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         // ACCESSORS
  75         //
  76
  77         /**
  78          * Expose this pipeline’s source.
  79          *
  80          * @return This pipeline’s source
  81          */
  82         public Source source() {
  83                 return source;
  84         }
  85
  86         /**
  87          * Returns all {@link Sink}s (or {@link Filter}s, really) that are connected to
  88          * the given source.
  89          *
  90          * @param source
  91          *              The source to get the sinks for
  92          * @return The sinks connected to the given source, or an empty list if the
  93          *         source does not exist in this pipeline
  94          */
  95         public Collection<Sink> sinks(Source source) {
  96                 return sinks.get(source);
  97         }
  98
  99         //
 100         // ACTIONS
 101         //
 102
 103         /**
 104          * Starts the pipeline.
 105          *
 106          * @throws IOException
 107          *              if any of the sinks can not be opened
 108          * @throws IllegalStateException
 109          *              if the pipeline is already running
 110          */
 111         public void start() throws IOException, IllegalStateException {
 112                 if (!feeders.isEmpty()) {
 113                         throw new IllegalStateException("Pipeline is already running!");
 114                 }
 115                 List<Source> sources = Lists.newArrayList();
 116                 sources.add(source);
 117                 /* collect all source->sink pairs. */
 118                 while (!sources.isEmpty()) {
 119                         Source source = sources.remove(0);
 120                         Collection<Sink> sinks = this.sinks.get(source);
 121                         feeders.add(new Feeder(source, sinks));
 122                         for (Sink sink : sinks) {
 123                                 sink.open(source.metadata());
 124                                 if (sink instanceof Filter) {
 125                                         sources.add((Source) sink);
 126                                 }
 127                         }
 128                 }
 129                 for (Feeder feeder : feeders) {
 130                         logger.info(String.format("Starting Feeder from %s to %s.", feeder.source, feeder.sinks));
 131                         new Thread(feeder).start();
 132                 }
 133         }
 134
 135         public void stop() {
 136                 if (!feeders.isEmpty()) {
 137                         /* pipeline is not running. */
 138                         return;
 139                 }
 140                 for (Feeder feeder : feeders) {
 141                         feeder.stop();
 142                 }
 143         }
 144
 145         //
 146         // STATIC METHODS
 147         //
 148
 149         /**
 150          * Returns a new pipeline builder.
 151          *
 152          * @param source
 153          *              The source at which to start
 154          * @return A builder for a new pipeline
 155          */
 156         public static Builder builder(Source source) {
 157                 return new Builder(source);
 158         }
 159
 160         /**
 161          * A builder for a {@link Pipeline}.
 162          *
 163          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
 164          */
 165         public static class Builder {
 166
 167                 /** The source of the pipeline. */
 168                 private final Source source;
 169
 170                 /** The sinks to which each source streams. */
 171                 private Multimap<Source, Sink> nextSinks = ArrayListMultimap.create();
 172
 173                 /** The last added source. */
 174                 private Source lastSource;
 175
 176                 /**
 177                  * Creates a new builder.
 178                  *
 179                  * @param source
 180                  *              The source that starts the pipeline
 181                  */
 182                 private Builder(Source source) {
 183                         this.source = source;
 184                         lastSource = source;
 185                 }
 186
 187                 /**
 188                  * Adds a {@link Sink} (or {@link Filter} as a recipient for the last added
 189                  * {@link Source}.
 190                  *
 191                  * @param sink
 192                  *              The sink to add
 193                  * @return This builder
 194                  * @throws IllegalStateException
 195                  *              if the last added {@link Sink} was not also a {@link Source}
 196                  */
 197                 public Builder to(Sink sink) {
 198                         Preconditions.checkState(lastSource != null, "last added Sink was not a Source");
 199                         nextSinks.put(lastSource, sink);
 200                         lastSource = (sink instanceof Filter) ? (Source) sink : null;
 201                         return this;
 202                 }
 203
 204                 /**
 205                  * Locates the given source and sets it as the last added node so that the
 206                  * next invocation of {@link #to(Sink)} can “fork” the pipeline.
 207                  *
 208                  * @param source
 209                  *              The source to locate
 210                  * @return This builder
 211                  * @throws IllegalStateException
 212                  *              if the given source was not previously added as a sink
 213                  */
 214                 public Builder find(Source source) {
 215                         Preconditions.checkState(nextSinks.containsValue(source));
 216                         lastSource = source;
 217                         return this;
 218                 }
 219
 220                 /**
 221                  * Builds the pipeline.
 222                  *
 223                  * @return The created pipeline
 224                  */
 225                 public Pipeline build() {
 226                         return new Pipeline(source, ImmutableMultimap.copyOf(nextSinks));
 227                 }
 228
 229         }
 230
 231         /**
 232          * A feeder is responsible for streaming audio from one {@link Source} to an
 233          * arbitrary number of {@link Sink}s it is connected to. A feeder is started by
 234          * creating a {@link Thread} wrapping it and starting said thread.
 235          *
 236          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
 237          */
 238         private class Feeder implements Runnable {
 239
 240                 /** The source. */
 241                 private final Source source;
 242
 243                 /** The sinks. */
 244                 private final Collection<Sink> sinks;
 245
 246                 /** Whether the feeder was stopped. */
 247                 private final AtomicBoolean stopped = new AtomicBoolean(false);
 248
 249                 /** The executor service. */
 250                 private final ExecutorService executorService;
 251
 252                 /**
 253                  * Creates a new feeder.
 254                  *
 255                  * @param source
 256                  *              The source of the stream
 257                  * @param sinks
 258                  *              The sinks to which to stream
 259                  */
 260                 public Feeder(Source source, Collection<Sink> sinks) {
 261                         this.source = source;
 262                         this.sinks = sinks;
 263                         if (sinks.size() == 1) {
 264                                 executorService = MoreExecutors.sameThreadExecutor();
 265                         } else {
 266                                 executorService = Executors.newCachedThreadPool();
 267                         }
 268                 }
 269
 270                 //
 271                 // ACTIONS
 272                 //
 273
 274                 /** Stops this feeder. */
 275                 public void stop() {
 276                         stopped.set(true);
 277                 }
 278
 279                 //
 280                 // RUNNABLE METHODS
 281                 //
 282
 283                 @Override
 284                 public void run() {
 285                         Metadata firstMetadata = null;
 286                         while (!stopped.get()) {
 287                                 try {
 288                                         final Metadata lastMetadata = firstMetadata;
 289                                         final Metadata metadata = firstMetadata = source.metadata();
 290                                         final byte[] buffer;
 291                                         try {
 292                                                 logger.finest(String.format("Getting %d bytes from %s...", 4096, source));
 293                                                 buffer = source.get(4096);
 294                                                 logger.finest(String.format("Got %d bytes from %s.", buffer.length, source));
 295                                         } catch (IOException ioe1) {
 296                                                 throw new IOException(String.format("I/O error while reading from %s.", source), ioe1);
 297                                         }
 298                                         List<Future<Void>> futures = executorService.invokeAll(FluentIterable.from(sinks).transform(new Function<Sink, Callable<Void>>() {
 299
 300                                                 @Override
 301                                                 public Callable<Void> apply(final Sink sink) {
 302                                                         return new Callable<Void>() {
 303
 304                                                                 @Override
 305                                                                 public Void call() throws Exception {
 306                                                                         if (!metadata.equals(lastMetadata)) {
 307                                                                                 sink.metadataUpdated(metadata);
 308                                                                         }
 309                                                                         try {
 310                                                                                 logger.finest(String.format("Sending %d bytes to %s.", buffer.length, sink));
 311                                                                                 sink.process(buffer);
 312                                                                                 logger.finest(String.format("Sent %d bytes to %s.", buffer.length, sink));
 313                                                                         } catch (IOException ioe1) {
 314                                                                                 throw new IOException(String.format("I/O error while writing to %s", sink), ioe1);
 315                                                                         }
 316                                                                         return null;
 317                                                                 }
 318                                                         };
 319                                                 }
 320                                         }).toList());
 321                                         /* check all threads for exceptions. */
 322                                         for (Future<Void> future : futures) {
 323                                                 future.get();
 324                                         }
 325                                 } catch (IOException e) {
 326                                         /* TODO */
 327                                         e.printStackTrace();
 328                                         break;
 329                                 } catch (InterruptedException e) {
 330                                         /* TODO */
 331                                         e.printStackTrace();
 332                                         break;
 333                                 } catch (ExecutionException e) {
 334                                         /* TODO */
 335                                         e.printStackTrace();
 336                                         break;
 337                                 }
 338                         }
 339                 }
 340
 341         }
 342
 343 }