pack-objects: match prune logic for discarding objects

diff --git a/builtin/pack-objects.c b/builtin/pack-objects.c
index 7950c4342f81544f719b20add2e1233be36fc718..4df9499040d4b740906f3a74c0217295371c4272 100644 (file)
--- a/builtin/pack-objects.c
+++ b/builtin/pack-objects.c
@@ -20,6 +20,8 @@
 #include "streaming.h"
 #include "thread-utils.h"
 #include "pack-bitmap.h"
+#include "reachable.h"
+#include "sha1-array.h"
 
 static const char *pack_usage[] = {
        N_("git pack-objects --stdout [options...] [< ref-list | < object-list]"),
@@ -89,8 +91,7 @@ static void index_commit_for_bitmap(struct commit *commit)
 {
        if (indexed_commits_nr >= indexed_commits_alloc) {
                indexed_commits_alloc = (indexed_commits_alloc + 32) * 2;
-               indexed_commits = xrealloc(indexed_commits,
-                       indexed_commits_alloc * sizeof(struct commit *));
+               REALLOC_ARRAY(indexed_commits, indexed_commits_alloc);
        }
 
        indexed_commits[indexed_commits_nr++] = commit;
@@ -1076,7 +1077,7 @@ static int pbase_tree_cache_ix_incr(int ix)
 static struct pbase_tree {
        struct pbase_tree *next;
        /* This is a phony "cache" entry; we are not
-        * going to evict it nor find it through _get()
+        * going to evict it or find it through _get()
         * mechanism -- this is for the toplevel node that
         * would almost always change with any commit.
         */
@@ -2214,10 +2215,6 @@ static int git_pack_config(const char *k, const char *v, void *cb)
                cache_max_small_delta_size = git_config_int(k, v);
                return 0;
        }
-       if (!strcmp(k, "pack.writebitmaps")) {
-               write_bitmap_index = git_config_bool(k, v);
-               return 0;
-       }
        if (!strcmp(k, "pack.writebitmaphashcache")) {
                if (git_config_bool(k, v))
                        write_bitmap_options |= BITMAP_OPT_HASH_CACHE;
@@ -2412,6 +2409,27 @@ static int has_sha1_pack_kept_or_nonlocal(const unsigned char *sha1)
        return 0;
 }
 
+/*
+ * Store a list of sha1s that are should not be discarded
+ * because they are either written too recently, or are
+ * reachable from another object that was.
+ *
+ * This is filled by get_object_list.
+ */
+static struct sha1_array recent_objects;
+
+static int loosened_object_can_be_discarded(const unsigned char *sha1,
+                                           unsigned long mtime)
+{
+       if (!unpack_unreachable_expiration)
+               return 0;
+       if (mtime > unpack_unreachable_expiration)
+               return 0;
+       if (sha1_array_lookup(&recent_objects, sha1) >= 0)
+               return 0;
+       return 1;
+}
+
 static void loosen_unused_packed_objects(struct rev_info *revs)
 {
        struct packed_git *p;
@@ -2422,29 +2440,37 @@ static void loosen_unused_packed_objects(struct rev_info *revs)
                if (!p->pack_local || p->pack_keep)
                        continue;
 
-               if (unpack_unreachable_expiration &&
-                   p->mtime < unpack_unreachable_expiration)
-                       continue;
-
                if (open_pack_index(p))
                        die("cannot open pack index");
 
                for (i = 0; i < p->num_objects; i++) {
                        sha1 = nth_packed_object_sha1(p, i);
                        if (!packlist_find(&to_pack, sha1, NULL) &&
-                               !has_sha1_pack_kept_or_nonlocal(sha1))
+                           !has_sha1_pack_kept_or_nonlocal(sha1) &&
+                           !loosened_object_can_be_discarded(sha1, p->mtime))
                                if (force_object_loose(sha1, p->mtime))
                                        die("unable to force loose object");
                }
        }
 }
 
+/*
+ * This tracks any options which a reader of the pack might
+ * not understand, and which would therefore prevent blind reuse
+ * of what we have on disk.
+ */
+static int pack_options_allow_reuse(void)
+{
+       return allow_ofs_delta;
+}
+
 static int get_object_list_from_bitmap(struct rev_info *revs)
 {
        if (prepare_bitmap_walk(revs) < 0)
                return -1;
 
-       if (!reuse_partial_packfile_from_bitmap(
+       if (pack_options_allow_reuse() &&
+           !reuse_partial_packfile_from_bitmap(
                        &reuse_packfile,
                        &reuse_packfile_objects,
                        &reuse_packfile_offset)) {
@@ -2457,6 +2483,19 @@ static int get_object_list_from_bitmap(struct rev_info *revs)
        return 0;
 }
 
+static void record_recent_object(struct object *obj,
+                                const struct name_path *path,
+                                const char *last,
+                                void *data)
+{
+       sha1_array_append(&recent_objects, obj->sha1);
+}
+
+static void record_recent_commit(struct commit *commit, void *data)
+{
+       sha1_array_append(&recent_objects, commit->object.sha1);
+}
+
 static void get_object_list(int ac, const char **av)
 {
        struct rev_info revs;
@@ -2487,6 +2526,7 @@ static void get_object_list(int ac, const char **av)
                                if (get_sha1_hex(line + 10, sha1))
                                        die("not an SHA-1 '%s'", line + 10);
                                register_shallow(sha1);
+                               use_bitmap_index = 0;
                                continue;
                        }
                        die("not a rev '%s'", line);
@@ -2503,10 +2543,23 @@ static void get_object_list(int ac, const char **av)
        mark_edges_uninteresting(&revs, show_edge);
        traverse_commit_list(&revs, show_commit, show_object, NULL);
 
+       if (unpack_unreachable_expiration) {
+               revs.ignore_missing_links = 1;
+               if (add_unseen_recent_objects_to_traversal(&revs,
+                               unpack_unreachable_expiration))
+                       die("unable to add recent objects");
+               if (prepare_revision_walk(&revs))
+                       die("revision walk setup failed");
+               traverse_commit_list(&revs, record_recent_commit,
+                                    record_recent_object, NULL);
+       }
+
        if (keep_unreachable)
                add_objects_in_unpacked_packs(&revs);
        if (unpack_unreachable)
                loosen_unused_packed_objects(&revs);
+
+       sha1_array_clear(&recent_objects);
 }
 
 static int option_parse_index_version(const struct option *opt,