Add git-pack-intersect
This patch adds the program git-pack-intersect. It is used to find redundant packs in git repositories. Signed-off-by: Lukas Sandström <lukass@etek.chalmers.se> Signed-off-by: Junio C Hamano <junkio@cox.net>
This commit is contained in:
Lukas_Sandström
Junio C Hamano
parent
fd66dbf529
commit
c283ab21c1
2
Makefile
2
Makefile
@ -122,7 +122,7 @@ PROGRAMS = \
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git-unpack-objects$X git-update-index$X git-update-server-info$X \
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git-upload-pack$X git-verify-pack$X git-write-tree$X \
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git-update-ref$X git-symbolic-ref$X git-check-ref-format$X \
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git-name-rev$X $(SIMPLE_PROGRAMS)
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git-name-rev$X git-pack-intersect$X $(SIMPLE_PROGRAMS)
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# Backward compatibility -- to be removed after 1.0
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PROGRAMS += git-ssh-pull$X git-ssh-push$X
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577
pack-intersect.c
Normal file
577
pack-intersect.c
Normal file
@ -0,0 +1,577 @@
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/*
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*
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* Copyright 2005, Lukas Sandstrom <lukass@etek.chalmers.se>
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*
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* This file is licensed under the GPL v2.
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*
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*/
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#include "cache.h"
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static const char pack_intersect_usage[] =
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"git-pack-intersect [ -v ] < -a | <.pack filename> ...>";
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int all = 0, verbose = 0;
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struct llist_item {
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struct llist_item *next;
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char *sha1;
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};
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struct llist {
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struct llist_item *front;
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struct llist_item *back;
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size_t size;
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} *all_objects;
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struct pack_list {
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struct pack_list *next;
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struct packed_git *pack;
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struct llist *unique_objects;
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struct llist *all_objects;
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} *pack_list;
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struct pll {
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struct pll *next;
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struct pack_list *pl;
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};
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inline void llist_free(struct llist *list)
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{
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while((list->back = list->front)) {
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list->front = list->front->next;
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free(list->back);
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}
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free(list);
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}
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inline void llist_init(struct llist **list)
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{
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*list = xmalloc(sizeof(struct llist));
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(*list)->front = (*list)->back = NULL;
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(*list)->size = 0;
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}
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struct llist * llist_copy(struct llist *list)
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{
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struct llist *ret;
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struct llist_item *new, *old, *prev;
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llist_init(&ret);
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if ((ret->size = list->size) == 0)
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return ret;
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new = ret->front = xmalloc(sizeof(struct llist_item));
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new->sha1 = list->front->sha1;
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old = list->front->next;
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while (old) {
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prev = new;
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new = xmalloc(sizeof(struct llist_item));
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prev->next = new;
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new->sha1 = old->sha1;
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old = old->next;
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}
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new->next = NULL;
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ret->back = new;
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return ret;
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}
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inline struct llist_item * llist_insert(struct llist *list,
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struct llist_item *after, char *sha1)
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{
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struct llist_item *new = xmalloc(sizeof(struct llist_item));
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new->sha1 = sha1;
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new->next = NULL;
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if (after != NULL) {
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new->next = after->next;
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after->next = new;
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if (after == list->back)
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list->back = new;
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} else {/* insert in front */
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if (list->size == 0)
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list->back = new;
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else
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new->next = list->front;
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list->front = new;
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}
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list->size++;
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return new;
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}
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inline struct llist_item * llist_insert_back(struct llist *list, char *sha1)
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{
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return llist_insert(list, list->back, sha1);
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}
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inline struct llist_item * llist_insert_sorted_unique(struct llist *list,
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char *sha1, struct llist_item *hint)
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{
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struct llist_item *prev = NULL, *l;
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l = (hint == NULL) ? list->front : hint;
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while (l) {
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int cmp = memcmp(l->sha1, sha1, 20);
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if (cmp > 0) { /* we insert before this entry */
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return llist_insert(list, prev, sha1);
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}
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if(!cmp) { /* already exists */
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return l;
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}
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prev = l;
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l = l->next;
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}
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/* insert at the end */
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return llist_insert_back(list, sha1);
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}
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/* computes A\B */
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struct llist * llist_sorted_difference(struct llist_item *A,
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struct llist_item *B)
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{
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struct llist *ret;
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llist_init(&ret);
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while (A != NULL && B != NULL) {
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int cmp = memcmp(A->sha1, B->sha1, 20);
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if (!cmp) {
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A = A->next;
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B = B->next;
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continue;
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}
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if(cmp > 0) { /* we'll never find this B */
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B = B->next;
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continue;
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}
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/* A has the object, B doesn't */
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llist_insert_back(ret, A->sha1);
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A = A->next;
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}
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while (A != NULL) {
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llist_insert_back(ret, A->sha1);
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A = A->next;
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}
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return ret;
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}
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/* returns a pointer to an item in front of sha1 */
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inline struct llist_item * llist_sorted_remove(struct llist *list, char *sha1,
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struct llist_item *hint)
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{
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struct llist_item *prev, *l;
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redo_from_start:
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l = (hint == NULL) ? list->front : hint;
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prev = NULL;
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while (l) {
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int cmp = memcmp(l->sha1, sha1, 20);
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if (cmp > 0) /* not in list, since sorted */
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return prev;
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if(!cmp) { /* found */
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if (prev == NULL) {
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if (hint != NULL && hint != list->front) {
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/* we don't know the previous element */
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hint = NULL;
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goto redo_from_start;
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}
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list->front = l->next;
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} else
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prev->next = l->next;
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if (l == list->back)
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list->back = prev;
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free(l);
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list->size--;
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return prev;
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}
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prev = l;
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l = l->next;
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}
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return prev;
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}
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inline struct pack_list * pack_list_insert(struct pack_list **pl,
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struct pack_list *entry)
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{
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struct pack_list *p = xmalloc(sizeof(struct pack_list));
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memcpy(p, entry, sizeof(struct pack_list));
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p->next = *pl;
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*pl = p;
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return p;
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}
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struct pack_list * pack_list_difference(struct pack_list *A,
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struct pack_list *B)
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{
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struct pack_list *ret, *pl;
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if (A == NULL)
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return NULL;
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pl = B;
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while (pl != NULL) {
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if (A->pack == pl->pack)
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return pack_list_difference(A->next, B);
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pl = pl->next;
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}
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ret = xmalloc(sizeof(struct pack_list));
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memcpy(ret, A, sizeof(struct pack_list));
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ret->next = pack_list_difference(A->next, B);
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return ret;
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}
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void cmp_two_packs(struct pack_list *p1, struct pack_list *p2)
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{
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int p1_off, p2_off;
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void *p1_base, *p2_base;
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struct llist_item *p1_hint = NULL, *p2_hint = NULL;
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p1_off = p2_off = 256 * 4 + 4;
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p1_base = (void *)p1->pack->index_base;
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p2_base = (void *)p2->pack->index_base;
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while (p1_off <= p1->pack->index_size - 3 * 20 &&
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p2_off <= p2->pack->index_size - 3 * 20)
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{
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int cmp = memcmp(p1_base + p1_off, p2_base + p2_off, 20);
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/* cmp ~ p1 - p2 */
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if (cmp == 0) {
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p1_hint = llist_sorted_remove(p1->unique_objects,
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p1_base + p1_off, p1_hint);
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p2_hint = llist_sorted_remove(p2->unique_objects,
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p1_base + p1_off, p2_hint);
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p1_off+=24;
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p2_off+=24;
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continue;
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}
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if (cmp < 0) { /* p1 has the object, p2 doesn't */
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p1_off+=24;
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} else { /* p2 has the object, p1 doesn't */
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p2_off+=24;
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}
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}
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}
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/* all the permutations have to be free()d at the same time,
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* since they refer to each other
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*/
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struct pll * get_all_permutations(struct pack_list *list)
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{
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struct pll *subset, *pll, *new_pll = NULL; /*silence warning*/
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if (list == NULL)
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return NULL;
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if (list->next == NULL) {
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new_pll = xmalloc(sizeof(struct pll));
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new_pll->next = NULL;
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new_pll->pl = list;
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return new_pll;
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}
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pll = subset = get_all_permutations(list->next);
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while (pll) {
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new_pll = xmalloc(sizeof(struct pll));
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new_pll->next = pll->next;
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pll->next = new_pll;
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new_pll->pl = xmalloc(sizeof(struct pack_list));
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memcpy(new_pll->pl, list, sizeof(struct pack_list));
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new_pll->pl->next = pll->pl;
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pll = new_pll->next;
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}
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/* add ourself to the end */
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new_pll->next = xmalloc(sizeof(struct pll));
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new_pll->next->pl = xmalloc(sizeof(struct pack_list));
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new_pll->next->next = NULL;
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memcpy(new_pll->next->pl, list, sizeof(struct pack_list));
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new_pll->next->pl->next = NULL;
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return subset;
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}
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int is_superset(struct pack_list *pl, struct llist *list)
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{
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struct llist *diff, *old;
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diff = llist_copy(list);
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while (pl) {
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old = diff;
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diff = llist_sorted_difference(diff->front,
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pl->all_objects->front);
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llist_free(old);
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if (diff->size == 0) { /* we're done */
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llist_free(diff);
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return 1;
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}
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pl = pl->next;
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}
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llist_free(diff);
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return 0;
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}
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size_t sizeof_union(struct packed_git *p1, struct packed_git *p2)
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{
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size_t ret = 0;
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int p1_off, p2_off;
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void *p1_base, *p2_base;
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p1_off = p2_off = 256 * 4 + 4;
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p1_base = (void *)p1->index_base;
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p2_base = (void *)p2->index_base;
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while (p1_off <= p1->index_size - 3 * 20 &&
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p2_off <= p2->index_size - 3 * 20)
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{
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int cmp = memcmp(p1_base + p1_off, p2_base + p2_off, 20);
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/* cmp ~ p1 - p2 */
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if (cmp == 0) {
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ret++;
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p1_off+=24;
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p2_off+=24;
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continue;
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}
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if (cmp < 0) { /* p1 has the object, p2 doesn't */
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p1_off+=24;
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} else { /* p2 has the object, p1 doesn't */
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p2_off+=24;
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}
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}
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return ret;
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}
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/* another O(n^2) function ... */
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size_t get_pack_redundancy(struct pack_list *pl)
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{
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struct pack_list *subset;
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size_t ret = 0;
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while ((subset = pl->next)) {
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while(subset) {
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ret += sizeof_union(pl->pack, subset->pack);
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subset = subset->next;
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}
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pl = pl->next;
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}
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return ret;
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}
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inline size_t pack_set_bytecount(struct pack_list *pl)
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{
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size_t ret = 0;
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while (pl) {
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ret += pl->pack->pack_size;
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ret += pl->pack->index_size;
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pl = pl->next;
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}
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return ret;
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}
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void minimize(struct pack_list **min)
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{
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struct pack_list *pl, *unique = NULL,
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*non_unique = NULL, *min_perm = NULL;
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struct pll *perm, *perm_all, *perm_ok = NULL, *new_perm;
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struct llist *missing, *old;
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size_t min_perm_size = (size_t)-1, perm_size;
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pl = pack_list;
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while (pl) {
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if(pl->unique_objects->size)
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pack_list_insert(&unique, pl);
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else
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pack_list_insert(&non_unique, pl);
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pl = pl->next;
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}
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/* find out which objects are missing from the set of unique packs */
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missing = llist_copy(all_objects);
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pl = unique;
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while (pl) {
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old = missing;
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missing = llist_sorted_difference(missing->front,
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pl->all_objects->front);
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llist_free(old);
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pl = pl->next;
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}
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if (missing->size == 0) {
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*min = unique;
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return;
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}
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/* find the permutations which contain all missing objects */
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perm_all = perm = get_all_permutations(non_unique);
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while (perm) {
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if (is_superset(perm->pl, missing)) {
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new_perm = xmalloc(sizeof(struct pll));
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new_perm->pl = perm->pl;
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new_perm->next = perm_ok;
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perm_ok = new_perm;
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}
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perm = perm->next;
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}
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if (perm_ok == NULL)
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die("Internal error: No complete sets found!\n");
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/* find the permutation with the smallest size */
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perm = perm_ok;
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while (perm) {
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perm_size = pack_set_bytecount(perm->pl);
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if (min_perm_size > perm_size) {
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min_perm_size = perm_size;
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min_perm = perm->pl;
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}
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perm = perm->next;
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}
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*min = min_perm;
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/* add the unique packs to the list */
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pl = unique;
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while(pl) {
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pack_list_insert(min, pl);
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pl = pl->next;
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}
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}
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void load_all_objects()
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{
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struct pack_list *pl = pack_list;
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struct llist_item *hint, *l;
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int i;
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llist_init(&all_objects);
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while (pl) {
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i = 0;
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hint = NULL;
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l = pl->all_objects->front;
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while (l) {
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hint = llist_insert_sorted_unique(all_objects,
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l->sha1, hint);
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l = l->next;
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}
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pl = pl->next;
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}
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}
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/* this scales like O(n^2) */
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void cmp_packs()
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{
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struct pack_list *subset, *curr = pack_list;
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while ((subset = curr)) {
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while((subset = subset->next))
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cmp_two_packs(curr, subset);
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curr = curr->next;
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}
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}
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struct pack_list * add_pack(struct packed_git *p)
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{
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struct pack_list l;
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size_t off;
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void *base;
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l.pack = p;
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llist_init(&l.all_objects);
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off = 256 * 4 + 4;
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base = (void *)p->index_base;
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while (off <= p->index_size - 3 * 20) {
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llist_insert_back(l.all_objects, base + off);
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off+=24;
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}
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/* this list will be pruned in cmp_two_packs later */
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l.unique_objects = llist_copy(l.all_objects);
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return pack_list_insert(&pack_list, &l);
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}
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struct pack_list * add_pack_file(char *filename)
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{
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struct packed_git *p = packed_git;
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if (strlen(filename) < 40)
|
||||
die("Bad pack filename: %s\n", filename);
|
||||
|
||||
while (p) {
|
||||
if (strstr(p->pack_name, filename))
|
||||
/* this will silently ignore packs in alt-odb */
|
||||
return add_pack(p);
|
||||
p = p->next;
|
||||
}
|
||||
die("Filename %s not found in packed_git\n", filename);
|
||||
}
|
||||
|
||||
void load_all()
|
||||
{
|
||||
struct packed_git *p = packed_git;
|
||||
|
||||
while (p) {
|
||||
if (p->pack_local) /* ignore alt-odb for now */
|
||||
add_pack(p);
|
||||
p = p->next;
|
||||
}
|
||||
}
|
||||
|
||||
int main(int argc, char **argv)
|
||||
{
|
||||
int i;
|
||||
struct pack_list *min, *red, *pl;
|
||||
|
||||
for (i = 1; i < argc; i++) {
|
||||
const char *arg = argv[i];
|
||||
if(!strcmp(arg, "--"))
|
||||
break;
|
||||
if(!strcmp(arg, "-a")) {
|
||||
all = 1;
|
||||
continue;
|
||||
}
|
||||
if(!strcmp(arg, "-v")) {
|
||||
verbose = 1;
|
||||
continue;
|
||||
}
|
||||
if(*arg == '-')
|
||||
usage(pack_intersect_usage);
|
||||
else
|
||||
break;
|
||||
}
|
||||
|
||||
prepare_packed_git();
|
||||
|
||||
if(all)
|
||||
load_all();
|
||||
else
|
||||
while (*(argv + i) != NULL)
|
||||
add_pack_file(*(argv + i++));
|
||||
|
||||
if (pack_list == NULL)
|
||||
die("Zero packs found!\n");
|
||||
|
||||
cmp_packs();
|
||||
|
||||
load_all_objects();
|
||||
|
||||
minimize(&min);
|
||||
if (verbose) {
|
||||
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 %ld duplicate objects "
|
||||
"with a total size of %ldkb.\n",
|
||||
get_pack_redundancy(min), pack_set_bytecount(min)/1024);
|
||||
fprintf(stderr, "Redundant packs (with indexes):\n");
|
||||
}
|
||||
pl = red = pack_list_difference(pack_list, min);
|
||||
while (pl) {
|
||||
printf("%s\n%s\n",
|
||||
sha1_pack_index_name(pl->pack->sha1), pl->pack->pack_name);
|
||||
pl = pl->next;
|
||||
}
|
||||
|
||||
return 0;
|
||||
}
|
||||
@ -424,6 +424,7 @@ struct packed_git *add_packed_git(char *path, int path_len, int local)
|
||||
struct packed_git *p;
|
||||
unsigned long idx_size;
|
||||
void *idx_map;
|
||||
char sha1[20];
|
||||
|
||||
if (check_packed_git_idx(path, &idx_size, &idx_map))
|
||||
return NULL;
|
||||
@ -447,6 +448,8 @@ struct packed_git *add_packed_git(char *path, int path_len, int local)
|
||||
p->pack_last_used = 0;
|
||||
p->pack_use_cnt = 0;
|
||||
p->pack_local = local;
|
||||
if (!get_sha1_hex(path + path_len - 40 - 4, sha1))
|
||||
memcpy(p->sha1, sha1, 20);
|
||||
return p;
|
||||
}
|
||||
|
||||
|
||||
Loading…
Reference in New Issue
Block a user