@matheusbsbs / matheus-bagliano / commits / c0a5423b6f

rerere: delay the recording of preimage

We record the preimage only when there is no directory to record the conflict we encountered, i.e. when $GIT_DIR/rr-cache/$ID does not exist. As the plan is to allow multiple <preimage,postimage> pairs as variants for the same conflict ID eventually, this logic needs to go. As the first step in that direction, stop the "did we create the directory? Then we record the preimage" logic. Instead, we record if a preimage does not exist when we saw a conflict in a path. Also make sure that we remove a stale postimage, which most likely is totally unrelated to the resolution of this new conflict, when we create a new preimage under $ID when $GIT_DIR/rr-cache/$ID already exists. In later patches, we will further update this logic to be "do we have <preimage,postimage> pair that cleanly resolve the current conflicts? If not, record a new preimage as a new variant", but that does not happen at this stage yet. Signed-off-by: Junio C Hamano <gitster@pobox.com>

Junio C Hamano committed Jul 20, 2015 at 15:19 UTC c0a5423b6f09f0c08749697b8d2860f956e905e9
1 file changed +25 -27
rerere.c
+25 -27
@@ -122,6 +122,11 @@ static int has_rerere_resolution(const struct rerere_id *id)
122 return ((id->collection->status & both) == both);
123 }
124
125 +static int has_rerere_preimage(const struct rerere_id *id)
126 +{
127 + return (id->collection->status & RR_HAS_PREIMAGE);
128 +}
129 +
130 static struct rerere_id *new_rerere_id_hex(char *hex)
131 {
132 struct rerere_id *id = xmalloc(sizeof(*id));
@@ -749,8 +754,24 @@ static void do_rerere_one_path(struct string_list_item *rr_item,
754 const char *path = rr_item->string;
755 const struct rerere_id *id = rr_item->util;
756
752 - /* Is there a recorded resolution we could attempt to apply? */
753 - if (has_rerere_resolution(id)) {
757 + if (!has_rerere_preimage(id)) {
758 + /*
759 + * We are the first to encounter this conflict. Ask
760 + * handle_file() to write the normalized contents to
761 + * the "preimage" file.
762 + */
763 + handle_file(path, NULL, rerere_path(id, "preimage"));
764 + if (id->collection->status & RR_HAS_POSTIMAGE) {
765 + const char *path = rerere_path(id, "postimage");
766 + if (unlink(path))
767 + die_errno("cannot unlink stray '%s'", path);
768 + id->collection->status &= ~RR_HAS_POSTIMAGE;
769 + }
770 + id->collection->status |= RR_HAS_PREIMAGE;
771 + fprintf(stderr, "Recorded preimage for '%s'\n", path);
772 + return;
773 + } else if (has_rerere_resolution(id)) {
774 + /* Is there a recorded resolution we could attempt to apply? */
775 if (merge(id, path))
776 return; /* failed to replay */
777
@@ -807,31 +828,8 @@ static int do_plain_rerere(struct string_list *rr, int fd)
828 id = new_rerere_id(sha1);
829 string_list_insert(rr, path)->util = id;
830
810 - /*
811 - * Ensure that the directory exists.
812 - * mkdir_in_gitdir() will fail with EEXIST if there
813 - * already is one.
814 - */
815 - if (mkdir_in_gitdir(rerere_path(id, NULL)) &&
816 - errno != EEXIST)
817 - continue; /* NEEDSWORK: perhaps we should die? */
818 -
819 - if (id->collection->status & RR_HAS_PREIMAGE) {
820 - ;
821 - } else {
822 - /*
823 - * We are the first to encounter this
824 - * conflict. Ask handle_file() to write the
825 - * normalized contents to the "preimage" file.
826 - *
827 - * NEEDSWORK: what should happen if we had a
828 - * leftover postimage that is totally
829 - * unrelated? Perhaps we should unlink it?
830 - */
831 - handle_file(path, NULL, rerere_path(id, "preimage"));
832 - id->collection->status |= RR_HAS_PREIMAGE;
833 - fprintf(stderr, "Recorded preimage for '%s'\n", path);
834 - }
831 + /* Ensure that the directory exists. */
832 + mkdir_in_gitdir(rerere_path(id, NULL));
833 }
834
835 for (i = 0; i < rr->nr; i++)