Attempt to wrangle memory usage from artwork

Now cache around NSData objects of individual pieces of album art,
unique by their byte contents. And the artwork image cacher will also
use the art ID keys from the database as the cache keys for NSImages,
so they'll not only be only read once per unique image, but also tracks
can have unique artwork per track, if the files so feature it.

Signed-off-by: Christopher Snowhill <kode54@gmail.com>

Playlist/PlaylistEntry.h

@@ -13,6 +13,7 @@
 	NSInteger shuffleIndex;
 	NSInteger dbIndex;
 	NSInteger entryId;
+	NSInteger artId;
 
 	BOOL current;
 	BOOL removed;
@@ -106,6 +107,7 @@
 @property NSInteger shuffleIndex;
 @property NSInteger dbIndex;
 @property NSInteger entryId;
+@property NSInteger artId;
 
 @property(readonly) NSString *status;
 @property(readonly) NSString *statusMessage;

Playlist/PlaylistEntry.m

@@ -15,6 +15,7 @@
 @synthesize shuffleIndex;
 @synthesize dbIndex;
 @synthesize entryId;
+@synthesize artId;
 
 @synthesize current;
 @synthesize removed;
@@ -373,7 +374,7 @@
 - (NSImage *)albumArt {
 	if(!albumArtInternal || ![albumArtInternal length]) return nil;
 
-	NSString *imageCacheTag = [NSString stringWithFormat:@"%@-%@-%@-%@", album, artist, genre, year];
+	NSString *imageCacheTag = [NSString stringWithFormat:@"%ld", artId];
 	NSImage *image = [NSImage imageNamed:imageCacheTag];
 
 	if(image == nil) {
@@ -457,6 +458,7 @@
 		pe->shuffleIndex = shuffleIndex;
 		pe->dbIndex = dbIndex;
 		pe->entryId = entryId;
+		pe->artId = artId;
 
 		pe->current = current;
 		pe->removed = removed;
@@ -482,7 +484,7 @@
 
 		pe->cuesheet = [cuesheet copyWithZone:zone];
 
-		pe->albumArtInternal = [albumArtInternal copyWithZone:zone];
+		pe->albumArtInternal = albumArtInternal; // Only allocated item not duplicated
 
 		pe->replayGainAlbumGain = replayGainAlbumGain;
 		pe->replayGainAlbumPeak = replayGainAlbumPeak;

Utils/SQLiteStore.h

@@ -19,6 +19,7 @@
 	sqlite3_stmt *stmt[39];
 	@private
 	NSMutableArray *databaseMirror;
+	NSMutableDictionary *artTable;
 }
 
 @property(nonatomic, readwrite) NSString *databasePath;

Utils/SQLiteStore.m

@@ -879,6 +879,8 @@ static SQLiteStore *g_sharedStore = NULL;
 		}
 	}
 
+	[artTable setValue:art forKey:[[NSNumber numberWithInteger:ret] stringValue]];
+
 	return ret;
 }
 
@@ -886,6 +888,9 @@ static SQLiteStore *g_sharedStore = NULL;
 	if(artId < 0)
 		return [NSData data];
 
+	NSData *ret = [artTable valueForKey:[[NSNumber numberWithInteger:artId] stringValue]];
+	if(ret) return ret;
+
 	sqlite3_stmt *st = stmt[stmt_select_art_value];
 
 	if(sqlite3_reset(st) ||
@@ -900,7 +905,7 @@ static SQLiteStore *g_sharedStore = NULL;
 		return [NSData data];
 	}
 
-	NSData *ret = [NSData data];
+	ret = [NSData data];
 
 	if(rc == SQLITE_ROW) {
 		const void *blob = sqlite3_column_blob(st, select_art_value_out_value);
@@ -912,6 +917,8 @@ static SQLiteStore *g_sharedStore = NULL;
 
 	sqlite3_reset(st);
 
+	[artTable setValue:ret forKey:[[NSNumber numberWithInteger:artId] stringValue]];
+
 	return ret;
 }
 
@@ -945,6 +952,8 @@ static SQLiteStore *g_sharedStore = NULL;
 	}
 
 	if(refcount <= 1) {
+		[artTable removeObjectForKey:[[NSNumber numberWithInteger:artId] stringValue]];
+
 		st = stmt[stmt_remove_art];
 
 		if(sqlite3_reset(st) ||
@@ -1361,6 +1370,7 @@ static SQLiteStore *g_sharedStore = NULL;
 		[entry setReplayGainTrackGain:replaygaintrackgain];
 		[entry setReplayGainTrackPeak:replaygaintrackpeak];
 
+		[entry setArtId:artId];
 		[entry setAlbumArtInternal:[self getArt:artId]];
 
 		[entry setMetadataLoaded:!!metadataloaded];