FCompressedBuffer Class Reference

#include <CompressedBuffer.h>

Public Member Functions
CORE_API void	Save (FArchive &Ar) const
void	Reset ()
	operator bool () const
bool	IsNull () const
bool	IsOwned () const
FCompressedBuffer	MakeOwned () const &
FCompressedBuffer	MakeOwned () &&
const FCompositeBuffer &	GetCompressed () const &
FCompositeBuffer	GetCompressed () &&
CORE_API uint64	GetCompressedSize () const
CORE_API uint64	GetRawSize () const
CORE_API FIoHash	GetRawHash () const
CORE_API bool	TryGetCompressParameters (ECompressedBufferCompressor &OutCompressor, ECompressedBufferCompressionLevel &OutCompressionLevel, uint64 &OutBlockSize) const
CORE_API bool	TryDecompressTo (FMutableMemoryView RawView, ECompressedBufferDecompressFlags Flags=ECompressedBufferDecompressFlags::None) const
CORE_API FSharedBuffer	Decompress () const
CORE_API FCompositeBuffer	DecompressToComposite () const

Static Public Member Functions
static CORE_API FCompressedBuffer	Compress (const FCompositeBuffer &RawData)
static CORE_API FCompressedBuffer	Compress (const FSharedBuffer &RawData)
static CORE_API FCompressedBuffer	Compress (const FCompositeBuffer &RawData, ECompressedBufferCompressor Compressor, ECompressedBufferCompressionLevel CompressionLevel, uint64 BlockSize=0)
static CORE_API FCompressedBuffer	Compress (const FSharedBuffer &RawData, ECompressedBufferCompressor Compressor, ECompressedBufferCompressionLevel CompressionLevel, uint64 BlockSize=0)
static CORE_API FCompressedBuffer	FromCompressed (const FCompositeBuffer &CompressedData)
static CORE_API FCompressedBuffer	FromCompressed (FCompositeBuffer &&CompressedData)
static CORE_API FCompressedBuffer	FromCompressed (const FSharedBuffer &CompressedData)
static CORE_API FCompressedBuffer	FromCompressed (FSharedBuffer &&CompressedData)
static CORE_API FCompressedBuffer	Load (FArchive &Ar)

Static Public Attributes
static CORE_API const FCompressedBuffer	Null

Detailed Description

A compressed buffer stores compressed data in a self-contained format.

A buffer is self-contained in the sense that it can be decompressed without external knowledge of the compression format or the size of the raw data.

The buffer may be partially decompressed using FCompressedBufferReader.

See also

FCompressedBufferReader

Member Function Documentation

Compress() [1/4]

FCompressedBuffer FCompressedBuffer::Compress ( const FCompositeBuffer &  RawData )

static

Compress the buffer using a balanced level of compression.

Returns

An owned compressed buffer, or null on error.

Compress() [2/4]

FCompressedBuffer FCompressedBuffer::Compress ( const FCompositeBuffer &  RawData, ECompressedBufferCompressor  Compressor, ECompressedBufferCompressionLevel  CompressionLevel, uint64  BlockSize = 0  )

static

Compress the buffer using the specified compressor and compression level.

Data that does not compress will be return uncompressed, as if with level None.

Note

Using a level of None will return a buffer that references owned raw data.

Parameters

RawData	The raw data to be compressed.
Compressor	The compressor to encode with. May use NotSet if level is None.
CompressionLevel	The compression level to encode with.
BlockSize	The power-of-two block size to encode raw data in. 0 is default.

Returns

An owned compressed buffer, or null on error.

Compress() [3/4]

FCompressedBuffer FCompressedBuffer::Compress ( const FSharedBuffer &  RawData )

static

Compress() [4/4]

FCompressedBuffer FCompressedBuffer::Compress ( const FSharedBuffer &  RawData, ECompressedBufferCompressor  Compressor, ECompressedBufferCompressionLevel  CompressionLevel, uint64  BlockSize = 0  )

static

Decompress()

FSharedBuffer FCompressedBuffer::Decompress

(

)

const

Decompress into an owned buffer.

Returns

An owned buffer containing the raw data, or null on error.

DecompressToComposite()

FCompositeBuffer FCompressedBuffer::DecompressToComposite

(

)

const

FromCompressed() [1/4]

FCompressedBuffer FCompressedBuffer::FromCompressed ( const FCompositeBuffer &  CompressedData )

static

Construct from a compressed buffer previously created by Compress().

Returns

A compressed buffer, or null on error, such as an invalid format or corrupt header.

FromCompressed() [2/4]

FCompressedBuffer FCompressedBuffer::FromCompressed ( const FSharedBuffer &  CompressedData )

static

FromCompressed() [3/4]

FCompressedBuffer FCompressedBuffer::FromCompressed ( FCompositeBuffer &&  CompressedData )

static

FromCompressed() [4/4]

FCompressedBuffer FCompressedBuffer::FromCompressed ( FSharedBuffer &&  CompressedData )

static

GetCompressed() [1/2]

FCompositeBuffer FCompressedBuffer::GetCompressed ( ) &&

inline

GetCompressed() [2/2]

const FCompositeBuffer & FCompressedBuffer::GetCompressed ( ) const &

inline

Returns a composite buffer containing the compressed data. May be null. May not be owned.

GetCompressedSize()

uint64 FCompressedBuffer::GetCompressedSize

(

)

const

Returns the size of the compressed data. Zero on error or if this is null.

GetRawHash()

FIoHash FCompressedBuffer::GetRawHash

(

)

const

Returns the hash of the raw data. Zero on error or if this is null.

GetRawSize()

uint64 FCompressedBuffer::GetRawSize

(

)

const

Returns the size of the raw data. Zero on error or if this is empty or null.

IsNull()

bool FCompressedBuffer::IsNull ( ) const

inline

Returns true if the compressed buffer is null.

IsOwned()

bool FCompressedBuffer::IsOwned ( ) const

inline

Returns true if the composite buffer is owned.

Load()

FCompressedBuffer FCompressedBuffer::Load ( FArchive &  Ar )

static

Load a compressed buffer from an archive, as saved by Save().

The entire compressed buffer will be loaded from the archive before this function returns. Prefer to use FCompressedBufferReader to stream from an archive when the compressed buffer does not need to be fully loaded into memory.

Returns

A compressed buffer, or null on error. Ar.IsError() will be true on error.

MakeOwned() [1/2]

FCompressedBuffer FCompressedBuffer::MakeOwned ( ) &&

inline

MakeOwned() [2/2]

FCompressedBuffer FCompressedBuffer::MakeOwned ( ) const &

inline

Returns a copy of the compressed buffer that owns its underlying memory.

operator bool()

FCompressedBuffer::operator bool ( ) const

inlineexplicit

Returns true if the compressed buffer is not null.

Reset()

void FCompressedBuffer::Reset ( )

inline

Reset this to null.

Save()

void FCompressedBuffer::Save

(

FArchive &

Ar

)

const

Save the compressed buffer to an archive.

TryDecompressTo()

bool FCompressedBuffer::TryDecompressTo	(	FMutableMemoryView	RawView,
		ECompressedBufferDecompressFlags	Flags = ECompressedBufferDecompressFlags::None
	)		const

Decompress into a memory view that is exactly equal to the raw size.

Returns

True if the requested range was decompressed, otherwise false.

TryGetCompressParameters()

bool FCompressedBuffer::TryGetCompressParameters	(	ECompressedBufferCompressor &	OutCompressor,
		ECompressedBufferCompressionLevel &	OutCompressionLevel,
		uint64 &	OutBlockSize
	)		const

Returns the compressor and compression level used by this buffer.

The compressor and compression level may differ from those specified when creating the buffer because an incompressible buffer is stored with no compression. Parameters cannot be accessed if this is null or uses a method other than Oodle, in which case this returns false.

Returns

True if parameters were written, otherwise false.

Member Data Documentation

Null

const FCompressedBuffer FCompressedBuffer::Null

static

A null compressed buffer.

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The documentation for this class was generated from the following files:

• Engine/Source/Runtime/Core/Public/Compression/CompressedBuffer.h
• Engine/Source/Runtime/Core/Private/Compression/CompressedBuffer.cpp