aboutsummaryrefslogtreecommitdiffhomepage
path: root/java/core/src/main/java/com/google/protobuf/MapField.java
diff options
context:
space:
mode:
authorGravatar nmittler <nathanmittler@google.com>2016-01-08 09:19:11 -0800
committerGravatar nmittler <nathanmittler@google.com>2016-01-13 08:15:15 -0800
commit49efe9d7db877022e76375df2d4daadab98619b6 (patch)
treee8d60f158c87db4135b80c8caba1ecd90f782fa3 /java/core/src/main/java/com/google/protobuf/MapField.java
parentd134a80f849d9fe7d3ca85f09f190351a3283f85 (diff)
Restructuring protobuf to multiple modules
protobuf/java will become a parent pom that will contain two modules: core - contains all of the code for the protobuf-java artifact util - contains all of the code for the protobuf-java-util artifact Also cleaned up various Maven warnings.
Diffstat (limited to 'java/core/src/main/java/com/google/protobuf/MapField.java')
-rw-r--r--java/core/src/main/java/com/google/protobuf/MapField.java286
1 files changed, 286 insertions, 0 deletions
diff --git a/java/core/src/main/java/com/google/protobuf/MapField.java b/java/core/src/main/java/com/google/protobuf/MapField.java
new file mode 100644
index 00000000..b290993c
--- /dev/null
+++ b/java/core/src/main/java/com/google/protobuf/MapField.java
@@ -0,0 +1,286 @@
+// 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();
+ }
+ }
+}