FZGPUModules 2.0
GPU-accelerated modular compression pipelines
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fz::LorenzoQuantStage< TInput, TCode > Class Template Reference

#include <lorenzo_quant.h>

+ Inheritance diagram for fz::LorenzoQuantStage< TInput, TCode >:

Classes

struct  Config
 

Public Member Functions

void execute (cudaStream_t stream, MemoryPool *pool, const std::vector< void * > &inputs, const std::vector< void * > &outputs, const std::vector< size_t > &sizes) override
 
void postStreamSync (cudaStream_t stream) override
 
std::string getName () const override
 
std::vector< std::string > getOutputNames () 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
 
void saveState () override
 
void setDims (const std::array< size_t, 3 > &dims) override
 
int ndim () const
 Returns the effective spatial dimensionality (1, 2, or 3).
 
void setInverse (bool inverse)
 
uint16_t getStageTypeId () const override
 
uint8_t getOutputDataType (size_t output_index) const override
 
uint8_t getInputDataType (size_t) const override
 
size_t serializeHeader (size_t output_index, uint8_t *header_buffer, size_t max_size) const override
 
size_t getMaxHeaderSize (size_t output_index) const override
 
void deserializeHeader (const uint8_t *header_buffer, size_t size) override
 
- Public Member Functions inherited from fz::Stage
virtual size_t getRequiredInputAlignment () const
 
int getOutputIndex (const std::string &name) const
 
virtual void onFinalize (size_t, MemoryPool *)
 
virtual size_t estimateDeviceFootprintBytes (size_t) const
 
virtual size_t estimatePinnedFootprintBytes (size_t) const
 
virtual bool isGraphCompatible () const
 
virtual size_t estimateScratchBytes (const std::vector< size_t > &input_sizes) const
 

Detailed Description

template<typename TInput = float, typename TCode = uint16_t>
class fz::LorenzoQuantStage< TInput, TCode >

Lorenzo predictor with error-bounded quantization (1-D, 2-D, 3-D).

Note
Prior work: fused predictor+quantizer kernels and the multi-output design follow the cuSZ Lorenzo implementation (lrz_c.cuhip.inl, lrz_x.cuhip.inl) by the cuSZ team (BSD-3-Clause). See THIRD_PARTY.md.

Forward outputs (compression):

  • [0] codes — quantization codes for all elements (TCode)
  • [1] outlier_errors — prediction errors for outliers (TInput)
  • [2] outlier_indices — outlier element indices (uint32_t)
  • [3] outlier_count — number of outliers (uint32_t, 4 bytes)

Inverse (decompression): takes the four forward outputs, produces the reconstructed data as a single TInput array.

Template Parameters
TInputFloating-point input type (float or double).
TCodeQuantization code type (uint8_t, uint16_t, uint32_t).

Member Function Documentation

◆ execute()

template<typename TInput = float, typename TCode = uint16_t>
void fz::LorenzoQuantStage< TInput, TCode >::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.

Stages may call cudaStreamSynchronize(stream) or issue blocking D2H copies when the algorithm requires it (e.g. Huffman histogram readback for codebook construction, ANS renormalization tables). Such stages must return false from isGraphCompatible() and must document the sync points.

Note: the DAG dispatches sibling nodes (same topological level) via a sequential CPU loop, each enqueuing to its own stream. A sync inside execute() blocks the CPU from dispatching subsequent siblings until the synced stream is idle — this delays parallel branches in wide DAGs. In a linear pipeline there are no siblings and no extra cost.

Implements fz::Stage.

◆ postStreamSync()

template<typename TInput = float, typename TCode = uint16_t>
void fz::LorenzoQuantStage< TInput, TCode >::postStreamSync ( cudaStream_t  stream)
overridevirtual

Reads back the actual outlier count from the device (4 bytes) and trims actual_output_sizes_ to the real values. Called by Pipeline::compress() after the stream is synchronized — avoids a mid-pipeline stall.

Reimplemented from fz::Stage.

◆ getName()

template<typename TInput = float, typename TCode = uint16_t>
std::string fz::LorenzoQuantStage< TInput, TCode >::getName ( ) const
inlineoverridevirtual

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

Implements fz::Stage.

◆ getOutputNames()

template<typename TInput = float, typename TCode = uint16_t>
std::vector< std::string > fz::LorenzoQuantStage< TInput, TCode >::getOutputNames ( ) const
inlineoverridevirtual

Output port names in order. Default: single port named "output". Multi-output stages (e.g. Lorenzo: "codes", "outliers") override this.

Reimplemented from fz::Stage.

◆ estimateOutputSizes()

template<typename TInput = float, typename TCode = uint16_t>
std::vector< size_t > fz::LorenzoQuantStage< TInput, TCode >::estimateOutputSizes ( const std::vector< size_t > &  input_sizes) const
overridevirtual

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 TInput = float, typename TCode = uint16_t>
std::unordered_map< std::string, size_t > fz::LorenzoQuantStage< TInput, TCode >::getActualOutputSizesByName ( ) const
inlineoverridevirtual

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

Implements fz::Stage.

◆ getActualOutputSize()

template<typename TInput = float, typename TCode = uint16_t>
size_t fz::LorenzoQuantStage< TInput, TCode >::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.

◆ saveState()

template<typename TInput = float, typename TCode = uint16_t>
void fz::LorenzoQuantStage< TInput, TCode >::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.

◆ setDims()

template<typename TInput = float, typename TCode = uint16_t>
void fz::LorenzoQuantStage< TInput, TCode >::setDims ( const std::array< size_t, 3 > &  dims)
inlineoverridevirtual

Called once by Pipeline::finalize() so stages can react to the dataset dimensions set via Pipeline::setDims() after construction.

Parameters
dims{x, y, z} extents (z==1 → 2-D; y==z==1 → 1-D)

Reimplemented from fz::Stage.

◆ setInverse()

template<typename TInput = float, typename TCode = uint16_t>
void fz::LorenzoQuantStage< TInput, TCode >::setInverse ( bool  inverse)
inlinevirtual

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

Reimplemented from fz::Stage.

◆ getStageTypeId()

template<typename TInput = float, typename TCode = uint16_t>
uint16_t fz::LorenzoQuantStage< TInput, TCode >::getStageTypeId ( ) const
inlineoverridevirtual

Stage type identifier written into the FZM file header.

Implements fz::Stage.

◆ getOutputDataType()

template<typename TInput = float, typename TCode = uint16_t>
uint8_t fz::LorenzoQuantStage< TInput, TCode >::getOutputDataType ( size_t  output_index) const
inlineoverridevirtual

DataType enum of the given output port.

Implements fz::Stage.

◆ getInputDataType()

template<typename TInput = float, typename TCode = uint16_t>
uint8_t fz::LorenzoQuantStage< TInput, TCode >::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 TInput = float, typename TCode = uint16_t>
size_t fz::LorenzoQuantStage< TInput, TCode >::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.

◆ getMaxHeaderSize()

template<typename TInput = float, typename TCode = uint16_t>
size_t fz::LorenzoQuantStage< TInput, TCode >::getMaxHeaderSize ( size_t  output_index) const
inlineoverridevirtual

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

Reimplemented from fz::Stage.

◆ deserializeHeader()

template<typename TInput = float, typename TCode = uint16_t>
void fz::LorenzoQuantStage< TInput, TCode >::deserializeHeader ( const uint8_t *  header_buffer,
size_t  size 
)
inlineoverridevirtual

Restore stage config from header_buffer during decompression.

Reimplemented from fz::Stage.