pack-objects: allow setting `pack.allowPackReuse` to "single"

In e704fc7978 (pack-objects: introduce pack.allowPackReuse, 2019-12-18),
the `pack.allowPackReuse` configuration option was introduced, allowing
users to disable the pack reuse mechanism.

To prepare for debugging multi-pack reuse, allow setting configuration
to "single" in addition to the usual bool-or-int values.

"single" implies the same behavior as "true", "1", "yes", and so on. But
it will complement a new "multi" value (to be introduced in a future
commit). When set to "single", we will only perform pack reuse on a
single pack, regardless of whether or not there are multiple MIDX'd
packs.

This requires no code changes (yet), since we only support single pack
reuse.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/Documentation/config/pack.txt b/Documentation/config/pack.txt
index f50df9dbce89891f0c6d4a5563c5ab73be4325df..fe100d0fb79df39d76ab5f070ed93f7d54b6355f 100644 (file)
--- a/Documentation/config/pack.txt
+++ b/Documentation/config/pack.txt
@@ -28,7 +28,7 @@ all existing objects. You can force recompression by passing the -F option
 to linkgit:git-repack[1].
 
 pack.allowPackReuse::
-       When true, and when reachability bitmaps are enabled,
+       When true or "single", and when reachability bitmaps are enabled,
        pack-objects will try to send parts of the bitmapped packfile
        verbatim. This can reduce memory and CPU usage to serve fetches,
        but might result in sending a slightly larger pack. Defaults to

diff --git a/builtin/pack-objects.c b/builtin/pack-objects.c
index 7aae9f104bff7534cbc8451c1bc7ece36f23d99f..684698f67968706495e7227fcd8fda6576958062 100644 (file)
--- a/builtin/pack-objects.c
+++ b/builtin/pack-objects.c
@@ -229,7 +229,10 @@ static struct bitmap *reuse_packfile_bitmap;
 
 static int use_bitmap_index_default = 1;
 static int use_bitmap_index = -1;
-static int allow_pack_reuse = 1;
+static enum {
+       NO_PACK_REUSE = 0,
+       SINGLE_PACK_REUSE,
+} allow_pack_reuse = SINGLE_PACK_REUSE;
 static enum {
        WRITE_BITMAP_FALSE = 0,
        WRITE_BITMAP_QUIET,
@@ -3244,7 +3247,17 @@ static int git_pack_config(const char *k, const char *v,
                return 0;
        }
        if (!strcmp(k, "pack.allowpackreuse")) {
-               allow_pack_reuse = git_config_bool(k, v);
+               int res = git_parse_maybe_bool_text(v);
+               if (res < 0) {
+                       if (!strcasecmp(v, "single"))
+                               allow_pack_reuse = SINGLE_PACK_REUSE;
+                       else
+                               die(_("invalid pack.allowPackReuse value: '%s'"), v);
+               } else if (res) {
+                       allow_pack_reuse = SINGLE_PACK_REUSE;
+               } else {
+                       allow_pack_reuse = NO_PACK_REUSE;
+               }
                return 0;
        }
        if (!strcmp(k, "pack.threads")) {
@@ -3999,7 +4012,7 @@ static void loosen_unused_packed_objects(void)
  */
 static int pack_options_allow_reuse(void)
 {
-       return allow_pack_reuse &&
+       return allow_pack_reuse != NO_PACK_REUSE &&
               pack_to_stdout &&
               !ignore_packed_keep_on_disk &&
               !ignore_packed_keep_in_core &&