FFileCache | Unreal Engine 5.7 Documentation

API > API/Developer > API/Developer/DirectoryWatcher

A class responsible for scanning a directory, and maintaining a cache of its state (files and timestamps). Changes in the cache can be retrieved through GetOutstandingChanges(). Changes will be reported for any change in the cached state even between runs of the process.


Name	FFileCache
Type	class
Header File	/Engine/Source/Developer/DirectoryWatcher/Public/FileCache.h
Include Path	#include "FileCache.h"

Syntax

class FFileCache

Constructors

Name	Remarks	Include Path	Unreal Specifiers
FFileCache ( const FFileCacheConfig& InConfig )	Construction from a config	FileCache.h
FFileCache ( const FFileCache& )		FileCache.h

Destructors

Name	Remarks	Include Path	Unreal Specifiers
~FFileCache()	Destructor	FileCache.h

Variables

Protected

Name	Type	Remarks	Include Path
AsyncFileHasher	TSharedPtr< FAsyncFileHasher, ESPMode::ThreadSafe >	Asynchronous task used to harvest the MD5 hashes of a set of filenames	FileCache.h
bPendingTransactionsDirty	bool	List of cached pending transactions	FileCache.h
bSavedCacheDirty	bool	True when the cached state we have in memory is more up to date than the serialized file.	FileCache.h
CachedDirectoryState	FDirectoryState	Our in-memory view of the cached directory state.	FileCache.h
Config	FFileCacheConfig	Configuration settings applied on construction	FileCache.h
ConfigDirectoryStandardized	FString		FileCache.h
DirectoryReader	TSharedPtr< FAsyncDirectoryReader, ESPMode::ThreadSafe >	Asynchronous directory reader responsible for gathering all file/timestamp information recursively from our cache directory	FileCache.h
DirtyFileHasher	TSharedPtr< FAsyncFileHasher, ESPMode::ThreadSafe >	Asynchronous task used to harvest the MD5 hashes of a set of recently changed filenames	FileCache.h
DirtyFiles	TMap< FImmutableString, FFileData >	A map of dirty files that we will use to report changes to the user.	FileCache.h
LastFileHashGetTime	double	The time we last retrieved file hashes from the thread	FileCache.h
PendingTransactions	TArray< FUpdateCacheTransaction >		FileCache.h
WatcherDelegate	FDelegateHandle	Handle to the directory watcher delegate so we can delete it properly	FileCache.h

Functions

Public

Name	Remarks	Include Path
void CompleteTransaction ( FUpdateCacheTransaction&& Transaction )	Return a transaction to the cache for completion.	FileCache.h
void Destroy()	Destroy this cache. Cleans out the in-memory state and deletes the cache file, if present.	FileCache.h
TArray< FUpdateCacheTransaction > FilterOutstandingChanges ( TFunctionRef< bool(const FUpdateCacheTransaction&, const FDateTime&)> InPredicate )	Get pending changes to the cache.	FileCache.h
const FFileData * FindFileData ( FImmutableString InFilename ) const	Attempt to locate file data pertaining to the specified filename.	FileCache.h
const FString & GetDirectory()	Get the absolute path of the directory this cache reflects	FileCache.h
int32 GetNumDirtyFiles()	Get the number of pending changes to the cache.	FileCache.h
TArray< FUpdateCacheTransaction > GetOutstandingChanges()		FileCache.h
bool HasStartedUp ()	Check whether this file cache has finished starting up yet.	FileCache.h
void IgnoreDeletedFile ( const FString& Filename )		FileCache.h
void IgnoreFileModification ( const FString& Filename )		FileCache.h
void IgnoreMovedFile ( const FString& SrcFilename, const FString& DstFilename )		FileCache.h
void IgnoreNewFile ( const FString& Filename )	Report an external change to the manager, such that a subsequent equal change reported by the os be ignored	FileCache.h
void IterateOutstandingChanges ( TFunctionRef< bool(const FUpdateCacheTransaction&, const FDateTime&)> InPredicate ) const	Iterate the number of pending changes to the cache with the specified predicate.	FileCache.h
bool MoveDetectionInitialized ()	Check whether this move/rename detection has been initiated or not.	FileCache.h
void Tick()	Tick this FileCache	FileCache.h
void WriteCache()	Write out the cached file, if we have any changes to write	FileCache.h

Operators

Name	Remarks	Include Path	Unreal Specifiers
FFileCache & operator= ( const FFileCache& )		FileCache.h

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