cache.c File Reference

Caching of timetable fitness values. More...

#include <stdlib.h>
#include <string.h>
#include "assert.h"
#include "modsup.h"
#include "chromo.h"
#include "error.h"
#include "params.h"

Functions
int	cache_init ()
	Prepare fitness cache for use.
void	cache_exit ()
	Free memory used by fitness cache.
static int	cache_table_changed (table *t1, table *t2)
	Compare variable chromosomes of two timetables.
static void	cache_table_copy (table *dest, table *source)
	Copy variable chromosomes and fitness information from source to destination timetable.
static int	cache_find (table *tab)
	Find a matching timetable in fitness cache.
void	cache_table_fitness (table *tab)
	Assign a fitness to a table by first checking the cache and then calling all fitness functions.
Variables
static table **	cache_array = NULL
	Cache of timetable fitness values.
static int	cache_next = 0
	Cache line that will be overwriten on the next cache miss.
static long long int	cache_hit = 0
	Number of cache hits.
static long long int	cache_miss = 0
	Number of cache misses.

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Detailed Description

Caching of timetable fitness values.

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Function Documentation

static int cache_find

(

table *

tab

)

[static]

Find a matching timetable in fitness cache.

Parameters:

tab

Timetable to search for.

Returns:

Cache line number if a matching timetable was found in cache or -1 if no match was found.

int cache_init

(

)

Prepare fitness cache for use.

Must be run after parser_main().

Returns:

0 on success and -1 on error.

static int cache_table_changed	(	table *	t1,
		table *	t2
	)			[static]

Compare variable chromosomes of two timetables.

Parameters:

	t1	Pointer to the first timetable structure.
	t2	Pointer to the second timetable structure.

Returns:

0 if timetables have identical variable chromosomes or 1 if not.

static void cache_table_copy	(	table *	dest,
		table *	source
	)			[static]

Copy variable chromosomes and fitness information from source to destination timetable.

Parameters:

	dest	Pointer to the destination timetable.
	source	Pointer to the source timetable.

void cache_table_fitness

(

table *

tab

)

Assign a fitness to a table by first checking the cache and then calling all fitness functions.

Uses table_fitness() if no matching timetable was found in fitness cache.

Parameters:

tab

Pointer to the table to be fitnessd.

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Variable Documentation

table** cache_array = NULL [static]

Cache of timetable fitness values.

This is an array of par_cachesize timetable structures. Only variable chromosomes and fitness values (members table_t::fitness, table_t::possible and table_t::subtotals) are valid in these structures. As far as caching logic is concerned if two timetables have identical variable chromosomes they are identical.

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