com.google.protobuf.AbstractProtobufList Maven / Gradle / Ivy
// 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,
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package com.google.protobuf;
import com.google.protobuf.Internal.ProtobufList;
import java.util.AbstractList;
import java.util.Collection;
import java.util.List;
import java.util.RandomAccess;
/**
* An abstract implementation of {@link ProtobufList} which manages mutability semantics. All mutate
* methods must check if the list is mutable before proceeding. Subclasses must invoke {@link
* #ensureIsMutable()} manually when overriding those methods.
*
* This implementation assumes all subclasses are array based, supporting random access.
*/
abstract class AbstractProtobufList extends AbstractList implements ProtobufList {
protected static final int DEFAULT_CAPACITY = 10;
/** Whether or not this list is modifiable. */
private boolean isMutable;
/** Constructs a mutable list by default. */
AbstractProtobufList() {
isMutable = true;
}
@Override
public boolean equals(Object o) {
if (o == this) {
return true;
}
if (!(o instanceof List)) {
return false;
}
// Handle lists that do not support RandomAccess as efficiently as possible by using an iterator
// based approach in our super class. Otherwise our index based approach will avoid those
// allocations.
if (!(o instanceof RandomAccess)) {
return super.equals(o);
}
List other = (List) o;
final int size = size();
if (size != other.size()) {
return false;
}
for (int i = 0; i < size; i++) {
if (!get(i).equals(other.get(i))) {
return false;
}
}
return true;
}
@Override
public int hashCode() {
final int size = size();
int hashCode = 1;
for (int i = 0; i < size; i++) {
hashCode = (31 * hashCode) + get(i).hashCode();
}
return hashCode;
}
@Override
public boolean add(E e) {
ensureIsMutable();
return super.add(e);
}
@Override
public void add(int index, E element) {
ensureIsMutable();
super.add(index, element);
}
@Override
public boolean addAll(Collection c) {
ensureIsMutable();
return super.addAll(c);
}
@Override
public boolean addAll(int index, Collection c) {
ensureIsMutable();
return super.addAll(index, c);
}
@Override
public void clear() {
ensureIsMutable();
super.clear();
}
@Override
public boolean isModifiable() {
return isMutable;
}
@Override
public final void makeImmutable() {
isMutable = false;
}
@Override
public E remove(int index) {
ensureIsMutable();
return super.remove(index);
}
@Override
public boolean remove(Object o) {
ensureIsMutable();
int index = indexOf(o);
if (index == -1) {
return false;
}
remove(index);
return true;
}
@Override
public boolean removeAll(Collection c) {
ensureIsMutable();
return super.removeAll(c);
}
@Override
public boolean retainAll(Collection c) {
ensureIsMutable();
return super.retainAll(c);
}
@Override
public E set(int index, E element) {
ensureIsMutable();
return super.set(index, element);
}
/**
* Throws an {@link UnsupportedOperationException} if the list is immutable. Subclasses are
* responsible for invoking this method on mutate operations.
*/
protected void ensureIsMutable() {
if (!isMutable) {
throw new UnsupportedOperationException();
}
}
}