src/main/java/net/pterodactylus/sonitus/data/Pipeline.java

   1 /*
   2  * Sonitus - Pipeline.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;
  19
  20 import java.io.IOException;
  21 import java.util.Collection;
  22 import java.util.List;
  23 import java.util.concurrent.Callable;
  24 import java.util.concurrent.ExecutionException;
  25 import java.util.concurrent.ExecutorService;
  26 import java.util.concurrent.Executors;
  27 import java.util.concurrent.Future;
  28 import java.util.concurrent.atomic.AtomicBoolean;
  29 import java.util.logging.Logger;
  30
  31 import com.google.common.base.Function;
  32 import com.google.common.base.Preconditions;
  33 import com.google.common.collect.ArrayListMultimap;
  34 import com.google.common.collect.FluentIterable;
  35 import com.google.common.collect.ImmutableMultimap;
  36 import com.google.common.collect.Lists;
  37 import com.google.common.collect.Multimap;
  38 import com.google.common.util.concurrent.MoreExecutors;
  39
  40 /**
  41  * A pipeline is responsible for streaming audio data from a {@link Source} to
  42  * an arbitrary number of connected {@link Filter}s and {@link Sink}s.
  43  *
  44  * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
  45  */
  46 public class Pipeline {
  47
  48         /** The logger. */
  49         private static final Logger logger = Logger.getLogger(Pipeline.class.getName());
  50
  51         /** The source of the audio stream. */
  52         private final Source source;
  53
  54         /** The sinks for each source. */
  55         private final Multimap<Source, Sink> sinks;
  56
  57         /** All started feeders. */
  58         private final List<Feeder> feeders = Lists.newArrayList();
  59
  60         /**
  61          * Creates a new pipeline.
  62          *
  63          * @param source
  64          *              The source of the audio stream
  65          * @param sinks
  66          *              The sinks for each source
  67          */
  68         private Pipeline(Source source, Multimap<Source, Sink> sinks) {
  69                 this.source = Preconditions.checkNotNull(source, "source must not be null");
  70                 this.sinks = Preconditions.checkNotNull(sinks, "sinks must not be null");
  71         }
  72
  73         //
  74         // ACTIONS
  75         //
  76
  77         /**
  78          * Starts the pipeline.
  79          *
  80          * @throws IOException
  81          *              if any of the sinks can not be opened
  82          * @throws IllegalStateException
  83          *              if the pipeline is already running
  84          */
  85         public void start() throws IOException, IllegalStateException {
  86                 if (!feeders.isEmpty()) {
  87                         throw new IllegalStateException("Pipeline is already running!");
  88                 }
  89                 List<Source> sources = Lists.newArrayList();
  90                 sources.add(source);
  91                 /* collect all source->sink pairs. */
  92                 while (!sources.isEmpty()) {
  93                         Source source = sources.remove(0);
  94                         Collection<Sink> sinks = this.sinks.get(source);
  95                         feeders.add(new Feeder(source, sinks));
  96                         for (Sink sink : sinks) {
  97                                 sink.open(source.metadata());
  98                                 if (sink instanceof Filter) {
  99                                         sources.add((Source) sink);
 100                                 }
 101                         }
 102                 }
 103                 for (Feeder feeder : feeders) {
 104                         logger.info(String.format("Starting Feeder from %s to %s.", feeder.source, feeder.sinks));
 105                         new Thread(feeder).start();
 106                 }
 107         }
 108
 109         public void stop() {
 110                 if (!feeders.isEmpty()) {
 111                         /* pipeline is not running. */
 112                         return;
 113                 }
 114                 for (Feeder feeder : feeders) {
 115                         feeder.stop();
 116                 }
 117         }
 118
 119         //
 120         // STATIC METHODS
 121         //
 122
 123         /**
 124          * Returns a new pipeline builder.
 125          *
 126          * @param source
 127          *              The source at which to start
 128          * @return A builder for a new pipeline
 129          */
 130         public static Builder builder(Source source) {
 131                 return new Builder(source);
 132         }
 133
 134         /**
 135          * A builder for a {@link Pipeline}.
 136          *
 137          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
 138          */
 139         public static class Builder {
 140
 141                 /** The source of the pipeline. */
 142                 private final Source source;
 143
 144                 /** The sinks to which each source streams. */
 145                 private Multimap<Source, Sink> nextSinks = ArrayListMultimap.create();
 146
 147                 /** The last added source. */
 148                 private Source lastSource;
 149
 150                 /**
 151                  * Creates a new builder.
 152                  *
 153                  * @param source
 154                  *              The source that starts the pipeline
 155                  */
 156                 private Builder(Source source) {
 157                         this.source = source;
 158                         lastSource = source;
 159                 }
 160
 161                 /**
 162                  * Adds a {@link Sink} (or {@link Filter} as a recipient for the last added
 163                  * {@link Source}.
 164                  *
 165                  * @param sink
 166                  *              The sink to add
 167                  * @return This builder
 168                  * @throws IllegalStateException
 169                  *              if the last added {@link Sink} was not also a {@link Source}
 170                  */
 171                 public Builder to(Sink sink) {
 172                         Preconditions.checkState(lastSource != null, "last added Sink was not a Source");
 173                         nextSinks.put(lastSource, sink);
 174                         lastSource = (sink instanceof Filter) ? (Source) sink : null;
 175                         return this;
 176                 }
 177
 178                 /**
 179                  * Locates the given source and sets it as the last added node so that the
 180                  * next invocation of {@link #to(Sink)} can “fork” the pipeline.
 181                  *
 182                  * @param source
 183                  *              The source to locate
 184                  * @return This builder
 185                  * @throws IllegalStateException
 186                  *              if the given source was not previously added as a sink
 187                  */
 188                 public Builder find(Source source) {
 189                         Preconditions.checkState(nextSinks.containsValue(source));
 190                         lastSource = source;
 191                         return this;
 192                 }
 193
 194                 /**
 195                  * Builds the pipeline.
 196                  *
 197                  * @return The created pipeline
 198                  */
 199                 public Pipeline build() {
 200                         return new Pipeline(source, ImmutableMultimap.copyOf(nextSinks));
 201                 }
 202
 203         }
 204
 205         /**
 206          * A feeder is responsible for streaming audio from one {@link Source} to an
 207          * arbitrary number of {@link Sink}s it is connected to. A feeder is started by
 208          * creating a {@link Thread} wrapping it and starting said thread.
 209          *
 210          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
 211          */
 212         private class Feeder implements Runnable {
 213
 214                 /** The source. */
 215                 private final Source source;
 216
 217                 /** The sinks. */
 218                 private final Collection<Sink> sinks;
 219
 220                 /** Whether the feeder was stopped. */
 221                 private final AtomicBoolean stopped = new AtomicBoolean(false);
 222
 223                 /** The executor service. */
 224                 private final ExecutorService executorService;
 225
 226                 /**
 227                  * Creates a new feeder.
 228                  *
 229                  * @param source
 230                  *              The source of the stream
 231                  * @param sinks
 232                  *              The sinks to which to stream
 233                  */
 234                 public Feeder(Source source, Collection<Sink> sinks) {
 235                         this.source = source;
 236                         this.sinks = sinks;
 237                         if (sinks.size() == 1) {
 238                                 executorService = MoreExecutors.sameThreadExecutor();
 239                         } else {
 240                                 executorService = Executors.newCachedThreadPool();
 241                         }
 242                 }
 243
 244                 //
 245                 // ACTIONS
 246                 //
 247
 248                 /** Stops this feeder. */
 249                 public void stop() {
 250                         stopped.set(true);
 251                 }
 252
 253                 //
 254                 // RUNNABLE METHODS
 255                 //
 256
 257                 @Override
 258                 public void run() {
 259                         Metadata firstMetadata = null;
 260                         while (!stopped.get()) {
 261                                 try {
 262                                         final Metadata lastMetadata = firstMetadata;
 263                                         final Metadata metadata = firstMetadata = source.metadata();
 264                                         final byte[] buffer;
 265                                         try {
 266                                                 logger.finest(String.format("Getting %d bytes from %s...", 4096, source));
 267                                                 buffer = source.get(4096);
 268                                                 logger.finest(String.format("Got %d bytes from %s.", buffer.length, source));
 269                                         } catch (IOException ioe1) {
 270                                                 throw new IOException(String.format("I/O error while reading from %s.", source), ioe1);
 271                                         }
 272                                         List<Future<Void>> futures = executorService.invokeAll(FluentIterable.from(sinks).transform(new Function<Sink, Callable<Void>>() {
 273
 274                                                 @Override
 275                                                 public Callable<Void> apply(final Sink sink) {
 276                                                         return new Callable<Void>() {
 277
 278                                                                 @Override
 279                                                                 public Void call() throws Exception {
 280                                                                         if (!metadata.equals(lastMetadata)) {
 281                                                                                 sink.metadataUpdated(metadata);
 282                                                                         }
 283                                                                         try {
 284                                                                                 logger.finest(String.format("Sending %d bytes to %s.", buffer.length, sink));
 285                                                                                 sink.process(buffer);
 286                                                                                 logger.finest(String.format("Sent %d bytes to %s.", buffer.length, sink));
 287                                                                         } catch (IOException ioe1) {
 288                                                                                 throw new IOException(String.format("I/O error while writing to %s", sink), ioe1);
 289                                                                         }
 290                                                                         return null;
 291                                                                 }
 292                                                         };
 293                                                 }
 294                                         }).toList());
 295                                         /* check all threads for exceptions. */
 296                                         for (Future<Void> future : futures) {
 297                                                 future.get();
 298                                         }
 299                                 } catch (IOException e) {
 300                                         /* TODO */
 301                                         e.printStackTrace();
 302                                         break;
 303                                 } catch (InterruptedException e) {
 304                                         /* TODO */
 305                                         e.printStackTrace();
 306                                         break;
 307                                 } catch (ExecutionException e) {
 308                                         /* TODO */
 309                                         e.printStackTrace();
 310                                         break;
 311                                 }
 312                         }
 313                 }
 314
 315         }
 316
 317 }