diff options
Diffstat (limited to 'core/upb_string.c')
-rw-r--r-- | core/upb_string.c | 30 |
1 files changed, 29 insertions, 1 deletions
diff --git a/core/upb_string.c b/core/upb_string.c index f9af9e9..2f487aa 100644 --- a/core/upb_string.c +++ b/core/upb_string.c @@ -82,7 +82,7 @@ char *upb_string_getrwbuf(upb_string *str, upb_strlen_t len) { } str->len = len; str->ptr = str->cached_mem; - return str->ptr; + return str->cached_mem; } void upb_string_substr(upb_string *str, upb_string *target_str, @@ -92,3 +92,31 @@ void upb_string_substr(upb_string *str, upb_string *target_str, str->ptr = upb_string_getrobuf(target_str) + start; str->len = len; } + +void upb_string_vprintf(upb_string *str, const char *format, va_list args) { + // Try once without reallocating. We have to va_copy because we might have + // to call vsnprintf again. + uint32_t size = UPB_MAX(upb_string_size(str), 16); + char *buf = upb_string_getrwbuf(str, size); + va_list args_copy; + va_copy(args_copy, args); + uint32_t true_size = vsnprintf(buf, size, format, args_copy); + va_end(args_copy); + + if (true_size > size) { + // Need to reallocate. + str = upb_string_tryrecycle(str); + buf = upb_string_getrwbuf(str, true_size); + vsnprintf(buf, true_size, format, args); + } + str->len = true_size; +} + +upb_string *upb_string_asprintf(const char *format, ...) { + upb_string *str = upb_string_new(); + va_list args; + va_start(args, format); + upb_string_vprintf(str, format, args); + va_end(args); + return str; +} |