X-Git-Url: https://git.opendaylight.org/gerrit/gitweb?a=blobdiff_plain;f=common%2Futil%2Fsrc%2Fmain%2Fjava%2Forg%2Fopendaylight%2Fyangtools%2Futil%2FImmutableOffsetMap.java;h=f2d34020ca4997342e853072329e33f71eb0d2cc;hb=ed6fff67cb0fed454ea6654752f23dc9f914c04d;hp=019722b509af3e0bbff16386effc121389de3287;hpb=b0b8d9ef5d43eb850a92203345a3e72c6eeaf043;p=yangtools.git

diff --git a/common/util/src/main/java/org/opendaylight/yangtools/util/ImmutableOffsetMap.java b/common/util/src/main/java/org/opendaylight/yangtools/util/ImmutableOffsetMap.java
index 019722b509..f2d34020ca 100644
--- a/common/util/src/main/java/org/opendaylight/yangtools/util/ImmutableOffsetMap.java
+++ b/common/util/src/main/java/org/opendaylight/yangtools/util/ImmutableOffsetMap.java
@@ -16,12 +16,14 @@ import java.io.ObjectInputStream;
 import java.io.ObjectOutputStream;
 import java.io.Serializable;
 import java.lang.reflect.Field;
+import java.util.AbstractMap.SimpleImmutableEntry;
 import java.util.AbstractSet;
 import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
-import java.util.Objects;
 import java.util.Set;
 import javax.annotation.Nonnull;
 
@@ -30,18 +32,16 @@ import javax.annotation.Nonnull;
  * a backing array. This is useful for situations where the same key set is shared across a multitude of maps, as this
  * class uses a global cache to share the key-to-offset mapping.
  *
- * This map supports creation of value objects on the fly. To achieve that, subclasses should override {@link #valueToObject(Object)},
- * {@link #objectToValue(Object, Object)}, {@link #clone()} and {@link #toModifiableMap()} methods.
- *
  * @param <K> the type of keys maintained by this map
  * @param <V> the type of mapped values
  */
 @Beta
-public class ImmutableOffsetMap<K, V> extends AbstractLazyValueMap<K, V> implements Cloneable, UnmodifiableMapPhase<K, V>, Serializable {
+public final class ImmutableOffsetMap<K, V> implements UnmodifiableMapPhase<K, V>, Serializable {
     private static final long serialVersionUID = 1L;
 
     private final Map<K, Integer> offsets;
-    private final Object[] objects;
+    private final V[] objects;
+    private int hashCode;
 
     /**
      * Construct a new instance backed by specified key-to-offset map and array of objects.
@@ -50,7 +50,7 @@ public class ImmutableOffsetMap<K, V> extends AbstractLazyValueMap<K, V> impleme
      * @param objects Array of value object, may not be null. The array is stored as is, the caller
      *              is responsible for ensuring its contents remain unmodified.
      */
-    ImmutableOffsetMap(@Nonnull final Map<K, Integer> offsets, @Nonnull final Object[] objects) {
+    ImmutableOffsetMap(@Nonnull final Map<K, Integer> offsets, @Nonnull final V[] objects) {
         this.offsets = Preconditions.checkNotNull(offsets);
         this.objects = Preconditions.checkNotNull(objects);
         Preconditions.checkArgument(offsets.size() == objects.length);
@@ -61,7 +61,7 @@ public class ImmutableOffsetMap<K, V> extends AbstractLazyValueMap<K, V> impleme
      *
      * @param m Instance to share data with, may not be null.
      */
-    protected ImmutableOffsetMap(@Nonnull final ImmutableOffsetMap<K, V> m) {
+    ImmutableOffsetMap(@Nonnull final ImmutableOffsetMap<K, V> m) {
         this.offsets = m.offsets;
         this.objects = m.objects;
     }
@@ -78,23 +78,25 @@ public class ImmutableOffsetMap<K, V> extends AbstractLazyValueMap<K, V> impleme
      * @return An isolated, immutable copy of the input map
      */
     @Nonnull public static <K, V> Map<K, V> copyOf(@Nonnull final Map<K, V> m) {
-        // Prevent a copy
-        if (m instanceof ImmutableOffsetMap) {
+        // Prevent a copy. Note that ImmutableMap is not listed here because of its potentially larger keySet overhead.
+        if (m instanceof ImmutableOffsetMap || m instanceof SharedSingletonMap) {
             return m;
         }
 
-        // Better-packed
+        // Familiar and efficient to copy
+        if (m instanceof MutableOffsetMap) {
+            return ((MutableOffsetMap<K, V>) m).toUnmodifiableMap();
+        }
+
         final int size = m.size();
         if (size == 0) {
+            // Shares a single object
             return ImmutableMap.of();
         }
         if (size == 1) {
-            return ImmutableMap.copyOf(m);
-        }
-
-        // Familiar and efficient
-        if (m instanceof MutableOffsetMap) {
-            return ((MutableOffsetMap<K, V>) m).toUnmodifiableMap();
+            // Efficient single-entry implementation
+            final Entry<K, V> e = m.entrySet().iterator().next();
+            return SharedSingletonMap.of(e.getKey(), e.getValue());
         }
 
         final Map<K, Integer> offsets = OffsetMapCache.offsetsFor(m.keySet());
@@ -108,83 +110,139 @@ public class ImmutableOffsetMap<K, V> extends AbstractLazyValueMap<K, V> impleme
     }
 
     @Override
-    public final int size() {
+    public int size() {
         return offsets.size();
     }
 
     @Override
-    public final boolean isEmpty() {
+    public boolean isEmpty() {
         return offsets.isEmpty();
     }
 
     @Override
-    public final boolean containsKey(final Object key) {
+    public int hashCode() {
+        if (hashCode != 0) {
+            return hashCode;
+        }
+
+        int result = 0;
+        for (Entry<K, Integer> e : offsets.entrySet()) {
+            result += e.getKey().hashCode() ^ objects[e.getValue()].hashCode();
+        }
+
+        hashCode = result;
+        return result;
+    }
+
+    @Override
+    public boolean equals(final Object o) {
+        if (o == this) {
+            return true;
+        }
+        if (o == null) {
+            return false;
+        }
+
+        if (o instanceof ImmutableOffsetMap) {
+            final ImmutableOffsetMap<?, ?> om = (ImmutableOffsetMap<?, ?>) o;
+            if (offsets.equals(om.offsets) && Arrays.deepEquals(objects, om.objects)) {
+                return true;
+            }
+        } else if (o instanceof MutableOffsetMap) {
+            // Let MutableOffsetMap do the actual work.
+            return o.equals(this);
+        } else if (o instanceof Map) {
+            final Map<?, ?> om = (Map<?, ?>)o;
+
+            // Size and key sets have to match
+            if (size() != om.size() || !keySet().equals(om.keySet())) {
+                return false;
+            }
+
+            try {
+                // Ensure all objects are present
+                for (Entry<K, Integer> e : offsets.entrySet()) {
+                    if (!objects[e.getValue()].equals(om.get(e.getKey()))) {
+                        return false;
+                    }
+                }
+            } catch (ClassCastException e) {
+                // Can be thrown by om.get() indicating we have incompatible key types
+                return false;
+            }
+
+            return true;
+        }
+
+        return false;
+    }
+
+    @Override
+    public boolean containsKey(final Object key) {
         return offsets.containsKey(key);
     }
 
     @Override
-    public final boolean containsValue(final Object value) {
-        @SuppressWarnings("unchecked")
-        final Object obj = valueToObject((V)value);
+    public boolean containsValue(final Object value) {
         for (Object o : objects) {
-            if (Objects.equals(obj, o)) {
+            if (value.equals(o)) {
                 return true;
             }
         }
         return false;
     }
 
-    @SuppressWarnings("unchecked")
     @Override
-    public final V get(final Object key) {
+    public V get(final Object key) {
         final Integer offset = offsets.get(key);
-        if (offset == null) {
-            return null;
-        }
+        return offset == null ? null : objects[offset];
+    }
 
-        return objectToValue((K) key, objects[offset]);
+    @Override
+    public V remove(final Object key) {
+        throw new UnsupportedOperationException();
     }
 
     @Override
-    public final V remove(final Object key) {
+    public V put(final K key, final V value) {
         throw new UnsupportedOperationException();
     }
 
     @Override
-    public final void putAll(final Map<? extends K, ? extends V> m) {
+    public void putAll(final Map<? extends K, ? extends V> m) {
         throw new UnsupportedOperationException();
     }
 
     @Override
-    public final void clear() {
+    public void clear() {
         throw new UnsupportedOperationException();
     }
 
     @Override
-    public final Set<K> keySet() {
+    public Set<K> keySet() {
         return offsets.keySet();
     }
 
     @Override
-    public final Set<Entry<K, V>> entrySet() {
-        return new EntrySet();
+    public Collection<V> values() {
+        return new ConstantArrayCollection<>(objects);
     }
 
     @Override
-    public MutableOffsetMap<K, V> toModifiableMap() {
-        return new MutableOffsetMap<>(this);
+    public Set<Entry<K, V>> entrySet() {
+        return new EntrySet();
     }
 
     @Override
-    public ImmutableOffsetMap<K, V> clone() throws CloneNotSupportedException {
-        return new ImmutableOffsetMap<>(this);
+    public MutableOffsetMap<K, V> toModifiableMap() {
+        return new MutableOffsetMap<>(this);
     }
 
     Map<K, Integer> offsets() {
         return offsets;
     }
 
-    Object[] objects() {
+    V[] objects() {
         return objects;
     }
 
@@ -202,7 +260,7 @@ public class ImmutableOffsetMap<K, V> extends AbstractLazyValueMap<K, V> impleme
                 @Override
                 public Entry<K, V> next() {
                     final Entry<K, Integer> e = it.next();
-                    return new SimpleEntry<>(e.getKey(), objectToValue(e.getKey(), objects[e.getValue()]));
+                    return new SimpleImmutableEntry<>(e.getKey(), objects[e.getValue()]);
                 }
             };
         }