#include <bitpack_stage.h>

Inheritance diagram for fz::BitpackStage< T >:

Public Member Functions
void	setInverse (bool inv) override

void	setNBits (uint8_t nbits)

void	setAutoDetect (bool enable)

void	execute (cudaStream_t stream, MemoryPool pool, const std::vector< void > &inputs, const std::vector< void * > &outputs, const std::vector< size_t > &sizes) override

std::string	getName () const override

std::vector< size_t >	estimateOutputSizes (const std::vector< size_t > &input_sizes) const override

std::unordered_map< std::string, size_t >	getActualOutputSizesByName () const override

size_t	getActualOutputSize (int index) const override

uint16_t	getStageTypeId () const override

uint8_t	getOutputDataType (size_t) const override

uint8_t	getInputDataType (size_t) const override

size_t	serializeHeader (size_t, uint8_t *buf, size_t max_size) const override

void	deserializeHeader (const uint8_t *buf, size_t size) override

size_t	getMaxHeaderSize (size_t) const override

void	saveState () override

bool	isGraphCompatible () const override

Public Member Functions inherited from fz::Stage
virtual size_t	getRequiredInputAlignment () const

virtual std::vector< std::string >	getOutputNames () const

int	getOutputIndex (const std::string &name) const

virtual void	setDims (const std::array< size_t, 3 > &dims)

virtual void	postStreamSync (cudaStream_t stream)

virtual size_t	estimateScratchBytes (const std::vector< size_t > &input_sizes) const

Detailed Description

template<typename T>
class fz::BitpackStage< T >

Bit-packing stage.

Forward: T[] → uint8_t[] Pack each element using only the low nbits bits. Inverse: uint8_t[] → T[] Unpack elements, zero-extending to full width.

Template Parameters

T	Input element type: `uint8_t`, `uint16_t`, or `uint32_t`.

Member Function Documentation

◆ setInverse()

template<typename T >

void fz::BitpackStage< T >::setInverse ( bool inverse )

inlineoverridevirtual

Switch between forward (compression) and inverse (decompression) mode. Affects getNumInputs()/getNumOutputs() for stages with asymmetric port counts.

Reimplemented from fz::Stage.

◆ setNBits()

template<typename T >

void fz::BitpackStage< T >::setNBits ( uint8_t nbits )

inline

Set the number of bits per element.

Must be a power of two between 1 and 8*sizeof(T) inclusive. Allowed values: uint8_t : 1, 2, 4, 8 uint16_t : 1, 2, 4, 8, 16 uint32_t : 1, 2, 4, 8, 16, 32

Ignored during forward execute when setAutoDetect(true) is active.

◆ setAutoDetect()

template<typename T >

void fz::BitpackStage< T >::setAutoDetect ( bool enable )

inline

Enable automatic bit-width detection.

When true, forward execute scans the input for its maximum value and selects the smallest valid power-of-two nbits that covers it. The chosen nbits is stored in the serialized header so the inverse pass can unpack correctly.

After compress(), getNBits() reflects the detected value.

Incompatible with CUDA Graph capture: isGraphCompatible() returns false while auto-detect is enabled.

◆ execute()

template<typename T >

void fz::BitpackStage< T >::execute	(	cudaStream_t	stream,
		MemoryPool *	pool,
		const std::vector< void * > &	inputs,
		const std::vector< void * > &	outputs,
		const std::vector< size_t > &	sizes
	)

overridevirtual

Execute the stage. Inputs, outputs, and sizes are device pointers/bytes.

Implements fz::Stage.

◆ getName()

template<typename T >

std::string fz::BitpackStage< T >::getName ( ) const

inlineoverridevirtual

Human-readable name used in error messages and debug output.

Implements fz::Stage.

◆ estimateOutputSizes()

template<typename T >

std::vector< size_t > fz::BitpackStage< T >::estimateOutputSizes ( const std::vector< size_t > & input_sizes ) const

inlineoverridevirtual

Estimate output buffer sizes given input sizes. Used for buffer allocation planning in PREALLOCATE mode — must be a safe upper bound; under-estimation causes buffer overruns.

Implements fz::Stage.

◆ getActualOutputSizesByName()

template<typename T >

std::unordered_map< std::string, size_t > fz::BitpackStage< T >::getActualOutputSizesByName ( ) const

inlineoverridevirtual

Actual output sizes after execute(), keyed by output port name.

Implements fz::Stage.

◆ getActualOutputSize()

template<typename T >

size_t fz::BitpackStage< T >::getActualOutputSize ( int index ) const

inlineoverridevirtual

Actual size of a single output by index after execute(). Avoids constructing the map for the common single-output case. Default delegates to getActualOutputSizesByName(); override to return directly from an internal field.

Reimplemented from fz::Stage.

◆ getStageTypeId()

template<typename T >

uint16_t fz::BitpackStage< T >::getStageTypeId ( ) const

inlineoverridevirtual

Stage type identifier written into the FZM file header.

Implements fz::Stage.

◆ getOutputDataType()

template<typename T >

uint8_t fz::BitpackStage< T >::getOutputDataType ( size_t output_index ) const

inlineoverridevirtual

DataType enum of the given output port.

Implements fz::Stage.

◆ getInputDataType()

template<typename T >

uint8_t fz::BitpackStage< T >::getInputDataType ( size_t ) const

inlineoverridevirtual

Expected DataType of the given input port.

Used by Pipeline::finalize() to detect type mismatches between connected stages before any execution. Return DataType::UNKNOWN to opt out of checking — byte-transparent stages (Bitshuffle, RZE) and mock stages must return UNKNOWN; finalize() skips any connection where either side is UNKNOWN.

Reimplemented from fz::Stage.

◆ serializeHeader()

template<typename T >

size_t fz::BitpackStage< T >::serializeHeader	(	size_t	output_index,
		uint8_t *	header_buffer,
		size_t	max_size
	)		const

inlineoverridevirtual

Serialize stage config into header_buffer (max 128 bytes) for the FZM file. Return the number of bytes written, or 0 if the stage has no config.

Reimplemented from fz::Stage.

◆ deserializeHeader()

template<typename T >

void fz::BitpackStage< T >::deserializeHeader	(	const uint8_t *	header_buffer,
		size_t	size
	)

inlineoverridevirtual

Restore stage config from header_buffer during decompression.

Reimplemented from fz::Stage.

◆ getMaxHeaderSize()

template<typename T >

size_t fz::BitpackStage< T >::getMaxHeaderSize ( size_t output_index ) const

inlineoverridevirtual

Maximum bytes this stage writes into its per-output FZM header slot.

Reimplemented from fz::Stage.

◆ saveState()

template<typename T >

void fz::BitpackStage< T >::saveState ( )

inlineoverridevirtual

Save/restore config state around a decompression pass. deserializeHeader() overwrites the stage's forward-pass config; saveState() is called before and restoreState() after so the stage returns to its original configuration.

Reimplemented from fz::Stage.

◆ isGraphCompatible()

template<typename T >

bool fz::BitpackStage< T >::isGraphCompatible ( ) const

inlineoverridevirtual

Whether this stage is safe inside a CUDA Graph capture.

A stage is graph-compatible if execute() enqueues only device-side work (kernel launches, cudaMemcpyAsync D2D/H2D) and makes no host-synchronous calls. Override and return false if execute() contains D2H copies or dynamic decisions based on device data — the DAG will throw at setCaptureMode(true) time rather than producing a broken graph.

Default: true. Inverse-mode stages that do D2H reads (e.g. RZE inverse) must return false.

Reimplemented from fz::Stage.

Public Member Functions

Detailed Description

Member Function Documentation

◆ setInverse()

◆ setNBits()

◆ setAutoDetect()

◆ execute()

◆ getName()

◆ estimateOutputSizes()

◆ getActualOutputSizesByName()

◆ getActualOutputSize()

◆ getStageTypeId()

◆ getOutputDataType()

◆ getInputDataType()

◆ serializeHeader()

◆ deserializeHeader()

◆ getMaxHeaderSize()

◆ saveState()

◆ isGraphCompatible()