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  3. FStreamableHandle

FStreamableHandle

A handle to a synchronous or async load.

API > API/Runtime > API/Runtime/Engine

A handle to a synchronous or async load. As long as the handle is Active, loaded assets will stay in memory

   
Name FStreamableHandle
Type struct
Header File /Engine/Source/Runtime/Engine/Classes/Engine/StreamableManager.h
Include Path #include "Engine/StreamableManager.h"

Syntax

struct FStreamableHandle : public TSharedFromThis< FStreamableHandle >

Inheritance Hierarchy

Constructors

Name Remarks Include Path Unreal Specifiers

FStreamableHandle ( FPrivateToken,
UE::FSourceLocation&& InLocation
)

   Engine/StreamableManager.h  
Not safe to copy or duplicate Engine/StreamableManager.h  
  Engine/StreamableManager.h  

Destructors

Name Remarks Include Path Unreal Specifiers

~FStreamableHandle()

 Destructor Engine/StreamableManager.h  

Structs

Name Remarks
FPrivateToken Constructor is private, but this allows use by MakeShared

Constants

Name Type Remarks Include Path
HandleDebugName_AssetList const FString   Engine/StreamableManager.h
HandleDebugName_CombinedHandle const FString   Engine/StreamableManager.h
HandleDebugName_Error const FString   Engine/StreamableManager.h
HandleDebugName_Preloading const FString   Engine/StreamableManager.h

Variables

Protected

Name Type Remarks Include Path Unreal Specifiers
AdditionalContextData TArray< TSharedPtr< FStreamableHandleContextDataBase > > Array of contextual data added by game/engine code Engine/StreamableManager.h  
bCanceled bool True if this request was explicitly canceled, which stops it from calling the completion delegate and immediately releases it Engine/StreamableManager.h  
bIsCombinedHandle bool If true, this is a combined handle that depends on child handles. Engine/StreamableManager.h  
bLoadCompleted bool True if this request has finished loading. It may still be active, or it may have been released Engine/StreamableManager.h  
bLoadStarted bool True if this request ever started loading from disk. Engine/StreamableManager.h  
bReleased bool True if this request was released, which will stop it from keeping hard GC references Engine/StreamableManager.h  
bReleaseWhenLoaded bool If true, this handle will be released when it finishes loading Engine/StreamableManager.h  
bStalled bool True if this handle has been created but not yet actually requested. Engine/StreamableManager.h  
CancelDelegate FStreamableDelegateWithHandle Delegate to call when streaming is canceled Engine/StreamableManager.h  
CanceledChildCount int32 How many of our children that have been canceled Engine/StreamableManager.h  
ChildHandles TArray< TSharedPtr< FStreamableHandle > > List of handles this depends on, these will keep the child references alive Engine/StreamableManager.h  
CompletedChildCount int32 How many of our children that have been completed Engine/StreamableManager.h  
CompleteDelegate FStreamableDelegateWithHandle Delegate to call when streaming is completed Engine/StreamableManager.h  
CookLoadType ECookLoadType   Engine/StreamableManager.h  
DebugName FString Name of this handle, passed in by caller to help in debugging Engine/StreamableManager.h  
DownloadCachePin FStreamableDownloadCachePin Handle that holds packages in the download cache Engine/StreamableManager.h  
DownloadContext TUniquePtr< UE::StreamableManager::Private::FDownloadContext > Download book-keeping, released when download finishes Engine/StreamableManager.h  
Error TOptional< UE::UnifiedError::FError > Error details in case of an error Engine/StreamableManager.h  
Location UE::FSourceLocation Holds a location where this asset list was requested from Engine/StreamableManager.h  
OwningManager FStreamableManager * This is set at the time of creation, and will be cleared when request completes or is canceled Engine/StreamableManager.h  
ParentHandles TArray< TWeakPtr< FStreamableHandle > > Backpointer to handles that depend on this Engine/StreamableManager.h  
Priority TAsyncLoadPriority The async priority for this request Engine/StreamableManager.h  
ReferencerPackage FName   Engine/StreamableManager.h  
ReferencerPackageOp FName   Engine/StreamableManager.h  
RequestedAssets TArray< FSoftObjectPath > List of assets that were referenced by this handle Engine/StreamableManager.h  
StreamablesLoading int32 How many FStreamables is this waiting on to finish loading Engine/StreamableManager.h  
UpdateDelegate FStreamableUpdateDelegate Called periodically during streaming to update progress UI Engine/StreamableManager.h  

Functions

Public

Name Remarks Include Path Unreal Specifiers

void AddContextData ( const TSharedPtr< T >& NewData
)

 Unconditionally adds a contextual data struct to this handle. Uniqueness is not enforced. Engine/StreamableManager.h  

bool BindCancelDelegate ( FStreamableDelegate NewDelegate
)

   Engine/StreamableManager.h  

bool BindCancelDelegate ( FStreamableDelegateWithHandle NewDelegate
)

 Bind delegate that is called if handle is canceled, only works if loading is in progress. Engine/StreamableManager.h  

bool BindCompleteDelegate ( FStreamableDelegate NewDelegate
)

   Engine/StreamableManager.h  

bool BindCompleteDelegate ( FStreamableDelegateWithHandle NewDelegate
)

 Bind delegate that is called when load completes, only works if loading is in progress. Engine/StreamableManager.h  

bool BindUpdateDelegate ( FStreamableUpdateDelegate NewDelegate
)

 Bind delegate that is called periodically as request updates, only works if loading is in progress. Engine/StreamableManager.h  

void CancelHandle()

 Cancel a request, callable from within the manager or externally This will immediately release the handle even if it is still in progress, and call the cancel callback if bound This stops the completion callback from happening, even if it is in the delayed callback queue Engine/StreamableManager.h  

TSharedPtr< FStreamableHandle > CreateCombinedHandle ( const TConstArrayView< TSharedPtr< FStreamableHandle > >& OtherHandles
)

 Creates a new merged handle which contains this handle as well as any external handles. Engine/StreamableManager.h  
Finds the first instance of a contextual data struct which is attached to this handle. Engine/StreamableManager.h  
Return a TSharedPtr of the first handle among this and descendants which satisfies the predicate. Engine/StreamableManager.h  

T & FindOrAddContextData()

 Gives you a mutable reference to a contextual data struct of the specified type. Engine/StreamableManager.h  

void ForEachLoadedAsset ( CallableT Callable
) const

 Invokes a callable for each loaded asset if load has succeeded. Engine/StreamableManager.h  

float GetAbsoluteDownloadProgress()

 Returns progress as a value between 0.0 and 1.0 representing the total percentage of installed packages for the request. Engine/StreamableManager.h  

TArray< TSharedPtr< T > > GetContextDataOfType()

 Finds all instances of a contextual data struct which are attached to this handle Engine/StreamableManager.h  

ECookLoadType GetCookLoadType()

   Engine/StreamableManager.h  

const FString & GetDebugName()

 Returns the debug name for this handle. Engine/StreamableManager.h  

FStreamableDownloadCachePin GetDownloadCachePin()

 Get download cache pin for this handle Engine/StreamableManager.h  

TArray< FStreamableDownloadCachePin > GetDownloadCachePins()

 Get download cache pins for this handle and all childern Engine/StreamableManager.h  

TOptional< FStreamableDownloadPriority > GetDownloadPriority()

 Returns download priority. Only valid if a download has been requested and is not yet complete. Engine/StreamableManager.h  

const TOptional< UE::UnifiedError::FError > & GetError()

 Get error details Engine/StreamableManager.h  
Templated version of above Engine/StreamableManager.h  
Returns first asset in requested asset list, if it's been successfully loaded. Engine/StreamableManager.h  

void GetLoadedAssets ( TArray< UObject* >& LoadedAssets
) const

 Adds all loaded assets if load has succeeded. Some entries will be null if loading failed Engine/StreamableManager.h  

void GetLoadedAssets ( TArray< T* >& LoadedAssets
) const

 Templated version of above. Entries that fail to cast will also be null. Engine/StreamableManager.h  

void GetLoadedCount ( int32& LoadedCount,
int32& RequestedCount
) const

 Returns number of assets that have completed loading out of initial list, failed loads will count as loaded Engine/StreamableManager.h  

float GetLoadProgress()

 Returns progress as a value between 0.0 and 1.0. Engine/StreamableManager.h  
Crawls out to the outermost handle and returns it. Engine/StreamableManager.h  

FStreamableManager * GetOwningManager()

 Get the StreamableManager for this handle Engine/StreamableManager.h  

TAsyncLoadPriority GetPriority()

 Returns the streaming priority. Engine/StreamableManager.h  

float GetProgress ( EStreamableProgressType Type
) const

 Returns progress as a value between 0.0 and 1.0. Engine/StreamableManager.h  

FName GetRefencerPackageOp()

   Engine/StreamableManager.h  

FName GetReferencerPackage()

   Engine/StreamableManager.h  

float GetRelativeDownloadProgress()

 Returns progress as a value between 0.0 and 1.0 representing progress of downloading packages that were not installed when the request was issued. Engine/StreamableManager.h  

void GetRequestedAssets ( TArray< FSoftObjectPath >& AssetList,
bool bIncludeChildren
) const

 Gets list of assets references this load was started with. Engine/StreamableManager.h  

bool HasCancelDelegate()

 Check to see whether or not the Cancel delegate is bound; useful for doing extra work before/without stomping the existing delegate. Engine/StreamableManager.h  

bool HasCompleteDelegate()

 Check to see whether or not the Complete delegate is bound; useful for doing extra work before/without stomping the existing delegate. Engine/StreamableManager.h  

bool HasError()

 True if an error occured Engine/StreamableManager.h  

bool HasLoadCompleted()

 If this request has finished loading, meaning all available assets were loaded Any assets that failed to load will still be null This can be true before the completion callback has happened as it may be in the delayed callback queue Engine/StreamableManager.h  

bool HasLoadCompletedOrStalled()

 Returns true if we've done all the loading we can now, ie all handles are either completed or stalled Engine/StreamableManager.h  

bool HasUpdateDelegate()

 Check to see whether or not the Update delegate is bound; useful for doing extra work before/without stomping the existing delegate. Engine/StreamableManager.h  

bool IsActive()

 If this handle is still active, meaning it wasn't canceled or released Engine/StreamableManager.h  

bool IsCombinedHandle()

 Returns true if this is a combined handle that depends on child handles. Engine/StreamableManager.h  

bool IsLoadingInProgress()

 True if load is still ongoing and we haven't been cancelled Engine/StreamableManager.h  

bool IsStalled()

 If this handle is stalled and waiting for another event to occur before it is actually requested Engine/StreamableManager.h  

void ReleaseHandle ()

 Release this handle. Engine/StreamableManager.h  

void SetDebugNameIfEmptyOrDefault ( const FString& NewName
)

 Allows user code to provide a more detailed name in the cases where a name is autogenerated or otherwise default. Engine/StreamableManager.h  

bool SetDownloadPriority ( FStreamableDownloadPriority Priority
)

 Set download priority. Only valid if a download has been requested and is not yet complete. Engine/StreamableManager.h  

void StartStalledHandle()

 Tells a stalled handle to start its actual request. Engine/StreamableManager.h  

EAsyncPackageState::Type WaitUntilComplete ( float Timeout,
bool bStartStalledHandles
)

 Blocks until the requested assets have loaded. Engine/StreamableManager.h  

bool WasCanceled ()

 If this request was cancelled. Engine/StreamableManager.h  

Static

Name Remarks Include Path Unreal Specifiers

static void ExecuteDelegate ( FStreamableDelegateWithHandle&& Delegate,
TSharedPtr< FStreamableHandle > AssociatedHandle,
FStreamableDelegateWithHandle&& CancelDelegate
)

 Overload taking the Delegate by rvalue. Engine/StreamableManager.h  

static void ExecuteDelegate ( const FStreamableDelegateWithHandle& Delegate,
TSharedPtr< FStreamableHandle > AssociatedHandle,
const FStreamableDelegateWithHandle& CancelDelegate
)

 Calls a StreamableDelegate, this will add to the delayed callback queue depending on s.StreamableDelegateDelayFrames Engine/StreamableManager.h  

static void ExecuteDelegate ( const FStreamableDelegate& Delegate,
TSharedPtr< FStreamableHandle > AssociatedHandle,
const FStreamableDelegate& CancelDelegate
)

 Calls a StreamableDelegate, this will add to the delayed callback queue depending on s.StreamableDelegateDelayFrames Engine/StreamableManager.h  

static void ExecuteDelegate ( FStreamableDelegate&& Delegate,
TSharedPtr< FStreamableHandle > AssociatedHandle,
FStreamableDelegate&& CancelDelegate
)

 Overload taking the Delegate by rvalue. Engine/StreamableManager.h  

Operators

Name Remarks Include Path Unreal Specifiers

FStreamableHandle & operator= ( const FStreamableHandle&
)

   Engine/StreamableManager.h  

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