throw new EOFException();
  70                 }
  71                 return Arrays.copyOf(buffer, read);
  72         }
  73
  74         @Override
  75         public void connect(Source source) throws ConnectException {
  76                 Preconditions.checkNotNull(source, "source must not be null");
  77
  78                 this.source = source;
  79                 try {
  80                         final Process process = Runtime.getRuntime().exec(Iterables.toArray(ImmutableList.<String>builder().add(binary(source.metadata())).addAll(parameters(source.metadata())).build(), String.class));
  81                         processInputStream = process.getInputStream();
  82                         final OutputStream processInput = process.getOutputStream();
  83                         final InputStream processError = process.getErrorStream();
  84                         final PipedOutputStream pipedOutputStream = new PipedOutputStream();
  85                         new Thread(new InputStreamDrainer(processError)).start();
  86                         new Thread(new Connection(source) {
  87
  88                                 @Override
  89                                 protected int bufferSize() {
  90                                         return 4096;
  91                                 }
  92
  93                                 @Override
  94                                 protected void feed(byte[] buffer) throws IOException {
  95                                         processInput.write(buffer);
  96                                         processInput.flush();
  97                                 }
  98
  99                                 @Override
 100                                 protected void finish() throws IOException {
 101                                         processInput.close();
 102                                         processError.close();
 103                                 }
 104                         }).start();
 105                 } catch (IOException ioe1) {
 106
 107                 }
 108         }
 109
 110         @Override
 111         public void metadataUpdated() {
 112                 /* ignore. */
 113         }
 114
 115         //
 116         // SUBCLASS METHODS
 117         //
 118
 119         /**
 120          * Returns the location of the binary to execute.
 121          *
 122          * @param metadata
 123          *              The metadata being processed
 124          * @return The location of the binary to execute
 125          */
 126         protected abstract String binary(Metadata metadata);
 127
 128         /**
 129          * Returns the parameters for the binary.
 130          *
 131          * @param metadata
 132          *              The metadata being processed
 133          * @return The parameters for the binary
 134          */
 135         protected abstract Iterable<String> parameters(Metadata metadata);
 136
 137 }