Hi,
Attached is the third re-roll of mine and Peff's series to introduce
'core.alternateRefsCommand', and 'core.alternateRefsPrefixes' to filter
the initial ".have" advertisement when an alternate has a pathologically
large number of references.
A range-diff against v2 is included below, but the major changes between
the two revisions are as follows:
1. Documentation and testing clean-up, per helpful input from Junio,
Peff, and brian carlson.
2. Included also is a preparatory patch from Peff, to change the
requirement that we provide refnames for alternate references. We
no longer allow this, and the first commit sent makes that such
change.
I imagine that we may hit one more re-roll, depending on the outcome of
this review. The series has not fundamentally changed since v2, so I
think that we are at a point of stasis there. Anything that is left
outstanding from v3 should hopefully be similarly-not-earth-shattering
;-).
Thanks in advance for your review.
Thanks,
Taylor
Jeff King (1):
transport: drop refnames from for_each_alternate_ref
Taylor Blau (3):
transport.c: extract 'fill_alternate_refs_command'
transport.c: introduce core.alternateRefsCommand
transport.c: introduce core.alternateRefsPrefixes
Documentation/config.txt | 18 +++++++++++++
builtin/receive-pack.c | 3 +--
fetch-pack.c | 3 +--
t/t5410-receive-pack.sh | 57 ++++++++++++++++++++++++++++++++++++++++
transport.c | 38 +++++++++++++++++++++------
transport.h | 2 +-
6 files changed, 108 insertions(+), 13 deletions(-)
create mode 100755 t/t5410-receive-pack.sh
Range-diff against v2:
-: ---------- > 1: 037273dab0 transport: drop refnames from for_each_alternate_ref
1: 6e3a58afe7 ! 2: 9479470cb1 transport.c: extract 'fill_alternate_refs_command'
@@ -24,7 +24,7 @@
+ cmd->git_cmd = 1;
+ argv_array_pushf(&cmd->args, "--git-dir=%s", repo_path);
+ argv_array_push(&cmd->args, "for-each-ref");
-+ argv_array_push(&cmd->args, "--format=%(objectname) %(refname)");
++ argv_array_push(&cmd->args, "--format=%(objectname)");
+ cmd->env = local_repo_env;
+ cmd->out = -1;
+}
@@ -39,7 +39,7 @@
- cmd.git_cmd = 1;
- argv_array_pushf(&cmd.args, "--git-dir=%s", path);
- argv_array_push(&cmd.args, "for-each-ref");
-- argv_array_push(&cmd.args, "--format=%(objectname) %(refname)");
+- argv_array_push(&cmd.args, "--format=%(objectname)");
- cmd.env = local_repo_env;
- cmd.out = -1;
+ fill_alternate_refs_command(&cmd, path);
2: 9797f52551 ! 3: 2dbcd54190 transport.c: introduce core.alternateRefsCommand
@@ -3,24 +3,24 @@
transport.c: introduce core.alternateRefsCommand
When in a repository containing one or more alternates, Git would
- sometimes like to list references from its alternates. For example, 'git
- receive-pack' list the objects pointed to by alternate references as
- special ".have" references.
+ sometimes like to list references from those alternates. For example,
+ 'git receive-pack' lists the "tips" pointed to by references in those
+ alternates as special ".have" references.
Listing ".have" references is designed to make pushing changes from
upstream to a fork a lightweight operation, by advertising to the pusher
that the fork already has the objects (via its alternate). Thus, the
client can avoid sending them.
- However, when the alternate has a pathologically large number of
- references, the initial advertisement is too expensive. In fact, it can
- dominate any such optimization where the pusher avoids sending certain
- objects.
+ However, when the alternate (upstream, in the previous example) has a
+ pathologically large number of references, the initial advertisement is
+ too expensive. In fact, it can dominate any such optimization where the
+ pusher avoids sending certain objects.
Introduce "core.alternateRefsCommand" in order to provide a facility to
limit or filter alternate references. This can be used, for example, to
- filter out "uninteresting" references from the initial advertisement in
- the above scenario.
+ filter out references the alternate does not wish to send (for space
+ concerns, or otherwise) during the initial advertisement.
Let the repository that has alternates configure this command to avoid
trusting the alternate to provide us a safe command to run in the shell.
@@ -38,15 +38,15 @@
expect HEAD to be a symbolic link.
+core.alternateRefsCommand::
-+ When listing references from an alternate (e.g., in the case of ".have"), use
-+ the shell to execute the specified command instead of
-+ linkgit:git-for-each-ref[1]. The first argument is the path of the alternate.
-+ Output must be of the form: `%(objectname) SPC %(refname)`.
++ When advertising tips of available history from an alternate, use the shell to
++ execute the specified command instead of linkgit:git-for-each-ref[1]. The
++ first argument is the absolute path of the alternate. Output must be of the
++ form: `%(objectname)`, where multiple tips are separated by newlines.
++
+This is useful when a repository only wishes to advertise some of its
+alternate's references as ".have"'s. For example, to only advertise branch
+heads, configure `core.alternateRefsCommand` to the path of a script which runs
-+`git --git-dir="$1" for-each-ref refs/heads`.
++`git --git-dir="$1" for-each-ref --format='%(objectname)' refs/heads`.
+
core.bare::
If true this repository is assumed to be 'bare' and has no
@@ -74,8 +74,7 @@
+ git clone fork pusher &&
+ (
+ cd fork &&
-+ git config receive.advertisealternates true &&
-+ cat <<-EOF | git update-ref --stdin &&
++ git update-ref --stdin <<-\EOF &&
+ delete refs/heads/a
+ delete refs/heads/b
+ delete refs/heads/c
@@ -88,23 +87,19 @@
+ )
+'
+
-+expect_haves () {
-+ printf "%s .have\n" $(git rev-parse $@) >expect
-+}
-+
+extract_haves () {
-+ depacketize - | grep '\.have' | sed -e 's/\\0.*$//g'
++ depacketize | perl -lne '/^(\S+) \.have/ and print $1'
+}
+
+test_expect_success 'with core.alternateRefsCommand' '
+ write_script fork/alternate-refs <<-\EOF &&
+ git --git-dir="$1" for-each-ref \
-+ --format="%(objectname) %(refname)" \
++ --format="%(objectname)" \
+ refs/heads/a \
+ refs/heads/c
+ EOF
+ test_config -C fork core.alternateRefsCommand alternate-refs &&
-+ expect_haves a c >expect &&
++ git rev-parse a c >expect &&
+ printf "0000" | git receive-pack fork >actual &&
+ extract_haves <actual >actual.haves &&
+ test_cmp expect actual.haves
@@ -122,7 +117,7 @@
- cmd->git_cmd = 1;
- argv_array_pushf(&cmd->args, "--git-dir=%s", repo_path);
- argv_array_push(&cmd->args, "for-each-ref");
-- argv_array_push(&cmd->args, "--format=%(objectname) %(refname)");
+- argv_array_push(&cmd->args, "--format=%(objectname)");
+ const char *value;
+
+ if (!git_config_get_value("core.alternateRefsCommand", &value)) {
@@ -135,7 +130,7 @@
+
+ argv_array_pushf(&cmd->args, "--git-dir=%s", repo_path);
+ argv_array_push(&cmd->args, "for-each-ref");
-+ argv_array_push(&cmd->args, "--format=%(objectname) %(refname)");
++ argv_array_push(&cmd->args, "--format=%(objectname)");
+ }
+
cmd->env = local_repo_env;
3: 6e8f65a16d ! 4: 48eb774c9e transport.c: introduce core.alternateRefsPrefixes
@@ -12,9 +12,7 @@
'core.alternateRefsCommand' would have to do:
$ git config core.alternateRefsCommand ' \
- git -C "$1" for-each-ref refs/tags \
- --format="%(objectname) %(refname)" \
- '
+ git -C "$1" for-each-ref refs/tags --format="%(objectname)"'
The above is cumbersome to write, so let's introduce a
"core.alternateRefsPrefixes" to address this common case. Instead, the
@@ -41,7 +39,7 @@
+++ b/Documentation/config.txt
@@
heads, configure `core.alternateRefsCommand` to the path of a script which runs
- `git --git-dir="$1" for-each-ref refs/heads`.
+ `git --git-dir="$1" for-each-ref --format='%(objectname)' refs/heads`.
+core.alternateRefsPrefixes::
+ When listing references from an alternate, list only references that begin
@@ -63,7 +61,7 @@
+test_expect_success 'with core.alternateRefsPrefixes' '
+ test_config -C fork core.alternateRefsPrefixes "refs/tags" &&
-+ expect_haves one three two >expect &&
++ git rev-parse one three two >expect &&
+ printf "0000" | git receive-pack fork >actual &&
+ extract_haves <actual >actual.haves &&
+ test_cmp expect actual.haves
@@ -77,7 +75,7 @@
@@
argv_array_pushf(&cmd->args, "--git-dir=%s", repo_path);
argv_array_push(&cmd->args, "for-each-ref");
- argv_array_push(&cmd->args, "--format=%(objectname) %(refname)");
+ argv_array_push(&cmd->args, "--format=%(objectname)");
+
+ if (!git_config_get_value("core.alternateRefsPrefixes", &value)) {
+ argv_array_push(&cmd->args, "--");
--
2.19.0.221.g150f307af
