// 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 static com.google.protobuf.
Internal.checkNotNull;
import com.google.protobuf.
Internal.
EnumLite;
import java.util.
Arrays;
import java.util.
Collections;
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> {
private boolean
isMutable;
private
MapFieldLite() {
this.
isMutable = true;
}
private
MapFieldLite(
Map<K, V>
mapData) {
super(
mapData);
this.
isMutable = true;
}
@
SuppressWarnings({"rawtypes", "unchecked"})
private static final
MapFieldLite EMPTY_MAP_FIELD = new
MapFieldLite();
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();
super.clear();
}
@
Override public V
put(K
key, V
value) {
ensureMutable();
checkNotNull(
key);
checkNotNull(
value);
return super.put(
key,
value);
}
public V
put(
Map.
Entry<K, V>
entry) {
return
put(
entry.
getKey(),
entry.
getValue());
}
@
Override public void
putAll(
Map<? extends K, ? extends V>
m) {
ensureMutable();
checkForNullKeysAndValues(
m);
super.putAll(
m);
}
@
Override public V
remove(
Object key) {
ensureMutable();
return super.remove(
key);
}
private static void
checkForNullKeysAndValues(
Map<?, ?>
m) {
for (
Object key :
m.
keySet()) {
checkNotNull(
key);
checkNotNull(
m.
get(
key));
}
}
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
* byte arrays.
*/
static <K, V> boolean
equals(
Map<K, V>
a,
Map<K, V>
b) {
if (
a ==
b) {
return true;
}
if (
a.
size() !=
b.
size()) {
return false;
}
for (
Map.
Entry<K, V>
entry :
a.
entrySet()) {
if (!
b.
containsKey(
entry.
getKey())) {
return false;
}
if (!
equals(
entry.
getValue(),
b.
get(
entry.
getKey()))) {
return false;
}
}
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);
}
private static int
calculateHashCodeForObject(
Object a) {
if (
a instanceof byte[]) {
return
Internal.
hashCode((byte[])
a);
}
// Enums should be stored as integers internally.
if (
a instanceof
EnumLite) {
throw new
UnsupportedOperationException();
}
return
a.
hashCode();
}
/**
* Calculates the hash code for a {@link Map}. We don't use the default hash
* code method of {@link Map} because for byte arrays and protobuf enums it
* use {@link Object#hashCode()}.
*/
static <K, V> int
calculateHashCodeForMap(
Map<K, V>
a) {
int
result = 0;
for (
Map.
Entry<K, V>
entry :
a.
entrySet()) {
result +=
calculateHashCodeForObject(
entry.
getKey())
^
calculateHashCodeForObject(
entry.
getValue());
}
return
result;
}
@
Override
public int
hashCode() {
return
calculateHashCodeForMap(this);
}
private static
Object copy(
Object object) {
if (
object instanceof byte[]) {
byte[]
data = (byte[])
object;
return
Arrays.
copyOf(
data,
data.length);
}
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
* have a copy (e.g., byte arrays, mutable messages).
*/
@
SuppressWarnings("unchecked")
static <K, V>
Map<K, V>
copy(
Map<K, V>
map) {
Map<K, V>
result = new
LinkedHashMap<K, V>();
for (
Map.
Entry<K, V>
entry :
map.
entrySet()) {
result.
put(
entry.
getKey(), (V)
copy(
entry.
getValue()));
}
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);
}
/**
* Makes this field 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;
}
private void
ensureMutable() {
if (!
isMutable()) {
throw new
UnsupportedOperationException();
}
}
}