NSByteStoreFile

Inherits From: NSByteStore : NSObject

Conforms To: NSObject (NSObject)

Declared In: Foundation/NSByteStore.h

Class Description

NSByteStoreFile is a subclass of NSByteStore that keeps its storage in a file. NSByteStoreFile guarantees the integrity of stored data against process and system crashes when protected by transactions (described in the NSByteStore class specification), provided that the physical media remains intact.

When you create an NSByteStoreFile, you specify a storage file and open it for reading only or for both reading and writing. The methods you use to access the contents of the file are implemented in NSByteStore.

To support the use of preconfigured files, a process using an NSByteStoreFile opened for reading only may freely modify the NSByteStoreFile; all modified pages are reflected only in the address space of the process. The modifications are never written to the file and are discarded when the NSByteStoreFile is freed.

Creating and Initializing an NSByteStoreFile Instance

• + (NSByteStore *)byteStoreFile:(NSString*)path Creates and initializes an NSByteStoreFile with path as its transactionsEnabled:(BOOL)enable storage file. If enable is YES, transactions are enabled. create:(BOOL)create If create is YES, the file path is created. If readOnly is readOnly:(BOOL)readOnly YES, path is opened for reading. If readOnly is NO, path is opened for reading and writing.
• - (id)initWithPath:(NSString*)path Initializes a newly allocated NSByteStoreFile with path as transactionsEnabled:(BOOL)enable its storage file. If enable is YES, transactions are create:(BOOL)create enabled. If create is YES, the file path is created. If readOnly:(BOOL)readOnly readOnly is YES, path is opened for reading. If readOnly is NO, path is opened for reading and writing.

• - (NSString *)storePath Returns the path of the storage file.

• - (void)compactUntilDate:(NSDate *)limitDate Removes free space by relocating blocks toward the origin of the virtual address space defined by the NSByteStoreFile. limitDate sets a time limit on this operation. No limitDate allows the compaction to run to completion.