mpv/ta/ta_utils.c

334 lines
8.9 KiB
C

/* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <assert.h>
#define TA_NO_WRAPPERS
#include "ta.h"
// Return element_size * count. If it overflows, return (size_t)-1 (SIZE_MAX).
// I.e. this returns the equivalent of: MIN(element_size * count, SIZE_MAX).
// The idea is that every real memory allocator will reject (size_t)-1, thus
// this is a valid way to handle too large array allocation requests.
size_t ta_calc_array_size(size_t element_size, size_t count)
{
if (count > (((size_t)-1) / element_size))
return (size_t)-1;
return element_size * count;
}
// This is used when an array has to be enlarged for appending new elements.
// Return a "good" size for the new array (in number of elements). This returns
// a value > nextidx, unless the calculation overflows, in which case SIZE_MAX
// is returned.
size_t ta_calc_prealloc_elems(size_t nextidx)
{
if (nextidx >= ((size_t)-1) / 2 - 1)
return (size_t)-1;
return (nextidx + 1) * 2;
}
static void dummy_dtor(void *p){}
/* Create an empty (size 0) TA allocation, which is prepared in a way such that
* using it as parent with ta_set_parent() always succeed. Calling
* ta_set_destructor() on it will always succeed as well.
*/
void *ta_new_context(void *ta_parent)
{
void *new = ta_alloc_size(ta_parent, 0);
// Force it to allocate an extended header.
if (!ta_set_destructor(new, dummy_dtor)) {
ta_free(new);
new = NULL;
}
return new;
}
/* Set parent of ptr to ta_parent, return the ptr.
* Note that ta_parent==NULL will simply unset the current parent of ptr.
* If the operation fails (on OOM), return NULL. (That's pretty bad behavior,
* but the only way to signal failure.)
*/
void *ta_steal_(void *ta_parent, void *ptr)
{
if (!ta_set_parent(ptr, ta_parent))
return NULL;
return ptr;
}
/* Duplicate the memory at ptr with the given size.
*/
void *ta_memdup(void *ta_parent, void *ptr, size_t size)
{
if (!ptr) {
assert(!size);
return NULL;
}
void *res = ta_alloc_size(ta_parent, size);
if (!res)
return NULL;
memcpy(res, ptr, size);
return res;
}
// *str = *str[0..at] + append[0..append_len]
// (append_len being a maximum length; shorter if embedded \0s are encountered)
static bool strndup_append_at(char **str, size_t at, const char *append,
size_t append_len)
{
assert(ta_get_size(*str) >= at);
if (!*str && !append)
return true; // stays NULL, but not an OOM condition
size_t real_len = append ? strnlen(append, append_len) : 0;
if (append_len > real_len)
append_len = real_len;
if (ta_get_size(*str) < at + append_len + 1) {
char *t = ta_realloc_size(NULL, *str, at + append_len + 1);
if (!t)
return false;
*str = t;
}
if (append_len)
memcpy(*str + at, append, append_len);
(*str)[at + append_len] = '\0';
ta_dbg_mark_as_string(*str);
return true;
}
/* Return a copy of str.
* Returns NULL on OOM.
*/
char *ta_strdup(void *ta_parent, const char *str)
{
return ta_strndup(ta_parent, str, str ? strlen(str) : 0);
}
/* Return a copy of str. If the string is longer than n, copy only n characters
* (the returned allocation will be n+1 bytes and contain a terminating '\0').
* The returned string will have the length MIN(strlen(str), n)
* If str==NULL, return NULL. Returns NULL on OOM as well.
*/
char *ta_strndup(void *ta_parent, const char *str, size_t n)
{
if (!str)
return NULL;
char *new = NULL;
strndup_append_at(&new, 0, str, n);
if (!ta_set_parent(new, ta_parent)) {
ta_free(new);
new = NULL;
}
return new;
}
/* Append a to *str. If *str is NULL, the string is newly allocated, otherwise
* ta_realloc() is used on *str as needed.
* Return success or failure (it can fail due to OOM only).
*/
bool ta_strdup_append(char **str, const char *a)
{
return strndup_append_at(str, *str ? strlen(*str) : 0, a, (size_t)-1);
}
/* Like ta_strdup_append(), but use ta_get_size(*str)-1 instead of strlen(*str).
* (See also: ta_asprintf_append_buffer())
*/
bool ta_strdup_append_buffer(char **str, const char *a)
{
size_t size = ta_get_size(*str);
if (size > 0)
size -= 1;
return strndup_append_at(str, size, a, (size_t)-1);
}
/* Like ta_strdup_append(), but limit the length of a with n.
* (See also: ta_strndup())
*/
bool ta_strndup_append(char **str, const char *a, size_t n)
{
return strndup_append_at(str, *str ? strlen(*str) : 0, a, n);
}
/* Like ta_strdup_append_buffer(), but limit the length of a with n.
* (See also: ta_strndup())
*/
bool ta_strndup_append_buffer(char **str, const char *a, size_t n)
{
size_t size = ta_get_size(*str);
if (size > 0)
size -= 1;
return strndup_append_at(str, size, a, n);
}
static bool ta_vasprintf_append_at(char **str, size_t at, const char *fmt,
va_list ap)
{
assert(ta_get_size(*str) >= at);
int size;
va_list copy;
va_copy(copy, ap);
char c;
size = vsnprintf(&c, 1, fmt, copy);
va_end(copy);
if (size < 0)
return false;
if (ta_get_size(*str) < at + size + 1) {
char *t = ta_realloc_size(NULL, *str, at + size + 1);
if (!t)
return false;
*str = t;
}
vsnprintf(*str + at, size + 1, fmt, ap);
ta_dbg_mark_as_string(*str);
return true;
}
/* Like snprintf(); returns the formatted string as allocation (or NULL on OOM
* or snprintf() errors).
*/
char *ta_asprintf(void *ta_parent, const char *fmt, ...)
{
char *res;
va_list ap;
va_start(ap, fmt);
res = ta_vasprintf(ta_parent, fmt, ap);
va_end(ap);
return res;
}
char *ta_vasprintf(void *ta_parent, const char *fmt, va_list ap)
{
char *res = NULL;
ta_vasprintf_append_at(&res, 0, fmt, ap);
if (!res || !ta_set_parent(res, ta_parent)) {
ta_free(res);
return NULL;
}
return res;
}
/* Append the formatted string to *str (after strlen(*str)). The allocation is
* ta_realloced if needed.
* Returns false on OOM or snprintf() errors, with *str left untouched.
*/
bool ta_asprintf_append(char **str, const char *fmt, ...)
{
bool res;
va_list ap;
va_start(ap, fmt);
res = ta_vasprintf_append(str, fmt, ap);
va_end(ap);
return res;
}
bool ta_vasprintf_append(char **str, const char *fmt, va_list ap)
{
return ta_vasprintf_append_at(str, *str ? strlen(*str) : 0, fmt, ap);
}
/* Append the formatted string at the end of the allocation of *str. It
* overwrites the last byte of the allocation too (which is assumed to be the
* '\0' terminating the string). Compared to ta_asprintf_append(), this is
* useful if you know that the string ends with the allocation, so that the
* extra strlen() can be avoided for better performance.
* Returns false on OOM or snprintf() errors, with *str left untouched.
*/
bool ta_asprintf_append_buffer(char **str, const char *fmt, ...)
{
bool res;
va_list ap;
va_start(ap, fmt);
res = ta_vasprintf_append_buffer(str, fmt, ap);
va_end(ap);
return res;
}
bool ta_vasprintf_append_buffer(char **str, const char *fmt, va_list ap)
{
size_t size = ta_get_size(*str);
if (size > 0)
size -= 1;
return ta_vasprintf_append_at(str, size, fmt, ap);
}
void *ta_oom_p(void *p)
{
if (!p)
abort();
return p;
}
void ta_oom_b(bool b)
{
if (!b)
abort();
}
char *ta_oom_s(char *s)
{
if (!s)
abort();
return s;
}
void *ta_xsteal_(void *ta_parent, void *ptr)
{
ta_oom_b(ta_set_parent(ptr, ta_parent));
return ptr;
}
void *ta_xmemdup(void *ta_parent, void *ptr, size_t size)
{
void *new = ta_memdup(ta_parent, ptr, size);
ta_oom_b(new || !ptr);
return new;
}
void *ta_xrealloc_size(void *ta_parent, void *ptr, size_t size)
{
ptr = ta_realloc_size(ta_parent, ptr, size);
ta_oom_b(ptr || !size);
return ptr;
}
char *ta_xstrdup(void *ta_parent, const char *str)
{
char *res = ta_strdup(ta_parent, str);
ta_oom_b(res || !str);
return res;
}
char *ta_xstrndup(void *ta_parent, const char *str, size_t n)
{
char *res = ta_strndup(ta_parent, str, n);
ta_oom_b(res || !str);
return res;
}