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