Report a dedicated exception on unique failure

[yangtools.git] / yang / yang-data-impl / src / main / java / org / opendaylight / yangtools / yang / data / impl / schema / nodes / UnmodifiableChildrenMap.java

diff --git a/yang/yang-data-impl/src/main/java/org/opendaylight/yangtools/yang/data/impl/schema/nodes/UnmodifiableChildrenMap.java b/yang/yang-data-impl/src/main/java/org/opendaylight/yangtools/yang/data/impl/schema/nodes/UnmodifiableChildrenMap.java
index 98598aa31e8d852b1dc284bd889dcc73375aaac6..6a2c3d2b202229b1609d57b9eafb28dc67a1f276 100644 (file)
--- a/yang/yang-data-impl/src/main/java/org/opendaylight/yangtools/yang/data/impl/schema/nodes/UnmodifiableChildrenMap.java
+++ b/yang/yang-data-impl/src/main/java/org/opendaylight/yangtools/yang/data/impl/schema/nodes/UnmodifiableChildrenMap.java
@@ -7,11 +7,14 @@
  */
 package org.opendaylight.yangtools.yang.data.impl.schema.nodes;
 
-import com.google.common.base.Preconditions;
+import static java.util.Objects.requireNonNull;
+
 import com.google.common.collect.ImmutableMap;
+import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
 import java.io.Serializable;
 import java.util.Collection;
 import java.util.Collections;
+import java.util.HashMap;
 import java.util.Map;
 import java.util.Set;
 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.PathArgument;
@@ -21,13 +24,22 @@ import org.opendaylight.yangtools.yang.data.api.schema.DataContainerChild;
  * Internal equivalent of {@link Collections}' unmodifiable Map. It does not retain
  * keySet/entrySet references, thus lowering the memory overhead.
  */
-final class UnmodifiableChildrenMap implements Map<PathArgument, DataContainerChild<? extends PathArgument, ?>>, Serializable {
+final class UnmodifiableChildrenMap
+        implements CloneableMap<PathArgument, DataContainerChild<? extends PathArgument, ?>>, Serializable {
     private static final long serialVersionUID = 1L;
+
+    /*
+     * Do not wrap maps which are smaller than this and instead copy them into an ImmutableMap.
+     */
+    private static final int WRAP_THRESHOLD = 9;
+
+    @SuppressFBWarnings(value = "SE_BAD_FIELD", justification = "Delegate is expected to be Serializable")
     private final Map<PathArgument, DataContainerChild<? extends PathArgument, ?>> delegate;
-    private transient Collection<DataContainerChild<? extends PathArgument, ?>> values;
+
+    private transient Collection<DataContainerChild<? extends PathArgument, ?>> values = null;
 
     private UnmodifiableChildrenMap(final Map<PathArgument, DataContainerChild<? extends PathArgument, ?>> delegate) {
-        this.delegate = Preconditions.checkNotNull(delegate);
+        this.delegate = requireNonNull(delegate);
     }
 
     /**
@@ -37,7 +49,8 @@ final class UnmodifiableChildrenMap implements Map<PathArgument, DataContainerCh
      * @param map Backing map
      * @return Unmodifiable view
      */
-    static Map<PathArgument, DataContainerChild<? extends PathArgument, ?>> create(final Map<PathArgument, DataContainerChild<? extends PathArgument, ?>> map) {
+    static Map<PathArgument, DataContainerChild<? extends PathArgument, ?>> create(
+            final Map<PathArgument, DataContainerChild<? extends PathArgument, ?>> map) {
         if (map instanceof UnmodifiableChildrenMap) {
             return map;
         }
@@ -45,7 +58,10 @@ final class UnmodifiableChildrenMap implements Map<PathArgument, DataContainerCh
             return map;
         }
         if (map.isEmpty()) {
-            return Collections.emptyMap();
+            return ImmutableMap.of();
+        }
+        if (map.size() < WRAP_THRESHOLD) {
+            return ImmutableMap.copyOf(map);
         }
 
         return new UnmodifiableChildrenMap(map);
@@ -88,6 +104,7 @@ final class UnmodifiableChildrenMap implements Map<PathArgument, DataContainerCh
     }
 
     @Override
+    @SuppressWarnings("checkstyle:parameterName")
     public void putAll(final Map<? extends PathArgument, ? extends DataContainerChild<? extends PathArgument, ?>> m) {
         throw new UnsupportedOperationException();
     }
@@ -123,8 +140,8 @@ final class UnmodifiableChildrenMap implements Map<PathArgument, DataContainerCh
     }
 
     @Override
-    public boolean equals(final Object o) {
-        return this == o || delegate.equals(o);
+    public boolean equals(final Object obj) {
+        return this == obj || delegate.equals(obj);
     }
 
     @Override
@@ -136,4 +153,15 @@ final class UnmodifiableChildrenMap implements Map<PathArgument, DataContainerCh
     public String toString() {
         return delegate.toString();
     }
+
+    @Override
+    @SuppressWarnings("unchecked")
+    public Map<PathArgument, DataContainerChild<? extends PathArgument, ?>> createMutableClone() {
+        if (delegate instanceof HashMap) {
+            return (Map<PathArgument, DataContainerChild<? extends PathArgument, ?>>)
+                    ((HashMap<?, ?>) delegate).clone();
+        }
+
+        return new HashMap<>(delegate);
+    }
 }