Passbolt/fcron-3.2.0/u_list.c

272 lines
7.7 KiB
C

/*
* FCRON - periodic command scheduler
*
* Copyright 2000-2014 Thibault Godouet <fcron@free.fr>
*
* 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* The GNU General Public License can also be found in the file
* `LICENSE' that comes with the fcron source distribution.
*/
/*
* Unordered list of generic items
*/
#include "global.h"
#include "mem.h"
#include "log.h"
#include "u_list.h"
/* private functions: */
int u_list_resize_array(u_list_t * l);
u_list_entry_t *u_list_last(u_list_t * l);
u_list_t *
u_list_init(size_t entry_size, int init_size, int grow_size)
/* Create a new unordered list
* Returns the newly created unorderd list
* Enough memory to hold init_size entries will initially be allocated,
* and it will grow by grow_size entries when more space is needed.
* Dies on error. */
{
u_list_t *l = NULL;
/* sanity check */
if (entry_size < 1 || init_size < 1 || grow_size < 1)
die("Invalid arguments for u_list_init(): entry_size=%d, init_size=%d, "
"grow_size=%d", entry_size, init_size, grow_size);
/* Allocate the list structure: */
l = alloc_safe(sizeof(struct u_list_t), "new u_list_t");
/* Initialize the structure and allocate the array: */
l->array_size = init_size;
l->entry_size = entry_size;
l->grow_size = grow_size;
l->cur_entry = NULL;
l->cur_removed = 0;
l->entries_array = alloc_safe(init_size * entry_size, "new u_list_t array");
return l;
}
u_list_t *
u_list_copy(u_list_t * list)
{
u_list_t *new_list = NULL;
if (list == NULL)
return NULL;
new_list = alloc_safe(sizeof(struct u_list_t), "u_list_t copy");
memcpy(new_list, list, sizeof(struct u_list_t));
new_list->cur_entry = NULL;
new_list->entries_array = alloc_safe(list->array_size * list->entry_size,
"u_list_t copy (array)");
memcpy(new_list->entries_array, list->entries_array,
(list->array_size * list->entry_size));
return new_list;
}
int
u_list_resize_array(u_list_t * l)
/* Resize l's entries_array up to l->max_entries
* Returns OK on success, ERR if the array is already at maximum size */
{
int offset = 0;
int old_size = l->array_size;
/* sanity check */
if (l == NULL)
die("Invalid argument for u_list_resize_array(): list=%d", l);
if (l->max_entries > 0 && l->array_size >= l->max_entries) {
debug
("Resizing u_list_t failed because it is already at max size (size: %d)",
l->array_size);
return ERR;
}
if (l->cur_entry != NULL)
/* Compute cur_entry's offset so as we can set cur_entry to the right place
* after we have allocated a new chunk of memory for the entries_array */
offset = (char *)l->cur_entry - (char *)l->entries_array;
l->array_size = (l->array_size + l->grow_size);
if (l->max_entries > 0 && l->array_size > l->max_entries)
l->array_size = l->max_entries;
debug("Resizing u_list_t (old size: %d, new size: %d)...", old_size,
l->array_size);
l->entries_array =
realloc_safe(l->entries_array, (l->array_size * l->entry_size),
"larger u_list_t array");
/* allocate newly allocated memory */
memset((char *)l->entries_array + (old_size * l->entry_size), '\0',
(l->array_size - old_size) * l->entry_size);
if (l->cur_entry != NULL)
l->cur_entry = (u_list_entry_t *) ((char *)l->entries_array + offset);
return OK;
}
u_list_entry_t *
u_list_last(u_list_t * l)
/* Returns the pointer of the last entry in the list, or NULL if l is empty */
{
if (l->num_entries <= 0)
return NULL;
else
return (u_list_entry_t *)
((char *)l->entries_array + l->entry_size * (l->num_entries - 1));
}
u_list_entry_t *
u_list_add(u_list_t * l, u_list_entry_t * e)
/* Add one entry to the list
* Returns a pointer to the added element, or NULL if list is already at max size */
{
u_list_entry_t *new = NULL;
/* sanity check */
if (l == NULL || e == NULL)
die("Invalid arguments for u_list_add(): list=%d, entry=%d", l, e);
/* Check there is some space left, or resize the array */
if (l->num_entries >= l->array_size) {
/* no more space: attempt to grow (the following function dies on error: */
if (u_list_resize_array(l) != OK)
return NULL;
}
l->num_entries++;
new = u_list_last(l);
memcpy(new, e, l->entry_size);
return new;
}
int
u_list_is_iterating(u_list_t * l)
{
/* sanity check */
if (l == NULL)
die("Invalid argument for u_list_iterating(): list=%d", l);
return (l->cur_entry != NULL);
}
u_list_entry_t *
u_list_first(u_list_t * l)
/* Return the first entry of the list (then u_list_next() can be used) */
{
/* sanity check */
if (l == NULL)
die("Invalid argument for u_list_first(): list=%d", l);
if (l->cur_entry != NULL)
die("u_list_first() called but there is already an iteration");
if (l->num_entries > 0) {
l->cur_entry = l->entries_array;
}
return l->cur_entry;
}
u_list_entry_t *
u_list_next(u_list_t * l)
/* Return the entry after e */
{
/* sanity checks */
if (l == NULL)
die("Invalid arguments for u_list_next(): list=%d", l);
if (l->cur_entry == NULL)
die("u_list_next() called outside an iteration: l->cur_entry=%d",
l->cur_entry);
if (l->cur_removed > 0) {
l->cur_removed = 0;
/* the current entry has just been removed and replaced by another one:
* we can return the same pointer again.
* However if the removed entry was the last one then we reached the end
* of the list */
if (l->cur_entry > u_list_last(l))
l->cur_entry = NULL;
}
else {
/* cur_entry *not* removed (standard behavior) */
if (l->cur_entry < u_list_last(l))
l->cur_entry =
(u_list_entry_t *) ((char *)l->cur_entry + l->entry_size);
else
/* reached the end of the list */
l->cur_entry = NULL;
}
return l->cur_entry;
}
void
u_list_end_iteration(u_list_t * list)
/* Stop an iteration before _next() reached the end of the list by itself */
{
list->cur_entry = NULL;
list->cur_removed = 0;
}
void
u_list_remove_cur(u_list_t * l)
{
u_list_entry_t *last = NULL;
/* sanity checks */
if (l == NULL)
die("Invalid arguments for u_list_remove(): list=%d", l);
if (l->cur_entry == NULL)
die("u_list_remove_cur() called outside of an iteration");
last = u_list_last(l);
if (l->cur_entry < last) {
/* Override e with the last entry */
memcpy(l->cur_entry, last, l->entry_size);
}
/* erase the last entry and update the number of entries */
memset(last, 0, l->entry_size);
l->num_entries--;
l->cur_removed = 1;
}
u_list_t *
u_list_destroy(u_list_t * list)
/* free() the memory allocated for list and returns NULL */
{
if (list == NULL)
die("Invalid argument for u_list_destroy(): list=%d", list);
Free_safe(list->entries_array);
Free_safe(list);
return NULL;
}