1 files changed, 109 insertions, 0 deletions
diff --git a/subsonic-android/src/net/sourceforge/subsonic/androidapp/util/ShufflePlayBuffer.java b/subsonic-android/src/net/sourceforge/subsonic/androidapp/util/ShufflePlayBuffer.java
new file mode 100644
index 00000000..825fcc44
--- /dev/null
+++ b/subsonic-android/src/net/sourceforge/subsonic/androidapp/util/ShufflePlayBuffer.java
@@ -0,0 +1,109 @@
+/*
+ This file is part of Subsonic.
+
+ Subsonic 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.
+
+ Subsonic 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 Subsonic.  If not, see <http://www.gnu.org/licenses/>.
+
+ Copyright 2009 (C) Sindre Mehus
+ */
+package net.sourceforge.subsonic.androidapp.util;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.concurrent.Executors;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.TimeUnit;
+
+import android.content.Context;
+import android.util.Log;
+import net.sourceforge.subsonic.androidapp.domain.MusicDirectory;
+import net.sourceforge.subsonic.androidapp.service.MusicService;
+import net.sourceforge.subsonic.androidapp.service.MusicServiceFactory;
+
+/**
+ * @author Sindre Mehus
+ * @version $Id$
+ */
+public class ShufflePlayBuffer {
+
+    private static final String TAG = ShufflePlayBuffer.class.getSimpleName();
+    private static final int CAPACITY = 50;
+    private static final int REFILL_THRESHOLD = 40;
+
+    private final ScheduledExecutorService executorService;
+    private final List<MusicDirectory.Entry> buffer = new ArrayList<MusicDirectory.Entry>();
+    private Context context;
+    private int currentServer;
+
+    public ShufflePlayBuffer(Context context) {
+        this.context = context;
+        executorService = Executors.newSingleThreadScheduledExecutor();
+        Runnable runnable = new Runnable() {
+            @Override
+            public void run() {
+                refill();
+            }
+        };
+        executorService.scheduleWithFixedDelay(runnable, 1, 10, TimeUnit.SECONDS);
+    }
+
+    public List<MusicDirectory.Entry> get(int size) {
+        clearBufferIfnecessary();
+
+        List<MusicDirectory.Entry> result = new ArrayList<MusicDirectory.Entry>(size);
+        synchronized (buffer) {
+            while (!buffer.isEmpty() && result.size() < size) {
+                result.add(buffer.remove(buffer.size() - 1));
+            }
+        }
+        Log.i(TAG, "Taking " + result.size() + " songs from shuffle play buffer. " + buffer.size() + " remaining.");
+        return result;
+    }
+
+    public void shutdown() {
+        executorService.shutdown();
+    }
+
+    private void refill() {
+
+        // Check if active server has changed.
+        clearBufferIfnecessary();
+
+        if (buffer.size() > REFILL_THRESHOLD || (!Util.isNetworkConnected(context) && !Util.isOffline(context))) {
+            return;
+        }
+
+        try {
+            MusicService service = MusicServiceFactory.getMusicService(context);
+            int n = CAPACITY - buffer.size();
+            MusicDirectory songs = service.getRandomSongs(n, context, null);
+
+            synchronized (buffer) {
+                buffer.addAll(songs.getChildren());
+                Log.i(TAG, "Refilled shuffle play buffer with " + songs.getChildren().size() + " songs.");
+            }
+        } catch (Exception x) {
+            Log.w(TAG, "Failed to refill shuffle play buffer.", x);
+        }
+    }
+
+    private void clearBufferIfnecessary() {
+        synchronized (buffer) {
+            if (currentServer != Util.getActiveServer(context)) {
+                currentServer = Util.getActiveServer(context);
+                buffer.clear();
+            }
+        }
+    }
+
+}