diff options
Diffstat (limited to 'java/src/main/java/com/google/protobuf/AbstractProtobufList.java')
-rwxr-xr-x | java/src/main/java/com/google/protobuf/AbstractProtobufList.java | 180 |
1 files changed, 180 insertions, 0 deletions
diff --git a/java/src/main/java/com/google/protobuf/AbstractProtobufList.java b/java/src/main/java/com/google/protobuf/AbstractProtobufList.java new file mode 100755 index 00000000..b17db6e0 --- /dev/null +++ b/java/src/main/java/com/google/protobuf/AbstractProtobufList.java @@ -0,0 +1,180 @@ +// 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.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. + * <p> + * This implementation assumes all subclasses are array based, supporting random access. + */ +abstract class AbstractProtobufList<E> extends AbstractList<E> implements ProtobufList<E> { + + 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<? extends E> c) { + ensureIsMutable(); + return super.addAll(c); + } + + @Override + public boolean addAll(int index, Collection<? extends E> 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(); + return super.remove(o); + } + + @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(); + } + } +} |