1. Epic GamesDeveloper
  3. FPakFile

FPakFile

Pak file.

API > API/Runtime > API/Runtime/PakFile

Pak file.

   
Name FPakFile
Type class
Header File /Engine/Source/Runtime/PakFile/Public/IPlatformFilePak.h
Include Path #include "IPlatformFilePak.h"

Syntax

class FPakFile :  
    private FNoncopyable,  
    public FRefCountBase,  
    public IPakFile

Inheritance Hierarchy

Implements Interfaces

Constructors

Name Remarks Include Path Unreal Specifiers

FPakFile ( FArchive* Archive
)

 Creates a pak file using the supplied archive. IPlatformFilePak.h  

FPakFile ( IPlatformFile* LowerLevel,
const TCHAR* Filename,
bool bIsSigned,
bool bLoadIndex
)

 Creates a pak file using the supplied file handle. IPlatformFilePak.h  

Destructors

Name Remarks Include Path Unreal Specifiers

virtual ~FPakFile()

 Private destructor, use AddRef/Release instead IPlatformFilePak.h  

Classes

Name Remarks
FBaseIterator Base functionality for iterating over the DirectoryIndex.
FFilenameIterator Iterator class used to iterate over just the files in the pak for which we have filenames.
FPakEntryIterator Iterator class for every FPakEntry in the FPakFile, but does not provide filenames unless the PakFile has an unpruned DirectoryIndex.

Structs

Name Remarks
FArchiveAndLastAccessTime  
FIndexSettings  
FScopedPakDirectoryIndexAccess A ReadLock wrapper that must be used to prevent threading errors around any call to FindPrunedDirectory or internal uses of DirectoryIndex
FVisitFilter  

Enums

Public

Name Remarks
ECacheType Pak files can share a cache or have their own
EFindResult Finds an entry in the pak file matching the given filename.
EIteratorType Internal IteratorType used by an FBaseIterator.

Typedefs

Name Type Remarks Include Path
FDirectoryIndex TMap< FString, FPakDirectory > Index data that keeps an in-memory directoryname/filename tree to map a Filename to an FPakEntryLocation IPlatformFilePak.h
FDirectoryTreeIndex UE::PakFile::Private::FDirectoryTreeIndex   IPlatformFilePak.h
FPathHashIndex TMap< uint64, FPakEntryLocation > Index data that provides a map from the hash of a Filename to an FPakEntryLocation IPlatformFilePak.h
ReadNextEntryFunction TFunction< FPakEntryPair &()> Read a list of (Filename, FPakEntry) pairs from a provided enumeration, attempt to encode each one, store each one in the appropriate given encoded and/or unencoded array, and populate the given Directories to map each filename to the location for the FPakEntry IPlatformFilePak.h

Constants

Name Type Remarks Include Path
bSomePakNeedsPruning bool Global flag for whether a Pak has indicated it needs Pruning IPlatformFilePak.h

Variables

Protected

Name Type Remarks Include Path Unreal Specifiers
bHasFullDirectoryIndex bool True if the DirectoryIndex has not been pruned and still contains a Filename for every FPakEntry in this PakFile IPlatformFilePak.h  
bHasPathHashIndex bool True if the PathHashIndex has been populated for this PakFile IPlatformFilePak.h  
bIsMounted bool Record of whether the pak file is still mounted, so PakPrecacher can reject requests to register it. IPlatformFilePak.h  
bIsValid bool True if this pak file is valid and usable. IPlatformFilePak.h  
bNeedsLegacyPruning bool True if the Index of this PakFile was a legacy index that did not have the precomputed Pruned DirectoryIndex and we need to compute it before swapping the Pruned DirectoryIndex IPlatformFilePak.h  
bSigned bool True if this is a signed pak file. IPlatformFilePak.h  
bWillPruneDirectoryIndex bool True if we have a FullDirectoryIndex that we will modify in OptimizeMemoryUsageForMountedPaks and therefore need to guard access with DirectoryIndexLock IPlatformFilePak.h  
CachedTotalSize int64 TotalSize of the pak file IPlatformFilePak.h  
CacheIndex int32 The index of this pak file into the cache array, -1 = not initialized IPlatformFilePak.h  
CacheType ECacheType The type of cache this pak file should have IPlatformFilePak.h  
CurrentlyUsedReaders std::atomic< int32 > How many readers have been loaned out and not yet returned. IPlatformFilePak.h  
Decryptor TUniquePtr< class FChunkCacheWorker > Archive to serialize the pak file from. IPlatformFilePak.h  
DirectoryIndex FDirectoryIndex Pak Index organized as a map of directories to support searches by path. IPlatformFilePak.h  
DirectoryIndexLock FRWLock ReaderWriter lock to guard DirectoryIndex iteration from being interrupted by the swap of PrunedDirectoryIndex IPlatformFilePak.h  
DirectoryTreeIndex FDirectoryTreeIndex   IPlatformFilePak.h  
EncodedPakEntries TArray< uint8 > FPakEntries that have been serialized into a compacted format in an array of bytes. IPlatformFilePak.h  
Files TArray< FPakEntry > Info on all files stored in pak. IPlatformFilePak.h  
Info FPakInfo Pak file info (trailer). IPlatformFilePak.h  
IoContainerHeader TUniquePtr< FIoContainerHeader >   IPlatformFilePak.h  
MappedFileHandle TSharedPtr< IMappedFileHandle >   IPlatformFilePak.h  
MappedFileHandleCriticalSection FCriticalSection   IPlatformFilePak.h  
MountPoint FString Mount point. IPlatformFilePak.h  
NumEntries int32 The number of file entries in the pak file IPlatformFilePak.h  
OptionalSegmentIoContainerHeader TUniquePtr< FIoContainerHeader >   IPlatformFilePak.h  
PakchunkIndex int32 ID for the chunk this pakfile is part of. IPlatformFilePak.h  
PakFilename FString Pak filename. IPlatformFilePak.h  
PakFilenameName FName   IPlatformFilePak.h  
PathHashIndex FPathHashIndex Index data that provides a map from the hash of a Filename to an FPakEntryLocation IPlatformFilePak.h  
PathHashSeed uint64 The seed passed to the hash function for hashing filenames in this pak. IPlatformFilePak.h  
PrunedDirectoryIndex FDirectoryIndex Temporary-lifetime copy of the Pruned DirectoryIndex; all Pruned files have been removed form this copy. IPlatformFilePak.h  
PrunedDirectoryTreeIndex FDirectoryTreeIndex   IPlatformFilePak.h  
Readers TArray< FArchiveAndLastAccessTime > List of readers and when they were last used. IPlatformFilePak.h  
ReadersCriticalSection FCriticalSection Critical section for accessing Readers. IPlatformFilePak.h  
Timestamp FDateTime Timestamp of this pak file. IPlatformFilePak.h  
UnderlyingCacheTrimDisabled bool Allow the cache of a pak file to never shrink, should be used with caution, it will burn memory IPlatformFilePak.h  

Functions

Public

Name Remarks Include Path Unreal Specifiers

bool Check()

 Checks the validity of the pak data by reading out the data for every file in the pak IPlatformFilePak.h  

bool DirectoryExistsInPruned ( const TCHAR* InPath
) const

 Checks if a directory exists in pak file. IPlatformFilePak.h  

EFindResult Find ( const FString& FullPath,
FPakEntry* OutEntry
) const

   IPlatformFilePak.h  

const FPakDirectory * FindPrunedDirectory ( const TCHAR* InPath
) const

 Finds a directory in pak file. IPlatformFilePak.h  

void FindPrunedFilesAtPath ( ContainerType& OutFiles,
const TCHAR* InPath,
bool bIncludeFiles,
bool bIncludeDirectories,
bool bRecursive
) const

   IPlatformFilePak.h  

void FindPrunedFilesAtPath ( const TCHAR* InPath,
TArray< FString >& OutFiles,
bool bIncludeFiles,
bool bIncludeDirectories,
bool bRecursive
) const

 Looks for files or directories within the Pruned DirectoryIndex of the pak file. IPlatformFilePak.h  

int32 GetCacheIndex()

   IPlatformFilePak.h  

ECacheType GetCacheType()

   IPlatformFilePak.h  

const FString & GetFilename()

 Gets pak filename. IPlatformFilePak.h  

FName GetFilenameName()

   IPlatformFilePak.h  

const FPakInfo & GetInfo()

 Gets this pak file info. IPlatformFilePak.h  

bool GetIsMounted()

   IPlatformFilePak.h  

const FString & GetMountPoint()

 Gets pak file mount point. IPlatformFilePak.h  

virtual int32 GetNumFiles()

 Gets the number of files in this pak. IPlatformFilePak.h  

void GetPrunedFilenames ( TArray< FString >& OutFileList
) const

 Returns the FullPath (includes Mount) Filename found in Pruned DirectoryIndex IPlatformFilePak.h  

void GetPrunedFilenamesInChunk ( const TArray< int32 >& InChunkIDs,
TArray< FString >& OutFileList
) const

 Returns the RelativePathFromMount Filename for every Filename found in the Pruned DirectoryIndex that points to a PakEntry in the given Chunk IPlatformFilePak.h  

FSharedPakReader GetSharedReader ( IPlatformFile* LowerLevel
)

 Gets shared pak file archive for given thread. IPlatformFilePak.h  

const FDateTime & GetTimestamp()

 Gets this pak file's tiemstamp. IPlatformFilePak.h  

bool GetUnderlyingCacheTrimDisabled()

   IPlatformFilePak.h  

bool HasFilenames()

 Returns whether filenames currently exist in the DirectoryIndex for all files in the Pak. IPlatformFilePak.h  

bool IsValid()

 Checks if the pak file is valid. IPlatformFilePak.h  

virtual bool PakContains ( const FString& FullPath
) const

   IPlatformFilePak.h  

virtual const FString & PakGetMountPoint()

   IPlatformFilePak.h  

virtual int32 PakGetPakchunkIndex()

   IPlatformFilePak.h  

virtual const FString & PakGetPakFilename()

 IPakFile interface, for users of PakFiles that cannot have a dependency on this header. IPlatformFilePak.h  

virtual void PakVisitPrunedFilenames ( IPlatformFile::FDirectoryVisitor& Visitor
) const

   IPlatformFilePak.h  

bool PassedSignatureChecks()

 Checks if the pak has valid chunk signature checking data, and that the data passed the initial signing check IPlatformFilePak.h  

void ReadHashFromPayload ( const FPakEntry& PakEntry,
uint8* OutBuffer
)

 FPakFile helper functions shared between the runtime and UnrealPak.exe. IPlatformFilePak.h  

bool RecreatePakReaders ( IPlatformFile* LowerLevel
)

 Recreates the pak reader for each thread IPlatformFilePak.h  

void ReleaseOldReaders ( double MaxAgeSeconds
)

 Delete all readers that haven't been used in MaxAgeSeconds. IPlatformFilePak.h  

void ReturnSharedReader ( FArchive* SharedReader
)

 Return a shared pak reader. Should only be called from the FSharedPakReader's destructor. IPlatformFilePak.h  

void SetCacheIndex ( int32 InCacheIndex
)

   IPlatformFilePak.h  

void SetCacheType ( ECacheType InCacheType
)

   IPlatformFilePak.h  

void SetIsMounted ( bool bInIsMounted
)

   IPlatformFilePak.h  

void SetMountPoint ( const TCHAR* Path
)

 Sets the pak file mount point. IPlatformFilePak.h  

void SetUnderlyingCacheTrimDisabled ( bool InUnderlyingCacheTrimDisabled
)

   IPlatformFilePak.h  

int64 TotalSize()

   IPlatformFilePak.h  

Static

Name Remarks Include Path Unreal Specifiers

static void AddEntryToIndex ( const FString& Filename,
const FPakEntryLocation& EntryLocation,
const FString& MountPoint,
uint64 PathHashSeed,
FDirectoryIndex* DirectoryIndex,
FDirectoryTreeIndex* DirectoryTreeIndex,
FPathHashIndex* PathHashIndex,
TMap< uint64, FString >* CollisionDetection,
int32 PakFileVersion
)

 Add the given (Filename,FPakEntryLocation) value into the provided indexes IPlatformFilePak.h  

static int32 CompareFilenameHashes ( const void* Left,
const void* Right
)

   IPlatformFilePak.h  

static void DecodePakEntry ( const uint8* SourcePtr,
FPakEntry& OutEntry,
const FPakInfo& InInfo
)

 Decodes a bit-encoded pak entry from a pointer to the start of its encoded bytes into the given OutEntry IPlatformFilePak.h  

static void EncodePakEntriesIntoIndex ( int32 InNumEntries,
const ReadNextEntryFunction& InReadNextEntry,
const TCHAR* InPakFilename,
const FPakInfo& InPakInfo,
const FString& MountPoint,
int32& OutNumEncodedEntries,
int32& OutNumDeletedEntries,
uint64* OutPathHashSeed,
FDirectoryIndex* OutDirectoryIndex,
FPathHashIndex* OutPathHashIndex,
TArray< uint8 >& OutEncodedPakEntries,
TArray< FPakEntry >& OutNonEncodableEntries,
TMap< uint64, FString >* InOutCollisionDetection,
int32 PakFileVersion
)

   IPlatformFilePak.h  

static bool EncodePakEntry ( FArchive& Ar,
const FPakEntry& InPakEntry,
const FPakInfo& InInfo
)

 Encodes a pak entry as an array of bytes into the given archive. IPlatformFilePak.h  

static void FindFilesAtPathInPakDirectoryInternal ( const FString& MountPoint,
FStringView RelPathInIndex,
const FPakDirectory& PakDirectory,
ContainerType& OutFiles,
TArray< FString >& OutDirectoriesInPak,
const FString& FullSearchPath,
const FVisitFilter< ShouldVisitFunc >& VisitFilter
)

   IPlatformFilePak.h  

static const FPakEntryLocation * FindLocationFromIndex ( const FString& FullPath,
const FString& MountPoint,
const FPathHashIndex& PathHashIndex,
uint64 PathHashSeed,
int32 PakFileVersion
)

 Lookup the FPakEntryLocation stored in the given PathHashIndex, return nullptr if not found IPlatformFilePak.h  

static const FPakEntryLocation * FindLocationFromIndex ( const FString& FullPath,
const FString& MountPoint,
const FDirectoryIndex& DirectoryIndex
)

 Lookup the FPakEntryLocation stored in the given DirectoryIndex, return nullptr if not found IPlatformFilePak.h  

static FIndexSettings & GetIndexSettings()

   IPlatformFilePak.h  

static EFindResult GetPakEntry ( const FPakEntryLocation& FPakEntryLocation,
FPakEntry* OutEntry,
const TArray< uint8 >& EncodedPakEntries,
const TArray< FPakEntry >& Files,
const FPakInfo& Info
)

 Returns the FPakEntry pointed to by the given FPakEntryLocation inside the given EncodedPakEntries or Files Can return Found or Deleted; if the FPakEntryLocation is invalid this function assumes the FPakEntry exists in this pack but as a deleted file If OutEntry is non-null, populates it with a copy of the FPakEntry found, or sets it to an FPakEntry with SetDeleteRecord(true) if not found IPlatformFilePak.h  

static const TCHAR * GetRelativeFilePathFromMountPointer ( const FString& Child,
const FString& MountPoint
)

 Helper function to return Filename's relative path from the mount point. IPlatformFilePak.h  

static bool GetRelativePathFromMountInline ( FString& Child,
const FString& MountPoint
)

 Helper function to return Child's relative path from the mount point. IPlatformFilePak.h  

static uint64 HashPath ( const TCHAR* RelativePathFromMount,
uint64 Seed,
int32 PakFileVersion
)

 Hash the given full-path filename using the hash function used by FPakFiles, with the given FPakFile-specific seed, with version provided for legacy pak files that used different hash function IPlatformFilePak.h  

static bool IsPakDelayPruning ()

 Returns the global,const flag for whether the current process should keep a copy of the Full DirectoryIndex around until OptimizeMemoryUsageForMountedPaks is called, so that systems can run directory queries against the full index until then. IPlatformFilePak.h  

static bool IsPakKeepFullDirectory()

 Returns the global,const flag for whether the current process is allowing PakFiles to keep their entire DirectoryIndex (if it exists in the PakFile on disk) rather than pruning it IPlatformFilePak.h  

static bool IsPakValidatePruning ()

 Returns the global,const flag for whether the current process should run directory queries on both the DirectoryIndex and the Pruned DirectoryIndex and log an error if they don't match. IPlatformFilePak.h  

static bool IsPakWriteFullDirectoryIndex()

 Returns the global,const flag for whether UnrealPak should write a copy of the full DirectoryIndex to the PakFile IPlatformFilePak.h  

static bool IsPakWritePathHashIndex()

 Returns the global,const flag for whether UnrealPak should write a copy of the full PathHashIndex and Pruned DirectoryIndex to the PakFile IPlatformFilePak.h  

static bool IsPathInDirectoryFormat ( const FString& Path
)

 Helper function to check that the given string is in our directory format (ends with '/') IPlatformFilePak.h  

static void MakeDirectoryFromPath ( FString& Path
)

 Helper function to modify the given string to append '/' at the end of path to normalize directory names for hash and string compares IPlatformFilePak.h  

static FString PakPathCombine ( FStringView Parent,
FUtf8StringView Child
)

   IPlatformFilePak.h  

static FString PakPathCombine ( FStringView Parent,
FStringView Child
)

 Helper function to join two path strings that are in the PakPath format IPlatformFilePak.h  

static void PruneDirectoryIndex ( FDirectoryIndex& InOutDirectoryIndex,
FDirectoryIndex* PrunedDirectoryIndex,
const FString& MountPoint
)

 Given a directory index, remove entries from it that are directed by ini to not have filenames kept at runtime. IPlatformFilePak.h  

static void PruneDirectoryIndexInternal ( FDirectoryIndex* InOutDirectoryIndex,
FDirectoryTreeIndex* InOutDirectoryTreeIndex,
FDirectoryIndex* PrunedDirectoryIndex,
FDirectoryTreeIndex* PrunedDirectoryTreeIndex,
const FString& MountPoint
)

   IPlatformFilePak.h  

static void SaveIndexInternal_DirectoryIndex ( FArchive& Ar,
const FDirectoryIndex& DirectoryTMap
)

 This is an internal function that should only be called by FPakFile or by PakFileUtilities.cpp; it can change without deprecation. IPlatformFilePak.h  

static bool SplitPathInline ( FStringView& InOutPath,
FStringView& OutFilename
)

 Helper function to split a PakDirectoryIndex-Formatted PathName into its PakDirectoryIndex-Formatted parent directory and the CleanFileName IPlatformFilePak.h  

static bool SplitPathInline ( FString& InOutPath,
FString& OutFilename
)

   IPlatformFilePak.h  

Ask questions and help your peers Developer Forums

Write your own tutorials or read those from others Learning Library

On this page