diff options
Diffstat (limited to 'dstring.c')
| -rw-r--r-- | dstring.c | 77 |
1 files changed, 55 insertions, 22 deletions
@@ -1,6 +1,6 @@ /**************************************************************************** * bfs * - * Copyright (C) 2016-2019 Tavian Barnes <tavianator@tavianator.com> * + * Copyright (C) 2016-2020 Tavian Barnes <tavianator@tavianator.com> * * * * Permission to use, copy, modify, and/or distribute this software for any * * purpose with or without fee is hereby granted. * @@ -124,6 +124,10 @@ int dstrncat(char **dest, const char *src, size_t n) { return dstrcat_impl(dest, src, strnlen(src, n)); } +int dstrdcat(char **dest, const char *src) { + return dstrcat_impl(dest, src, dstrlen(src)); +} + int dstrapp(char **str, char c) { return dstrcat_impl(str, &c, 1); } @@ -139,40 +143,69 @@ char *dstrprintf(const char *format, ...) { } char *dstrvprintf(const char *format, va_list args) { - // Guess a length to try to avoid calling vsnprintf() twice - int len, cap = 2*strlen(format); - char *str = dstralloc(cap); + // Guess a capacity to try to avoid reallocating + char *str = dstralloc(2*strlen(format)); if (!str) { return NULL; } - va_list args2; - va_copy(args2, args); + if (dstrvcatf(&str, format, args) != 0) { + dstrfree(str); + return NULL; + } - len = vsnprintf(str, cap + 1, format, args); - if (len > cap) { - if (dstreserve(&str, len) != 0) { - goto fail; - } + return str; +} - cap = len; - len = vsnprintf(str, cap + 1, format, args2); - assert(len == cap); - } +int dstrcatf(char **str, const char *format, ...) { + va_list args; + + va_start(args, format); + int ret = dstrvcatf(str, format, args); + va_end(args); - va_end(args2); + return ret; +} + +int dstrvcatf(char **str, const char *format, va_list args) { + // Guess a capacity to try to avoid calling vsnprintf() twice + size_t len = dstrlen(*str); + dstreserve(str, len + 2*strlen(format)); + size_t cap = dstrheader(*str)->capacity; - if (len < 0) { + va_list copy; + va_copy(copy, args); + + char *tail = *str + len; + int ret = vsnprintf(tail, cap - len + 1, format, args); + if (ret < 0) { goto fail; } - struct dstring *header = dstrheader(str); - header->length = len; - return str; + size_t tail_len = ret; + if (tail_len > cap - len) { + cap = len + tail_len; + if (dstreserve(str, cap) != 0) { + goto fail; + } + + tail = *str + len; + ret = vsnprintf(tail, tail_len + 1, format, copy); + if (ret < 0 || (size_t)ret != tail_len) { + assert(false); + goto fail; + } + } + + va_end(copy); + + struct dstring *header = dstrheader(*str); + header->length += tail_len; + return 0; fail: - dstrfree(str); - return NULL; + *tail = '\0'; + return -1; } void dstrfree(char *dstr) { |