SPR-6775

+ remove class definitions for sticking around (by forcing eager metadata initialization)
+ improve cache size by eliminating the numbers of method metadata objects created
+ improve lookup access on method metadata

org.springframework.core/src/main/java/org/springframework/core/type/classreading/AnnotationMetadataReadingVisitor.java

@@ -19,6 +19,7 @@ package org.springframework.core.type.classreading;
 import java.util.Collection;
 import java.util.LinkedHashMap;
 import java.util.LinkedHashSet;
+import java.util.List;
 import java.util.Map;
 import java.util.Set;
 
@@ -27,6 +28,9 @@ import org.springframework.asm.MethodVisitor;
 import org.springframework.asm.Type;
 import org.springframework.core.type.AnnotationMetadata;
 import org.springframework.core.type.MethodMetadata;
+import org.springframework.util.CollectionUtils;
+import org.springframework.util.LinkedMultiValueMap;
+import org.springframework.util.MultiValueMap;
 
 /**
  * ASM class visitor which looks for the class name and implemented types as
@@ -35,6 +39,7 @@ import org.springframework.core.type.MethodMetadata;
  *
  * @author Juergen Hoeller
  * @author Mark Fisher
+ * @author Costin Leau
  * @since 2.5
  */
 final class AnnotationMetadataReadingVisitor extends ClassMetadataReadingVisitor implements AnnotationMetadata {
@@ -43,12 +48,11 @@ final class AnnotationMetadataReadingVisitor extends ClassMetadataReadingVisitor
 
 	private final Set<String> annotationSet = new LinkedHashSet<String>();
 
-	private final Map<String, Set<String>> metaAnnotationMap = new LinkedHashMap<String, Set<String>>();
+	private final Map<String, Set<String>> metaAnnotationMap = new LinkedHashMap<String, Set<String>>(4);
 
-	private final Map<String, Map<String, Object>> attributeMap = new LinkedHashMap<String, Map<String, Object>>();
-
-	private final Set<MethodMetadata> methodMetadataSet = new LinkedHashSet<MethodMetadata>();
+	private final Map<String, Map<String, Object>> attributeMap = new LinkedHashMap<String, Map<String, Object>>(4);
 
+	private final MultiValueMap<String, MethodMetadata> methodMetadataMap = new LinkedMultiValueMap<String, MethodMetadata>();
 
 	public AnnotationMetadataReadingVisitor(ClassLoader classLoader) {
 		this.classLoader = classLoader;
@@ -57,9 +61,7 @@ final class AnnotationMetadataReadingVisitor extends ClassMetadataReadingVisitor
 
 	@Override
 	public MethodVisitor visitMethod(int access, String name, String desc, String signature, String[] exceptions) {
-		MethodMetadataReadingVisitor mm = new MethodMetadataReadingVisitor(name, access, this.getClassName(), this.classLoader);
-		this.methodMetadataSet.add(mm);
-		return mm;
+		return new MethodMetadataReadingVisitor(name, access, this.getClassName(), this.classLoader, methodMetadataMap);
 	}
 
 	@Override
@@ -132,22 +134,16 @@ final class AnnotationMetadataReadingVisitor extends ClassMetadataReadingVisitor
 	}
 
 	public boolean hasAnnotatedMethods(String annotationType) {
-		for (MethodMetadata method : this.methodMetadataSet) {
-			if (method.isAnnotated(annotationType)) {
-				return true;
-			}
-		}
-		return false;
+		return methodMetadataMap.containsKey(annotationType);
 	}
 
 	public Set<MethodMetadata> getAnnotatedMethods(String annotationType) {
-		Set<MethodMetadata> annotatedMethods = new LinkedHashSet<MethodMetadata>();
-		for (MethodMetadata method : this.methodMetadataSet) {
-			if (method.isAnnotated(annotationType)) {
-				annotatedMethods.add(method);
-			}
+		List<MethodMetadata> list = methodMetadataMap.get(annotationType);
+		if (CollectionUtils.isEmpty(list)) {
+			return new LinkedHashSet<MethodMetadata>(0);
 		}
+		Set<MethodMetadata> annotatedMethods = new LinkedHashSet<MethodMetadata>(list.size());
+		annotatedMethods.addAll(list);
 		return annotatedMethods;
 	}
-
-}
+}

org.springframework.core/src/main/java/org/springframework/core/type/classreading/MethodMetadataReadingVisitor.java

@@ -25,6 +25,7 @@ import org.springframework.asm.Opcodes;
 import org.springframework.asm.Type;
 import org.springframework.asm.commons.EmptyVisitor;
 import org.springframework.core.type.MethodMetadata;
+import org.springframework.util.MultiValueMap;
 
 /**
  * ASM method visitor which looks for the annotations defined on the method,
@@ -33,6 +34,7 @@ import org.springframework.core.type.MethodMetadata;
  *
  * @author Juergen Hoeller
  * @author Mark Pollack
+ * @author Costin Leau
  * @since 3.0
  */
 final class MethodMetadataReadingVisitor extends MethodAdapter implements MethodMetadata {
@@ -45,25 +47,27 @@ final class MethodMetadataReadingVisitor extends MethodAdapter implements Method
 
 	private final ClassLoader classLoader;
 
-	private final Map<String, Map<String, Object>> attributeMap = new LinkedHashMap<String, Map<String, Object>>();
+	private final MultiValueMap<String, MethodMetadata> methodMetadataMap;
 
+	private final Map<String, Map<String, Object>> attributeMap = new LinkedHashMap<String, Map<String, Object>>(2);
 
-	public MethodMetadataReadingVisitor(String name, int access, String declaringClassName, ClassLoader classLoader) {
+	public MethodMetadataReadingVisitor(String name, int access, String declaringClassName, ClassLoader classLoader,
+			MultiValueMap<String, MethodMetadata> methodMetadataMap) {
 		super(new EmptyVisitor());
 		this.name = name;
 		this.access = access;
 		this.declaringClassName = declaringClassName;
 		this.classLoader = classLoader;
+		this.methodMetadataMap = methodMetadataMap;
 	}
 
-
 	@Override
 	public AnnotationVisitor visitAnnotation(final String desc, boolean visible) {
 		String className = Type.getType(desc).getClassName();
+		methodMetadataMap.add(className, this);
 		return new AnnotationAttributesReadingVisitor(className, this.attributeMap, null, this.classLoader);
 	}
 
-
 	public String getMethodName() {
 		return this.name;
 	}
@@ -91,5 +95,4 @@ final class MethodMetadataReadingVisitor extends MethodAdapter implements Method
 	public String getDeclaringClassName() {
 		return this.declaringClassName;
 	}
-
-}
+}

org.springframework.core/src/main/java/org/springframework/core/type/classreading/SimpleMetadataReader.java

@@ -32,55 +32,42 @@ import org.springframework.core.type.ClassMetadata;
  * without effect on users of the <code>core.type</code> package.
  *
  * @author Juergen Hoeller
+ * @author Costin Leau
  * @since 2.5
  */
 final class SimpleMetadataReader implements MetadataReader {
 
 	private final Resource resource;
-
-	private final ClassReader classReader;
-
-	private final ClassLoader classLoader;
-
-	private ClassMetadata classMetadata;
-
-	private AnnotationMetadata annotationMetadata;
-
+	private final ClassMetadata classMetadata;
+	private final AnnotationMetadata annotationMetadata;
 
 	SimpleMetadataReader(Resource resource, ClassLoader classLoader) throws IOException {
-		this.resource = resource;
-		InputStream is = this.resource.getInputStream();
+		InputStream is = resource.getInputStream();
+		ClassReader classReader = null;
 		try {
-			this.classReader = new ClassReader(is);
-		}
-		finally {
+			classReader = new ClassReader(is);
+		} finally {
 			is.close();
 		}
-		this.classLoader = classLoader;
-	}
 
+		AnnotationMetadataReadingVisitor visitor = new AnnotationMetadataReadingVisitor(classLoader);
+		classReader.accept(visitor, true);
+		
+		this.annotationMetadata = visitor;
+		// (since AnnotationMetadataReader extends ClassMetadataReadingVisitor)
+		this.classMetadata = visitor;
+		this.resource = resource;
+	}
 
 	public Resource getResource() {
 		return this.resource;
 	}
 
 	public ClassMetadata getClassMetadata() {
-		if (this.classMetadata == null) {
-			ClassMetadataReadingVisitor visitor = new ClassMetadataReadingVisitor();
-			this.classReader.accept(visitor, true);
-			this.classMetadata = visitor;
-		}
 		return this.classMetadata;
 	}
 
 	public AnnotationMetadata getAnnotationMetadata() {
-		if (this.annotationMetadata == null) {
-			AnnotationMetadataReadingVisitor visitor = new AnnotationMetadataReadingVisitor(this.classLoader);
-			this.classReader.accept(visitor, true);
-			this.annotationMetadata = visitor;
-			this.classMetadata = visitor;
-		}
 		return this.annotationMetadata;
 	}
-
-}
+}

org.springframework.core/src/test/java/org/springframework/core/type/CachingMetadataReaderLeakTest.java

@@ -48,7 +48,8 @@ public class CachingMetadataReaderLeakTest {
 
 	@Test
 	public void testSignificantLoad() throws Exception {
-		URL url = getClass().getResource("/org/springframework/beans/TestBean.class");
+		// the biggest public class in the JDK (>60k)
+		URL url = getClass().getResource("/java/awt/Component.class");
 		assertThat(url, notNullValue());
 
 		// look at a LOT of items
@@ -71,5 +72,8 @@ public class CachingMetadataReaderLeakTest {
 			MetadataReader reader = mrf.getMetadataReader(resource);
 			assertThat(reader, notNullValue());
 		}
+
+		// useful for profiling to take snapshots
+		//System.in.read();
 	}
 }