operations_research::glop::ColumnsSaver Class Reference

Detailed Description

ColumnDeletionHelper Some preprocessors need to save columns/rows of the matrix for the postsolve. This class helps them do that.

Note

we used to simply use a SparseMatrix, which is like a vector of SparseColumn. However on large problem with 10+ millions columns, each empty SparseColumn take 48 bytes, so if we run like 10 presolve step that save as little as 1 columns, we already are at 4GB memory for nothing!

Definition at line 161 of file preprocessor.h.

#include <preprocessor.h>

Public Member Functions
void	SaveColumn (ColIndex col, const SparseColumn &column)
	Saves a column. The first version CHECKs that it is not already done.
void	SaveColumnIfNotAlreadyDone (ColIndex col, const SparseColumn &column)
const SparseColumn &	SavedColumn (ColIndex col) const
	Returns the saved column. The first version CHECKs that it was saved.
const SparseColumn &	SavedOrEmptyColumn (ColIndex col) const

Member Function Documentation

SaveColumn()

void operations_research::glop::ColumnsSaver::SaveColumn	(	ColIndex	col,
		const SparseColumn &	column )

Saves a column. The first version CHECKs that it is not already done.

ColumnDeletionHelper

Definition at line 216 of file preprocessor.cc.

SaveColumnIfNotAlreadyDone()

void operations_research::glop::ColumnsSaver::SaveColumnIfNotAlreadyDone	(	ColIndex	col,
		const SparseColumn &	column )

Definition at line 222 of file preprocessor.cc.

SavedColumn()

const SparseColumn & operations_research::glop::ColumnsSaver::SavedColumn

(

ColIndex

col

)

const

Returns the saved column. The first version CHECKs that it was saved.

Definition at line 229 of file preprocessor.cc.

SavedOrEmptyColumn()

const SparseColumn & operations_research::glop::ColumnsSaver::SavedOrEmptyColumn

(

ColIndex

col

)

const

Definition at line 235 of file preprocessor.cc.

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

• ortools/glop/preprocessor.h
• ortools/glop/preprocessor.cc