[PATCH 09/17] refs.c: remove extra git_path calls from read_loose_refs
- From
Jeff King <peff@peff.net>
- Date
- Aug 10, 2015, 09:36 UTC
- Message-ID
- <20150810093619.GI30981@sigill.intra.peff.net>
- In-Reply-To
- <20150810092731.GA9027@sigill.intra.peff.net>
In iterating over the loose refs in "refs/foo/", we keep a running strbuf with "refs/foo/one", "refs/foo/two", etc. But we also need to access these files in the filesystem, as ".git/refs/foo/one", etc. For this latter purpose, we make a series of independent calls to git_path(). These are safe (we only use the result to call stat()), but assigning the result of git_path is a suspicious pattern that we'd rather avoid.
This patch keeps a running buffer with ".git/refs/foo/", and we can just append/reset each directory element as we loop. This matches how we handle the refnames. It should also be more efficient, as we do not keep formatting the same ".git/refs/foo" prefix (which can be arbitrarily deep).
Technically we are dropping a call to strbuf_cleanup() on each generated filename, but that's OK; it wasn't doing anything, as we are putting in single-level names we read from the filesystem (so it could not possibly be cleaning up cruft like "./" in this instance).
A clever reader may also note that the running refname buffer ("refs/foo/") is actually a subset of the filesystem path buffer (".git/refs/foo/"). We could get by with one buffer, indexing the length of $GIT_DIR when we want the refname. However, having tried this, the resulting code actually ends up a little more confusing, and the efficiency improvement is tiny (and almost certainly dwarfed by the system calls we are making).
Signed-off-by: Jeff King <peff@peff.net> --- refs.c | 23 +++++++++++++---------- 1 file changed, 13 insertions(+), 10 deletions(-)
diff --git a/refs.c b/refs.c index e70941a..06f95c4 100644 --- a/refs.c +++ b/refs.c @@ -1352,19 +1352,23 @@ static void read_loose_refs(const char *dirname, struct ref_dir *dir) { struct ref_cache *refs = dir->ref_cache; DIR *d; - const char *path; struct dirent *de; int dirnamelen = strlen(dirname); struct strbuf refname; + struct strbuf path = STRBUF_INIT; + size_t path_baselen; if (*refs->name) - path = git_path_submodule(refs->name, "%s", dirname); + strbuf_git_path_submodule(&path, refs->name, "%s", dirname); else - path = git_path("%s", dirname); + strbuf_git_path(&path, "%s", dirname); + path_baselen = path.len; - d = opendir(path); - if (!d) + d = opendir(path.buf); + if (!d) { + strbuf_release(&path); return; + } strbuf_init(&refname, dirnamelen + 257); strbuf_add(&refname, dirname, dirnamelen); @@ -1373,17 +1377,14 @@ static void read_loose_refs(const char *dirname, struct ref_dir *dir) unsigned char sha1[20]; struct stat st; int flag; - const char *refdir; if (de->d_name[0] == '.') continue; if (ends_with(de->d_name, ".lock")) continue; strbuf_addstr(&refname, de->d_name); - refdir = *refs->name - ? git_path_submodule(refs->name, "%s", refname.buf) - : git_path("%s", refname.buf); - if (stat(refdir, &st) < 0) { + strbuf_addstr(&path, de->d_name); + if (stat(path.buf, &st) < 0) { ; /* silently ignore */ } else if (S_ISDIR(st.st_mode)) { strbuf_addch(&refname, '/'); @@ -1430,8 +1431,10 @@ static void read_loose_refs(const char *dirname, struct ref_dir *dir) create_ref_entry(refname.buf, sha1, flag, 0)); } strbuf_setlen(&refname, dirnamelen); + strbuf_setlen(&path, path_baselen); } strbuf_release(&refname); + strbuf_release(&path); closedir(d); }
-- 2.5.0.414.g670f2a4