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  3. FChunkDownloader

FChunkDownloader

API > API/Plugins > API/Plugins/ChunkDownloader

   
Name FChunkDownloader
Type class
Header File /Engine/Plugins/Runtime/ChunkDownloader/Source/Public/ChunkDownloader.h
Include Path #include "ChunkDownloader.h"

Syntax

class FChunkDownloader : public TSharedFromThis< FChunkDownloader >

Inheritance Hierarchy

  • TSharedFromThis< FChunkDownloader > → FChunkDownloader

Constructors

Name Remarks Include Path Unreal Specifiers

FChunkDownloader()

   ChunkDownloader.h  

Destructors

Name Remarks Include Path Unreal Specifiers

~FChunkDownloader()

   ChunkDownloader.h  

Classes

Name Remarks
FMultiCallback  
FPakMountWork  

Structs

Name Remarks
FChunk Entry per chunk
FPakFile Entry per pak file
FStats  

Enums

Public

Name Remarks
EChunkStatus  

Typedefs

Name Type Remarks Include Path
FCallback TFunction< void(bool bSuccess)>   ChunkDownloader.h
FMountTask FAsyncTask< FPakMountWork >   ChunkDownloader.h

Variables

Public

Name Type Remarks Include Path Unreal Specifiers
OnChunkMounted FPlatformChunkInstallMultiDelegate Called whenever a chunk mounts (success or failure). ONLY USE THIS IF YOU WANT TO PASSIVELY LISTEN FOR MOUNTS (otherwise use the proper request callback on MountChunk) ChunkDownloader.h  
OnDownloadAnalytics TFunction< void(const FString &FileName, const FString &Url, uint64 SizeBytes, const FTimespan &DownloadTime, int32 HttpStatus)> Called each time a download attempt finishes (success or failure). ONLY USE THIS IF YOU WANT TO PASSIVELY LISTEN. Downloads retry until successful. ChunkDownloader.h  

Protected

Name Type Remarks Include Path Unreal Specifiers
bNeedsManifestSave bool Do we need to save the manifest (done whenever new downloads have started) ChunkDownloader.h  
BuildBaseUrls TArray< FString >   ChunkDownloader.h  
CacheFolder FString Folders to save pak files into on disk ChunkDownloader.h  
Chunks TMap< int32, TSharedRef< FChunk > > Chunk id to chunk record ChunkDownloader.h  
ContentBuildId FString   ChunkDownloader.h  
DownloadRequests TArray< TSharedRef< FPakFile > > List of pak files that have been requested ChunkDownloader.h  
EmbeddedFolder FString Content folder where we can find some chunks shipped with the build ChunkDownloader.h  
EmbeddedPaks TMap< FString, FPakFileEntry > Pak files embedded in the build (immutable, compressed) ChunkDownloader.h  
LastDeploymentName FString Build specific ID and URL paths ChunkDownloader.h  
LoadingCompleteLatch int32   ChunkDownloader.h  
LoadingModeStats FStats Cumulative stats for loading screen mode ChunkDownloader.h  
ManifestRequest TSharedPtr< IHttpRequest, ESPMode::ThreadSafe > Manifest download request ChunkDownloader.h  
MountTicker FTSTicker::FDelegateHandle Handle for the per-frame mount ticker in the main thread ChunkDownloader.h  
PakFiles TMap< FString, TSharedRef< FPakFile > > Pak file name to pak file record ChunkDownloader.h  
PlatformName FString Platform name (determines the manifest) ChunkDownloader.h  
PostLoadCallbacks TArray< FCallback >   ChunkDownloader.h  
TargetDownloadsInFlight int32 Maximum number of downloads to allow concurrently ChunkDownloader.h  
UpdateBuildCallback FCallback   ChunkDownloader.h  

Functions

Public

Name Remarks Include Path Unreal Specifiers

void BeginLoadingMode ( const FCallback& Callback
)

 Snapshot stats and enter into loading screen mode (pauses all background downloads). ChunkDownloader.h  

void DownloadChunk ( int32 ChunkId,
const FCallback& Callback,
int32 Priority
)

 Download all pak files in the chunk, but don't mount. ChunkDownloader.h  

void DownloadChunks ( const TArray< int32 >& ChunkIds,
const FCallback& Callback,
int32 Priority
)

 Download (Cache) all pak files in these chunks then fire the callback (convenience wrapper managing multiple DownloadChunk calls) ChunkDownloader.h  

void Finalize ()

 Unmount all chunks and cancel any downloads in progress (preserving partial downloads). ChunkDownloader.h  

int FlushCache ()

 Flush any cached files (on disk) that are not currently being downloaded to or mounting (does not unmount the corresponding pak files). ChunkDownloader.h  

void GetAllChunkIds ( TArray< int32 >& OutChunkIds
) const

 Return a list of all chunk IDs in the current manifest ChunkDownloader.h  

EChunkStatus GetChunkStatus ( int32 ChunkId
) const

 Get the current status of the specified chunk ChunkDownloader.h  

const FString & GetContentBuildId()

 Get the current content build ID ChunkDownloader.h  

const FString & GetDeploymentName()

 Get the most recent deployment name ChunkDownloader.h  

const FStats & GetLoadingStats()

 Get the current loading stats (generally only useful if you're in loading mode see BeginLoadingMode) ChunkDownloader.h  

int32 GetNumDownloadRequests()

 Get current number of download requests, so we know whether download is in progress. Downlading Requests will be removed from this array in it's FDownload::OnCompleted callback. ChunkDownloader.h  

void Initialize ( const FString& PlatformName,
int32 TargetDownloadsInFlight
)

 Initialize the download manager (populates the list of cached pak files from disk). Call only once. ChunkDownloader.h  

bool LoadCachedBuild ( const FString& DeploymentName
)

 Try to load a cached build ID from disk (good to do before updating build so it can possibly no-op) ChunkDownloader.h  

void MountChunk ( int32 ChunkId,
const FCallback& Callback
)

 Download all pak files, then asynchronously mount them in order (in order among themselves, async with game thread). ChunkDownloader.h  

void MountChunks ( const TArray< int32 >& ChunkIds,
const FCallback& Callback
)

 Download and mount all chunks then fire the callback (convenience wrapper managing multiple MountChunk calls) ChunkDownloader.h  

void UpdateBuild ( const FString& DeploymentName,
const FString& ContentBuildId,
const FCallback& Callback
)

 Set the the content build id if the content build id has changed, we pull the new BuildManifest from CDN and load it. ChunkDownloader.h  

int ValidateCache ()

 Validate all fully cached files (blocking) by attempting to read them and check their Version hash. ChunkDownloader.h  

Protected

Static

Name Remarks Include Path Unreal Specifiers

static bool CheckFileSha1Hash ( const FString& FullPathOnDisk,
const FString& Sha1HashStr
)

   ChunkDownloader.h  

static const TCHAR * ChunkStatusToString ( EChunkStatus Status
)

 Chunk status as logable string ChunkDownloader.h  

static void DumpLoadedChunks()

   ChunkDownloader.h  

static TSharedPtr< FChunkDownloader > Get()

 Static getters ChunkDownloader.h  

static TSharedRef< FChunkDownloader > GetChecked()

   ChunkDownloader.h  

static TSharedRef< FChunkDownloader > GetOrCreate()

   ChunkDownloader.h  

static void Shutdown()

   ChunkDownloader.h  

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