/* * Copyright 2017 Google * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #import "Firestore/Source/Model/FSTDocumentDictionary.h" #import "Firestore/Source/Model/FSTDocumentKey.h" NS_ASSUME_NONNULL_BEGIN @implementation FSTImmutableSortedDictionary (FSTMaybeDocumentDictionary) + (instancetype)maybeDocumentDictionary { // Immutable dictionaries are contravariant in their value type, so just return a // FSTDocumentDictionary here. return [FSTDocumentDictionary documentDictionary]; } + (instancetype)documentDictionary { static FSTDocumentDictionary *singleton; static dispatch_once_t onceToken; dispatch_once(&onceToken, ^{ singleton = [FSTDocumentDictionary dictionaryWithComparator:FSTDocumentKeyComparator]; }); return singleton; } @end NS_ASSUME_NONNULL_END