Merge branch 'tb/filter-alternate-refs'

When pushing into a repository that borrows its objects from an
alternate object store, "git receive-pack" that responds to the
push request on the other side lists the tips of refs in the
alternate to reduce the amount of objects transferred.  This
sometimes is detrimental when the number of refs in the alternate
is absurdly large, in which case the bandwidth saved in potentially
fewer objects transferred is wasted in excessively large ref
advertisement.  The alternate refs that are advertised are now
configurable with a pair of configuration variables.

* tb/filter-alternate-refs:
transport.c: introduce core.alternateRefsPrefixes
transport.c: introduce core.alternateRefsCommand
transport.c: extract 'fill_alternate_refs_command'
transport: drop refnames from for_each_alternate_ref

diff --git a/Documentation/config.txt b/Documentation/config.txt
index 0ae4d7077bf70ec0df02e29af0df250d61ed7c07..552827935ae16d809a26e937d53ef07710526264 100644 (file)
--- a/Documentation/config.txt
+++ b/Documentation/config.txt
@@ -616,6 +616,24 @@ core.preferSymlinkRefs::
        This is sometimes needed to work with old scripts that
        expect HEAD to be a symbolic link.
 
+core.alternateRefsCommand::
+       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 contain one
+       hex object id per line (i.e., the same as produce by `git for-each-ref
+       --format='%(objectname)'`).
++
+Note that you cannot generally put `git for-each-ref` directly into the config
+value, as it does not take a repository path as an argument (but you can wrap
+the command above in a shell script).
+
+core.alternateRefsPrefixes::
+       When listing references from an alternate, list only references that begin
+       with the given prefix. Prefixes match as if they were given as arguments to
+       linkgit:git-for-each-ref[1]. To list multiple prefixes, separate them with
+       whitespace. If `core.alternateRefsCommand` is set, setting
+       `core.alternateRefsPrefixes` has no effect.
+
 core.bare::
        If true this repository is assumed to be 'bare' and has no
        working directory associated with it.  If this is the case a

diff --git a/builtin/receive-pack.c b/builtin/receive-pack.c
index 95740f4f0e71de95484edf53a2b86dc71952c5a7..7f089be11e2b33d222af7d217f7d228ee482ec5a 100644 (file)
--- a/builtin/receive-pack.c
+++ b/builtin/receive-pack.c
@@ -281,8 +281,7 @@ static int show_ref_cb(const char *path_full, const struct object_id *oid,
        return 0;
 }
 
-static void show_one_alternate_ref(const char *refname,
-                                  const struct object_id *oid,
+static void show_one_alternate_ref(const struct object_id *oid,
                                   void *data)
 {
        struct oidset *seen = data;

diff --git a/fetch-pack.c b/fetch-pack.c
index bff05ee69e54c5beabdc6415aba1c4e3a0118244..b3ed7121bc86805e87e909ff995eb8b439a2f995 100644 (file)
--- a/fetch-pack.c
+++ b/fetch-pack.c
@@ -76,8 +76,7 @@ struct alternate_object_cache {
        size_t nr, alloc;
 };
 
-static void cache_one_alternate(const char *refname,
-                               const struct object_id *oid,
+static void cache_one_alternate(const struct object_id *oid,
                                void *vcache)
 {
        struct alternate_object_cache *cache = vcache;

diff --git a/t/t5410-receive-pack-alternates.sh b/t/t5410-receive-pack-alternates.sh
new file mode 100755 (executable)
index 0000000..457c20c
--- /dev/null
+++ b/t/t5410-receive-pack-alternates.sh
@@ -0,0 +1,41 @@
+#!/bin/sh
+
+test_description='git receive-pack with alternate ref filtering'
+
+. ./test-lib.sh
+
+test_expect_success 'setup' '
+       test_commit base &&
+       git clone -s --bare . fork &&
+       git checkout -b public/branch master &&
+       test_commit public &&
+       git checkout -b private/branch master &&
+       test_commit private
+'
+
+extract_haves () {
+       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)" \
+                       refs/heads/public/
+       EOF
+       test_config -C fork core.alternateRefsCommand alternate-refs &&
+       git rev-parse public/branch >expect &&
+       printf "0000" | git receive-pack fork >actual &&
+       extract_haves <actual >actual.haves &&
+       test_cmp expect actual.haves
+'
+
+test_expect_success 'with core.alternateRefsPrefixes' '
+       test_config -C fork core.alternateRefsPrefixes "refs/heads/private" &&
+       git rev-parse private/branch >expect &&
+       printf "0000" | git receive-pack fork >actual &&
+       extract_haves <actual >actual.haves &&
+       test_cmp expect actual.haves
+'
+
+test_done

diff --git a/transport.c b/transport.c
index 046b2f6d8c96cdb8e2c28556cb295282fc76f7b9..f4ffbd96cb65fdbac3c74d3d60c253bc3a8884f6 100644 (file)
--- a/transport.c
+++ b/transport.c
@@ -1370,6 +1370,33 @@ char *transport_anonymize_url(const char *url)
        return xstrdup(url);
 }
 
+static void fill_alternate_refs_command(struct child_process *cmd,
+                                       const char *repo_path)
+{
+       const char *value;
+
+       if (!git_config_get_value("core.alternateRefsCommand", &value)) {
+               cmd->use_shell = 1;
+
+               argv_array_push(&cmd->args, value);
+               argv_array_push(&cmd->args, repo_path);
+       } else {
+               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)");
+
+               if (!git_config_get_value("core.alternateRefsPrefixes", &value)) {
+                       argv_array_push(&cmd->args, "--");
+                       argv_array_split(&cmd->args, value);
+               }
+       }
+
+       cmd->env = local_repo_env;
+       cmd->out = -1;
+}
+
 static void read_alternate_refs(const char *path,
                                alternate_ref_fn *cb,
                                void *data)
@@ -1378,12 +1405,7 @@ static void read_alternate_refs(const char *path,
        struct strbuf line = STRBUF_INIT;
        FILE *fh;
 
-       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)");
-       cmd.env = local_repo_env;
-       cmd.out = -1;
+       fill_alternate_refs_command(&cmd, path);
 
        if (start_command(&cmd))
                return;
@@ -1393,13 +1415,13 @@ static void read_alternate_refs(const char *path,
                struct object_id oid;
 
                if (get_oid_hex(line.buf, &oid) ||
-                   line.buf[GIT_SHA1_HEXSZ] != ' ') {
+                   line.buf[GIT_SHA1_HEXSZ]) {
                        warning(_("invalid line while parsing alternate refs: %s"),
                                line.buf);
                        break;
                }
 
-               cb(line.buf + GIT_SHA1_HEXSZ + 1, &oid, data);
+               cb(&oid, data);
        }
 
        fclose(fh);

diff --git a/transport.h b/transport.h
index 01e717c29ee6e0f0724b5757ebc7538a72e7e807..9baeca2d7a34cf064a632a7677429f477cb8e014 100644 (file)
--- a/transport.h
+++ b/transport.h
@@ -261,6 +261,6 @@ int transport_refs_pushed(struct ref *ref);
 void transport_print_push_status(const char *dest, struct ref *refs,
                  int verbose, int porcelain, unsigned int *reject_reasons);
 
-typedef void alternate_ref_fn(const char *refname, const struct object_id *oid, void *);
+typedef void alternate_ref_fn(const struct object_id *oid, void *);
 extern void for_each_alternate_ref(alternate_ref_fn, void *);
 #endif