git/strvec.c
Ævar Arnfjörð Bjarmason 5726a6b401 *.c *_init(): define in terms of corresponding *_INIT macro
Change the common patter in the codebase of duplicating the
initialization logic between an *_INIT macro and a
corresponding *_init() function to use the macro as the canonical
source of truth.

Now we no longer need to keep the function up-to-date with the macro
version. This implements a suggestion by Jeff King who found that
under -O2 [1] modern compilers will init new version in place without
the extra copy[1]. The performance of a single *_init() won't matter
in most cases, but even if it does we're going to be producing
efficient machine code to perform these operations.

1. https://lore.kernel.org/git/YNyrDxUO1PlGJvCn@coredump.intra.peff.net/

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-07-01 12:32:22 -07:00

109 lines
2.0 KiB
C

#include "cache.h"
#include "strvec.h"
#include "strbuf.h"
const char *empty_strvec[] = { NULL };
void strvec_init(struct strvec *array)
{
struct strvec blank = STRVEC_INIT;
memcpy(array, &blank, sizeof(*array));
}
static void strvec_push_nodup(struct strvec *array, const char *value)
{
if (array->v == empty_strvec)
array->v = NULL;
ALLOC_GROW(array->v, array->nr + 2, array->alloc);
array->v[array->nr++] = value;
array->v[array->nr] = NULL;
}
const char *strvec_push(struct strvec *array, const char *value)
{
strvec_push_nodup(array, xstrdup(value));
return array->v[array->nr - 1];
}
const char *strvec_pushf(struct strvec *array, const char *fmt, ...)
{
va_list ap;
struct strbuf v = STRBUF_INIT;
va_start(ap, fmt);
strbuf_vaddf(&v, fmt, ap);
va_end(ap);
strvec_push_nodup(array, strbuf_detach(&v, NULL));
return array->v[array->nr - 1];
}
void strvec_pushl(struct strvec *array, ...)
{
va_list ap;
const char *arg;
va_start(ap, array);
while ((arg = va_arg(ap, const char *)))
strvec_push(array, arg);
va_end(ap);
}
void strvec_pushv(struct strvec *array, const char **items)
{
for (; *items; items++)
strvec_push(array, *items);
}
void strvec_pop(struct strvec *array)
{
if (!array->nr)
return;
free((char *)array->v[array->nr - 1]);
array->v[array->nr - 1] = NULL;
array->nr--;
}
void strvec_split(struct strvec *array, const char *to_split)
{
while (isspace(*to_split))
to_split++;
for (;;) {
const char *p = to_split;
if (!*p)
break;
while (*p && !isspace(*p))
p++;
strvec_push_nodup(array, xstrndup(to_split, p - to_split));
while (isspace(*p))
p++;
to_split = p;
}
}
void strvec_clear(struct strvec *array)
{
if (array->v != empty_strvec) {
int i;
for (i = 0; i < array->nr; i++)
free((char *)array->v[i]);
free(array->v);
}
strvec_init(array);
}
const char **strvec_detach(struct strvec *array)
{
if (array->v == empty_strvec)
return xcalloc(1, sizeof(const char *));
else {
const char **ret = array->v;
strvec_init(array);
return ret;
}
}