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#ifndef _EXTENTS_H
#define _EXTENTS_H
#include <time.h>
#include <unistd.h>
#include <stdint.h>
struct program_params;
/** extent statistics */
struct extent_stats {
struct extent *extents;
size_t length;
char *lv_name;
};
/** single extent data */
struct extent {
char *dev; // reference, not allocated string
off_t pe;
off_t le;
float score; // calculated score at time of stats reading
float read_score; // read score at time last_read_access
time_t last_read_access;
float write_score; // write score at time last_write_access
time_t last_write_access;
};
/**
* List of sorted extent references according to score
*/
struct extents {
struct extent **extents;
size_t length;
int sort;
};
void free_extents(struct extents *e);
void free_extent_stats(struct extent_stats *es);
void free_extent(struct extent *e); // do nothing
/** strcmp for extents
* @return -1 if e1 is "smaller" than e2, 0 if they're equal and 1 if e1 is
* "bigger" than e2
*/
int compare_extents(struct extents *e1, struct extents *e2);
// sort order selection
enum hot_cold {
ES_HOT = 1, // for getting hottest extents
ES_COLD = 2 // for getting coldest extents
};
/**
* Return embedded score from provided reference
*/
float get_extent_score(struct extent *e);
/** Returns a reference for nmemb'th extent in *e
*/
struct extent * get_extent(struct extents *e, size_t nmemb);
/**
* Count extents that are colder/hotter than provided score
*/
int count_extents(struct extents *e, float score, int hot_cold);
/**
* truncate (remove from end) extents to leave len positions
*/
void truncate_extents(struct extents *e, size_t len);
/**
* Returns tier of provided extent in logical volume
*/
int get_extent_tier(struct program_params *pp, const char *lv_name,
struct extent *e);
/**
* Returns amount of free space left that we can use on provided tier
*
* Space left is equal to maxUsedSpace - already used space
*/
off_t get_avaiable_space(struct program_params *pp, const char *lv_name,
int tier);
#endif