Signal-iOS/SignalServiceKit/src/Util/DataSource.h

77 lines
2.2 KiB
Objective-C
Executable File

//
// Copyright (c) 2019 Open Whisper Systems. All rights reserved.
//
NS_ASSUME_NONNULL_BEGIN
// A base class that abstracts away a source of NSData
// and allows us to:
//
// * Lazy-load if possible.
// * Avoid duplicate reads & writes.
@protocol DataSource <NSObject>
@property (nonatomic, nullable) NSString *sourceFilename;
// Should not be called unless necessary as it can involve an expensive read.
- (NSData *)data;
// The URL for the data. Should always be a File URL.
//
// Should not be called unless necessary as it can involve an expensive write.
//
// Will only return nil in the error case.
- (nullable NSURL *)dataUrl;
// Will return zero in the error case.
- (NSUInteger)dataLength;
// Returns YES on success.
- (BOOL)writeToUrl:(NSURL *)dstUrl error:(NSError **)error;
// Faster than `writeToUrl`, but a DataSource can only be moved once,
// and cannot be used after it's been moved.
- (BOOL)moveToUrlAndConsume:(NSURL *)dstUrl error:(NSError **)error;
- (BOOL)isValidImage;
- (BOOL)isValidVideo;
@end
#pragma mark -
@interface DataSourceValue : NSObject <DataSource>
+ (_Nullable id<DataSource>)dataSourceWithData:(NSData *)data fileExtension:(NSString *)fileExtension;
+ (_Nullable id<DataSource>)dataSourceWithData:(NSData *)data utiType:(NSString *)utiType;
+ (_Nullable id<DataSource>)dataSourceWithOversizeText:(NSString *_Nullable)text;
+ (id<DataSource>)emptyDataSource;
@end
#pragma mark -
@interface DataSourcePath : NSObject <DataSource>
+ (_Nullable id<DataSource>)dataSourceWithURL:(NSURL *)fileUrl
shouldDeleteOnDeallocation:(BOOL)shouldDeleteOnDeallocation
error:(NSError **)error;
+ (_Nullable id<DataSource>)dataSourceWithFilePath:(NSString *)filePath
shouldDeleteOnDeallocation:(BOOL)shouldDeleteOnDeallocation
error:(NSError **)error;
+ (_Nullable id<DataSource>)dataSourceWritingTempFileData:(NSData *)data
fileExtension:(NSString *)fileExtension
error:(NSError **)error;
+ (_Nullable id<DataSource>)dataSourceWritingSyncMessageData:(NSData *)data error:(NSError **)error;
@end
NS_ASSUME_NONNULL_END