Make git-pack-redundant consider alt-odbs

This patch changes git-pack-redundant so that packfiles
in alternate object directories also are considered when
deciding which objects are redundant.

This functionality is controlled by the flag '--alt-odb'.

Also convert the other flags to the long form, and update
docs and git-repack accordingly.

Signed-off-by: Lukas Sandström <lukass@etek.chalmers.se>
Signed-off-by: Junio C Hamano <junkio@cox.net>

diff --git a/Documentation/git-pack-redundant.txt b/Documentation/git-pack-redundant.txt
index 55c0d48..5ba9272 100644 (file)
--- a/Documentation/git-pack-redundant.txt
+++ b/Documentation/git-pack-redundant.txt
@@ -8,7 +8,7 @@ git-pack-redundant - Program used to find redundant pack files.
 
 SYNOPSIS
 --------
-'git-pack-redundant [ -v ] < -a | .pack filename ... >'
+'git-pack-redundant [ --verbose ] [ --alt-odb ] < --all | .pack filename ... >'
 
 DESCRIPTION
 -----------
@@ -19,13 +19,16 @@ are redundant. The output is suitable for piping to
 OPTIONS
 -------
 
--v::
-       Verbose. Outputs some statistics to stderr.
-       Has a small performance penalty.
 
--a::
-       All. Processes all the local packs. Any filenames on
-       the commandline are ignored.
+--all::
+       Processes all packs. Any filenames on the commandline are ignored.
+
+--alt-odb::
+       Don't require objects present in packs from alternate object
+       directories to be present in local packs.
+
+--verbose::
+       Outputs some statistics to stderr. Has a small performance penalty.
 
 Author
 ------

diff --git a/git-repack.sh b/git-repack.sh
index 4ce0022..f347207 100755 (executable)
--- a/git-repack.sh
+++ b/git-repack.sh
@@ -45,7 +45,7 @@ if [ -z "$name" ]; then
        if test "$remove_redandant" = t ; then
                echo "Removing redundant packs."
                sync
-               redundant=$(git-pack-redundant -a)
+               redundant=$(git-pack-redundant --all)
                if test "$redundant" != "" ; then
                        echo $redundant | xargs rm
                fi
@@ -63,7 +63,7 @@ exit
 if test "$remove_redandant" = t
 then
        sync
-       redundant=$(git-pack-redundant -a)
+       redundant=$(git-pack-redundant --all)
        if test "$redundant" != "" ; then
                echo $redundant | xargs rm
        fi

diff --git a/pack-redundant.c b/pack-redundant.c
index db3dcde..1f8c577 100644 (file)
--- a/pack-redundant.c
+++ b/pack-redundant.c
@@ -9,9 +9,9 @@
 #include "cache.h"
 
 static const char pack_redundant_usage[] =
-"git-pack-redundant [ -v ]  < -a | <.pack filename> ...>";
+"git-pack-redundant [ --verbose ] [ --alt-odb ] < --all | <.pack filename> ...>";
 
-int all = 0, verbose = 0;
+int load_all_packs = 0, verbose = 0, alt_odb = 0;
 
 struct llist_item {
        struct llist_item *next;
@@ -21,14 +21,14 @@ struct llist {
        struct llist_item *front;
        struct llist_item *back;
        size_t size;
-} *all_objects;
+} *all_objects; /* all objects which must be present in local packfiles */
 
 struct pack_list {
        struct pack_list *next;
        struct packed_git *pack;
        struct llist *unique_objects;
        struct llist *all_objects;
-} *pack_list;
+} *local_packs = NULL, *altodb_packs = NULL;
 
 struct pll {
        struct pll *next;
@@ -128,32 +128,35 @@ inline struct llist_item * llist_insert_sorted_unique(struct llist *list,
 }
 
 /* computes A\B */
-struct llist * llist_sorted_difference(struct llist_item *A,
-                                      struct llist_item *B)
+void llist_sorted_difference_inplace(struct llist *A,
+                                    struct llist *B)
 {
-       struct llist *ret;
-       llist_init(&ret);
+       struct llist_item *prev, *a, *b, *x;
 
-       while (A != NULL && B != NULL) {
-               int cmp = memcmp(A->sha1, B->sha1, 20);
+       prev = a = A->front;
+       b = B->front;
+
+       while (a != NULL && b != NULL) {
+               int cmp = memcmp(a->sha1, b->sha1, 20);
                if (!cmp) {
-                       A = A->next;
-                       B = B->next;
-                       continue;
-               }
-               if(cmp > 0) { /* we'll never find this B */
-                       B = B->next;
-                       continue;
-               }
-               /* A has the object, B doesn't */
-               llist_insert_back(ret, A->sha1);
-               A = A->next;
-       }
-       while (A != NULL) {
-               llist_insert_back(ret, A->sha1);
-               A = A->next;
+                       x = a;
+                       if (a == A->front)
+                               A->front = a->next;
+                       a = prev->next = a->next;
+
+                       if (a == NULL) /* end of list */
+                               A->back = prev;
+                       A->size--;
+                       free(x);
+                       b = b->next;
+               } else
+                       if (cmp > 0)
+                               b = b->next;
+                       else {
+                               prev = a;
+                               a = a->next;
+                       }
        }
-       return ret;
 }
 
 /* returns a pointer to an item in front of sha1 */
@@ -201,6 +204,16 @@ inline struct pack_list * pack_list_insert(struct pack_list **pl,
        return p;
 }
 
+inline size_t pack_list_size(struct pack_list *pl)
+{
+       size_t ret = 0;
+       while(pl) {
+               ret++;
+               pl = pl->next;
+       }
+       return ret;
+}
+
 struct pack_list * pack_list_difference(struct pack_list *A,
                                        struct pack_list *B)
 {
@@ -294,15 +307,13 @@ struct pll * get_all_permutations(struct pack_list *list)
 
 int is_superset(struct pack_list *pl, struct llist *list)
 {
-       struct llist *diff, *old;
+       struct llist *diff;
 
        diff = llist_copy(list);
 
        while (pl) {
-               old = diff;
-               diff = llist_sorted_difference(diff->front,
-                                              pl->all_objects->front);
-               llist_free(old);
+               llist_sorted_difference_inplace(diff,
+                                               pl->all_objects);
                if (diff->size == 0) { /* we're done */
                        llist_free(diff);
                        return 1;
@@ -347,6 +358,10 @@ size_t sizeof_union(struct packed_git *p1, struct packed_git *p2)
 size_t get_pack_redundancy(struct pack_list *pl)
 {
        struct pack_list *subset;
+
+       if (pl == NULL)
+               return 0;
+
        size_t ret = 0;
        while ((subset = pl->next)) {
                while(subset) {
@@ -374,10 +389,10 @@ 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, *old;
+       struct llist *missing;
        size_t min_perm_size = (size_t)-1, perm_size;
 
-       pl = pack_list;
+       pl = local_packs;
        while (pl) {
                if(pl->unique_objects->size)
                        pack_list_insert(&unique, pl);
@@ -389,13 +404,12 @@ void minimize(struct pack_list **min)
        missing = llist_copy(all_objects);
        pl = unique;
        while (pl) {
-               old = missing;
-               missing = llist_sorted_difference(missing->front,
-                                                 pl->all_objects->front);
-               llist_free(old);
+               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;
@@ -437,7 +451,7 @@ void minimize(struct pack_list **min)
 
 void load_all_objects()
 {
-       struct pack_list *pl = pack_list;
+       struct pack_list *pl = local_packs;
        struct llist_item *hint, *l;
        int i;
 
@@ -454,17 +468,34 @@ void load_all_objects()
                }
                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) */
 void cmp_packs()
 {
-       struct pack_list *subset, *curr = pack_list;
+       struct pack_list *subset, *pl = local_packs;
 
-       while ((subset = curr)) {
+       while ((subset = pl)) {
                while((subset = subset->next))
-                       cmp_two_packs(curr, subset);
-               curr = curr->next;
+                       cmp_two_packs(pl, subset);
+               pl = pl->next;
+       }
+
+       pl = altodb_packs;
+       while (pl) {
+               subset = local_packs;
+               while (subset) {
+                       llist_sorted_difference_inplace(subset->unique_objects,
+                                                       pl->all_objects);
+                       subset = subset->next;
+               }
+               pl = pl->next;
        }
 }
 
@@ -485,7 +516,10 @@ struct pack_list * add_pack(struct packed_git *p)
        }
        /* this list will be pruned in cmp_two_packs later */
        l.unique_objects = llist_copy(l.all_objects);
-       return pack_list_insert(&pack_list, &l);
+       if (p->pack_local)
+               return pack_list_insert(&local_packs, &l);
+       else
+               return alt_odb ? pack_list_insert(&altodb_packs, &l) : NULL;
 }
 
 struct pack_list * add_pack_file(char *filename)
@@ -497,7 +531,6 @@ struct pack_list * add_pack_file(char *filename)
 
        while (p) {
                if (strstr(p->pack_name, filename))
-                       /* this will silently ignore packs in alt-odb */
                        return add_pack(p);
                p = p->next;
        }
@@ -509,8 +542,7 @@ void load_all()
        struct packed_git *p = packed_git;
 
        while (p) {
-               if (p->pack_local) /* ignore alt-odb for now */
-                       add_pack(p);
+               add_pack(p);
                p = p->next;
        }
 }
@@ -526,14 +558,18 @@ int main(int argc, char **argv)
                        i++;
                        break;
                }
-               if(!strcmp(arg, "-a")) {
-                       all = 1;
+               if(!strcmp(arg, "--all")) {
+                       load_all_packs = 1;
                        continue;
                }
-               if(!strcmp(arg, "-v")) {
+               if(!strcmp(arg, "--verbose")) {
                        verbose = 1;
                        continue;
                }
+               if(!strcmp(arg, "--alt-odb")) {
+                       alt_odb = 1;
+                       continue;
+               }
                if(*arg == '-')
                        usage(pack_redundant_usage);
                else
@@ -542,13 +578,13 @@ int main(int argc, char **argv)
 
        prepare_packed_git();
 
-       if(all)
+       if (load_all_packs)
                load_all();
        else
                while (*(argv + i) != NULL)
                        add_pack_file(*(argv + i++));
 
-       if (pack_list == NULL)
+       if (local_packs == NULL)
                die("Zero packs found!\n");
 
        cmp_packs();
@@ -557,6 +593,8 @@ int main(int argc, char **argv)
 
        minimize(&min);
        if (verbose) {
+               fprintf(stderr, "There are %ld packs available in alt-odbs.\n",
+                       pack_list_size(altodb_packs));
                fprintf(stderr, "The smallest (bytewise) set of packs is:\n");
                pl = min;
                while (pl) {
@@ -566,12 +604,15 @@ int main(int argc, char **argv)
                fprintf(stderr, "containing %ld duplicate objects "
                                "with a total size of %ldkb.\n",
                        get_pack_redundancy(min), pack_set_bytecount(min)/1024);
+               fprintf(stderr, "A total of %ld unique objects were considered.\n",
+                       all_objects->size);
                fprintf(stderr, "Redundant packs (with indexes):\n");
        }
-       pl = red = pack_list_difference(pack_list, min);
+       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);
+                      sha1_pack_index_name(pl->pack->sha1),
+                      pl->pack->pack_name);
                pl = pl->next;
        }