Move RG-Parsing into BastpUtil and provide an LRU cache

src/ch/blinkenlights/android/vanilla/BastpUtil.java

@@ -0,0 +1,80 @@
+/*
+ * Copyright (C) 2013 Adrian Ulrich <adrian@blinkenlights.ch>
+ *
+ * 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 <http://www.gnu.org/licenses/>. 
+ */
+ 
+package ch.blinkenlights.android.vanilla;
+
+import android.util.LruCache;
+import ch.blinkenlights.bastp.Bastp;
+import java.util.HashMap;
+import java.util.Vector;
+import android.util.Log;
+
+public class BastpUtil {
+	private RGLruCache rgCache;
+	
+	public BastpUtil() {
+		rgCache = new RGLruCache(16); /* Cache up to 16 entries */
+	}
+	
+	
+	/** Returns the ReplayGain values of 'path' as <track,album>
+	 */
+	public float[] getReplayGainValues(String path) {
+		float[] cached = rgCache.get(path);
+		Log.d("VanillaMusic", "LRU cache("+rgCache.size()+"): "+path+" -> "+cached);
+		if(cached == null) {
+			cached = getReplayGainValuesFromFile(path);
+			rgCache.put(path, cached);
+		}
+		return cached;
+	}
+	
+	
+	
+	/** Parse given file and return track,album replay gain values
+	 */
+	private float[] getReplayGainValuesFromFile(String path) {
+		String[] keys = { "REPLAYGAIN_TRACK_GAIN", "REPLAYGAIN_ALBUM_GAIN" };
+		float[] adjust= { 0f                     , 0f                      };
+		HashMap tags  = (new Bastp()).getTags(path);
+		
+		for (int i=0; i<keys.length; i++) {
+			String curKey = keys[i];
+			if(tags.containsKey(curKey)) {
+				String rg_raw = (String)((Vector)tags.get(curKey)).get(0);
+				String rg_numonly = "";
+				float rg_float = 0f;
+				try {
+					String nums = rg_raw.replaceAll("[^0-9.-]","");
+					rg_float = Float.parseFloat(nums);
+				} catch(Exception e) {}
+				adjust[i] = rg_float;
+			}
+		}
+		return adjust;
+	}
+	
+	/** LRU cache for ReplayGain values
+	 */
+	private class RGLruCache extends LruCache<String, float[]> {
+		public RGLruCache(int size) {
+			super(size);
+		}
+	}
+
+}
+

src/ch/blinkenlights/android/vanilla/PlaybackService.java

@@ -66,9 +66,6 @@ import java.io.EOFException;
 import java.io.File;
 import java.io.IOException;
 import java.util.ArrayList;
-import java.util.HashMap;
-import java.util.Vector;
-import ch.blinkenlights.bastp.Bastp;
 
 
 /**
@@ -374,6 +371,8 @@ public final class PlaybackService extends Service
 	private boolean mReplayGainAlbumEnabled;
 	private int mReplayGainBump;
 	
+	private BastpUtil mBastpUtil;
+	
 	@Override
 	public void onCreate()
 	{
@@ -385,6 +384,7 @@ public final class PlaybackService extends Service
 		int state = loadState();
 
 		mMediaPlayer = getNewMediaPlayer();
+		mBastpUtil = new BastpUtil();
 		
 		mNotificationManager = (NotificationManager)getSystemService(NOTIFICATION_SERVICE);
 		mAudioManager = (AudioManager)getSystemService(AUDIO_SERVICE);
@@ -610,7 +610,7 @@ public final class PlaybackService extends Service
 		if(mReplayGainAlbumEnabled == false && mReplayGainTrackEnabled == false)
 			return; /* no need to parse tags: RG is disabled */
 		
-		float[] rg = calculateReplayGainAdjustment(path); /* track, album */
+		float[] rg = getReplayGainValues(path); /* track, album */
 		float adjust = 0f;
 		
 		if(mReplayGainAlbumEnabled) {
@@ -635,29 +635,8 @@ public final class PlaybackService extends Service
 		
 	}
 	
-	/**
+	public float[] getReplayGainValues(String path) {
-	 * Returns TRACK, ALBUM gain values for given path
+		return mBastpUtil.getReplayGainValues(path);
-	 * A value of 0 means that the tag was not found in given file
-	*/
-	private float[] calculateReplayGainAdjustment(String path) {
-		String[] keys = { "REPLAYGAIN_TRACK_GAIN", "REPLAYGAIN_ALBUM_GAIN" };
-		float[] adjust= { 0f                     , 0f                      };
-		HashMap tags  = (new Bastp()).getTags(path);
-		
-		for (int i=0; i<keys.length; i++) {
-			String curKey = keys[i];
-			if(tags.containsKey(curKey)) {
-				String rg_raw = (String)((Vector)tags.get(curKey)).get(0);
-				String rg_numonly = "";
-				float rg_float = 0f;
-				try {
-					String nums = rg_raw.replaceAll("[^0-9.-]","");
-					rg_float = Float.parseFloat(nums);
-				} catch(Exception e) {}
-				adjust[i] = rg_float;
-			}
-		}
-		return adjust;
 	}
 	
 	/**