xgboost::tree::BoundedHistCollection Class Reference

A persistent cache for CPU histogram. More...

#include <hist_cache.h>

Public Member Functions
common::GHistRow	operator[] (std::size_t idx)
common::ConstGHistRow	operator[] (std::size_t idx) const
void	Reset (bst_bin_t n_total_bins, std::size_t n_cached_nodes)
void	Clear (bool exceeded)
	Clear the cache, mark whether the cache is exceeded the limit.
bool	CanHost (common::Span< bst_node_t const > nodes_to_build, common::Span< bst_node_t const > nodes_to_sub) const
void	AllocateHistograms (common::Span< bst_node_t const > nodes_to_build, common::Span< bst_node_t const > nodes_to_sub)
	Allocate histogram buffers for all nodes.
void	AllocateHistograms (std::vector< bst_node_t > const &nodes)
bool	HasExceeded () const
bool	HistogramExists (bst_node_t nidx) const
std::size_t	Size () const

Detailed Description

A persistent cache for CPU histogram.

The size of the cache is first bounded by the Driver class then by this cache implementaiton. The former limits the number of nodes that can be built for each node batch, while this cache limits the number of all nodes up to the size of max(|node_batch|, n_cached_node).

The caller is responsible for clearing up the cache as it needs to rearrange the nodes before making overflowed allocations. The strcut only reports whether the size limit has benn reached.

Member Function Documentation

AllocateHistograms()

void xgboost::tree::BoundedHistCollection::AllocateHistograms ( common::Span< bst_node_t const >  nodes_to_build, common::Span< bst_node_t const >  nodes_to_sub  )

inline

Allocate histogram buffers for all nodes.

The resulting histogram buffer is contiguous for all nodes in the order of allocation.

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

• External/xgboost/src/tree/hist/hist_cache.h