fix performance problems with package annotations. Close #190

jqno · Jun 19, 2018 · 7a7ee29 · 7a7ee29
1 parent 8131be2
commit 7a7ee29
Show file tree

Hide file tree

Showing 3 changed files with 35 additions and 3 deletions.
diff --git a/src/main/java/nl/jqno/equalsverifier/internal/reflection/ClassAccessor.java b/src/main/java/nl/jqno/equalsverifier/internal/reflection/ClassAccessor.java
@@ -10,7 +10,9 @@
 
 import java.lang.reflect.Field;
 import java.lang.reflect.Modifier;
+import java.util.AbstractMap.SimpleImmutableEntry;
 import java.util.HashSet;
+import java.util.Map;
 import java.util.Set;
 
 /**
@@ -21,6 +23,7 @@
  * @param <T> A class.
  */
 public class ClassAccessor<T> {
+    private static final Map<Map.Entry<String, Annotation>, Boolean> PACKAGE_ANNOTATION_CACHE = Util.newLruCache(512);
     private final Class<T> type;
     private final PrefabValues prefabValues;
     private final Annotation[] supportedAnnotations;
@@ -107,10 +110,19 @@ public boolean packageHasAnnotation(Annotation annotation) {
                 return false;
             }
 
-            String className = pkg.getName() + ".package-info";
+            String packageName = pkg.getName();
+            Map.Entry<String, Annotation> entry = new SimpleImmutableEntry<>(packageName, annotation);
+            Boolean hasAnnotation = PACKAGE_ANNOTATION_CACHE.get(entry);
+            if (hasAnnotation != null) {
+                return hasAnnotation;
+            }
+
+            String className = packageName + ".package-info";
             Class<?> packageType = Class.forName(className);
             AnnotationAccessor accessor = new AnnotationAccessor(supportedAnnotations, packageType, ignoredAnnotations, ignoreAnnotationFailure);
-            return accessor.typeHas(annotation);
+            hasAnnotation = accessor.typeHas(annotation);
+            PACKAGE_ANNOTATION_CACHE.put(entry, hasAnnotation);
+            return hasAnnotation;
         }
         catch (ClassNotFoundException e) {
             return false;

diff --git a/src/main/java/nl/jqno/equalsverifier/internal/reflection/Util.java b/src/main/java/nl/jqno/equalsverifier/internal/reflection/Util.java
@@ -1,5 +1,9 @@
 package nl.jqno.equalsverifier.internal.reflection;
 
+import java.util.Collections;
+import java.util.LinkedHashMap;
+import java.util.Map;
+
 public final class Util {
     private Util() {
         // Do not instantiate
@@ -40,4 +44,20 @@ public static Class<?>[] classes(Class<?>... classes) {
     public static Object[] objects(Object... objects) {
         return objects;
     }
+
+    /**
+     * Helper method to create simple LRU cache implementation
+     *
+     * @param maxSize maximum size of map
+     * @return simple thread-safe map with maximum-size eviction by LRU algorithm
+     */
+    public static <K, V> Map<K, V> newLruCache(final int maxSize) {
+        LinkedHashMap<K, V> map = new LinkedHashMap<K, V>(16, 0.75f, true) {
+            @Override
+            protected boolean removeEldestEntry(Map.Entry eldest) {
+                return size() > maxSize;
+            }
+        };
+        return Collections.synchronizedMap(map);
+    }
 }
diff --git a/...ain/java/nl/jqno/equalsverifier/internal/reflection/annotations/SupportedAnnotations.java b/...ain/java/nl/jqno/equalsverifier/internal/reflection/annotations/SupportedAnnotations.java
@@ -49,7 +49,7 @@ public enum SupportedAnnotations implements Annotation {
      * {@link NullPointerException}s being thrown if any of the fields in that
      * class or package are null.
      *
-     * Note that @DefaultAnnotation is deprectated. Nevertheless, EqualsVerifier
+     * Note that @DefaultAnnotation is deprecated. Nevertheless, EqualsVerifier
      * still supports it.
      */
     FINDBUGS1X_DEFAULT_ANNOTATION_NONNULL(false,