add git_path_buf helper function

If you have a function that uses git_path a lot, but would
prefer to avoid the static buffers, it's useful to keep a
single scratch buffer locally and reuse it for each call.
You used to be able to do this with git_snpath:

char buf[PATH_MAX];

foo(git_snpath(buf, sizeof(buf), "foo"));
bar(git_snpath(buf, sizeof(buf), "bar"));

but since 1a83c24, git_snpath has been replaced with
strbuf_git_path. This is good, because it removes the
arbitrary PATH_MAX limit. But using strbuf_git_path is more
awkward for two reasons:

1. It adds to the buffer, rather than replacing it. This
is consistent with other strbuf functions, but makes
reuse of a single buffer more tedious.

2. It doesn't return the buffer, so you can't format
as part of a function's arguments.

The new git_path_buf solves both of these, so you can use it
like:

struct strbuf buf = STRBUF_INIT;

foo(git_path_buf(&buf, "foo"));
bar(git_path_buf(&buf, "bar"));

strbuf_release(&buf);

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/cache.h b/cache.h
index 79066e57dc806d118366d9807e0af338b72e2fb2..e231e47121283d8458c45fbb79cb5e8268c28f04 100644 (file)
--- a/cache.h
+++ b/cache.h
@@ -723,6 +723,8 @@ extern char *mksnpath(char *buf, size_t n, const char *fmt, ...)
        __attribute__((format (printf, 3, 4)));
 extern void strbuf_git_path(struct strbuf *sb, const char *fmt, ...)
        __attribute__((format (printf, 2, 3)));
+extern char *git_path_buf(struct strbuf *buf, const char *fmt, ...)
+       __attribute__((format (printf, 2, 3)));
 extern void strbuf_git_path_submodule(struct strbuf *sb, const char *path,
                                      const char *fmt, ...)
        __attribute__((format (printf, 3, 4)));

diff --git a/path.c b/path.c
index 95acbafa6883b4418f19a208cb9889f5642f3925..46a4d2714b98b87c264d01c57bc7ff6bbd49af68 100644 (file)
--- a/path.c
+++ b/path.c
@@ -175,6 +175,16 @@ static void do_git_path(struct strbuf *buf, const char *fmt, va_list args)
        strbuf_cleanup_path(buf);
 }
 
+char *git_path_buf(struct strbuf *buf, const char *fmt, ...)
+{
+       va_list args;
+       strbuf_reset(buf);
+       va_start(args, fmt);
+       do_git_path(buf, fmt, args);
+       va_end(args);
+       return buf->buf;
+}
+
 void strbuf_git_path(struct strbuf *sb, const char *fmt, ...)
 {
        va_list args;