diff options
Diffstat (limited to 'pack-redundant.c')
-rw-r--r-- | pack-redundant.c | 697 |
1 files changed, 0 insertions, 697 deletions
diff --git a/pack-redundant.c b/pack-redundant.c deleted file mode 100644 index 69a7ab2e27..0000000000 --- a/pack-redundant.c +++ /dev/null @@ -1,697 +0,0 @@ -/* -* -* Copyright 2005, Lukas Sandstrom <lukass@etek.chalmers.se> -* -* This file is licensed under the GPL v2. -* -*/ - -#include "cache.h" -#include "exec_cmd.h" - -#define BLKSIZE 512 - -static const char pack_redundant_usage[] = -"git pack-redundant [ --verbose ] [ --alt-odb ] < --all | <.pack filename> ...>"; - -static int load_all_packs, verbose, alt_odb; - -struct llist_item { - struct llist_item *next; - const unsigned char *sha1; -}; -static struct llist { - struct llist_item *front; - struct llist_item *back; - size_t size; -} *all_objects; /* all objects which must be present in local packfiles */ - -static struct pack_list { - struct pack_list *next; - struct packed_git *pack; - struct llist *unique_objects; - struct llist *all_objects; -} *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) -{ - item->next = free_nodes; - free_nodes = item; -} - -static inline struct llist_item *llist_item_get(void) -{ - struct llist_item *new; - if ( free_nodes ) { - new = free_nodes; - free_nodes = free_nodes->next; - } else { - int i = 1; - new = xmalloc(sizeof(struct llist_item) * BLKSIZE); - for (; i < BLKSIZE; i++) - llist_item_put(&new[i]); - } - return new; -} - -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)); - (*list)->front = (*list)->back = NULL; - (*list)->size = 0; -} - -static struct llist * llist_copy(struct llist *list) -{ - struct llist *ret; - struct llist_item *new, *old, *prev; - - llist_init(&ret); - - if ((ret->size = list->size) == 0) - return ret; - - new = ret->front = llist_item_get(); - new->sha1 = list->front->sha1; - - old = list->front->next; - while (old) { - prev = new; - new = llist_item_get(); - prev->next = new; - new->sha1 = old->sha1; - old = old->next; - } - new->next = NULL; - ret->back = new; - - return ret; -} - -static inline struct llist_item *llist_insert(struct llist *list, - struct llist_item *after, - const unsigned char *sha1) -{ - struct llist_item *new = llist_item_get(); - new->sha1 = sha1; - new->next = NULL; - - if (after != NULL) { - new->next = after->next; - after->next = new; - if (after == list->back) - list->back = new; - } else {/* insert in front */ - if (list->size == 0) - list->back = new; - else - new->next = list->front; - list->front = new; - } - list->size++; - return new; -} - -static inline struct llist_item *llist_insert_back(struct llist *list, - const unsigned char *sha1) -{ - return llist_insert(list, list->back, sha1); -} - -static inline struct llist_item *llist_insert_sorted_unique(struct llist *list, - const unsigned char *sha1, struct llist_item *hint) -{ - struct llist_item *prev = NULL, *l; - - l = (hint == NULL) ? list->front : hint; - while (l) { - int cmp = hashcmp(l->sha1, sha1); - if (cmp > 0) { /* we insert before this entry */ - return llist_insert(list, prev, sha1); - } - if (!cmp) { /* already exists */ - return l; - } - prev = l; - l = l->next; - } - /* insert at the end */ - return llist_insert_back(list, sha1); -} - -/* returns a pointer to an item in front of sha1 */ -static inline struct llist_item * llist_sorted_remove(struct llist *list, const unsigned char *sha1, struct llist_item *hint) -{ - struct llist_item *prev, *l; - -redo_from_start: - l = (hint == NULL) ? list->front : hint; - prev = NULL; - while (l) { - int cmp = hashcmp(l->sha1, sha1); - if (cmp > 0) /* not in list, since sorted */ - return prev; - if (!cmp) { /* found */ - if (prev == NULL) { - if (hint != NULL && hint != list->front) { - /* we don't know the previous element */ - hint = NULL; - goto redo_from_start; - } - list->front = l->next; - } else - prev->next = l->next; - if (l == list->back) - list->back = prev; - llist_item_put(l); - list->size--; - return prev; - } - prev = l; - l = l->next; - } - return prev; -} - -/* computes A\B */ -static void llist_sorted_difference_inplace(struct llist *A, - struct llist *B) -{ - struct llist_item *hint, *b; - - hint = NULL; - b = B->front; - - while (b) { - hint = llist_sorted_remove(A, b->sha1, hint); - b = b->next; - } -} - -static inline struct pack_list * pack_list_insert(struct pack_list **pl, - struct pack_list *entry) -{ - struct pack_list *p = xmalloc(sizeof(struct pack_list)); - memcpy(p, entry, sizeof(struct pack_list)); - p->next = *pl; - *pl = p; - return p; -} - -static inline size_t pack_list_size(struct pack_list *pl) -{ - size_t ret = 0; - while (pl) { - ret++; - pl = pl->next; - } - return ret; -} - -static struct pack_list * pack_list_difference(const struct pack_list *A, - const struct pack_list *B) -{ - struct pack_list *ret; - const struct pack_list *pl; - - if (A == NULL) - return NULL; - - pl = B; - while (pl != NULL) { - if (A->pack == pl->pack) - return pack_list_difference(A->next, B); - pl = pl->next; - } - ret = xmalloc(sizeof(struct pack_list)); - memcpy(ret, A, sizeof(struct pack_list)); - ret->next = pack_list_difference(A->next, B); - return ret; -} - -static void cmp_two_packs(struct pack_list *p1, struct pack_list *p2) -{ - unsigned long p1_off = 0, p2_off = 0, p1_step, p2_step; - const unsigned char *p1_base, *p2_base; - struct llist_item *p1_hint = NULL, *p2_hint = NULL; - - p1_base = p1->pack->index_data; - p2_base = p2->pack->index_data; - p1_base += 256 * 4 + ((p1->pack->index_version < 2) ? 4 : 8); - p2_base += 256 * 4 + ((p2->pack->index_version < 2) ? 4 : 8); - p1_step = (p1->pack->index_version < 2) ? 24 : 20; - p2_step = (p2->pack->index_version < 2) ? 24 : 20; - - while (p1_off < p1->pack->num_objects * p1_step && - p2_off < p2->pack->num_objects * p2_step) - { - int cmp = hashcmp(p1_base + p1_off, p2_base + p2_off); - /* cmp ~ p1 - p2 */ - if (cmp == 0) { - p1_hint = llist_sorted_remove(p1->unique_objects, - p1_base + p1_off, p1_hint); - p2_hint = llist_sorted_remove(p2->unique_objects, - p1_base + p1_off, p2_hint); - p1_off += p1_step; - p2_off += p2_step; - continue; - } - if (cmp < 0) { /* p1 has the object, p2 doesn't */ - p1_off += p1_step; - } else { /* p2 has the object, p1 doesn't */ - p2_off += p2_step; - } - } -} - -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, *pll; - - if (list == NULL || pack_list_size(list) < n || n == 0) - return NULL; - - if (n == 1) { - while (list) { - new_pll = xmalloc(sizeof(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(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; - unsigned long p1_off = 0, p2_off = 0, p1_step, p2_step; - const unsigned char *p1_base, *p2_base; - - p1_base = p1->index_data; - p2_base = p2->index_data; - p1_base += 256 * 4 + ((p1->index_version < 2) ? 4 : 8); - p2_base += 256 * 4 + ((p2->index_version < 2) ? 4 : 8); - p1_step = (p1->index_version < 2) ? 24 : 20; - p2_step = (p2->index_version < 2) ? 24 : 20; - - while (p1_off < p1->num_objects * p1_step && - p2_off < p2->num_objects * p2_step) - { - int cmp = hashcmp(p1_base + p1_off, p2_base + p2_off); - /* cmp ~ p1 - p2 */ - if (cmp == 0) { - ret++; - p1_off += p1_step; - p2_off += p2_step; - continue; - } - if (cmp < 0) { /* p1 has the object, p2 doesn't */ - p1_off += p1_step; - } else { /* p2 has the object, p1 doesn't */ - p2_off += p2_step; - } - } - return ret; -} - -/* another O(n^2) function ... */ -static size_t get_pack_redundancy(struct pack_list *pl) -{ - struct pack_list *subset; - size_t ret = 0; - - if (pl == NULL) - return 0; - - while ((subset = pl->next)) { - while (subset) { - ret += sizeof_union(pl->pack, subset->pack); - subset = subset->next; - } - pl = pl->next; - } - return ret; -} - -static inline off_t pack_set_bytecount(struct pack_list *pl) -{ - off_t ret = 0; - while (pl) { - ret += pl->pack->pack_size; - ret += pl->pack->index_size; - pl = pl->next; - } - return ret; -} - -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; - - pl = local_packs; - while (pl) { - if (pl->unique_objects->size) - pack_list_insert(&unique, pl); - else - pack_list_insert(&non_unique, pl); - pl = pl->next; - } - /* find out which objects are missing from the set of unique packs */ - missing = llist_copy(all_objects); - pl = unique; - while (pl) { - llist_sorted_difference_inplace(missing, pl->all_objects); - pl = pl->next; - } - - /* return if there are no objects missing from the unique set */ - if (missing->size == 0) { - *min = unique; - 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!"); - - /* 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; - while (pl) { - pack_list_insert(min, pl); - pl = pl->next; - } -} - -static void load_all_objects(void) -{ - struct pack_list *pl = local_packs; - struct llist_item *hint, *l; - - llist_init(&all_objects); - - while (pl) { - hint = NULL; - l = pl->all_objects->front; - while (l) { - hint = llist_insert_sorted_unique(all_objects, - l->sha1, hint); - l = l->next; - } - pl = pl->next; - } - /* remove objects present in remote packs */ - pl = altodb_packs; - while (pl) { - llist_sorted_difference_inplace(all_objects, pl->all_objects); - pl = pl->next; - } -} - -/* this scales like O(n^2) */ -static void cmp_local_packs(void) -{ - struct pack_list *subset, *pl = local_packs; - - while ((subset = pl)) { - while ((subset = subset->next)) - cmp_two_packs(pl, subset); - pl = pl->next; - } -} - -static void scan_alt_odb_packs(void) -{ - struct pack_list *local, *alt; - - alt = altodb_packs; - while (alt) { - local = local_packs; - while (local) { - llist_sorted_difference_inplace(local->unique_objects, - alt->all_objects); - local = local->next; - } - llist_sorted_difference_inplace(all_objects, alt->all_objects); - alt = alt->next; - } -} - -static struct pack_list * add_pack(struct packed_git *p) -{ - struct pack_list l; - unsigned long off = 0, step; - const unsigned char *base; - - if (!p->pack_local && !(alt_odb || verbose)) - return NULL; - - l.pack = p; - llist_init(&l.all_objects); - - if (open_pack_index(p)) - return NULL; - - base = p->index_data; - base += 256 * 4 + ((p->index_version < 2) ? 4 : 8); - step = (p->index_version < 2) ? 24 : 20; - while (off < p->num_objects * step) { - llist_insert_back(l.all_objects, base + off); - off += step; - } - /* this list will be pruned in cmp_two_packs later */ - l.unique_objects = llist_copy(l.all_objects); - if (p->pack_local) - return pack_list_insert(&local_packs, &l); - else - return pack_list_insert(&altodb_packs, &l); -} - -static struct pack_list * add_pack_file(char *filename) -{ - struct packed_git *p = packed_git; - - if (strlen(filename) < 40) - die("Bad pack filename: %s", filename); - - while (p) { - if (strstr(p->pack_name, filename)) - return add_pack(p); - p = p->next; - } - die("Filename %s not found in packed_git", filename); -} - -static void load_all(void) -{ - struct packed_git *p = packed_git; - - while (p) { - add_pack(p); - p = p->next; - } -} - -int main(int argc, char **argv) -{ - int i; - struct pack_list *min, *red, *pl; - struct llist *ignore; - unsigned char *sha1; - char buf[42]; /* 40 byte sha1 + \n + \0 */ - - git_extract_argv0_path(argv[0]); - - setup_git_directory(); - - for (i = 1; i < argc; i++) { - const char *arg = argv[i]; - if (!strcmp(arg, "--")) { - i++; - break; - } - if (!strcmp(arg, "--all")) { - load_all_packs = 1; - continue; - } - if (!strcmp(arg, "--verbose")) { - verbose = 1; - continue; - } - if (!strcmp(arg, "--alt-odb")) { - alt_odb = 1; - continue; - } - if (*arg == '-') - usage(pack_redundant_usage); - else - break; - } - - prepare_packed_git(); - - if (load_all_packs) - load_all(); - else - while (*(argv + i) != NULL) - add_pack_file(*(argv + i++)); - - if (local_packs == NULL) - die("Zero packs found!"); - - load_all_objects(); - - cmp_local_packs(); - if (alt_odb) - scan_alt_odb_packs(); - - /* ignore objects given on stdin */ - llist_init(&ignore); - if (!isatty(0)) { - while (fgets(buf, sizeof(buf), stdin)) { - sha1 = xmalloc(20); - if (get_sha1_hex(buf, sha1)) - die("Bad sha1 on stdin: %s", buf); - llist_insert_sorted_unique(ignore, sha1, NULL); - } - } - llist_sorted_difference_inplace(all_objects, ignore); - pl = local_packs; - while (pl) { - llist_sorted_difference_inplace(pl->unique_objects, ignore); - pl = pl->next; - } - - minimize(&min); - - if (verbose) { - fprintf(stderr, "There are %lu packs available in alt-odbs.\n", - (unsigned long)pack_list_size(altodb_packs)); - fprintf(stderr, "The smallest (bytewise) set of packs is:\n"); - pl = min; - while (pl) { - fprintf(stderr, "\t%s\n", pl->pack->pack_name); - pl = pl->next; - } - fprintf(stderr, "containing %lu duplicate objects " - "with a total size of %lukb.\n", - (unsigned long)get_pack_redundancy(min), - (unsigned long)pack_set_bytecount(min)/1024); - fprintf(stderr, "A total of %lu unique objects were considered.\n", - (unsigned long)all_objects->size); - fprintf(stderr, "Redundant packs (with indexes):\n"); - } - pl = red = pack_list_difference(local_packs, min); - while (pl) { - printf("%s\n%s\n", - sha1_pack_index_name(pl->pack->sha1), - pl->pack->pack_name); - pl = pl->next; - } - if (verbose) - fprintf(stderr, "%luMB of redundant packs in total.\n", - (unsigned long)pack_set_bytecount(red)/(1024*1024)); - - return 0; -} |