com.google.protobuf.ListFieldSchema Maven / Gradle / Ivy
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// 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
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package com.google.protobuf;
import com.google.protobuf.Internal.ProtobufList;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
/**
* Utility class that aids in properly manipulating list fields for either the lite or full runtime.
*/
@CheckReturnValue
abstract class ListFieldSchema {
// Disallow construction.
private ListFieldSchema() {}
private static final ListFieldSchema FULL_INSTANCE = new ListFieldSchemaFull();
private static final ListFieldSchema LITE_INSTANCE = new ListFieldSchemaLite();
abstract List mutableListAt(Object msg, long offset);
abstract void makeImmutableListAt(Object msg, long offset);
abstract void mergeListsAt(Object msg, Object otherMsg, long offset);
static ListFieldSchema full() {
return FULL_INSTANCE;
}
static ListFieldSchema lite() {
return LITE_INSTANCE;
}
/** Implementation for the full runtime. */
private static final class ListFieldSchemaFull extends ListFieldSchema {
private static final Class UNMODIFIABLE_LIST_CLASS =
Collections.unmodifiableList(Collections.emptyList()).getClass();
@Override
List mutableListAt(Object message, long offset) {
return mutableListAt(message, offset, AbstractProtobufList.DEFAULT_CAPACITY);
}
@Override
void makeImmutableListAt(Object message, long offset) {
List list = (List) UnsafeUtil.getObject(message, offset);
Object immutable = null;
if (list instanceof LazyStringList) {
immutable = ((LazyStringList) list).getUnmodifiableView();
} else if (UNMODIFIABLE_LIST_CLASS.isAssignableFrom(list.getClass())) {
// already immutable
return;
} else if (list instanceof PrimitiveNonBoxingCollection && list instanceof ProtobufList) {
if (((ProtobufList) list).isModifiable()) {
((ProtobufList) list).makeImmutable();
}
return;
} else {
immutable = Collections.unmodifiableList((List) list);
}
UnsafeUtil.putObject(message, offset, immutable);
}
@SuppressWarnings("unchecked")
private static List mutableListAt(Object message, long offset, int additionalCapacity) {
List list = getList(message, offset);
if (list.isEmpty()) {
if (list instanceof LazyStringList) {
list = (List) new LazyStringArrayList(additionalCapacity);
} else if (list instanceof PrimitiveNonBoxingCollection && list instanceof ProtobufList) {
list = ((ProtobufList) list).mutableCopyWithCapacity(additionalCapacity);
} else {
list = new ArrayList(additionalCapacity);
}
UnsafeUtil.putObject(message, offset, list);
} else if (UNMODIFIABLE_LIST_CLASS.isAssignableFrom(list.getClass())) {
ArrayList newList = new ArrayList(list.size() + additionalCapacity);
newList.addAll(list);
list = newList;
UnsafeUtil.putObject(message, offset, list);
} else if (list instanceof UnmodifiableLazyStringList) {
LazyStringArrayList newList = new LazyStringArrayList(list.size() + additionalCapacity);
newList.addAll((UnmodifiableLazyStringList) list);
list = (List) newList;
UnsafeUtil.putObject(message, offset, list);
} else if (list instanceof PrimitiveNonBoxingCollection
&& list instanceof ProtobufList
&& !((ProtobufList) list).isModifiable()) {
list = ((ProtobufList) list).mutableCopyWithCapacity(list.size() + additionalCapacity);
UnsafeUtil.putObject(message, offset, list);
}
return list;
}
@Override
void mergeListsAt(Object msg, Object otherMsg, long offset) {
List other = getList(otherMsg, offset);
List mine = mutableListAt(msg, offset, other.size());
int size = mine.size();
int otherSize = other.size();
if (size > 0 && otherSize > 0) {
mine.addAll(other);
}
List merged = size > 0 ? mine : other;
UnsafeUtil.putObject(msg, offset, merged);
}
@SuppressWarnings("unchecked")
static List getList(Object message, long offset) {
return (List) UnsafeUtil.getObject(message, offset);
}
}
/** Implementation for the lite runtime. */
private static final class ListFieldSchemaLite extends ListFieldSchema {
@Override
List mutableListAt(Object message, long offset) {
ProtobufList list = getProtobufList(message, offset);
if (!list.isModifiable()) {
int size = list.size();
list =
list.mutableCopyWithCapacity(
size == 0 ? AbstractProtobufList.DEFAULT_CAPACITY : size * 2);
UnsafeUtil.putObject(message, offset, list);
}
return list;
}
@Override
void makeImmutableListAt(Object message, long offset) {
ProtobufList list = getProtobufList(message, offset);
list.makeImmutable();
}
@Override
void mergeListsAt(Object msg, Object otherMsg, long offset) {
ProtobufList mine = getProtobufList(msg, offset);
ProtobufList other = getProtobufList(otherMsg, offset);
int size = mine.size();
int otherSize = other.size();
if (size > 0 && otherSize > 0) {
if (!mine.isModifiable()) {
mine = mine.mutableCopyWithCapacity(size + otherSize);
}
mine.addAll(other);
}
ProtobufList merged = size > 0 ? mine : other;
UnsafeUtil.putObject(msg, offset, merged);
}
@SuppressWarnings("unchecked")
static ProtobufList getProtobufList(Object message, long offset) {
return (ProtobufList) UnsafeUtil.getObject(message, offset);
}
}
}