From: Sebastian Harl Date: Wed, 4 Sep 2013 20:41:03 +0000 (+0200) Subject: utils strbuf: Allow the initial size to be zero. X-Git-Tag: sysdb-0.1.0~354 X-Git-Url: https://git.tokkee.org/?a=commitdiff_plain;h=e292f5e4f78e892fa12cafcb837021b1db4a0057;p=sysdb.git utils strbuf: Allow the initial size to be zero. --- diff --git a/src/utils/strbuf.c b/src/utils/strbuf.c index bc24fef..c8e7e63 100644 --- a/src/utils/strbuf.c +++ b/src/utils/strbuf.c @@ -48,18 +48,19 @@ struct sdb_strbuf { */ static int -strbuf_resize(sdb_strbuf_t *strbuf) +strbuf_resize(sdb_strbuf_t *strbuf, size_t new_size) { char *tmp; - assert(strbuf->size); + if (new_size <= strbuf->size) + return 0; - tmp = realloc(strbuf->string, 2 * strbuf->size); + tmp = realloc(strbuf->string, new_size); if (! tmp) return -1; strbuf->string = tmp; - strbuf->size *= 2; + strbuf->size = new_size; return 0; } /* strbuf_resize */ @@ -72,20 +73,21 @@ sdb_strbuf_create(size_t size) { sdb_strbuf_t *strbuf; - if (! size) - return NULL; - strbuf = calloc(1, sizeof(*strbuf)); if (! strbuf) return NULL; - strbuf->string = malloc(size); - if (! strbuf->string) { - free(strbuf); - return NULL; + strbuf->string = NULL; + if (size) { + strbuf->string = malloc(size); + if (! strbuf->string) { + free(strbuf); + return NULL; + } + + strbuf->string[0] = '\0'; } - strbuf->string[0] = '\0'; strbuf->size = size; strbuf->pos = 0; @@ -98,7 +100,8 @@ sdb_strbuf_destroy(sdb_strbuf_t *strbuf) if (! strbuf) return; - free(strbuf->string); + if (strbuf->string) + free(strbuf->string); free(strbuf); } /* sdb_strbuf_destroy */ @@ -111,12 +114,16 @@ sdb_strbuf_vappend(sdb_strbuf_t *strbuf, const char *fmt, va_list ap) if ((! strbuf) || (! fmt)) return -1; - assert(strbuf->string[strbuf->pos] == '\0'); + assert((strbuf->size == 0) || (strbuf->string[strbuf->pos] == '\0')); if (strbuf->pos >= strbuf->size) - if (strbuf_resize(strbuf)) + /* use some arbitrary but somewhat reasonable default */ + if (strbuf_resize(strbuf, strbuf->size ? 2 * strbuf->size : 64)) return -1; + assert(strbuf->size && strbuf->string); + assert(strbuf->pos < strbuf->size); + /* 'ap' is invalid after calling vsnprintf; thus copy before using it */ va_copy(aq, ap); status = vsnprintf(strbuf->string + strbuf->pos, @@ -128,7 +135,7 @@ sdb_strbuf_vappend(sdb_strbuf_t *strbuf, const char *fmt, va_list ap) } if ((size_t)status >= strbuf->size - strbuf->pos) { - strbuf_resize(strbuf); + strbuf_resize(strbuf, (size_t)status + 1); /* reset string and try again */ strbuf->string[strbuf->pos] = '\0'; @@ -160,8 +167,10 @@ sdb_strbuf_vsprintf(sdb_strbuf_t *strbuf, const char *fmt, va_list ap) if (! strbuf) return -1; - strbuf->string[0] = '\0'; - strbuf->pos = 0; + if (strbuf->size) { + strbuf->string[0] = '\0'; + strbuf->pos = 0; + } return sdb_strbuf_vappend(strbuf, fmt, ap); } /* sdb_strbuf_vsprintf */ @@ -187,6 +196,9 @@ sdb_strbuf_chomp(sdb_strbuf_t *strbuf) if (! strbuf) return -1; + assert(strbuf->size || (strbuf->pos < strbuf->size)); + assert(strbuf->pos <= strbuf->size); + while ((strbuf->pos > 0) && (strbuf->string[strbuf->pos - 1] == '\n')) { --strbuf->pos; @@ -202,6 +214,8 @@ sdb_strbuf_string(sdb_strbuf_t *strbuf) { if (! strbuf) return NULL; + if (! strbuf->size) + return ""; return strbuf->string; } /* sdb_strbuf_string */