Reverts third_party/protobuf: Update to HEAD (f52e188fe4)

third_party/protobuf/java/core/src/main/java/com/google/protobuf/MapFieldLite.java

Index: third_party/protobuf/java/core/src/main/java/com/google/protobuf/MapFieldLite.java
diff --git a/third_party/protobuf/java/core/src/main/java/com/google/protobuf/MapFieldLite.java b/third_party/protobuf/java/core/src/main/java/com/google/protobuf/MapFieldLite.java
index 16b3fefe138b7d238d9ec89b0e66ba3de54d2c28..960b633909a064b526deeb9c16948c92eed10212 100644
--- a/third_party/protobuf/java/core/src/main/java/com/google/protobuf/MapFieldLite.java
+++ b/third_party/protobuf/java/core/src/main/java/com/google/protobuf/MapFieldLite.java
@@ -33,85 +33,71 @@ package com.google.protobuf;
 import com.google.protobuf.Internal.EnumLite;
 
 import java.util.Arrays;
+import java.util.Collection;
 import java.util.Collections;
+import java.util.Iterator;
 import java.util.LinkedHashMap;
 import java.util.Map;
 import java.util.Set;
 
 /**
  * Internal representation of map fields in generated lite-runtime messages.
- *
+ * 
  * This class is a protobuf implementation detail. Users shouldn't use this
  * class directly.
  */
-public final class MapFieldLite<K, V> extends LinkedHashMap<K, V> {
-
+public final class MapFieldLite<K, V> implements MutabilityOracle {
+  private MutatabilityAwareMap<K, V> mapData;
   private boolean isMutable;
-
-  private MapFieldLite() {
-    this.isMutable = true;
-  }
-
+  
   private MapFieldLite(Map<K, V> mapData) {
-    super(mapData);
+    this.mapData = new MutatabilityAwareMap<K, V>(this, mapData);
     this.isMutable = true;
   }
-
+  
   @SuppressWarnings({"rawtypes", "unchecked"})
-  private static final MapFieldLite EMPTY_MAP_FIELD = new MapFieldLite();
+  private static final MapFieldLite EMPTY_MAP_FIELD =
+      new MapFieldLite(Collections.emptyMap());
   static {
     EMPTY_MAP_FIELD.makeImmutable();
   }
-
+  
   /** Returns an singleton immutable empty MapFieldLite instance. */
   @SuppressWarnings({"unchecked", "cast"})
   public static <K, V> MapFieldLite<K, V> emptyMapField() {
     return (MapFieldLite<K, V>) EMPTY_MAP_FIELD;
   }
-
-  public void mergeFrom(MapFieldLite<K, V> other) {
-    ensureMutable();
-    if (!other.isEmpty()) {
-      putAll(other);
-    }
-  }
-
-  @SuppressWarnings({"unchecked", "cast"})
-  @Override public Set<Map.Entry<K, V>> entrySet() {
-    return isEmpty() ? Collections.<Map.Entry<K, V>>emptySet() : super.entrySet();
-  }
-
-  @Override public void clear() {
-    ensureMutable();
-    clear();
+  
+  /** Creates a new MapFieldLite instance. */
+  public static <K, V> MapFieldLite<K, V> newMapField() {
+    return new MapFieldLite<K, V>(new LinkedHashMap<K, V>());
   }
-
-  @Override public V put(K key, V value) {
-    ensureMutable();
-    return super.put(key, value);
+  
+  /** Gets the content of this MapField as a read-only Map. */
+  public Map<K, V> getMap() {
+    return Collections.unmodifiableMap(mapData);
   }
-
-  public V put(Map.Entry<K, V> entry) {
-    return put(entry.getKey(), entry.getValue());
+  
+  /** Gets a mutable Map view of this MapField. */
+  public Map<K, V> getMutableMap() {
+    return mapData;
   }
-
-  @Override public void putAll(Map<? extends K, ? extends V> m) {
-    ensureMutable();
-    super.putAll(m);
+  
+  public void mergeFrom(MapFieldLite<K, V> other) {
+    mapData.putAll(copy(other.mapData));
   }
-
-  @Override public V remove(Object key) {
-    ensureMutable();
-    return super.remove(key);
+  
+  public void clear() {
+    mapData.clear();
   }
-
+  
   private static boolean equals(Object a, Object b) {
     if (a instanceof byte[] && b instanceof byte[]) {
       return Arrays.equals((byte[]) a, (byte[]) b);
     }
     return a.equals(b);
   }
-
+  
   /**
    * Checks whether two {@link Map}s are equal. We don't use the default equals
    * method of {@link Map} because it compares by identity not by content for
@@ -134,16 +120,20 @@ public final class MapFieldLite<K, V> extends LinkedHashMap<K, V> {
     }
     return true;
   }
-
+  
   /**
    * Checks whether two map fields are equal.
    */
   @SuppressWarnings("unchecked")
   @Override
   public boolean equals(Object object) {
-    return (object instanceof Map) && equals(this, (Map<K, V>) object);
+    if (!(object instanceof MapFieldLite)) {
+      return false;
+    }
+    MapFieldLite<K, V> other = (MapFieldLite<K, V>) object;
+    return equals(mapData, other.mapData);
   }
-
+  
   private static int calculateHashCodeForObject(Object a) {
     if (a instanceof byte[]) {
       return Internal.hashCode((byte[]) a);
@@ -166,14 +156,14 @@ public final class MapFieldLite<K, V> extends LinkedHashMap<K, V> {
       result += calculateHashCodeForObject(entry.getKey())
           ^ calculateHashCodeForObject(entry.getValue());
     }
-    return result;
+    return result;    
   }
-
+  
   @Override
   public int hashCode() {
-    return calculateHashCodeForMap(this);
+    return calculateHashCodeForMap(mapData);
   }
-
+  
   private static Object copy(Object object) {
     if (object instanceof byte[]) {
       byte[] data = (byte[]) object;
@@ -181,7 +171,7 @@ public final class MapFieldLite<K, V> extends LinkedHashMap<K, V> {
     }
     return object;
   }
-
+  
   /**
    * Makes a deep copy of a {@link Map}. Immutable objects in the map will be
    * shared (e.g., integers, strings, immutable messages) and mutable ones will
@@ -195,12 +185,12 @@ public final class MapFieldLite<K, V> extends LinkedHashMap<K, V> {
     }
     return result;
   }
-
+  
   /** Returns a deep copy of this map field. */
-  public MapFieldLite<K, V> mutableCopy() {
-    return isEmpty() ? new MapFieldLite<K, V>() : new MapFieldLite<K, V>(this);
+  public MapFieldLite<K, V> copy() {
+    return new MapFieldLite<K, V>(copy(mapData));
   }
-
+  
   /**
    * Makes this field immutable. All subsequent modifications will throw an
    * {@link UnsupportedOperationException}.
@@ -208,17 +198,352 @@ public final class MapFieldLite<K, V> extends LinkedHashMap<K, V> {
   public void makeImmutable() {
     isMutable = false;
   }
-
+  
   /**
    * Returns whether this field can be modified.
    */
   public boolean isMutable() {
     return isMutable;
   }
-
-  private void ensureMutable() {
+  
+  @Override
+  public void ensureMutable() {
     if (!isMutable()) {
       throw new UnsupportedOperationException();
     }
   }
+
+  /**
+   * An internal map that checks for mutability before delegating.
+   */
+  static class MutatabilityAwareMap<K, V> implements Map<K, V> {    
+    private final MutabilityOracle mutabilityOracle;
+    private final Map<K, V> delegate;
+    
+    MutatabilityAwareMap(MutabilityOracle mutabilityOracle, Map<K, V> delegate) {
+      this.mutabilityOracle = mutabilityOracle;
+      this.delegate = delegate;
+    }
+
+    @Override
+    public int size() {
+      return delegate.size();
+    }
+
+    @Override
+    public boolean isEmpty() {
+      return delegate.isEmpty();
+    }
+
+    @Override
+    public boolean containsKey(Object key) {
+      return delegate.containsKey(key);
+    }
+
+    @Override
+    public boolean containsValue(Object value) {
+      return delegate.containsValue(value);
+    }
+
+    @Override
+    public V get(Object key) {
+      return delegate.get(key);
+    }
+
+    @Override
+    public V put(K key, V value) {
+      mutabilityOracle.ensureMutable();
+      return delegate.put(key, value);
+    }
+
+    @Override
+    public V remove(Object key) {
+      mutabilityOracle.ensureMutable();
+      return delegate.remove(key);
+    }
+
+    @Override
+    public void putAll(Map<? extends K, ? extends V> m) {
+      mutabilityOracle.ensureMutable();
+      delegate.putAll(m);
+    }
+
+    @Override
+    public void clear() {
+      mutabilityOracle.ensureMutable();
+      delegate.clear();
+    }
+
+    @Override
+    public Set<K> keySet() {
+      return new MutatabilityAwareSet<K>(mutabilityOracle, delegate.keySet());
+    }
+
+    @Override
+    public Collection<V> values() {
+      return new MutatabilityAwareCollection<V>(mutabilityOracle, delegate.values());
+    }
+
+    @Override
+    public Set<java.util.Map.Entry<K, V>> entrySet() {
+      return new MutatabilityAwareSet<Entry<K, V>>(mutabilityOracle, delegate.entrySet());
+    }
+
+    @Override
+    public boolean equals(Object o) {
+      return delegate.equals(o);
+    }
+
+    @Override
+    public int hashCode() {
+      return delegate.hashCode();
+    }
+
+    @Override
+    public String toString() {
+      return delegate.toString();
+    }
+  }
+
+  /**
+   * An internal collection that checks for mutability before delegating.
+   */
+  private static class MutatabilityAwareCollection<E> implements Collection<E> {
+    private final MutabilityOracle mutabilityOracle;
+    private final Collection<E> delegate;
+    
+    MutatabilityAwareCollection(MutabilityOracle mutabilityOracle, Collection<E> delegate) {
+      this.mutabilityOracle = mutabilityOracle;
+      this.delegate = delegate;
+    }
+
+    @Override
+    public int size() {
+      return delegate.size();
+    }
+
+    @Override
+    public boolean isEmpty() {
+      return delegate.isEmpty();
+    }
+
+    @Override
+    public boolean contains(Object o) {
+      return delegate.contains(o);
+    }
+
+    @Override
+    public Iterator<E> iterator() {
+      return new MutatabilityAwareIterator<E>(mutabilityOracle, delegate.iterator());
+    }
+
+    @Override
+    public Object[] toArray() {
+      return delegate.toArray();
+    }
+
+    @Override
+    public <T> T[] toArray(T[] a) {
+      return delegate.toArray(a);
+    }
+
+    @Override
+    public boolean add(E e) {
+      // Unsupported operation in the delegate.
+      throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public boolean remove(Object o) {
+      mutabilityOracle.ensureMutable();
+      return delegate.remove(o);
+    }
+
+    @Override
+    public boolean containsAll(Collection<?> c) {
+      return delegate.containsAll(c);
+    }
+
+    @Override
+    public boolean addAll(Collection<? extends E> c) {
+      // Unsupported operation in the delegate.
+      throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public boolean removeAll(Collection<?> c) {
+      mutabilityOracle.ensureMutable();
+      return delegate.removeAll(c);
+    }
+
+    @Override
+    public boolean retainAll(Collection<?> c) {
+      mutabilityOracle.ensureMutable();
+      return delegate.retainAll(c);
+    }
+
+    @Override
+    public void clear() {
+      mutabilityOracle.ensureMutable();
+      delegate.clear();
+    }
+
+    @Override
+    public boolean equals(Object o) {
+      return delegate.equals(o);
+    }
+
+    @Override
+    public int hashCode() {
+      return delegate.hashCode();
+    }
+    
+    @Override
+    public String toString() {
+      return delegate.toString();
+    }
+  }
+
+  /**
+   * An internal set that checks for mutability before delegating.
+   */
+  private static class MutatabilityAwareSet<E> implements Set<E> {
+    private final MutabilityOracle mutabilityOracle;
+    private final Set<E> delegate;
+    
+    MutatabilityAwareSet(MutabilityOracle mutabilityOracle, Set<E> delegate) {
+      this.mutabilityOracle = mutabilityOracle;
+      this.delegate = delegate;
+    }
+
+    @Override
+    public int size() {
+      return delegate.size();
+    }
+
+    @Override
+    public boolean isEmpty() {
+      return delegate.isEmpty();
+    }
+
+    @Override
+    public boolean contains(Object o) {
+      return delegate.contains(o);
+    }
+
+    @Override
+    public Iterator<E> iterator() {
+      return new MutatabilityAwareIterator<E>(mutabilityOracle, delegate.iterator());
+    }
+
+    @Override
+    public Object[] toArray() {
+      return delegate.toArray();
+    }
+
+    @Override
+    public <T> T[] toArray(T[] a) {
+      return delegate.toArray(a);
+    }
+
+    @Override
+    public boolean add(E e) {
+      mutabilityOracle.ensureMutable();
+      return delegate.add(e);
+    }
+
+    @Override
+    public boolean remove(Object o) {
+      mutabilityOracle.ensureMutable();
+      return delegate.remove(o);
+    }
+
+    @Override
+    public boolean containsAll(Collection<?> c) {
+      return delegate.containsAll(c);
+    }
+
+    @Override
+    public boolean addAll(Collection<? extends E> c) {
+      mutabilityOracle.ensureMutable();
+      return delegate.addAll(c);
+    }
+
+    @Override
+    public boolean retainAll(Collection<?> c) {
+      mutabilityOracle.ensureMutable();
+      return delegate.retainAll(c);
+    }
+
+    @Override
+    public boolean removeAll(Collection<?> c) {
+      mutabilityOracle.ensureMutable();
+      return delegate.removeAll(c);
+    }
+
+    @Override
+    public void clear() {
+      mutabilityOracle.ensureMutable();
+      delegate.clear();
+    }
+
+    @Override
+    public boolean equals(Object o) {
+      return delegate.equals(o);
+    }
+
+    @Override
+    public int hashCode() {
+      return delegate.hashCode();
+    }
+
+    @Override
+    public String toString() {
+      return delegate.toString();
+    }
+  }
+  
+  /**
+   * An internal iterator that checks for mutability before delegating.
+   */
+  private static class MutatabilityAwareIterator<E> implements Iterator<E> {
+    private final MutabilityOracle mutabilityOracle;
+    private final Iterator<E> delegate;
+    
+    MutatabilityAwareIterator(MutabilityOracle mutabilityOracle, Iterator<E> delegate) {
+      this.mutabilityOracle = mutabilityOracle;
+      this.delegate = delegate;
+    }
+
+    @Override
+    public boolean hasNext() {
+      return delegate.hasNext();
+    }
+
+    @Override
+    public E next() {
+      return delegate.next();
+    }
+
+    @Override
+    public void remove() {
+      mutabilityOracle.ensureMutable();
+      delegate.remove();
+    }
+    
+    @Override
+    public boolean equals(Object obj) {
+      return delegate.equals(obj);
+    }
+    
+    @Override
+    public int hashCode() {
+      return delegate.hashCode();
+    }
+
+    @Override
+    public String toString() {
+      return delegate.toString();
+    }
+  }
 }