| /* |
| * |
| * Copyright 2005, Lukas Sandstrom <lukass@etek.chalmers.se> |
| * |
| * This file is licensed under the GPL v2. |
| * |
| */ |
| |
| #include "cache.h" |
| |
| static const char pack_redundant_usage[] = |
| "git-pack-redundant [ --verbose ] [ --alt-odb ] < --all | <.pack filename> ...>"; |
| |
| static int load_all_packs = 0, verbose = 0, alt_odb = 0; |
| |
| struct llist_item { |
| struct llist_item *next; |
| 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; |
| size_t pl_size; |
| }; |
| |
| static struct llist_item *free_nodes = NULL; |
| |
| static inline struct llist_item *llist_item_get() |
| { |
| struct llist_item *new; |
| if ( free_nodes ) { |
| new = free_nodes; |
| free_nodes = free_nodes->next; |
| } else |
| new = xmalloc(sizeof(struct llist_item)); |
| |
| 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) |
| { |
| 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, |
| 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, unsigned char *sha1) |
| { |
| return llist_insert(list, list->back, sha1); |
| } |
| |
| static inline struct llist_item *llist_insert_sorted_unique(struct llist *list, unsigned char *sha1, struct llist_item *hint) |
| { |
| struct llist_item *prev = NULL, *l; |
| |
| l = (hint == NULL) ? list->front : hint; |
| while (l) { |
| int cmp = memcmp(l->sha1, sha1, 20); |
| 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 = memcmp(l->sha1, sha1, 20); |
| 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) |
| { |
| int p1_off, p2_off; |
| void *p1_base, *p2_base; |
| struct llist_item *p1_hint = NULL, *p2_hint = NULL; |
| |
| p1_off = p2_off = 256 * 4 + 4; |
| p1_base = (void *)p1->pack->index_base; |
| p2_base = (void *)p2->pack->index_base; |
| |
| while (p1_off <= p1->pack->index_size - 3 * 20 && |
| p2_off <= p2->pack->index_size - 3 * 20) |
| { |
| int cmp = memcmp(p1_base + p1_off, p2_base + p2_off, 20); |
| /* 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+=24; |
| p2_off+=24; |
| continue; |
| } |
| if (cmp < 0) { /* p1 has the object, p2 doesn't */ |
| p1_off+=24; |
| } else { /* p2 has the object, p1 doesn't */ |
| p2_off+=24; |
| } |
| } |
| } |
| |
| static void pll_insert(struct pll **pll, struct pll **hint_table) |
| { |
| struct pll *prev; |
| int i = (*pll)->pl_size - 1; |
| |
| if (hint_table[i] == NULL) { |
| hint_table[i--] = *pll; |
| for (; i >= 0; --i) { |
| if (hint_table[i] != NULL) |
| break; |
| } |
| if (hint_table[i] == NULL) /* no elements in list */ |
| die("Why did this happen?"); |
| } |
| |
| 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, |
| * since they refer to each other |
| */ |
| static struct pll * get_all_permutations(struct pack_list *list) |
| { |
| struct pll *subset, *pll, *new_pll = NULL; /*silence warning*/ |
| static struct pll **hint = NULL; |
| if (hint == NULL) |
| hint = xcalloc(pack_list_size(list), sizeof(struct pll *)); |
| |
| if (list == NULL) |
| return NULL; |
| |
| if (list->next == NULL) { |
| new_pll = xmalloc(sizeof(struct pll)); |
| hint[0] = new_pll; |
| new_pll->next = NULL; |
| new_pll->pl = list; |
| new_pll->pl_size = 1; |
| return new_pll; |
| } |
| |
| pll = subset = get_all_permutations(list->next); |
| while (pll) { |
| if (pll->pl->pack == list->pack) { |
| pll = pll->next; |
| continue; |
| } |
| 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 = 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) |
| { |
| 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; |
| int p1_off, p2_off; |
| void *p1_base, *p2_base; |
| |
| p1_off = p2_off = 256 * 4 + 4; |
| p1_base = (void *)p1->index_base; |
| p2_base = (void *)p2->index_base; |
| |
| while (p1_off <= p1->index_size - 3 * 20 && |
| p2_off <= p2->index_size - 3 * 20) |
| { |
| int cmp = memcmp(p1_base + p1_off, p2_base + p2_off, 20); |
| /* cmp ~ p1 - p2 */ |
| if (cmp == 0) { |
| ret++; |
| p1_off+=24; |
| p2_off+=24; |
| continue; |
| } |
| if (cmp < 0) { /* p1 has the object, p2 doesn't */ |
| p1_off+=24; |
| } else { /* p2 has the object, p1 doesn't */ |
| p2_off+=24; |
| } |
| } |
| 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 size_t pack_set_bytecount(struct pack_list *pl) |
| { |
| size_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; |
| size_t min_perm_size = (size_t)-1, perm_size; |
| |
| 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 */ |
| perm_all = perm = get_all_permutations(non_unique); |
| while (perm) { |
| if (perm_ok && perm->pl_size > perm_ok->pl_size) |
| break; /* ignore all larger permutations */ |
| 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 == NULL) |
| die("Internal error: No complete sets found!\n"); |
| |
| /* find the permutation with the smallest size */ |
| perm = perm_ok; |
| while (perm) { |
| perm_size = pack_set_bytecount(perm->pl); |
| if (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; |
| } |
| alt = alt->next; |
| } |
| } |
| |
| static struct pack_list * add_pack(struct packed_git *p) |
| { |
| struct pack_list l; |
| size_t off; |
| void *base; |
| |
| if (!p->pack_local && !(alt_odb || verbose)) |
| return NULL; |
| |
| l.pack = p; |
| llist_init(&l.all_objects); |
| |
| off = 256 * 4 + 4; |
| base = (void *)p->index_base; |
| while (off <= p->index_size - 3 * 20) { |
| llist_insert_back(l.all_objects, base + off); |
| off += 24; |
| } |
| /* 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\n", filename); |
| |
| while (p) { |
| if (strstr(p->pack_name, filename)) |
| return add_pack(p); |
| p = p->next; |
| } |
| die("Filename %s not found in packed_git\n", 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 */ |
| |
| 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!\n"); |
| |
| 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; |
| } |