mirror of
https://github.com/firebase/firebase-ios-sdk
synced 2026-11-10 22:45:59 +05:45
67 lines
2.5 KiB
Objective-C
67 lines
2.5 KiB
Objective-C
/*
|
|
* 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 <Foundation/Foundation.h>
|
|
|
|
NS_ASSUME_NONNULL_BEGIN
|
|
|
|
@protocol FSTRemoteDocumentCache;
|
|
@class FSTMaybeDocument;
|
|
@class FSTDocumentKey;
|
|
@class FSTWriteGroup;
|
|
|
|
/**
|
|
* An in-memory buffer of entries to be written to an FSTRemoteDocumentCache. It can be used to
|
|
* batch up a set of changes to be written to the cache, but additionally supports reading entries
|
|
* back with the `entryForKey:` method, falling back to the underlying FSTRemoteDocumentCache if
|
|
* no entry is buffered. In the absence of LevelDB transactions (that would allow reading back
|
|
* uncommitted writes), this greatly simplifies the implementation of complex operations that
|
|
* may want to freely read/write entries to the FSTRemoteDocumentCache while still ensuring that
|
|
* the final writing of the buffered entries is atomic.
|
|
*
|
|
* For doing blind writes that don't depend on the current state of the FSTRemoteDocumentCache
|
|
* or for plain reads, you can/should still just use the FSTRemoteDocumentCache directly.
|
|
*/
|
|
@interface FSTRemoteDocumentChangeBuffer : NSObject
|
|
|
|
+ (instancetype)changeBufferWithCache:(id<FSTRemoteDocumentCache>)cache;
|
|
|
|
- (instancetype)init __attribute__((unavailable("Use a static constructor instead")));
|
|
|
|
/** Buffers an `FSTRemoteDocumentCache addEntry:group:` call. */
|
|
- (void)addEntry:(FSTMaybeDocument *)maybeDocument;
|
|
|
|
// NOTE: removeEntryForKey: is not presently necessary and so is omitted.
|
|
|
|
/**
|
|
* Looks up an entry in the cache. The buffered changes will first be checked, and if no
|
|
* buffered change applies, this will forward to `FSTRemoteDocumentCache entryForKey:`.
|
|
*
|
|
* @param documentKey The key of the entry to look up.
|
|
* @return The cached FSTDocument or FSTDeletedDocument entry, or nil if we have nothing cached.
|
|
*/
|
|
- (nullable FSTMaybeDocument *)entryForKey:(FSTDocumentKey *)documentKey;
|
|
|
|
/**
|
|
* Applies buffered changes to the underlying FSTRemoteDocumentCache, using the provided
|
|
* FSTWriteGroup.
|
|
*/
|
|
- (void)applyToWriteGroup:(FSTWriteGroup *)group;
|
|
|
|
@end
|
|
|
|
NS_ASSUME_NONNULL_END
|