Couple of basic tests for the repository optimizations

bcel-builder/src/main/java/org/aspectj/apache/bcel/util/ClassLoaderRepository.java

@@ -94,16 +94,17 @@ public class ClassLoaderRepository implements Repository {
 	// For fast translation of the classname *intentionally not static*
 	private SoftHashMap /* <String,URL> */nameMap = new SoftHashMap(new HashMap(), false);
 
-	public static boolean useSharedCache = System.getProperty("org.aspectj.apache.bcel.useSharedCache", "true").equalsIgnoreCase("true");
+	public static boolean useSharedCache =
+		System.getProperty("org.aspectj.apache.bcel.useSharedCache", "true").equalsIgnoreCase("true");
 
-	//Cache not found classes as well to prevent unnecessary file I/O operations
-	public static final boolean useUnavailableClassesCache =
+	// Cache not found classes as well to prevent unnecessary file I/O operations
+	public static boolean useUnavailableClassesCache =
 		System.getProperty("org.aspectj.apache.bcel.useUnavailableClassesCache", "false").equalsIgnoreCase("true");
-	//Ignore cache clear requests to not build up the cache over and over again
-	public static final boolean ignoreCacheClearRequests =
+	// Ignore cache clear requests to not build up the cache over and over again
+	public static boolean ignoreCacheClearRequests =
 		System.getProperty("org.aspectj.apache.bcel.ignoreCacheClearRequests", "false").equalsIgnoreCase("true");
 
-	//Second cache for the unavailable classes
+	// Second cache for the unavailable classes
 	private static Set<String> unavailableClasses = new HashSet<String>();
 
 	private static int cacheHitsShared = 0;
@@ -113,6 +114,7 @@ public class ClassLoaderRepository implements Repository {
 	private int classesLoadedCount = 0;
 	private int misses = 0;
 	private int cacheHitsLocal = 0;
+	private int unavailableClassesCacheHits = 0;
 	private int missLocalEvicted = 0; // Misses in local cache access due to reference GC
 
 	public ClassLoaderRepository(java.lang.ClassLoader loader) {
@@ -290,26 +292,26 @@ public class ClassLoaderRepository implements Repository {
 	}
 
 	/**
-	 * Lookup a JavaClass object from the Class Name provided.
+	 * Lookup a JavaClass object from the classname provided.
 	 */
 	public JavaClass loadClass(String className) throws ClassNotFoundException {
-
-		//Quick evaluation of unavailable classes to prevent unnecessary file I/O
-		if (useUnavailableClassesCache && unavailableClasses.contains(className))
+		// Quick evaluation of unavailable classes to prevent unnecessary file I/O
+		if (useUnavailableClassesCache && unavailableClasses.contains(className)) {
+			unavailableClassesCacheHits++;
 			throw new ClassNotFoundException(className + " not found.");
+		}
 
-		// translate to a URL
 		long time = System.currentTimeMillis();
 		java.net.URL url = toURL(className);
 		timeManipulatingURLs += (System.currentTimeMillis() - time);
 		if (url == null) {
-			if (useUnavailableClassesCache)
+			if (useUnavailableClassesCache) {
 				unavailableClasses.add(className);
+			}
 			throw new ClassNotFoundException(className + " not found - unable to determine URL");
 		}
 
 		JavaClass clazz = null;
-
 		// Look in the appropriate cache
 		if (useSharedCache) {
 			clazz = findClassShared(url);
@@ -386,7 +388,7 @@ public class ClassLoaderRepository implements Repository {
 	 */
 	public long[] reportStats() {
 		return new long[] { timeSpentLoading, timeManipulatingURLs, classesLoadedCount, cacheHitsShared, missSharedEvicted,
-				cacheHitsLocal, missLocalEvicted, sharedCache.size() };
+				cacheHitsLocal, missLocalEvicted, sharedCache.size(), unavailableClassesCacheHits };
 	}
 
 	/**
@@ -400,6 +402,7 @@ public class ClassLoaderRepository implements Repository {
 		cacheHitsShared = 0;
 		missSharedEvicted = 0;
 		missLocalEvicted = 0;
+		unavailableClassesCacheHits = 0;
 		misses = 0;
 		clear();
 	}
@@ -411,10 +414,12 @@ public class ClassLoaderRepository implements Repository {
 	/** Clear all entries from the local cache */
 	public void clear() {
 		if (!ignoreCacheClearRequests) {
-			if (useSharedCache)
+			if (useSharedCache) {
 				sharedCache.clear();
-			else
+			} else {
 				localCache.clear();
+			}
+			unavailableClasses.clear();
 		}
 	}
 

bcel-builder/src/test/java/org/aspectj/apache/bcel/classfile/tests/ClassloaderRepositoryTest.java

@@ -10,6 +10,8 @@ import junit.framework.TestCase;
 
 /*
  * Tests create a simple classloader repository configuration and check sharing of information.
+ * 
+ * @author Andy Clement
  */
 public class ClassloaderRepositoryTest extends TestCase {
 
@@ -69,6 +71,88 @@ public class ClassloaderRepositoryTest extends TestCase {
 		}
 	}
 
+	// ClassLoaderRepository.ignoreCacheClearRequests
+	public void testIgnoreCacheClearRequests() throws Exception {
+		ClassLoaderRepository.useSharedCache = false;
+		try {
+			// the 'normal' flow with ignore in default of false
+			ClassLoaderRepository.ignoreCacheClearRequests = false;
+			try {
+				ClassLoaderRepository repository = setupRepository();
+				repository.loadClass("java.lang.String");
+				long localCacheHits = repository.reportStats()[5];
+				assertEquals(0, localCacheHits);
+				repository.clear();
+				repository.loadClass("java.lang.String");
+				localCacheHits = repository.reportStats()[5];
+				assertEquals(0, localCacheHits); // cache was cleared, so no hit
+			} finally {
+				ClassLoaderRepository.ignoreCacheClearRequests = false;
+			}
+			// with ignore cache clear turned on
+			ClassLoaderRepository.ignoreCacheClearRequests = true;
+			try {
+				ClassLoaderRepository repository = setupRepository();
+				repository.loadClass("java.lang.String");
+				long localCacheHits = repository.reportStats()[5];
+				assertEquals(0, localCacheHits);
+				repository.clear();
+				repository.loadClass("java.lang.String");
+				localCacheHits = repository.reportStats()[5];
+				assertEquals(1, localCacheHits);
+			} finally {
+				ClassLoaderRepository.ignoreCacheClearRequests = false;
+			}
+		} finally {
+			ClassLoaderRepository.useSharedCache = true;
+		}
+	}
+
+	// ClassLoaderRepository.useUnavailableClassesCache
+	public void testUnavailableClassesCache() throws Exception {
+		ClassLoaderRepository.useUnavailableClassesCache = false;
+		try {
+			ClassLoaderRepository repository = setupRepository();
+			attemptLoadThatWillFail(repository);
+			for (int i = 0; i < 1000; i++) {
+				attemptLoadThatWillFail(repository);
+			}
+			assertEquals(0, repository.reportStats()[8]);
+		} finally {
+			ClassLoaderRepository.useUnavailableClassesCache = false; // back to default
+		}
+		
+		ClassLoaderRepository.useUnavailableClassesCache = true;
+		try {
+			ClassLoaderRepository repository = setupRepository();
+			assertNotNull(repository.loadClass("java.lang.String"));
+			attemptLoadThatWillFail(repository);
+			for (int i = 0; i < 1000; i++) {
+				attemptLoadThatWillFail(repository);
+			}
+			assertEquals(1000,repository.reportStats()[8]);
+		} finally {
+			ClassLoaderRepository.useUnavailableClassesCache = false;
+		}
+		// If checking the report stats for time spent manipulating URLs it will be massively reduced
+	}
+
+	private ClassLoaderRepository setupRepository() throws Exception {
+		ClassLoader cl = Thread.currentThread().getContextClassLoader();
+		ClassLoader res = new URLClassLoader(new URL[] {}, cl);
+		ClassLoaderRepository rep = new ClassLoaderRepository(res);
+		return rep;
+	}
+
+	private void attemptLoadThatWillFail(ClassLoaderRepository repository) {
+		try {
+			repository.loadClass("this.is.made.up");
+			throw new IllegalStateException("Should not have found 'this.is.made.up'");
+		} catch (ClassNotFoundException cnfe) {
+			// ... expected ...
+		}
+	}
+
 	public void tearDown() throws Exception {
 		super.tearDown();
 		System.err.println("Rep1: "+rep1.reportStats());

weaver/src/main/java/org/aspectj/weaver/reflect/Java15AnnotationFinder.java

@@ -49,8 +49,8 @@ public class Java15AnnotationFinder implements AnnotationFinder, ArgNameFinder {
 	private World world;
 	private static boolean useCachingClassLoaderRepository;
 
-	//Use single instance of Repository and ClassLoader
-	public static final boolean useSingleInstances =
+	// Use single instance of Repository and ClassLoader
+	public static boolean useSingleInstances =
 		System.getProperty("org.aspectj.apache.bcel.useSingleRepositoryInstance", "false").equalsIgnoreCase("true");
 
 	static {
@@ -66,24 +66,26 @@ public class Java15AnnotationFinder implements AnnotationFinder, ArgNameFinder {
 	}
 
 	public void setClassLoader(ClassLoader aLoader) {
-		//Set class loader ref
-		if (useSingleInstances && staticClassLoaderRef == null)
+		// Set class loader ref
+		if (useSingleInstances && staticClassLoaderRef == null) {
 			staticClassLoaderRef = new BcelWeakClassLoaderReference(aLoader);
-		else
+		} else {
 			this.classLoaderRef = new BcelWeakClassLoaderReference(aLoader);
+		}
 
-		//Set repository
+		// Set repository
 		if (useCachingClassLoaderRepository) {
-			if (useSingleInstances && staticBcelRepository == null)
+			if (useSingleInstances && staticBcelRepository == null) {
 				staticBcelRepository = new ClassLoaderRepository(getClassLoader());
-			else
+			} else {
 				this.bcelRepository = new ClassLoaderRepository(classLoaderRef);
-		}
-		else {
-			if (useSingleInstances && staticBcelRepository == null)
+			}
+		} else {
+			if (useSingleInstances && staticBcelRepository == null) {
 				staticBcelRepository = new NonCachingClassLoaderRepository(getClassLoader());
-			else
+			} else {
 				this.bcelRepository = new NonCachingClassLoaderRepository(classLoaderRef);
+			}
 		}
 	}