pack-objects: match prune logic for discarding objects

A recent commit taught git-prune to keep non-recent objects
that are reachable from recent ones. However, pack-objects,
when loosening unreachable objects, tries to optimize out
the write in the case that the object will be immediately
pruned. It now gets this wrong, since its rule does not
reflect the new prune code (and this can be seen by running
t6501 with a strategically placed repack).

Let's teach pack-objects similar logic.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/pack-objects.c b/builtin/pack-objects.c
index 2fe2ab0603d6b0a426e6ba8a9f1f559665ecd07f..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 "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]"),
 
 static const char *pack_usage[] = {
        N_("git pack-objects --stdout [options...] [< ref-list | < object-list]"),


@@ -2407,6 +2409,15 @@ static int has_sha1_pack_kept_or_nonlocal(const unsigned char *sha1)
        return 0;
 }
 
        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)
 {
 static int loosened_object_can_be_discarded(const unsigned char *sha1,
                                            unsigned long mtime)
 {


@@ -2414,6 +2425,8 @@ static int loosened_object_can_be_discarded(const unsigned char *sha1,
                return 0;
        if (mtime > unpack_unreachable_expiration)
                return 0;
                return 0;
        if (mtime > unpack_unreachable_expiration)
                return 0;

+       if (sha1_array_lookup(&recent_objects, sha1) >= 0)
+               return 0;

        return 1;
 }
 
        return 1;
 }
 


@@ -2470,6 +2483,19 @@ static int get_object_list_from_bitmap(struct rev_info *revs)
        return 0;
 }
 
        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;
 static void get_object_list(int ac, const char **av)
 {
        struct rev_info revs;


@@ -2517,10 +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);
 
        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);
        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,
 }
 
 static int option_parse_index_version(const struct option *opt,

diff --git a/reachable.c b/reachable.c
index 55589a02eb86590a399082742673b51b559f1651..0176a88b816ec76ccd6a6b0faf3f026132d8ae21 100644 (file)
--- a/reachable.c
+++ b/reachable.c
@@ -183,8 +183,8 @@ static int add_recent_packed(const unsigned char *sha1,
        return 0;
 }
 
        return 0;
 }
 

-static int add_unseen_recent_objects_to_traversal(struct rev_info *revs,
-                                                 unsigned long timestamp)
+int add_unseen_recent_objects_to_traversal(struct rev_info *revs,
+                                          unsigned long timestamp)

 {
        struct recent_data data;
        int r;
 {
        struct recent_data data;
        int r;

diff --git a/reachable.h b/reachable.h
index 141fe308790eddfda3e731453dd92e2eb8ef0c01..d23efc36ec5f198b9edab76f2aadff9461b83f45 100644 (file)
--- a/reachable.h
+++ b/reachable.h
@@ -2,6 +2,8 @@
 #define REACHEABLE_H
 
 struct progress;
 #define REACHEABLE_H
 
 struct progress;

+extern int add_unseen_recent_objects_to_traversal(struct rev_info *revs,
+                                                 unsigned long timestamp);

 extern void mark_reachable_objects(struct rev_info *revs, int mark_reflog,
                                   unsigned long mark_recent, struct progress *);
 
 extern void mark_reachable_objects(struct rev_info *revs, int mark_reflog,
                                   unsigned long mark_recent, struct progress *);
 

diff --git a/t/t6501-freshen-objects.sh b/t/t6501-freshen-objects.sh
index de941c2cb2211f01a06c5a6dcc60fbefd65f6c7c..e25c47dd5cd9dde18a6cba978f01fee61f994f57 100755 (executable)
--- a/t/t6501-freshen-objects.sh
+++ b/t/t6501-freshen-objects.sh
@@ -39,50 +39,67 @@ commit () {
        git commit -m "$1"
 }
 
        git commit -m "$1"
 }
 

-test_expect_success 'disable reflogs' '
-       git config core.logallrefupdates false &&
-       rm -rf .git/logs
-'
+maybe_repack () {
+       if test -n "$repack"; then
+               git repack -ad
+       fi
+}
+
+for repack in '' true; do
+       title=${repack:+repack}
+       title=${title:-loose}
+
+       test_expect_success "make repo completely empty ($title)" '
+               rm -rf .git &&
+               git init
+       '
+
+       test_expect_success "disable reflogs ($title)" '
+               git config core.logallrefupdates false &&
+               rm -rf .git/logs
+       '

 
 

-test_expect_success 'setup basic history' '
-       commit base
-'
+       test_expect_success "setup basic history ($title)" '
+               commit base
+       '

 
 

-test_expect_success 'create and abandon some objects' '
-       git checkout -b experiment &&
-       commit abandon &&
-       git checkout master &&
-       git branch -D experiment
-'
+       test_expect_success "create and abandon some objects ($title)" '
+               git checkout -b experiment &&
+               commit abandon &&
+               maybe_repack &&
+               git checkout master &&
+               git branch -D experiment
+       '

 
 

-test_expect_success 'simulate time passing' '
-       find .git/objects -type f |
-       xargs test-chmtime -v -86400
-'
+       test_expect_success "simulate time passing ($title)" '
+               find .git/objects -type f |
+               xargs test-chmtime -v -86400
+       '

 
 

-test_expect_success 'start writing new commit with old blob' '
-       tree=$(
-               GIT_INDEX_FILE=index.tmp &&
-               export GIT_INDEX_FILE &&
-               git read-tree HEAD &&
-               add unrelated &&
-               add abandon &&
-               git write-tree
-       )
-'
+       test_expect_success "start writing new commit with old blob ($title)" '
+               tree=$(
+                       GIT_INDEX_FILE=index.tmp &&
+                       export GIT_INDEX_FILE &&
+                       git read-tree HEAD &&
+                       add unrelated &&
+                       add abandon &&
+                       git write-tree
+               )
+       '

 
 

-test_expect_success 'simultaneous gc' '
-       git gc --prune=12.hours.ago
-'
+       test_expect_success "simultaneous gc ($title)" '
+               git gc --prune=12.hours.ago
+       '

 
 

-test_expect_success 'finish writing out commit' '
-       commit=$(echo foo | git commit-tree -p HEAD $tree) &&
-       git update-ref HEAD $commit
-'
+       test_expect_success "finish writing out commit ($title)" '
+               commit=$(echo foo | git commit-tree -p HEAD $tree) &&
+               git update-ref HEAD $commit
+       '

 
 

-# "abandon" blob should have been rescued by reference from new tree
-test_expect_success 'repository passes fsck' '
-       git fsck
-'
+       # "abandon" blob should have been rescued by reference from new tree
+       test_expect_success "repository passes fsck ($title)" '
+               git fsck
+       '
+done

 
 test_done
 
 test_done