From cdeef283bcf8529fc858cfe7d18a7522294519c4 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Ren=C3=A9=20Scharfe?= Date: Tue, 12 May 2026 13:56:00 +0200 Subject: [PATCH] strbuf: add strbuf_add_uint() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit strbuf_addf() calls vsnprintf(3) underneath, which supports a plethora of formatting options. We can avoid its overhead in basic cases by providing specialized functions like strbuf_addstr() for strings. Add another one, strbuf_add_uint(), for unsigned integers. Prepare the number string in a temporary buffer. Make it big enough for any unsigned integer value: A decimal digit can represent ln(10)/ln(2) ≈ 3.32 bits; dividing the number of bits of uintmax_t by 3.3 and rounding up gives a sufficiently close conservative size estimate. Signed-off-by: René Scharfe Signed-off-by: Junio C Hamano --- strbuf.c | 12 ++++++++++++ strbuf.h | 6 ++++++ 2 files changed, 18 insertions(+) diff --git a/strbuf.c b/strbuf.c index 3e04addc22..9731ecdc1f 100644 --- a/strbuf.c +++ b/strbuf.c @@ -361,6 +361,18 @@ void strbuf_addf(struct strbuf *sb, const char *fmt, ...) va_end(ap); } +void strbuf_add_uint(struct strbuf *sb, uintmax_t value) +{ + char buf[DIV_ROUND_UP(bitsizeof(value) * 10, 33)]; + char *end = buf + sizeof(buf); + char *p = end; + + do + *--p = "0123456789"[value % 10]; + while (value /= 10); + strbuf_add(sb, p, end - p); +} + static void add_lines(struct strbuf *out, const char *prefix, const char *buf, size_t size, diff --git a/strbuf.h b/strbuf.h index 06e284f9cc..1089ae687b 100644 --- a/strbuf.h +++ b/strbuf.h @@ -410,6 +410,12 @@ void strbuf_humanise_rate(struct strbuf *buf, off_t bytes); __attribute__((format (printf,2,3))) void strbuf_addf(struct strbuf *sb, const char *fmt, ...); + +/** + * Add an unsigned decimal number. + */ +void strbuf_add_uint(struct strbuf *sb, uintmax_t value); + /** * Add a formatted string prepended by a comment character and a * blank to the buffer.