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/*
Unix SMB/Netbios implementation.
Version 3.0
Samba temporary memory allocation functions
Copyright (C) Andrew Tridgell 2000
Copyright (C) 2001 by Martin Pool <mbp@samba.org>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
/**
@defgroup talloc Simple memory allocator
@{
This is a very simple temporary memory allocator. To use it do the following:
1) when you first want to allocate a pool of meomry use
talloc_init() and save the resulting context pointer somewhere
2) to allocate memory use talloc()
3) when _all_ of the memory allocated using this context is no longer needed
use talloc_destroy()
talloc does not zero the memory. It guarantees memory of a
TALLOC_ALIGN alignment
@sa talloc.h
*/
/**
* @todo We could allocate both the talloc_chunk structure, and the
* memory it contains all in one allocation, which might be a bit
* faster and perhaps use less memory overhead.
*
* That smells like a premature optimization, though. -- mbp */
#include "includes.h"
/** Create a new talloc context. **/
TALLOC_CTX *talloc_init(void)
{
TALLOC_CTX *t;
t = (TALLOC_CTX *)malloc(sizeof(*t));
if (!t) return NULL;
t->list = NULL;
t->total_alloc_size = 0;
return t;
}
/**
* Create a new talloc context, with a name specifying its purpose.
* Please call this in preference to talloc_init().
**/
TALLOC_CTX *talloc_init_named(char const *fmt, ...)
{
TALLOC_CTX *t;
va_list ap;
t = talloc_init();
va_start(ap, fmt);
t->name = talloc_vasprintf(t, fmt, ap);
va_end(ap);
return t;
}
/** Allocate a bit of memory from the specified pool **/
void *talloc(TALLOC_CTX *t, size_t size)
{
void *p;
struct talloc_chunk *tc;
if (size == 0) return NULL;
p = malloc(size);
if (!p) return p;
tc = malloc(sizeof(*tc));
if (!tc) {
SAFE_FREE(p);
return NULL;
}
tc->ptr = p;
tc->size = size;
tc->next = t->list;
t->list = tc;
t->total_alloc_size += size;
return p;
}
/** A talloc version of realloc */
void *talloc_realloc(TALLOC_CTX *t, void *ptr, size_t size)
{
struct talloc_chunk *tc;
/* size zero is equivalent to free() */
if (size == 0)
return NULL;
/* realloc(NULL) is equavalent to malloc() */
if (ptr == NULL)
return talloc(t, size);
for (tc=t->list; tc; tc=tc->next) {
if (tc->ptr == ptr) {
ptr = Realloc(ptr, size);
if (ptr) {
t->total_alloc_size += (size - tc->size);
tc->size = size;
tc->ptr = ptr;
}
return ptr;
}
}
return NULL;
}
/** Destroy all the memory allocated inside @p t, but not @p t
* itself. */
void talloc_destroy_pool(TALLOC_CTX *t)
{
struct talloc_chunk *c;
if (!t)
return;
while (t->list) {
c = t->list->next;
SAFE_FREE(t->list->ptr);
SAFE_FREE(t->list);
t->list = c;
}
t->total_alloc_size = 0;
}
/** Destroy a whole pool including the context */
void talloc_destroy(TALLOC_CTX *t)
{
if (!t)
return;
talloc_destroy_pool(t);
memset(t, 0, sizeof(*t));
SAFE_FREE(t);
}
/** Return the current total size of the pool. */
size_t talloc_pool_size(TALLOC_CTX *t)
{
return t->total_alloc_size;
}
/** talloc and zero memory. */
void *talloc_zero(TALLOC_CTX *t, size_t size)
{
void *p = talloc(t, size);
if (p)
memset(p, '\0', size);
return p;
}
/** memdup with a talloc. */
void *talloc_memdup(TALLOC_CTX *t, const void *p, size_t size)
{
void *newp = talloc(t,size);
if (!newp)
return 0;
memcpy(newp, p, size);
return newp;
}
/** strdup with a talloc */
char *talloc_strdup(TALLOC_CTX *t, const char *p)
{
return talloc_memdup(t, p, strlen(p) + 1);
}
/**
* Perform string formatting, and return a pointer to newly allocated
* memory holding the result, inside a memory pool.
**/
char *talloc_asprintf(TALLOC_CTX *t, const char *fmt, ...)
{
va_list ap;
char *ret;
/* work out how long it will be */
va_start(ap, fmt);
ret = talloc_vasprintf(t, fmt, ap);
va_end(ap);
return ret;
}
char *talloc_vasprintf(TALLOC_CTX *t, const char *fmt, va_list ap)
{
int len;
char *ret;
len = vsnprintf(NULL, 0, fmt, ap);
ret = talloc(t, len+1);
if (!ret) return NULL;
vsnprintf(ret, len+1, fmt, ap);
return ret;
}
/** @} */
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