From e1c3f4db2b1eadd90bdadc4781d91b18b1337cf0 Mon Sep 17 00:00:00 2001 From: =?utf8?q?David=20=E2=80=98Bombe=E2=80=99=20Roden?= Date: Sat, 16 Mar 2013 18:22:57 +0100 Subject: [PATCH] Add filter that supports changing sources. --- .../sonitus/data/filter/MultiSourceFilter.java | 182 +++++++++++++++++++++ 1 file changed, 182 insertions(+) create mode 100644 src/main/java/net/pterodactylus/sonitus/data/filter/MultiSourceFilter.java diff --git a/src/main/java/net/pterodactylus/sonitus/data/filter/MultiSourceFilter.java b/src/main/java/net/pterodactylus/sonitus/data/filter/MultiSourceFilter.java new file mode 100644 index 0000000..57c313e --- /dev/null +++ b/src/main/java/net/pterodactylus/sonitus/data/filter/MultiSourceFilter.java @@ -0,0 +1,182 @@ +/* + * Sonitus - MultiSource.java - Copyright © 2013 David Roden + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see . + */ + +package net.pterodactylus.sonitus.data.filter; + +import static com.google.common.base.Preconditions.*; + +import java.io.EOFException; +import java.io.IOException; +import java.io.InputStream; +import java.io.OutputStream; +import java.io.PipedInputStream; +import java.io.PipedOutputStream; +import java.util.Arrays; +import java.util.logging.Level; +import java.util.logging.Logger; + +import net.pterodactylus.sonitus.data.ConnectException; +import net.pterodactylus.sonitus.data.Filter; +import net.pterodactylus.sonitus.data.Format; +import net.pterodactylus.sonitus.data.ReusableSink; +import net.pterodactylus.sonitus.data.Source; + +/** + * {@link ReusableSink} implementation that supports changing the source without + * letting the {@link net.pterodactylus.sonitus.data.Sink} know. + * + * @author David ‘Bombe’ Roden + */ +public class MultiSourceFilter implements Filter, ReusableSink { + + /** The logger. */ + private static final Logger logger = Logger.getLogger(MultiSourceFilter.class.getName()); + + /** Object used for synchronization. */ + private final Object syncObject = new Object(); + + /** The connection. */ + private Connection connection; + + /** The format. */ + private Format format; + + @Override + public Format format() { + return format; + } + + @Override + public byte[] get(int bufferSize) throws EOFException, IOException { + byte[] buffer = new byte[bufferSize]; + InputStream inputStream; + synchronized (syncObject) { + inputStream = connection.pipedInputStream; + } + int read = inputStream.read(buffer); + return Arrays.copyOf(buffer, read); + } + + @Override + public void connect(Source source) throws ConnectException { + checkNotNull(source, "source must not be null"); + if (format != null) { + checkArgument(format.equals(source.format()), "source’s format must equal this sink’s format"); + } else { + format = source.format(); + } + + if (connection == null) { + connection = new Connection(); + new Thread(connection).start(); + } + try { + connection.source(source); + } catch (IOException ioe1) { + throw new ConnectException(ioe1); + } + } + + /** + * The connection feeds the input from the currently connected source to the + * input stream that {@link #get(int)} will get its data from. + * + * @author David ‘Bombe’ Roden + */ + private class Connection implements Runnable { + + /** The currently connected source. */ + /* synchronized by syncObject. */ + private Source source; + + /** The input stream that {@link #get(int)} will read from. */ + /* synchronized by syncObject. */ + private PipedInputStream pipedInputStream; + + /** The output stream that the source will be fed into. */ + /* synchronized by syncObject. */ + private PipedOutputStream pipedOutputStream; + + /** + * Changes the source of the connection. + * + * @param source + * The new source of the connection + * @return This connection + * @throws IOException + * if an I/O error occurs + */ + public Connection source(Source source) throws IOException { + synchronized (syncObject) { + this.source = source; + pipedInputStream = new PipedInputStream(); + pipedOutputStream = new PipedOutputStream(pipedInputStream); + syncObject.notifyAll(); + } + return this; + } + + @Override + public void run() { + while (true) { + /* wait for source to be set. */ + OutputStream outputStream; + logger.finest("Entering synchronized block..."); + synchronized (syncObject) { + logger.finest("Entered synchronized block."); + while (source == null) { + try { + logger.finest("Waiting for source to connect..."); + syncObject.wait(); + } catch (InterruptedException ie1) { + /* ignore, keep waiting. */ + } + } + outputStream = pipedOutputStream; + } + logger.finest("Exited synchronized block."); + + byte[] buffer = null; + boolean readSuccessful = false; + while (!readSuccessful) { + try { + buffer = source.get(4096); + logger.finest(String.format("Read %d Bytes.", buffer.length)); + if (buffer.length > 0) { + readSuccessful = true; + } + } catch (IOException e) { + /* TODO - notify & wait */ + } + } + + try { + outputStream.write(buffer); + logger.finest(String.format("Wrote %d Bytes.", buffer.length)); + } catch (IOException ioe1) { + /* okay, the sink has died, exit. */ + logger.log(Level.WARNING, "Could not write to pipe!", ioe1); + break; + } + } + + logger.info("Exiting."); + } + + } + +} -- 2.7.4