Revert https://codereview.chromium.org/1291903002 (protobuf roll).

third_party/protobuf/java/src/main/java/com/google/protobuf/MapField.java

Index: third_party/protobuf/java/src/main/java/com/google/protobuf/MapField.java
diff --git a/third_party/protobuf/java/src/main/java/com/google/protobuf/MapField.java b/third_party/protobuf/java/src/main/java/com/google/protobuf/MapField.java
deleted file mode 100644
index b290993ca1ab76246e091615ece46c14e3ffc4a1..0000000000000000000000000000000000000000
--- a/third_party/protobuf/java/src/main/java/com/google/protobuf/MapField.java
+++ /dev/null
@@ -1,286 +0,0 @@
-// Protocol Buffers - Google's data interchange format
-// Copyright 2008 Google Inc.  All rights reserved.
-// https://developers.google.com/protocol-buffers/
-//
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are
-// met:
-//
-//     * Redistributions of source code must retain the above copyright
-// notice, this list of conditions and the following disclaimer.
-//     * Redistributions in binary form must reproduce the above
-// copyright notice, this list of conditions and the following disclaimer
-// in the documentation and/or other materials provided with the
-// distribution.
-//     * Neither the name of Google Inc. nor the names of its
-// contributors may be used to endorse or promote products derived from
-// this software without specific prior written permission.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-package com.google.protobuf;
-
-import com.google.protobuf.MapFieldLite.MutatabilityAwareMap;
-
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.LinkedHashMap;
-import java.util.List;
-import java.util.Map;
-
-/**
- * Internal representation of map fields in generated messages.
- * 
- * This class supports accessing the map field as a {@link Map} to be used in
- * generated API and also supports accessing the field as a {@link List} to be
- * used in reflection API. It keeps track of where the data is currently stored
- * and do necessary conversions between map and list.  
- * 
- * This class is a protobuf implementation detail. Users shouldn't use this
- * class directly.
- * 
- * THREAD-SAFETY NOTE: Read-only access is thread-safe. Users can call getMap()
- * and getList() concurrently in multiple threads. If write-access is needed,
- * all access must be synchronized.
- */
-public class MapField<K, V> implements MutabilityOracle {
-  /**
-   * Indicates where the data of this map field is currently stored.
-   * 
-   * MAP: Data is stored in mapData.
-   * LIST: Data is stored in listData.
-   * BOTH: mapData and listData have the same data.
-   *
-   * When the map field is accessed (through generated API or reflection API),
-   * it will shift between these 3 modes:
-   * 
-   *          getMap()   getList()   getMutableMap()   getMutableList()
-   *   MAP      MAP        BOTH          MAP               LIST
-   *   LIST     BOTH       LIST          MAP               LIST
-   *   BOTH     BOTH       BOTH          MAP               LIST
-   *   
-   * As the map field changes its mode, the list/map reference returned in a
-   * previous method call may be invalidated. 
-   */
-  private enum StorageMode {MAP, LIST, BOTH}
-
-  private volatile boolean isMutable;
-  private volatile StorageMode mode;
-  private MutatabilityAwareMap<K, V> mapData;
-  private List<Message> listData;
-  
-  // Convert between a map entry Message and a key-value pair.
-  private static interface Converter<K, V> {
-    Message convertKeyAndValueToMessage(K key, V value);
-    void convertMessageToKeyAndValue(Message message, Map<K, V> map);
-    
-    Message getMessageDefaultInstance();
-  }
-  
-  private static class ImmutableMessageConverter<K, V> implements Converter<K, V> {
-    private final MapEntry<K, V> defaultEntry;
-    public ImmutableMessageConverter(MapEntry<K, V> defaultEntry) {
-      this.defaultEntry = defaultEntry;
-    }
-    
-    public Message convertKeyAndValueToMessage(K key, V value) {
-      return defaultEntry.newBuilderForType().setKey(key).setValue(value).buildPartial();
-    }
-    
-    public void convertMessageToKeyAndValue(Message message, Map<K, V> map) {
-      MapEntry<K, V> entry = (MapEntry<K, V>) message;
-      map.put(entry.getKey(), entry.getValue());
-    }
-
-    public Message getMessageDefaultInstance() {
-      return defaultEntry;
-    }
-  }
-  
-
-  private final Converter<K, V> converter;
-  
-  private MapField(
-      Converter<K, V> converter,
-      StorageMode mode,
-      Map<K, V> mapData) {
-    this.converter = converter;
-    this.isMutable = true;
-    this.mode = mode;
-    this.mapData = new MutatabilityAwareMap<K, V>(this, mapData);
-    this.listData = null;
-  }
-    
-  private MapField(
-      MapEntry<K, V> defaultEntry,
-      StorageMode mode,
-      Map<K, V> mapData) {
-    this(new ImmutableMessageConverter<K, V>(defaultEntry), mode, mapData);
-  }
-  
-  
-  /** Returns an immutable empty MapField. */
-  public static <K, V> MapField<K, V> emptyMapField(
-      MapEntry<K, V> defaultEntry) {
-    return new MapField<K, V>(
-        defaultEntry, StorageMode.MAP, Collections.<K, V>emptyMap());
-  }
-  
-  
-  /** Creates a new mutable empty MapField. */
-  public static <K, V> MapField<K, V> newMapField(MapEntry<K, V> defaultEntry) {
-    return new MapField<K, V>(
-        defaultEntry, StorageMode.MAP, new LinkedHashMap<K, V>());
-  }
-  
-  
-  private Message convertKeyAndValueToMessage(K key, V value) {
-    return converter.convertKeyAndValueToMessage(key, value);
-  }
-  
-  @SuppressWarnings("unchecked")
-  private void convertMessageToKeyAndValue(Message message, Map<K, V> map) {
-    converter.convertMessageToKeyAndValue(message, map);
-  }
-
-  private List<Message> convertMapToList(MutatabilityAwareMap<K, V> mapData) {
-    List<Message> listData = new ArrayList<Message>();
-    for (Map.Entry<K, V> entry : mapData.entrySet()) {
-      listData.add(
-          convertKeyAndValueToMessage(
-              entry.getKey(), entry.getValue()));
-    }
-    return listData;
-  }
-
-  private MutatabilityAwareMap<K, V> convertListToMap(List<Message> listData) {
-    Map<K, V> mapData = new LinkedHashMap<K, V>();
-    for (Message item : listData) {
-      convertMessageToKeyAndValue(item, mapData);
-    }
-    return new MutatabilityAwareMap<K, V>(this, mapData);
-  }
-  
-  /** Returns the content of this MapField as a read-only Map. */
-  public Map<K, V> getMap() {
-    if (mode == StorageMode.LIST) {
-      synchronized (this) {
-        if (mode == StorageMode.LIST) {
-          mapData = convertListToMap(listData);
-          mode = StorageMode.BOTH;
-        }
-      }
-    }
-    return Collections.unmodifiableMap(mapData);
-  }
-  
-  /** Gets a mutable Map view of this MapField. */
-  public Map<K, V> getMutableMap() {
-    if (mode != StorageMode.MAP) {
-      if (mode == StorageMode.LIST) {
-        mapData = convertListToMap(listData);
-      }
-      listData = null;
-      mode = StorageMode.MAP; 
-    }
-    return mapData;
-  }
-  
-  public void mergeFrom(MapField<K, V> other) {
-    getMutableMap().putAll(MapFieldLite.copy(other.getMap()));
-  }
-  
-  public void clear() {
-    mapData = new MutatabilityAwareMap<K, V>(this, new LinkedHashMap<K, V>());
-    mode = StorageMode.MAP;
-  }
-  
-  @SuppressWarnings("unchecked")
-  @Override
-  public boolean equals(Object object) {
-    if (!(object instanceof MapField)) {
-      return false;
-    }
-    MapField<K, V> other = (MapField<K, V>) object;
-    return MapFieldLite.<K, V>equals(getMap(), other.getMap());
-  }
-  
-  @Override
-  public int hashCode() {
-    return MapFieldLite.<K, V>calculateHashCodeForMap(getMap());
-  }
-  
-  /** Returns a deep copy of this MapField. */
-  public MapField<K, V> copy() {
-    return new MapField<K, V>(
-        converter, StorageMode.MAP, MapFieldLite.copy(getMap()));
-  }
-  
-  /** Gets the content of this MapField as a read-only List. */
-  List<Message> getList() {
-    if (mode == StorageMode.MAP) {
-      synchronized (this) {
-        if (mode == StorageMode.MAP) {
-          listData = convertMapToList(mapData);
-          mode = StorageMode.BOTH;
-        }
-      }
-    }
-    return Collections.unmodifiableList(listData);
-  }
-  
-  /** Gets a mutable List view of this MapField. */
-  List<Message> getMutableList() {
-    if (mode != StorageMode.LIST) {
-      if (mode == StorageMode.MAP) {
-        listData = convertMapToList(mapData);
-      }
-      mapData = null;
-      mode = StorageMode.LIST;
-    }
-    return listData;
-  }
-  
-  /**
-   * Gets the default instance of the message stored in the list view of this
-   * map field.
-   */
-  Message getMapEntryMessageDefaultInstance() {
-    return converter.getMessageDefaultInstance();
-  }
-  
-  /**
-   * Makes this list immutable. All subsequent modifications will throw an
-   * {@link UnsupportedOperationException}.
-   */
-  public void makeImmutable() {
-    isMutable = false;
-  }
-  
-  /**
-   * Returns whether this field can be modified.
-   */
-  public boolean isMutable() {
-    return isMutable;
-  }
-  
-  /* (non-Javadoc)
-   * @see com.google.protobuf.MutabilityOracle#ensureMutable()
-   */
-  @Override
-  public void ensureMutable() {
-    if (!isMutable()) {
-      throw new UnsupportedOperationException();
-    }
-  }
-}