libvirt-python/libvirt-utils.c

/*
 * libvirt-utils.c: misc helper APIs for python binding
 *
 * Copyright (C) 2013 Red Hat, Inc.
 *
 * 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
 * <http://www.gnu.org/licenses/>.
 *
 */

#include <errno.h>
#include <stddef.h>
#include <stdlib.h>
#include <unistd.h>
#include <libvirt/libvirt.h>
#include "libvirt-utils.h"

/**
 * virAlloc:
 * @ptrptr: pointer to pointer for address of allocated memory
 * @size: number of bytes to allocate
 *
 * Allocate  'size' bytes of memory. Return the address of the
 * allocated memory in 'ptrptr'. The newly allocated memory is
 * filled with zeros.
 *
 * Returns -1 on failure to allocate, zero on success
 */
int virAlloc(void *ptrptr,
             size_t size)
{
    *(void **)ptrptr = calloc(1, size);
    if (*(void **)ptrptr == NULL) {
        return -1;
    }
    return 0;
}

/**
 * virAllocN:
 * @ptrptr: pointer to pointer for address of allocated memory
 * @size: number of bytes to allocate
 * @count: number of elements to allocate
 *
 * Allocate an array of memory 'count' elements long,
 * each with 'size' bytes. Return the address of the
 * allocated memory in 'ptrptr'.  The newly allocated
 * memory is filled with zeros.
 *
 * Returns -1 on failure to allocate, zero on success
 */
int virAllocN(void *ptrptr,
              size_t size,
              size_t count)
{
    *(void**)ptrptr = calloc(count, size);
    if (*(void**)ptrptr == NULL) {
        return -1;
    }
    return 0;
}

/**
 * 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 -1 on failure to allocate, zero on success
 */
int virReallocN(void *ptrptr,
                size_t size,
                size_t count)
{
    void *tmp;

    if (xalloc_oversized(count, size)) {
        errno = ENOMEM;
        return -1;
    }
    tmp = realloc(*(void**)ptrptr, size * count);
    if (!tmp && (size * count)) {
        return -1;
    }
    *(void**)ptrptr = tmp;
    return 0;
}


/**
 * virFree:
 * @ptrptr: pointer to pointer for address of memory to be freed
 *
 * Release the chunk of memory in the pointer pointed to by
 * the 'ptrptr' variable. After release, 'ptrptr' will be
 * updated to point to NULL.
 */
void virFree(void *ptrptr)
{
    int save_errno = errno;

    free(*(void**)ptrptr);
    *(void**)ptrptr = NULL;
    errno = save_errno;
}


int virFileClose(int *fdptr)
{
    int saved_errno = 0;
    int rc = 0;

    saved_errno = errno;

    if (*fdptr < 0)
        return 0;

    rc = close(*fdptr);
    *fdptr = -1;

    errno = saved_errno;

    return rc;
}

#if ! LIBVIR_CHECK_VERSION(1, 0, 2)
/**
 * virTypedParamsClear:
 * @params: the array of the typed parameters
 * @nparams: number of parameters in the @params array
 *
 * Frees all memory used by string parameters. The memory occupied by @params
 * is not free; use virTypedParamsFree if you want it to be freed too.
 *
 * Returns nothing.
 */
void
virTypedParamsClear(virTypedParameterPtr params,
                    int nparams)
{
    size_t i;

    if (!params)
        return;

    for (i = 0; i < nparams; i++) {
        if (params[i].type == VIR_TYPED_PARAM_STRING)
            VIR_FREE(params[i].value.s);
    }
}

/**
 * virTypedParamsFree:
 * @params: the array of the typed parameters
 * @nparams: number of parameters in the @params array
 *
 * Frees all memory used by string parameters and the memory occuiped by
 * @params.
 *
 * Returns nothing.
 */
void
virTypedParamsFree(virTypedParameterPtr params,
                   int nparams)
{
    virTypedParamsClear(params, nparams);
    VIR_FREE(params);
}
#endif /* ! LIBVIR_CHECK_VERSION(1, 0, 2) */