| /* |
| * |
| * Copyright 2005, Lukas Sandstrom <lukass@etek.chalmers.se> |
| * |
| * This file is licensed under the GPL v2. |
| * |
| */ |
| |
| #include "builtin.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(const 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 cmd_pack_redundant(int argc, const char **argv, const char *prefix) |
| { |
| int i; |
| struct pack_list *min, *red, *pl; |
| struct llist *ignore; |
| unsigned char *sha1; |
| char buf[42]; /* 40 byte sha1 + \n + \0 */ |
| |
| if (argc == 2 && !strcmp(argv[1], "-h")) |
| usage(pack_redundant_usage); |
| |
| 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; |
| } |