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Merge branch 'sc/pack-redundant'

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Update the implementation of pack-redundant for performance in a
repository with many packfiles.

* sc/pack-redundant:
  pack-redundant: consistent sort method
  pack-redundant: rename pack_list.all_objects
  pack-redundant: new algorithm to find min packs
  pack-redundant: delete redundant code
  pack-redundant: delay creation of unique_objects
  t5323: test cases for git-pack-redundant
This commit is contained in:
Junio C Hamano
2019-03-07 09:59:54 +09:00
parent 3710f60a80 0e37abd2e8
commit cf0879f7e9
2 changed files with 558 additions and 139 deletions
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230
builtin/pack-redundant.c
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@@ -32,14 +32,10 @@ static struct pack_list {
struct pack_list *next;
struct packed_git *pack;
struct llist *unique_objects;
struct llist *all_objects;
struct llist *remaining_objects;
size_t all_objects_size;
} *local_packs = NULL, *altodb_packs = NULL;
struct pll {
struct pll *next;
struct pack_list *pl;
};
static struct llist_item *free_nodes;
static inline void llist_item_put(struct llist_item *item)
@@ -63,15 +59,6 @@ static inline struct llist_item *llist_item_get(void)
return new_item;
}
static void llist_free(struct llist *list)
{
while ((list->back = list->front)) {
list->front = list->front->next;
llist_item_put(list->back);
}
free(list);
}
static inline void llist_init(struct llist **list)
{
*list = xmalloc(sizeof(struct llist));
@@ -254,6 +241,11 @@ static void cmp_two_packs(struct pack_list *p1, struct pack_list *p2)
struct llist_item *p1_hint = NULL, *p2_hint = NULL;
const unsigned int hashsz = the_hash_algo->rawsz;
if (!p1->unique_objects)
p1->unique_objects = llist_copy(p1->remaining_objects);
if (!p2->unique_objects)
p2->unique_objects = llist_copy(p2->remaining_objects);
p1_base = p1->pack->index_data;
p2_base = p2->pack->index_data;
p1_base += 256 * 4 + ((p1->pack->index_version < 2) ? 4 : 8);
@@ -285,78 +277,6 @@ static void cmp_two_packs(struct pack_list *p1, struct pack_list *p2)
}
}
static void pll_free(struct pll *l)
{
struct pll *old;
struct pack_list *opl;
while (l) {
old = l;
while (l->pl) {
opl = l->pl;
l->pl = opl->next;
free(opl);
}
l = l->next;
free(old);
}
}
/* all the permutations have to be free()d at the same time,
* since they refer to each other
*/
static struct pll * get_permutations(struct pack_list *list, int n)
{
struct pll *subset, *ret = NULL, *new_pll = NULL;
if (list == NULL || pack_list_size(list) < n || n == 0)
return NULL;
if (n == 1) {
while (list) {
new_pll = xmalloc(sizeof(*new_pll));
new_pll->pl = NULL;
pack_list_insert(&new_pll->pl, list);
new_pll->next = ret;
ret = new_pll;
list = list->next;
}
return ret;
}
while (list->next) {
subset = get_permutations(list->next, n - 1);
while (subset) {
new_pll = xmalloc(sizeof(*new_pll));
new_pll->pl = subset->pl;
pack_list_insert(&new_pll->pl, list);
new_pll->next = ret;
ret = new_pll;
subset = subset->next;
}
list = list->next;
}
return ret;
}
static int is_superset(struct pack_list *pl, struct llist *list)
{
struct llist *diff;
diff = llist_copy(list);
while (pl) {
llist_sorted_difference_inplace(diff, pl->all_objects);
if (diff->size == 0) { /* we're done */
llist_free(diff);
return 1;
}
pl = pl->next;
}
llist_free(diff);
return 0;
}
static size_t sizeof_union(struct packed_git *p1, struct packed_git *p2)
{
size_t ret = 0;
@@ -421,14 +341,58 @@ static inline off_t pack_set_bytecount(struct pack_list *pl)
return ret;
}
static int cmp_remaining_objects(const void *a, const void *b)
{
struct pack_list *pl_a = *((struct pack_list **)a);
struct pack_list *pl_b = *((struct pack_list **)b);
if (pl_a->remaining_objects->size == pl_b->remaining_objects->size) {
/* have the same remaining_objects, big pack first */
if (pl_a->all_objects_size == pl_b->all_objects_size)
return 0;
else if (pl_a->all_objects_size < pl_b->all_objects_size)
return 1;
else
return -1;
} else if (pl_a->remaining_objects->size < pl_b->remaining_objects->size) {
/* sort by remaining objects, more objects first */
return 1;
} else {
return -1;
}
}
/* Sort pack_list, greater size of remaining_objects first */
static void sort_pack_list(struct pack_list **pl)
{
struct pack_list **ary, *p;
int i;
size_t n = pack_list_size(*pl);
if (n < 2)
return;
/* prepare an array of packed_list for easier sorting */
ary = xcalloc(n, sizeof(struct pack_list *));
for (n = 0, p = *pl; p; p = p->next)
ary[n++] = p;
QSORT(ary, n, cmp_remaining_objects);
/* link them back again */
for (i = 0; i < n - 1; i++)
ary[i]->next = ary[i + 1];
ary[n - 1]->next = NULL;
*pl = ary[0];
free(ary);
}
static void minimize(struct pack_list **min)
{
struct pack_list *pl, *unique = NULL,
*non_unique = NULL, *min_perm = NULL;
struct pll *perm, *perm_all, *perm_ok = NULL, *new_perm;
struct llist *missing;
off_t min_perm_size = 0, perm_size;
int n;
struct pack_list *pl, *unique = NULL, *non_unique = NULL;
struct llist *missing, *unique_pack_objects;
pl = local_packs;
while (pl) {
@@ -442,53 +406,41 @@ static void minimize(struct pack_list **min)
missing = llist_copy(all_objects);
pl = unique;
while (pl) {
llist_sorted_difference_inplace(missing, pl->all_objects);
llist_sorted_difference_inplace(missing, pl->remaining_objects);
pl = pl->next;
}
*min = unique;
/* return if there are no objects missing from the unique set */
if (missing->size == 0) {
*min = unique;
free(missing);
return;
}
/* find the permutations which contain all missing objects */
for (n = 1; n <= pack_list_size(non_unique) && !perm_ok; n++) {
perm_all = perm = get_permutations(non_unique, n);
while (perm) {
if (is_superset(perm->pl, missing)) {
new_perm = xmalloc(sizeof(struct pll));
memcpy(new_perm, perm, sizeof(struct pll));
new_perm->next = perm_ok;
perm_ok = new_perm;
}
perm = perm->next;
}
if (perm_ok)
break;
pll_free(perm_all);
}
if (perm_ok == NULL)
die("Internal error: No complete sets found!");
unique_pack_objects = llist_copy(all_objects);
llist_sorted_difference_inplace(unique_pack_objects, missing);
/* find the permutation with the smallest size */
perm = perm_ok;
while (perm) {
perm_size = pack_set_bytecount(perm->pl);
if (!min_perm_size || min_perm_size > perm_size) {
min_perm_size = perm_size;
min_perm = perm->pl;
}
perm = perm->next;
}
*min = min_perm;
/* add the unique packs to the list */
pl = unique;
/* remove unique pack objects from the non_unique packs */
pl = non_unique;
while (pl) {
pack_list_insert(min, pl);
llist_sorted_difference_inplace(pl->remaining_objects, unique_pack_objects);
pl = pl->next;
}
while (non_unique) {
/* sort the non_unique packs, greater size of remaining_objects first */
sort_pack_list(&non_unique);
if (non_unique->remaining_objects->size == 0)
break;
pack_list_insert(min, non_unique);
for (pl = non_unique->next; pl && pl->remaining_objects->size > 0; pl = pl->next)
llist_sorted_difference_inplace(pl->remaining_objects, non_unique->remaining_objects);
non_unique = non_unique->next;
}
}
static void load_all_objects(void)
@@ -500,7 +452,7 @@ static void load_all_objects(void)
while (pl) {
hint = NULL;
l = pl->all_objects->front;
l = pl->remaining_objects->front;
while (l) {
hint = llist_insert_sorted_unique(all_objects,
l->oid, hint);
@@ -511,7 +463,7 @@ static void load_all_objects(void)
/* remove objects present in remote packs */
pl = altodb_packs;
while (pl) {
llist_sorted_difference_inplace(all_objects, pl->all_objects);
llist_sorted_difference_inplace(all_objects, pl->remaining_objects);
pl = pl->next;
}
}
@@ -536,11 +488,10 @@ static void scan_alt_odb_packs(void)
while (alt) {
local = local_packs;
while (local) {
llist_sorted_difference_inplace(local->unique_objects,
alt->all_objects);
llist_sorted_difference_inplace(local->remaining_objects,
alt->remaining_objects);
local = local->next;
}
llist_sorted_difference_inplace(all_objects, alt->all_objects);
alt = alt->next;
}
}
@@ -555,7 +506,7 @@ static struct pack_list * add_pack(struct packed_git *p)
return NULL;
l.pack = p;
llist_init(&l.all_objects);
llist_init(&l.remaining_objects);
if (open_pack_index(p))
return NULL;
@@ -564,11 +515,11 @@ static struct pack_list * add_pack(struct packed_git *p)
base += 256 * 4 + ((p->index_version < 2) ? 4 : 8);
step = the_hash_algo->rawsz + ((p->index_version < 2) ? 4 : 0);
while (off < p->num_objects * step) {
llist_insert_back(l.all_objects, (const struct object_id *)(base + off));
llist_insert_back(l.remaining_objects, (const struct object_id *)(base + off));
off += step;
}
/* this list will be pruned in cmp_two_packs later */
l.unique_objects = llist_copy(l.all_objects);
l.all_objects_size = l.remaining_objects->size;
l.unique_objects = NULL;
if (p->pack_local)
return pack_list_insert(&local_packs, &l);
else
@@ -603,7 +554,7 @@ static void load_all(void)
int cmd_pack_redundant(int argc, const char **argv, const char *prefix)
{
int i;
struct pack_list *min, *red, *pl;
struct pack_list *min = NULL, *red, *pl;
struct llist *ignore;
struct object_id *oid;
char buf[GIT_MAX_HEXSZ + 2]; /* hex hash + \n + \0 */
@@ -646,7 +597,6 @@ int cmd_pack_redundant(int argc, const char **argv, const char *prefix)
load_all_objects();
cmp_local_packs();
if (alt_odb)
scan_alt_odb_packs();
@@ -663,10 +613,12 @@ int cmd_pack_redundant(int argc, const char **argv, const char *prefix)
llist_sorted_difference_inplace(all_objects, ignore);
pl = local_packs;
while (pl) {
llist_sorted_difference_inplace(pl->unique_objects, ignore);
llist_sorted_difference_inplace(pl->remaining_objects, ignore);
pl = pl->next;
}
cmp_local_packs();
minimize(&min);
if (verbose) {