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.Iterator;
  23 import java.util.List;
  24 import java.util.concurrent.Callable;
  25 import java.util.concurrent.ExecutionException;
  26 import java.util.concurrent.ExecutorService;
  27 import java.util.concurrent.Executors;
  28 import java.util.concurrent.Future;
  29 import java.util.concurrent.atomic.AtomicBoolean;
  30 import java.util.logging.Logger;
  31
  32 import com.google.common.base.Function;
  33 import com.google.common.base.Preconditions;
  34 import com.google.common.collect.ArrayListMultimap;
  35 import com.google.common.collect.FluentIterable;
  36 import com.google.common.collect.ImmutableMultimap;
  37 import com.google.common.collect.ImmutableSet;
  38 import com.google.common.collect.Lists;
  39 import com.google.common.collect.Multimap;
  40 import com.google.common.util.concurrent.MoreExecutors;
  41
  42 /**
  43  * A pipeline is responsible for streaming audio data from a {@link Source} to
  44  * an arbitrary number of connected {@link Filter}s and {@link Sink}s.
  45  *
  46  * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
  47  */
  48 public class Pipeline implements Iterable<Controlled> {
  49
  50         /** The logger. */
  51         private static final Logger logger = Logger.getLogger(Pipeline.class.getName());
  52
  53         /** The source of the audio stream. */
  54         private final Source source;
  55
  56         /** The sinks for each source. */
  57         private final Multimap<Source, Sink> sinks;
  58
  59         /** All started connections. */
  60         private final List<Connection> connections = Lists.newArrayList();
  61
  62         /**
  63          * Creates a new pipeline.
  64          *
  65          * @param source
  66          *              The source of the audio stream
  67          * @param sinks
  68          *              The sinks for each source
  69          */
  70         private Pipeline(Source source, Multimap<Source, Sink> sinks) {
  71                 this.source = Preconditions.checkNotNull(source, "source must not be null");
  72                 this.sinks = Preconditions.checkNotNull(sinks, "sinks must not be null");
  73         }
  74
  75         //
  76         // ACCESSORS
  77         //
  78
  79         /**
  80          * Expose this pipeline’s source.
  81          *
  82          * @return This pipeline’s source
  83          */
  84         public Source source() {
  85                 return source;
  86         }
  87
  88         /**
  89          * Returns all {@link Sink}s (or {@link Filter}s, really) that are connected to
  90          * the given source.
  91          *
  92          * @param source
  93          *              The source to get the sinks for
  94          * @return The sinks connected to the given source, or an empty list if the
  95          *         source does not exist in this pipeline
  96          */
  97         public Collection<Sink> sinks(Source source) {
  98                 return sinks.get(source);
  99         }
 100
 101         //
 102         // ACTIONS
 103         //
 104
 105         /**
 106          * Starts the pipeline.
 107          *
 108          * @throws IOException
 109          *              if any of the sinks can not be opened
 110          * @throws IllegalStateException
 111          *              if the pipeline is already running
 112          */
 113         public void start() throws IOException, IllegalStateException {
 114                 if (!connections.isEmpty()) {
 115                         throw new IllegalStateException("Pipeline is already running!");
 116                 }
 117                 List<Source> sources = Lists.newArrayList();
 118                 sources.add(source);
 119                 /* collect all source->sink pairs. */
 120                 while (!sources.isEmpty()) {
 121                         Source source = sources.remove(0);
 122                         Collection<Sink> sinks = this.sinks.get(source);
 123                         connections.add(new Connection(source, sinks));
 124                         for (Sink sink : sinks) {
 125                                 sink.open(source.metadata());
 126                                 if (sink instanceof Filter) {
 127                                         sources.add((Source) sink);
 128                                 }
 129                         }
 130                 }
 131                 for (Connection connection : connections) {
 132                         logger.info(String.format("Starting Connection from %s to %s.", connection.source, connection.sinks));
 133                         new Thread(connection).start();
 134                 }
 135         }
 136
 137         public void stop() {
 138                 if (!connections.isEmpty()) {
 139                         /* pipeline is not running. */
 140                         return;
 141                 }
 142                 for (Connection connection : connections) {
 143                         connection.stop();
 144                 }
 145         }
 146
 147         //
 148         // ITERABLE METHODS
 149         //
 150
 151         @Override
 152         public Iterator<Controlled> iterator() {
 153                 return ImmutableSet.<Controlled>builder().add(source).addAll(sinks.values()).build().iterator();
 154         }
 155
 156         //
 157         // STATIC METHODS
 158         //
 159
 160         /**
 161          * Returns a new pipeline builder.
 162          *
 163          * @param source
 164          *              The source at which to start
 165          * @return A builder for a new pipeline
 166          */
 167         public static Builder builder(Source source) {
 168                 return new Builder(source);
 169         }
 170
 171         /**
 172          * A builder for a {@link Pipeline}.
 173          *
 174          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
 175          */
 176         public static class Builder {
 177
 178                 /** The source of the pipeline. */
 179                 private final Source source;
 180
 181                 /** The sinks to which each source streams. */
 182                 private Multimap<Source, Sink> nextSinks = ArrayListMultimap.create();
 183
 184                 /** The last added source. */
 185                 private Source lastSource;
 186
 187                 /**
 188                  * Creates a new builder.
 189                  *
 190                  * @param source
 191                  *              The source that starts the pipeline
 192                  */
 193                 private Builder(Source source) {
 194                         this.source = source;
 195                         lastSource = source;
 196                 }
 197
 198                 /**
 199                  * Adds a {@link Sink} (or {@link Filter} as a recipient for the last added
 200                  * {@link Source}.
 201                  *
 202                  * @param sink
 203                  *              The sink to add
 204                  * @return This builder
 205                  * @throws IllegalStateException
 206                  *              if the last added {@link Sink} was not also a {@link Source}
 207                  */
 208                 public Builder to(Sink sink) {
 209                         Preconditions.checkState(lastSource != null, "last added Sink was not a Source");
 210                         nextSinks.put(lastSource, sink);
 211                         lastSource = (sink instanceof Filter) ? (Source) sink : null;
 212                         return this;
 213                 }
 214
 215                 /**
 216                  * Locates the given source and sets it as the last added node so that the
 217                  * next invocation of {@link #to(Sink)} can “fork” the pipeline.
 218                  *
 219                  * @param source
 220                  *              The source to locate
 221                  * @return This builder
 222                  * @throws IllegalStateException
 223                  *              if the given source was not previously added as a sink
 224                  */
 225                 public Builder find(Source source) {
 226                         Preconditions.checkState(nextSinks.containsValue(source));
 227                         lastSource = source;
 228                         return this;
 229                 }
 230
 231                 /**
 232                  * Builds the pipeline.
 233                  *
 234                  * @return The created pipeline
 235                  */
 236                 public Pipeline build() {
 237                         return new Pipeline(source, ImmutableMultimap.copyOf(nextSinks));
 238                 }
 239
 240         }
 241
 242         /**
 243          * A connection is responsible for streaming audio from one {@link Source} to
 244          * an arbitrary number of {@link Sink}s it is connected to. A connection is
 245          * started by creating a {@link Thread} wrapping it and starting said thread.
 246          *
 247          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
 248          */
 249         public class Connection implements Runnable {
 250
 251                 /** The source. */
 252                 private final Source source;
 253
 254                 /** The sinks. */
 255                 private final Collection<Sink> sinks;
 256
 257                 /** Whether the feeder was stopped. */
 258                 private final AtomicBoolean stopped = new AtomicBoolean(false);
 259
 260                 /** The executor service. */
 261                 private final ExecutorService executorService;
 262
 263                 /**
 264                  * Creates a new connection.
 265                  *
 266                  * @param source
 267                  *              The source of the stream
 268                  * @param sinks
 269                  *              The sinks to which to stream
 270                  */
 271                 public Connection(Source source, Collection<Sink> sinks) {
 272                         this.source = source;
 273                         this.sinks = sinks;
 274                         if (sinks.size() == 1) {
 275                                 executorService = MoreExecutors.sameThreadExecutor();
 276                         } else {
 277                                 executorService = Executors.newCachedThreadPool();
 278                         }
 279                 }
 280
 281                 //
 282                 // ACTIONS
 283                 //
 284
 285                 /** Stops this connection. */
 286                 public void stop() {
 287                         stopped.set(true);
 288                 }
 289
 290                 //
 291                 // RUNNABLE METHODS
 292                 //
 293
 294                 @Override
 295                 public void run() {
 296                         Metadata firstMetadata = null;
 297                         while (!stopped.get()) {
 298                                 try {
 299                                         final Metadata lastMetadata = firstMetadata;
 300                                         final Metadata metadata = firstMetadata = source.metadata();
 301                                         final byte[] buffer;
 302                                         try {
 303                                                 logger.finest(String.format("Getting %d bytes from %s...", 4096, source));
 304                                                 buffer = source.get(4096);
 305                                                 logger.finest(String.format("Got %d bytes from %s.", buffer.length, source));
 306                                         } catch (IOException ioe1) {
 307                                                 throw new IOException(String.format("I/O error while reading from %s.", source), ioe1);
 308                                         }
 309                                         List<Future<Void>> futures = executorService.invokeAll(FluentIterable.from(sinks).transform(new Function<Sink, Callable<Void>>() {
 310
 311                                                 @Override
 312                                                 public Callable<Void> apply(final Sink sink) {
 313                                                         return new Callable<Void>() {
 314
 315                                                                 @Override
 316                                                                 public Void call() throws Exception {
 317                                                                         if (!metadata.equals(lastMetadata)) {
 318                                                                                 sink.metadataUpdated(metadata);
 319                                                                         }
 320                                                                         try {
 321                                                                                 logger.finest(String.format("Sending %d bytes to %s.", buffer.length, sink));
 322                                                                                 sink.process(buffer);
 323                                                                                 logger.finest(String.format("Sent %d bytes to %s.", buffer.length, sink));
 324                                                                         } catch (IOException ioe1) {
 325                                                                                 throw new IOException(String.format("I/O error while writing to %s", sink), ioe1);
 326                                                                         }
 327                                                                         return null;
 328                                                                 }
 329                                                         };
 330                                                 }
 331                                         }).toList());
 332                                         /* check all threads for exceptions. */
 333                                         for (Future<Void> future : futures) {
 334                                                 future.get();
 335                                         }
 336                                 } catch (IOException e) {
 337                                         /* TODO */
 338                                         e.printStackTrace();
 339                                         break;
 340                                 } catch (InterruptedException e) {
 341                                         /* TODO */
 342                                         e.printStackTrace();
 343                                         break;
 344                                 } catch (ExecutionException e) {
 345                                         /* TODO */
 346                                         e.printStackTrace();
 347                                         break;
 348                                 }
 349                         }
 350                 }
 351
 352         }
 353
 354 }