Merge "Get rid of SoftReference in RepositoryCache"

org.eclipse.jgit/src/org/eclipse/jgit/lib/RepositoryCache.java

@@ -45,8 +45,6 @@ package org.eclipse.jgit.lib;
 
 import java.io.File;
 import java.io.IOException;
-import java.lang.ref.Reference;
-import java.lang.ref.SoftReference;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Iterator;
@@ -202,8 +200,7 @@ public class RepositoryCache {
 			return false;
 		}
 		FileKey key = new FileKey(gitDir, repo.getFS());
-		Reference<Repository> repoRef = cache.cacheMap.get(key);
-		return repoRef != null && repoRef.get() == repo;
+		return cache.cacheMap.get(key) == repo;
 	}
 
 	/** Unregister all repositories from the cache. */
@@ -219,7 +216,7 @@ public class RepositoryCache {
 		cache.configureEviction(repositoryCacheConfig);
 	}
 
-	private final ConcurrentHashMap<Key, Reference<Repository>> cacheMap;
+	private final ConcurrentHashMap<Key, Repository> cacheMap;
 
 	private final Lock[] openLocks;
 
@@ -228,7 +225,7 @@ public class RepositoryCache {
 	private volatile long expireAfter;
 
 	private RepositoryCache() {
-		cacheMap = new ConcurrentHashMap<Key, Reference<Repository>>();
+		cacheMap = new ConcurrentHashMap<Key, Repository>();
 		openLocks = new Lock[4];
 		for (int i = 0; i < openLocks.length; i++) {
 			openLocks[i] = new Lock();
@@ -261,19 +258,15 @@ public class RepositoryCache {
 		}
 	}
 
-	@SuppressWarnings("resource")
 	private Repository openRepository(final Key location,
 			final boolean mustExist) throws IOException {
-		Reference<Repository> ref = cacheMap.get(location);
-		Repository db = ref != null ? ref.get() : null;
+		Repository db = cacheMap.get(location);
 		if (db == null) {
 			synchronized (lockFor(location)) {
-				ref = cacheMap.get(location);
-				db = ref != null ? ref.get() : null;
+				db = cacheMap.get(location);
 				if (db == null) {
 					db = location.open(mustExist);
-					ref = new SoftReference<Repository>(db);
-					cacheMap.put(location, ref);
+					cacheMap.put(location, db);
 				} else {
 					db.incrementOpen();
 				}
@@ -285,16 +278,13 @@ public class RepositoryCache {
 	}
 
 	private void registerRepository(final Key location, final Repository db) {
-		SoftReference<Repository> newRef = new SoftReference<Repository>(db);
-		Reference<Repository> oldRef = cacheMap.put(location, newRef);
-		Repository oldDb = oldRef != null ? oldRef.get() : null;
+		Repository oldDb = cacheMap.put(location, db);
 		if (oldDb != null)
 			oldDb.close();
 	}
 
 	private Repository unregisterRepository(final Key location) {
-		Reference<Repository> oldRef = cacheMap.remove(location);
-		return oldRef != null ? oldRef.get() : null;
+		return cacheMap.remove(location);
 	}
 
 	private boolean isExpired(Repository db) {
@@ -316,8 +306,7 @@ public class RepositoryCache {
 	}
 
 	private void clearAllExpired() {
-		for (Reference<Repository> ref : cacheMap.values()) {
-			Repository db = ref.get();
+		for (Repository db : cacheMap.values()) {
 			if (isExpired(db)) {
 				RepositoryCache.close(db);
 			}
@@ -325,7 +314,7 @@ public class RepositoryCache {
 	}
 
 	private void clearAll() {
-		for (Iterator<Map.Entry<Key, Reference<Repository>>> i = cacheMap
+		for (Iterator<Map.Entry<Key, Repository>> i = cacheMap
 				.entrySet().iterator(); i.hasNext();) {
 			unregisterAndCloseRepository(i.next().getKey());
 		}

org.eclipse.jgit/src/org/eclipse/jgit/lib/RepositoryCacheConfig.java

@@ -53,8 +53,8 @@ public class RepositoryCacheConfig {
 
 	/**
 	 * Set cleanupDelayMillis to this value in order to switch off time-based
-	 * cache eviction. The JVM can still expire cache entries when heap memory
-	 * runs low.
+	 * cache eviction. Expired cache entries will only be evicted when
+	 * RepositoryCache.clearExpired or RepositoryCache.clear are called.
 	 */
 	public static final long NO_CLEANUP = 0;