/*
* viralloc.c: safer memory allocation
*
* Copyright (C) 2010-2014 Red Hat, Inc.
* Copyright (C) 2008 Daniel P. Berrange
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library. If not, see
* .
*
*/
#include
#include "viralloc.h"
#include "virlog.h"
#include "virerror.h"
#define VIR_FROM_THIS VIR_FROM_NONE
VIR_LOG_INIT("util.alloc");
/**
* virReallocN:
* @ptrptr: pointer to pointer for address of allocated memory
* @size: number of bytes to allocate
* @count: number of elements in array
*
* Resize the block of memory in 'ptrptr' to be an array of
* 'count' elements, each 'size' bytes in length. Update 'ptrptr'
* with the address of the newly allocated memory. On failure,
* 'ptrptr' is not changed and still points to the original memory
* block. Any newly allocated memory in 'ptrptr' is uninitialized.
*
* Returns zero on success, aborts on OOM
*/
int virReallocN(void *ptrptr,
size_t size,
size_t count)
{
*(void **)ptrptr = g_realloc_n(*(void**)ptrptr, size, count);
return 0;
}
/**
* virExpandN:
* @ptrptr: pointer to pointer for address of allocated memory
* @size: number of bytes per element
* @countptr: pointer to number of elements in array
* @add: number of elements to add
*
* Resize the block of memory in 'ptrptr' to be an array of
* '*countptr' + 'add' elements, each 'size' bytes in length.
* Update 'ptrptr' and 'countptr' with the details of the newly
* allocated memory. On failure, 'ptrptr' and 'countptr' are not
* changed. Any newly allocated memory in 'ptrptr' is zero-filled.
*
* Returns zero on success, aborts on OOM
*/
int virExpandN(void *ptrptr,
size_t size,
size_t *countptr,
size_t add)
{
if (*countptr + add < *countptr)
abort();
if (virReallocN(ptrptr, size, *countptr + add) < 0)
abort();
memset(*(char **)ptrptr + (size * *countptr), 0, size * add);
*countptr += add;
return 0;
}
/**
* virResizeN:
* @ptrptr: pointer to pointer for address of allocated memory
* @size: number of bytes per element
* @allocptr: pointer to number of elements allocated in array
* @count: number of elements currently used in array
* @add: minimum number of additional elements to support in array
*
* If 'count' + 'add' is larger than '*allocptr', then resize the
* block of memory in 'ptrptr' to be an array of at least 'count' +
* 'add' elements, each 'size' bytes in length. Update 'ptrptr' and
* 'allocptr' with the details of the newly allocated memory. On
* failure, 'ptrptr' and 'allocptr' are not changed. Any newly
* allocated memory in 'ptrptr' is zero-filled.
*
* Returns zero on success, aborts on OOM
*/
int virResizeN(void *ptrptr,
size_t size,
size_t *allocptr,
size_t count,
size_t add)
{
size_t delta;
if (count + add < count)
abort();
if (count + add <= *allocptr)
return 0;
delta = count + add - *allocptr;
if (delta < *allocptr / 2)
delta = *allocptr / 2;
return virExpandN(ptrptr, size, allocptr, delta);
}
/**
* virShrinkN:
* @ptrptr: pointer to pointer for address of allocated memory
* @size: number of bytes per element
* @countptr: pointer to number of elements in array
* @toremove: number of elements to remove
*
* Resize the block of memory in 'ptrptr' to be an array of
* '*countptr' - 'toremove' elements, each 'size' bytes in length.
* Update 'ptrptr' and 'countptr' with the details of the newly
* allocated memory. If 'toremove' is larger than 'countptr', free
* the entire array.
*/
void virShrinkN(void *ptrptr, size_t size, size_t *countptr, size_t toremove)
{
if (toremove < *countptr) {
if (virReallocN(ptrptr, size, *countptr -= toremove) < 0)
abort();
} else {
g_free(*((void **)ptrptr));
*((void **)ptrptr) = NULL;
*countptr = 0;
}
}
/**
* virInsertElementsN:
* @ptrptr: pointer to hold address of allocated memory
* @size: the size of one element in bytes
* @at: index within array where new elements should be added, -1 for end
* @countptr: variable tracking number of elements currently allocated
* @add: number of elements to add
* @newelems: pointer to array of one or more new elements to move into
* place (the originals will be zeroed out if successful
* and if clearOriginal is true)
* @clearOriginal: false if the new item in the array should be copied
* from the original, and the original left intact.
* true if the original should be 0'd out on success.
* @inPlace: false if we should expand the allocated memory before
* moving, true if we should assume someone else *has
* already* done that.
*
* Re-allocate an array of *countptr elements, each sizeof(*ptrptr) bytes
* long, to be *countptr+add elements long, then appropriately move
* the elements starting at ptrptr[at] up by add elements, copy the
* items from newelems into ptrptr[at], then store the address of
* allocated memory in *ptrptr and the new size in *countptr. If
* newelems is NULL, the new elements at ptrptr[at] are instead filled
* with zero. at must be between [0,*countptr], except that -1 is
* treated the same as *countptr for convenience.
*
* Returns -1 on failure, 0 on success
*/
int
virInsertElementsN(void *ptrptr, size_t size, size_t at,
size_t *countptr,
size_t add, void *newelems,
bool clearOriginal, bool inPlace)
{
if (at == -1) {
at = *countptr;
} else if (at > *countptr) {
virReportError(VIR_ERR_INTERNAL_ERROR,
_("out of bounds index - count %zu at %zu add %zu"),
*countptr, at, add);
return -1;
}
if (inPlace) {
*countptr += add;
} else {
if (virExpandN(ptrptr, size, countptr, add) < 0)
abort();
}
/* memory was successfully re-allocated. Move up all elements from
* ptrptr[at] to the end (if we're not "inserting" at the end
* already), memcpy in the new elements, and clear the elements
* from their original location. Remember that *countptr has
* already been updated with new element count!
*/
if (at < *countptr - add) {
memmove(*(char**)ptrptr + (size * (at + add)),
*(char**)ptrptr + (size * at),
size * (*countptr - add - at));
}
if (newelems) {
memcpy(*(char**)ptrptr + (size * at), newelems, size * add);
if (clearOriginal)
memset((char*)newelems, 0, size * add);
} else if (inPlace || (at < *countptr - add)) {
/* NB: if inPlace, assume memory at the end wasn't initialized */
memset(*(char**)ptrptr + (size * at), 0, size * add);
}
return 0;
}
/**
* virDeleteElementsN:
* @ptrptr: pointer to hold address of allocated memory
* @size: the size of one element in bytes
* @at: index within array where new elements should be deleted
* @countptr: variable tracking number of elements currently allocated
* @toremove: number of elements to remove
* @inPlace: false if we should shrink the allocated memory when done,
* true if we should assume someone else will do that.
*
* Re-allocate an array of *countptr elements, each sizeof(*ptrptr)
* bytes long, to be *countptr-remove elements long, then store the
* address of allocated memory in *ptrptr and the new size in *countptr.
* If *countptr <= remove, the entire array is freed.
*
* Returns -1 on failure, 0 on success
*/
int
virDeleteElementsN(void *ptrptr, size_t size, size_t at,
size_t *countptr, size_t toremove,
bool inPlace)
{
if (at + toremove > *countptr) {
VIR_WARN("out of bounds index - count %zu at %zu toremove %zu",
*countptr, at, toremove);
return -1;
}
/* First move down the elements at the end that won't be deleted,
* then realloc. We assume that the items being deleted have
* already been cleared.
*/
memmove(*(char**)ptrptr + (size * at),
*(char**)ptrptr + (size * (at + toremove)),
size * (*countptr - toremove - at));
if (inPlace)
*countptr -= toremove;
else
virShrinkN(ptrptr, size, countptr, toremove);
return 0;
}