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authorJonathan Tan <jonathantanmy@google.com>2019-10-15 00:12:31 (GMT)
committerJunio C Hamano <gitster@pobox.com>2019-10-16 02:07:51 (GMT)
commit5374a290aa56390f9f44547d52f8f30fb2e866aa (patch)
tree046ddf404e5b98365119a7fd12d3cb34a5a35919
parent08da6496b61341ec45eac36afcc8f94242763468 (diff)
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fetch-pack: write fetched refs to .promisor
The specification of promisor packfiles (in partial-clone.txt) states that the .promisor files that accompany packfiles do not matter (just like .keep files), so whenever a packfile is fetched from the promisor remote, Git has been writing empty .promisor files. But these files could contain more useful information. So instead of writing empty files, write the refs fetched to these files. This makes it easier to debug issues with partial clones, as we can identify what refs (and their associated hashes) were fetched at the time the packfile was downloaded, and if necessary, compare those hashes against what the promisor remote reports now. This is implemented by teaching fetch-pack to write its own non-empty .promisor file whenever it knows the name of the pack's lockfile. This covers the case wherein the user runs "git fetch" with an internal protocol or HTTP protocol v2 (fetch_refs_via_pack() in transport.c sets lock_pack) and with HTTP protocol v0/v1 (fetch_git() in remote-curl.c passes "--lock-pack" to "fetch-pack"). Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Acked-by: Josh Steadmon <steadmon@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
-rw-r--r--builtin/repack.c7
-rw-r--r--fetch-pack.c47
-rwxr-xr-xt/t5616-partial-clone.sh8
3 files changed, 58 insertions, 4 deletions
diff --git a/builtin/repack.c b/builtin/repack.c
index 094c2f8..78b23d7 100644
--- a/builtin/repack.c
+++ b/builtin/repack.c
@@ -233,6 +233,13 @@ static void repack_promisor_objects(const struct pack_objects_args *args,
/*
* pack-objects creates the .pack and .idx files, but not the
* .promisor file. Create the .promisor file, which is empty.
+ *
+ * NEEDSWORK: fetch-pack sometimes generates non-empty
+ * .promisor files containing the ref names and associated
+ * hashes at the point of generation of the corresponding
+ * packfile, but this would not preserve their contents. Maybe
+ * concatenate the contents of all .promisor files instead of
+ * just creating a new empty file.
*/
promisor_name = mkpathdup("%s-%s.promisor", packtmp,
line.buf);
diff --git a/fetch-pack.c b/fetch-pack.c
index 947da54..b9e63b5 100644
--- a/fetch-pack.c
+++ b/fetch-pack.c
@@ -754,8 +754,33 @@ static int sideband_demux(int in, int out, void *data)
return ret;
}
+static void write_promisor_file(const char *keep_name,
+ struct ref **sought, int nr_sought)
+{
+ struct strbuf promisor_name = STRBUF_INIT;
+ int suffix_stripped;
+ FILE *output;
+ int i;
+
+ strbuf_addstr(&promisor_name, keep_name);
+ suffix_stripped = strbuf_strip_suffix(&promisor_name, ".keep");
+ if (!suffix_stripped)
+ BUG("name of pack lockfile should end with .keep (was '%s')",
+ keep_name);
+ strbuf_addstr(&promisor_name, ".promisor");
+
+ output = xfopen(promisor_name.buf, "w");
+ for (i = 0; i < nr_sought; i++)
+ fprintf(output, "%s %s\n", oid_to_hex(&sought[i]->old_oid),
+ sought[i]->name);
+ fclose(output);
+
+ strbuf_release(&promisor_name);
+}
+
static int get_pack(struct fetch_pack_args *args,
- int xd[2], char **pack_lockfile)
+ int xd[2], char **pack_lockfile,
+ struct ref **sought, int nr_sought)
{
struct async demux;
int do_keep = args->keep_pack;
@@ -817,7 +842,13 @@ static int get_pack(struct fetch_pack_args *args,
}
if (args->check_self_contained_and_connected)
argv_array_push(&cmd.args, "--check-self-contained-and-connected");
- if (args->from_promisor)
+ /*
+ * If we're obtaining the filename of a lockfile, we'll use
+ * that filename to write a .promisor file with more
+ * information below. If not, we need index-pack to do it for
+ * us.
+ */
+ if (!(do_keep && pack_lockfile) && args->from_promisor)
argv_array_push(&cmd.args, "--promisor");
}
else {
@@ -871,6 +902,14 @@ static int get_pack(struct fetch_pack_args *args,
die(_("%s failed"), cmd_name);
if (use_sideband && finish_async(&demux))
die(_("error in sideband demultiplexer"));
+
+ /*
+ * Now that index-pack has succeeded, write the promisor file using the
+ * obtained .keep filename if necessary
+ */
+ if (do_keep && pack_lockfile && args->from_promisor)
+ write_promisor_file(*pack_lockfile, sought, nr_sought);
+
return 0;
}
@@ -1006,7 +1045,7 @@ static struct ref *do_fetch_pack(struct fetch_pack_args *args,
alternate_shallow_file = setup_temporary_shallow(si->shallow);
else
alternate_shallow_file = NULL;
- if (get_pack(args, fd, pack_lockfile))
+ if (get_pack(args, fd, pack_lockfile, sought, nr_sought))
die(_("git fetch-pack: fetch failed."));
all_done:
@@ -1453,7 +1492,7 @@ static struct ref *do_fetch_pack_v2(struct fetch_pack_args *args,
/* get the pack */
process_section_header(&reader, "packfile", 0);
- if (get_pack(args, fd, pack_lockfile))
+ if (get_pack(args, fd, pack_lockfile, sought, nr_sought))
die(_("git fetch-pack: fetch failed."));
state = FETCH_DONE;
diff --git a/t/t5616-partial-clone.sh b/t/t5616-partial-clone.sh
index 79f7b65..eaa33a8 100755
--- a/t/t5616-partial-clone.sh
+++ b/t/t5616-partial-clone.sh
@@ -46,6 +46,14 @@ test_expect_success 'do partial clone 1' '
test "$(git -C pc1 config --local remote.origin.partialclonefilter)" = "blob:none"
'
+test_expect_success 'verify that .promisor file contains refs fetched' '
+ ls pc1/.git/objects/pack/pack-*.promisor >promisorlist &&
+ test_line_count = 1 promisorlist &&
+ git -C srv.bare rev-list HEAD >headhash &&
+ grep "$(cat headhash) HEAD" $(cat promisorlist) &&
+ grep "$(cat headhash) refs/heads/master" $(cat promisorlist)
+'
+
# checkout master to force dynamic object fetch of blobs at HEAD.
test_expect_success 'verify checkout with dynamic object fetch' '
git -C pc1 rev-list --quiet --objects --missing=print HEAD >observed &&