strbuf: add strbuf_vaddf

In a variable-args function, the code for writing into a strbuf is
non-trivial. We ended up cutting and pasting it in several places
because there was no vprintf-style function for strbufs (which in turn
was held up by a lack of va_copy).

Now that we have a fallback va_copy, we can add strbuf_vaddf, the
strbuf equivalent of vsprintf. And we can clean up the cut and paste
mess.

Signed-off-by: Jeff King <peff@peff.net>
Improved-by: Christian Couder <christian.couder@gmail.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Jeff King
2011-02-25 23:08:53 -06:00
committed by Junio C Hamano
parent ab8632ae36
commit ebeb60900f
5 changed files with 25 additions and 63 deletions

View File

@ -195,24 +195,29 @@ void strbuf_adddup(struct strbuf *sb, size_t pos, size_t len)
void strbuf_addf(struct strbuf *sb, const char *fmt, ...)
{
int len;
va_list ap;
va_start(ap, fmt);
strbuf_vaddf(sb, fmt, ap);
va_end(ap);
}
void strbuf_vaddf(struct strbuf *sb, const char *fmt, va_list ap)
{
int len;
va_list cp;
if (!strbuf_avail(sb))
strbuf_grow(sb, 64);
va_start(ap, fmt);
len = vsnprintf(sb->buf + sb->len, sb->alloc - sb->len, fmt, ap);
va_end(ap);
va_copy(cp, ap);
len = vsnprintf(sb->buf + sb->len, sb->alloc - sb->len, fmt, cp);
va_end(cp);
if (len < 0)
die("your vsnprintf is broken");
die("BUG: your vsnprintf is broken (returned %d)", len);
if (len > strbuf_avail(sb)) {
strbuf_grow(sb, len);
va_start(ap, fmt);
len = vsnprintf(sb->buf + sb->len, sb->alloc - sb->len, fmt, ap);
va_end(ap);
if (len > strbuf_avail(sb)) {
die("this should not happen, your snprintf is broken");
}
if (len > strbuf_avail(sb))
die("BUG: your vsnprintf is broken (insatiable)");
}
strbuf_setlen(sb, sb->len + len);
}