Merge pull request #404 from gsmet/rightsize-maps

Avoid having a ton of empty HashMaps in memory
smallrye · Jun 26, 2024 · 1352479 · 1352479
2 parents 9563819 + 8dc2254
commit 1352479
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Showing 2 changed files with 13 additions and 2 deletions.
diff --git a/core/src/main/java/org/jboss/jandex/ClassInfo.java b/core/src/main/java/org/jboss/jandex/ClassInfo.java
@@ -654,7 +654,7 @@ public final Map<DotName, List<AnnotationInstance>> annotationsMap() {
     }
 
     final void setAnnotations(Map<DotName, List<AnnotationInstance>> annotations) {
-        this.annotations = annotations;
+        this.annotations = Utils.minimize(annotations);
     }
 
     /**

diff --git a/core/src/main/java/org/jboss/jandex/Utils.java b/core/src/main/java/org/jboss/jandex/Utils.java
@@ -61,8 +61,19 @@ static <K, V> Map<K, V[]> unfold(Map<K, List<V>> map, Class<V> listElementType)
         return result;
     }
 
+    static <K, V> Map<K, V> minimize(Map<K, V> map) {
+        if (map.isEmpty()) {
+            return Collections.emptyMap();
+        } else if (map.size() == 1) {
+            Map.Entry<K, V> entry = map.entrySet().iterator().next();
+            return Collections.singletonMap(entry.getKey(), entry.getValue());
+        } else {
+            return map;
+        }
+    }
+
     static <T> List<T> listOfCapacity(int capacity) {
-        return capacity > 0 ? new ArrayList<T>(capacity) : Collections.<T> emptyList();
+        return capacity > 0 ? new ArrayList<>(capacity) : Collections.emptyList();
     }
 
     static final class ReusableBufferedDataInputStream extends DataInputStream {