pack-objects --keep-unreachable

This new option is meant to be used in conjunction with the
options "git repack -a -d" usually invokes the underlying
pack-objects with.  When this option is given, objects unreachable
from the refs in packs named with --unpacked= option are added
to the resulting pack, in addition to the reachable objects that
are not in packs marked with *.keep files.

Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin-pack-objects.c b/builtin-pack-objects.c
index 12509faa777bb2903e98c79a98be151380911b87..ba7c8da5bf0b91c5ddab3fa692ca49d025d85e29 100644 (file)
--- a/builtin-pack-objects.c
+++ b/builtin-pack-objects.c
@@ -21,7 +21,7 @@ git-pack-objects [{ -q | --progress | --all-progress }] \n\
        [--window=N] [--window-memory=N] [--depth=N] \n\
        [--no-reuse-delta] [--no-reuse-object] [--delta-base-offset] \n\
        [--non-empty] [--revs [--unpacked | --all]*] [--reflog] \n\
-       [--stdout | base-name] [<ref-list | <object-list]";
+       [--stdout | base-name] [--keep-unreachable] [<ref-list | <object-list]";
 
 struct object_entry {
        struct pack_idx_entry idx;
@@ -57,7 +57,7 @@ static struct object_entry **written_list;
 static uint32_t nr_objects, nr_alloc, nr_result, nr_written;
 
 static int non_empty;
-static int no_reuse_delta, no_reuse_object;
+static int no_reuse_delta, no_reuse_object, keep_unreachable;
 static int local;
 static int incremental;
 static int allow_ofs_delta;
@@ -1625,15 +1625,19 @@ static void read_object_list_from_stdin(void)
        }
 }
 
+#define OBJECT_ADDED (1u<<20)
+
 static void show_commit(struct commit *commit)
 {
        add_object_entry(commit->object.sha1, OBJ_COMMIT, NULL, 0);
+       commit->object.flags |= OBJECT_ADDED;
 }
 
 static void show_object(struct object_array_entry *p)
 {
        add_preferred_base_object(p->name);
        add_object_entry(p->item->sha1, p->item->type, p->name, 0);
+       p->item->flags |= OBJECT_ADDED;
 }
 
 static void show_edge(struct commit *commit)
@@ -1641,6 +1645,86 @@ static void show_edge(struct commit *commit)
        add_preferred_base(commit->object.sha1);
 }
 
+struct in_pack_object {
+       off_t offset;
+       struct object *object;
+};
+
+struct in_pack {
+       int alloc;
+       int nr;
+       struct in_pack_object *array;
+};
+
+static void mark_in_pack_object(struct object *object, struct packed_git *p, struct in_pack *in_pack)
+{
+       in_pack->array[in_pack->nr].offset = find_pack_entry_one(object->sha1, p);
+       in_pack->array[in_pack->nr].object = object;
+       in_pack->nr++;
+}
+
+/*
+ * Compare the objects in the offset order, in order to emulate the
+ * "git-rev-list --objects" output that produced the pack originally.
+ */
+static int ofscmp(const void *a_, const void *b_)
+{
+       struct in_pack_object *a = (struct in_pack_object *)a_;
+       struct in_pack_object *b = (struct in_pack_object *)b_;
+
+       if (a->offset < b->offset)
+               return -1;
+       else if (a->offset > b->offset)
+               return 1;
+       else
+               return hashcmp(a->object->sha1, b->object->sha1);
+}
+
+static void add_objects_in_unpacked_packs(struct rev_info *revs)
+{
+       struct packed_git *p;
+       struct in_pack in_pack;
+       uint32_t i;
+
+       memset(&in_pack, 0, sizeof(in_pack));
+
+       for (p = packed_git; p; p = p->next) {
+               const unsigned char *sha1;
+               struct object *o;
+
+               for (i = 0; i < revs->num_ignore_packed; i++) {
+                       if (matches_pack_name(p, revs->ignore_packed[i]))
+                               break;
+               }
+               if (revs->num_ignore_packed <= i)
+                       continue;
+               if (open_pack_index(p))
+                       die("cannot open pack index");
+
+               ALLOC_GROW(in_pack.array,
+                          in_pack.nr + p->num_objects,
+                          in_pack.alloc);
+
+               for (i = 0; i < p->num_objects; i++) {
+                       sha1 = nth_packed_object_sha1(p, i);
+                       o = lookup_unknown_object(sha1);
+                       if (!(o->flags & OBJECT_ADDED))
+                               mark_in_pack_object(o, p, &in_pack);
+                       o->flags |= OBJECT_ADDED;
+               }
+       }
+
+       if (in_pack.nr) {
+               qsort(in_pack.array, in_pack.nr, sizeof(in_pack.array[0]),
+                     ofscmp);
+               for (i = 0; i < in_pack.nr; i++) {
+                       struct object *o = in_pack.array[i].object;
+                       add_object_entry(o->sha1, o->type, "", 0);
+               }
+       }
+       free(in_pack.array);
+}
+
 static void get_object_list(int ac, const char **av)
 {
        struct rev_info revs;
@@ -1672,6 +1756,9 @@ static void get_object_list(int ac, const char **av)
        prepare_revision_walk(&revs);
        mark_edges_uninteresting(revs.commits, &revs, show_edge);
        traverse_commit_list(&revs, show_commit, show_object);
+
+       if (keep_unreachable)
+               add_objects_in_unpacked_packs(&revs);
 }
 
 static int adjust_perm(const char *path, mode_t mode)
@@ -1789,6 +1876,10 @@ int cmd_pack_objects(int argc, const char **argv, const char *prefix)
                        use_internal_rev_list = 1;
                        continue;
                }
+               if (!strcmp("--keep-unreachable", arg)) {
+                       keep_unreachable = 1;
+                       continue;
+               }
                if (!strcmp("--unpacked", arg) ||
                    !prefixcmp(arg, "--unpacked=") ||
                    !strcmp("--reflog", arg) ||