Re: [PATCH v2 2/8] submodule--helper: get remote names from any repository
From: Junio C Hamano <hidden>
Date: 2021-09-20 16:54:50
Atharva Raykar [off-list ref] writes:
`get_default_remote()` retrieves the name of a remote by resolving the refs from of the current repository's ref store. Thus in order to use it for retrieving the remote name of a submodule, we have to start a new subprocess which runs from the submodule directory. Let's instead introduce a function called `repo_get_default_remote()` which takes any repository object and retrieves the remote accordingly. `get_default_remote()` is then defined as a call to `repo_get_default_remote()` with 'the_repository' passed to it. Now that we have `repo_get_default_remote()`, we no longer have to start a subprocess that called `submodule--helper get-default-remote` from within the submodule directory. So let's make a function called `get_default_remote_submodule()` which takes a submodule path, and returns the default remote for that submodule, all within the same process. We can now use this function to save an unnecessary subprocess spawn in `sync_submodule()`, and also in the next patch, which will require this functionality. Mentored-by: Christian Couder [off-list ref] Mentored-by: Shourya Shukla [off-list ref] Signed-off-by: Atharva Raykar <redacted> --- builtin/submodule--helper.c | 34 +++++++++++++++++++++++----------- 1 file changed, 23 insertions(+), 11 deletions(-)
The above covers a lot of stuff, because this change does a lot of things ;-) The commit could be split into 3 logically distinct phases (two independent, the third depends on the other two): - extract the part that uses the run-command() API to run "submodule--helper print-default-remote" from sync_submodule() and create get_default_remote_submodule() function out of it. - move bulk of get_default_remote() into repo_get_default_remote() and reimplement the former as a thin wrapper of the latter. - using the repo_get_default_remote() created in the second step, update the get_default_remote_submodule() created in the first step to work in-process without a subprocess. but a bit larger granularity used here is probably OK.
quoted hunk
diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c index 97512ccf0b..f6c4fc349b 100644 --- a/builtin/submodule--helper.c +++ b/builtin/submodule--helper.c@@ -29,11 +29,10 @@ typedef void (*each_submodule_fn)(const struct cache_entry *list_item, void *cb_data); -static char *get_default_remote(void) +static char *repo_get_default_remote(struct repository *repo, const char *refname) { char *dest = NULL, *ret; struct strbuf sb = STRBUF_INIT; - const char *refname = resolve_ref_unsafe("HEAD", 0, NULL, NULL); if (!refname) die(_("No such ref: %s"), "HEAD");@@ -46,7 +45,7 @@ static char *get_default_remote(void) die(_("Expecting a full ref name, got %s"), refname); strbuf_addf(&sb, "branch.%s.remote", refname); - if (git_config_get_string(sb.buf, &dest)) + if (repo_config_get_string(repo, sb.buf, &dest)) ret = xstrdup("origin"); else ret = dest;@@ -55,6 +54,25 @@ static char *get_default_remote(void) return ret; } +static char *get_default_remote_submodule(const char *module_path) +{ + const char *refname; + const struct submodule *sub; + struct repository subrepo; + + refname = refs_resolve_ref_unsafe(get_submodule_ref_store(module_path), + "HEAD", 0, NULL, NULL); + sub = submodule_from_path(the_repository, null_oid(), module_path); + repo_submodule_init(&subrepo, the_repository, sub); + return repo_get_default_remote(&subrepo, refname); +} + +static char *get_default_remote(void) +{ + const char *refname = resolve_ref_unsafe("HEAD", 0, NULL, NULL); + return repo_get_default_remote(the_repository, refname); +} + static int print_default_remote(int argc, const char **argv, const char *prefix) { char *remote;@@ -1369,7 +1387,6 @@ static void sync_submodule(const char *path, const char *prefix, char *remote_key = NULL; char *sub_origin_url, *super_config_url, *displaypath; struct strbuf sb = STRBUF_INIT; - struct child_process cp = CHILD_PROCESS_INIT; char *sub_config_path = NULL; if (!is_submodule_active(the_repository, path))@@ -1418,14 +1435,9 @@ static void sync_submodule(const char *path, const char *prefix, if (!is_submodule_populated_gently(path, NULL)) goto cleanup; - prepare_submodule_repo_env(&cp.env_array); - cp.git_cmd = 1; - cp.dir = path; - strvec_pushl(&cp.args, "submodule--helper", - "print-default-remote", NULL); - strbuf_reset(&sb); - if (capture_command(&cp, &sb, 0)) + strbuf_addstr(&sb, get_default_remote_submodule(path)); + if (!sb.buf) die(_("failed to get the default remote for submodule '%s'"), path);
There is this line after the post context presented here:
strbuf_strip_suffix(&sb, "\n");
remote_key = xstrfmt("remote.%s.url", sb.buf);
The LF was expected to come from the capture_command(), but it no
longer is needed after get_default_remote_submodule() switches to
use the in-process method. In fact, the use of sb for the purpose
of forming remote_key is not needed.
tmp = get_default_remote_submodule(path);
if (!tmp)
die(_("failed to get..."));
remote_key = xstrfmt("remote.%s.url", tmp);
free(tmp);
Yes, I think the new code leaks, and makes it impossible not to
leak, the returned value from get_default_remote_submodule() by
passing the call as an argument to strbuf_addstr().
Both of the two bugs pointed out here would have been easier to spot
if the commits were smaller, I would think, but as I said, a bit
larger granularity used here was still manageable.
Thanks.