Merge "Make DeltaBaseCache per-ObjectReader"

org.eclipse.jgit/src/org/eclipse/jgit/storage/file/DeltaBaseCache.java

@@ -54,35 +54,36 @@ class DeltaBaseCache {
 		return (((int) position) << 22) >>> 22;
 	}
 
-	private static int maxByteCount;
+	private static volatile int defaultMaxByteCount;
 
-	private static final Slot[] cache;
+	private final int maxByteCount;
 
-	private static Slot lruHead;
+	private final Slot[] cache;
 
-	private static Slot lruTail;
+	private Slot lruHead;
 
-	private static int openByteCount;
+	private Slot lruTail;
+
+	private int openByteCount;
 
 	static {
 		DEAD = new SoftReference<Entry>(null);
-		maxByteCount = new WindowCacheConfig().getDeltaBaseCacheLimit();
+		reconfigure(new WindowCacheConfig());
+	}
 
-		cache = new Slot[CACHE_SZ];
-		for (int i = 0; i < CACHE_SZ; i++)
-			cache[i] = new Slot();
+	static void reconfigure(WindowCacheConfig cfg) {
+		defaultMaxByteCount = cfg.getDeltaBaseCacheLimit();
 	}
 
-	static synchronized void reconfigure(final WindowCacheConfig cfg) {
-		final int dbLimit = cfg.getDeltaBaseCacheLimit();
-		if (maxByteCount != dbLimit) {
-			maxByteCount = dbLimit;
-			releaseMemory();
-		}
+	DeltaBaseCache() {
+		maxByteCount = defaultMaxByteCount;
+		cache = new Slot[CACHE_SZ];
 	}
 
-	static synchronized Entry get(final PackFile pack, final long position) {
-		final Slot e = cache[hash(position)];
+	Entry get(final PackFile pack, final long position) {
+		Slot e = cache[hash(position)];
+		if (e == null)
+			return null;
 		if (e.provider == pack && e.position == position) {
 			final Entry buf = e.data.get();
 			if (buf != null) {
@@ -93,13 +94,18 @@ class DeltaBaseCache {
 		return null;
 	}
 
-	static synchronized void store(final PackFile pack, final long position,
+	void store(final PackFile pack, final long position,
 			final byte[] data, final int objectType) {
 		if (data.length > maxByteCount)
 			return; // Too large to cache.
 
-		final Slot e = cache[hash(position)];
-		clearEntry(e);
+		Slot e = cache[hash(position)];
+		if (e == null) {
+			e = new Slot();
+			cache[hash(position)] = e;
+		} else {
+			clearEntry(e);
+		}
 
 		openByteCount += data.length;
 		releaseMemory();
@@ -111,7 +117,7 @@ class DeltaBaseCache {
 		moveToHead(e);
 	}
 
-	private static void releaseMemory() {
+	private void releaseMemory() {
 		while (openByteCount > maxByteCount && lruTail != null) {
 			final Slot currOldest = lruTail;
 			final Slot nextOldest = currOldest.lruPrev;
@@ -128,16 +134,7 @@ class DeltaBaseCache {
 		}
 	}
 
-	static synchronized void purge(final PackFile file) {
-		for (final Slot e : cache) {
-			if (e.provider == file) {
-				clearEntry(e);
-				unlink(e);
-			}
-		}
-	}
-
-	private static void moveToHead(final Slot e) {
+	private void moveToHead(final Slot e) {
 		unlink(e);
 		e.lruPrev = null;
 		e.lruNext = lruHead;
@@ -148,7 +145,7 @@ class DeltaBaseCache {
 		lruHead = e;
 	}
 
-	private static void unlink(final Slot e) {
+	private void unlink(final Slot e) {
 		final Slot prev = e.lruPrev;
 		final Slot next = e.lruNext;
 		if (prev != null)
@@ -157,17 +154,13 @@ class DeltaBaseCache {
 			next.lruPrev = prev;
 	}
 
-	private static void clearEntry(final Slot e) {
+	private void clearEntry(final Slot e) {
 		openByteCount -= e.sz;
 		e.provider = null;
 		e.data = DEAD;
 		e.sz = 0;
 	}
 
-	private DeltaBaseCache() {
-		throw new UnsupportedOperationException();
-	}
-
 	static class Entry {
 		final byte[] data;
 

org.eclipse.jgit/src/org/eclipse/jgit/storage/file/PackFile.java

@@ -236,7 +236,6 @@ public class PackFile implements Iterable<PackIndex.MutableEntry> {
 	 * Close the resources utilized by this repository
 	 */
 	public void close() {
-		DeltaBaseCache.purge(this);
 		WindowCache.purge(this);
 		synchronized (this) {
 			loadedIdx = null;
@@ -723,7 +722,7 @@ public class PackFile implements Iterable<PackIndex.MutableEntry> {
 					if (sz != delta.deltaSize)
 						break SEARCH;
 
-					DeltaBaseCache.Entry e = DeltaBaseCache.get(this, base);
+					DeltaBaseCache.Entry e = curs.getDeltaBaseCache().get(this, base);
 					if (e != null) {
 						type = e.type;
 						data = e.data;
@@ -741,7 +740,7 @@ public class PackFile implements Iterable<PackIndex.MutableEntry> {
 					if (sz != delta.deltaSize)
 						break SEARCH;
 
-					DeltaBaseCache.Entry e = DeltaBaseCache.get(this, base);
+					DeltaBaseCache.Entry e = curs.getDeltaBaseCache().get(this, base);
 					if (e != null) {
 						type = e.type;
 						data = e.data;
@@ -769,7 +768,7 @@ public class PackFile implements Iterable<PackIndex.MutableEntry> {
 				if (cached)
 					cached = false;
 				else if (delta.next == null)
-					DeltaBaseCache.store(this, delta.basePos, data, type);
+					curs.getDeltaBaseCache().store(this, delta.basePos, data, type);
 
 				pos = delta.deltaPos;
 

org.eclipse.jgit/src/org/eclipse/jgit/storage/file/WindowCursor.java

@@ -83,12 +83,20 @@ final class WindowCursor extends ObjectReader implements ObjectReuseAsIs {
 
 	private ByteWindow window;
 
+	private DeltaBaseCache baseCache;
+
 	final FileObjectDatabase db;
 
 	WindowCursor(FileObjectDatabase db) {
 		this.db = db;
 	}
 
+	DeltaBaseCache getDeltaBaseCache() {
+		if (baseCache == null)
+			baseCache = new DeltaBaseCache();
+		return baseCache;
+	}
+
 	@Override
 	public ObjectReader newReader() {
 		return new WindowCursor(db);
@@ -334,6 +342,7 @@ final class WindowCursor extends ObjectReader implements ObjectReuseAsIs {
 	/** Release the current window cursor. */
 	public void release() {
 		window = null;
+		baseCache = null;
 		try {
 			InflaterCache.release(inf);
 		} finally {