API to remove repositories from RepositoryCache

Add methods that allow to unregister repositories from the
RepositoryCache individually.

Bug: 470234
Change-Id: Ib918a634d829c9898072ae7bdeb22b099a32b1c9
Signed-off-by: Tobias Oberlies <tobias.oberlies@sap.com>
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

org.eclipse.jgit.test/tst/org/eclipse/jgit/lib/RepositoryCacheTest.java

@@ -43,11 +43,14 @@
 
 package org.eclipse.jgit.lib;
 
+import static org.hamcrest.CoreMatchers.hasItem;
+import static org.hamcrest.CoreMatchers.is;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertNotSame;
 import static org.junit.Assert.assertSame;
+import static org.junit.Assert.assertThat;
 import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
 
@@ -59,6 +62,7 @@
 import org.eclipse.jgit.lib.RepositoryCache.FileKey;
 import org.junit.Test;
 
+@SuppressWarnings("boxing")
 public class RepositoryCacheTest extends RepositoryTestCase {
 	@Test
 	public void testNonBareFileKey() throws IOException {
@@ -147,4 +151,28 @@ public void testCacheOpen() throws Exception {
 		d2.close();
 		d2.close();
 	}
+
+	@Test
+	public void testGetRegisteredWhenEmpty() {
+		assertThat(RepositoryCache.getRegisteredKeys().size(), is(0));
+	}
+
+	@Test
+	public void testGetRegistered() {
+		RepositoryCache.register(db);
+
+		assertThat(RepositoryCache.getRegisteredKeys(),
+				hasItem(FileKey.exact(db.getDirectory(), db.getFS())));
+		assertThat(RepositoryCache.getRegisteredKeys().size(), is(1));
+	}
+
+	@Test
+	public void testUnregister() {
+		RepositoryCache.register(db);
+		RepositoryCache
+				.unregister(FileKey.exact(db.getDirectory(), db.getFS()));
+
+		assertThat(RepositoryCache.getRegisteredKeys().size(), is(0));
+	}
+
 }

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

@@ -47,6 +47,8 @@
 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;
 import java.util.Map;
 import java.util.concurrent.ConcurrentHashMap;
@@ -143,6 +145,28 @@ public static void close(final Repository db) {
 		}
 	}
 
+	/**
+	 * Remove a repository from the cache.
+	 * <p>
+	 * Removes a repository from the cache, if it is still registered here,
+	 * permitting it to close.
+	 *
+	 * @param location
+	 *            location of the repository to remove.
+	 * @since 4.1
+	 */
+	public static void unregister(Key location) {
+		cache.unregisterRepository(location);
+	}
+
+	/**
+	 * @return the locations of all repositories registered in the cache.
+	 * @since 4.1
+	 */
+	public static Collection<Key> getRegisteredKeys() {
+		return cache.getKeys();
+	}
+
 	/** Unregister all repositories from the cache. */
 	public static void clear() {
 		cache.clearAll();
@@ -195,6 +219,10 @@ private void unregisterRepository(final Key location) {
 			oldDb.close();
 	}
 
+	private Collection<Key> getKeys() {
+		return new ArrayList<Key>(cacheMap.keySet());
+	}
+
 	private void clearAll() {
 		for (int stage = 0; stage < 2; stage++) {
 			for (Iterator<Map.Entry<Key, Reference<Repository>>> i = cacheMap