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git-pack-redundant: speed and memory usage improvements

Slab allocation of llist entries gives some speed improvements.

Not computing the pack_list permutaions all at once reduces memory
usage greatly on repositories with many packs.

Signed-off-by: Lukas Sandström <lukass@etek.chalmers.se>
Signed-off-by: Junio C Hamano <junkio@cox.net>
maint
Lukas Sandström 19 years ago committed by Junio C Hamano
parent
commit
6d016c9c7f
  1. 149
      pack-redundant.c

149
pack-redundant.c

@ -8,6 +8,8 @@


#include "cache.h" #include "cache.h"


#define BLKSIZE 512

static const char pack_redundant_usage[] = static const char pack_redundant_usage[] =
"git-pack-redundant [ --verbose ] [ --alt-odb ] < --all | <.pack filename> ...>"; "git-pack-redundant [ --verbose ] [ --alt-odb ] < --all | <.pack filename> ...>";


@ -33,29 +35,32 @@ static struct pack_list {
struct pll { struct pll {
struct pll *next; struct pll *next;
struct pack_list *pl; struct pack_list *pl;
size_t pl_size;
}; };


static struct llist_item *free_nodes = NULL; static struct llist_item *free_nodes = NULL;


static inline void llist_item_put(struct llist_item *item)
{
item->next = free_nodes;
free_nodes = item;
}

static inline struct llist_item *llist_item_get() static inline struct llist_item *llist_item_get()
{ {
struct llist_item *new; struct llist_item *new;
if ( free_nodes ) { if ( free_nodes ) {
new = free_nodes; new = free_nodes;
free_nodes = free_nodes->next; free_nodes = free_nodes->next;
} else } else {
new = xmalloc(sizeof(struct llist_item)); int i = 1;

new = xmalloc(sizeof(struct llist_item) * BLKSIZE);
for(;i < BLKSIZE; i++) {
llist_item_put(&new[i]);
}
}
return new; return new;
} }


static inline void llist_item_put(struct llist_item *item)
{
item->next = free_nodes;
free_nodes = item;
}

static void llist_free(struct llist *list) static void llist_free(struct llist *list)
{ {
while((list->back = list->front)) { while((list->back = list->front)) {
@ -270,77 +275,58 @@ static void cmp_two_packs(struct pack_list *p1, struct pack_list *p2)
} }
} }


static void pll_insert(struct pll **pll, struct pll **hint_table) void pll_free(struct pll *l)
{ {
struct pll *prev; struct pll *old;
int i = (*pll)->pl_size - 1; struct pack_list *opl;


if (hint_table[i] == NULL) { while (l) {
hint_table[i--] = *pll; old = l;
for (; i >= 0; --i) { while (l->pl) {
if (hint_table[i] != NULL) opl = l->pl;
break; l->pl = opl->next;
free(opl);
} }
if (hint_table[i] == NULL) /* no elements in list */ l = l->next;
die("Why did this happen?"); free(old);
} }

prev = hint_table[i];
while (prev->next && prev->next->pl_size < (*pll)->pl_size)
prev = prev->next;

(*pll)->next = prev->next;
prev->next = *pll;
} }


/* all the permutations have to be free()d at the same time, /* all the permutations have to be free()d at the same time,
* since they refer to each other * since they refer to each other
*/ */
static struct pll * get_all_permutations(struct pack_list *list) static struct pll * get_permutations(struct pack_list *list, int n)
{ {
struct pll *subset, *pll, *new_pll = NULL; /*silence warning*/ struct pll *subset, *ret = NULL, *new_pll = NULL, *pll;
static struct pll **hint = NULL;
if (hint == NULL) if (list == NULL || pack_list_size(list) < n || n == 0)
hint = xcalloc(pack_list_size(list), sizeof(struct pll *));
if (list == NULL)
return NULL; return NULL;


if (list->next == NULL) { if (n == 1) {
new_pll = xmalloc(sizeof(struct pll)); while (list) {
hint[0] = new_pll; new_pll = xmalloc(sizeof(pll));
new_pll->next = NULL; new_pll->pl = NULL;
new_pll->pl = list; pack_list_insert(&new_pll->pl, list);
new_pll->pl_size = 1; new_pll->next = ret;
return new_pll; ret = new_pll;
list = list->next;
}
return ret;
} }


pll = subset = get_all_permutations(list->next); while (list->next) {
while (pll) { subset = get_permutations(list->next, n - 1);
if (pll->pl->pack == list->pack) { while (subset) {
pll = pll->next; new_pll = xmalloc(sizeof(pll));
continue; new_pll->pl = subset->pl;
pack_list_insert(&new_pll->pl, list);
new_pll->next = ret;
ret = new_pll;
subset = subset->next;
} }
new_pll = xmalloc(sizeof(struct pll)); list = list->next;

}
new_pll->pl = xmalloc(sizeof(struct pack_list)); return ret;
memcpy(new_pll->pl, list, sizeof(struct pack_list));
new_pll->pl->next = pll->pl;
new_pll->pl_size = pll->pl_size + 1;
pll_insert(&new_pll, hint);

pll = pll->next;
}
/* add ourself */
new_pll = xmalloc(sizeof(struct pll));
new_pll->pl = xmalloc(sizeof(struct pack_list));
memcpy(new_pll->pl, list, sizeof(struct pack_list));
new_pll->pl->next = NULL;
new_pll->pl_size = 1;
pll_insert(&new_pll, hint);

return hint[0];
} }


static int is_superset(struct pack_list *pl, struct llist *list) static int is_superset(struct pack_list *pl, struct llist *list)
@ -428,6 +414,7 @@ static void minimize(struct pack_list **min)
struct pll *perm, *perm_all, *perm_ok = NULL, *new_perm; struct pll *perm, *perm_all, *perm_ok = NULL, *new_perm;
struct llist *missing; struct llist *missing;
size_t min_perm_size = (size_t)-1, perm_size; size_t min_perm_size = (size_t)-1, perm_size;
int n;


pl = local_packs; pl = local_packs;
while (pl) { while (pl) {
@ -441,8 +428,7 @@ static void minimize(struct pack_list **min)
missing = llist_copy(all_objects); missing = llist_copy(all_objects);
pl = unique; pl = unique;
while (pl) { while (pl) {
llist_sorted_difference_inplace(missing, llist_sorted_difference_inplace(missing, pl->all_objects);
pl->all_objects);
pl = pl->next; pl = pl->next;
} }


@ -453,19 +439,21 @@ static void minimize(struct pack_list **min)
} }


/* find the permutations which contain all missing objects */ /* find the permutations which contain all missing objects */
perm_all = perm = get_all_permutations(non_unique); for (n = 1; n <= pack_list_size(non_unique) && !perm_ok; n++) {
while (perm) { perm_all = perm = get_permutations(non_unique, n);
if (perm_ok && perm->pl_size > perm_ok->pl_size) while (perm) {
break; /* ignore all larger permutations */ if (is_superset(perm->pl, missing)) {
if (is_superset(perm->pl, missing)) { new_perm = xmalloc(sizeof(struct pll));
new_perm = xmalloc(sizeof(struct pll)); memcpy(new_perm, perm, sizeof(struct pll));
memcpy(new_perm, perm, sizeof(struct pll)); new_perm->next = perm_ok;
new_perm->next = perm_ok; perm_ok = new_perm;
perm_ok = new_perm; }
perm = perm->next;
} }
perm = perm->next; if (perm_ok)
break;
pll_free(perm_all);
} }
if (perm_ok == NULL) if (perm_ok == NULL)
die("Internal error: No complete sets found!\n"); die("Internal error: No complete sets found!\n");


@ -537,6 +525,7 @@ static void scan_alt_odb_packs(void)
alt->all_objects); alt->all_objects);
local = local->next; local = local->next;
} }
llist_sorted_difference_inplace(all_objects, alt->all_objects);
alt = alt->next; alt = alt->next;
} }
} }

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