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Diffstat (limited to 'backend/list.c')
-rw-r--r-- | backend/list.c | 198 |
1 files changed, 198 insertions, 0 deletions
diff --git a/backend/list.c b/backend/list.c new file mode 100644 index 0000000..7e0810c --- /dev/null +++ b/backend/list.c @@ -0,0 +1,198 @@ +/* list.c -- A poor implementation of a linked list + * Copyright (C) 2008 SEIKO EPSON CORPORATION + * + * License: GPLv2+|iscan + * Authors: AVASYS CORPORATION + * + * This file is part of the SANE backend distributed with Image Scan! + * + * Image Scan!'s SANE backend 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 ought to have received a copy of the GNU General Public License + * along with this package. If not, see <http://www.gnu.org/licenses/>. + * + * + * Linking Image Scan!'s SANE backend statically or dynamically with + * other modules is making a combined work based on this SANE backend. + * Thus, the terms and conditions of the GNU General Public License + * cover the whole combination. + * + * As a special exception, the copyright holders of Image Scan!'s SANE + * backend give you permission to link Image Scan!'s SANE backend with + * SANE frontends that communicate with Image Scan!'s SANE backend + * solely through the SANE Application Programming Interface, + * regardless of the license terms of these SANE frontends, and to + * copy and distribute the resulting combined work under terms of your + * choice, provided that every copy of the combined work is + * accompanied by a complete copy of the source code of Image Scan!'s + * SANE backend (the version of Image Scan!'s SANE backend used to + * produce the combined work), being distributed under the terms of + * the GNU General Public License plus this exception. An independent + * module is a module which is not derived from or based on Image + * Scan!'s SANE backend. + * + * As a special exception, the copyright holders of Image Scan!'s SANE + * backend give you permission to link Image Scan!'s SANE backend with + * independent modules that communicate with Image Scan!'s SANE + * backend solely through the "Interpreter" interface, regardless of + * the license terms of these independent modules, and to copy and + * distribute the resulting combined work under terms of your choice, + * provided that every copy of the combined work is accompanied by a + * complete copy of the source code of Image Scan!'s SANE backend (the + * version of Image Scan!'s SANE backend used to produce the combined + * work), being distributed under the terms of the GNU General Public + * License plus this exception. An independent module is a module + * which is not derived from or based on Image Scan!'s SANE backend. + * + * Note that people who make modified versions of Image Scan!'s SANE + * backend are not obligated to grant special exceptions for their + * modified versions; it is their choice whether to do so. The GNU + * General Public License gives permission to release a modified + * version without this exception; this exception also makes it + * possible to release a modified version which carries forward this + * exception. + */ + + +/*! \file + \brief Implements a linked list. + */ + +#ifdef HAVE_CONFIG_H +#include <config.h> +#endif + +#include "list.h" + +#include <string.h> + +/*! Create a new list. + */ +list* list_create () +{ + list* lst = 0; + + lst = t_calloc (1, list); + return lst; +} + +/*! Destroy a list. + * Deletes the list related structures, and the contained data with the + * given destructor function. If a destructor is not provided the data is + * left as is. + */ +void list_destroy (list* lst, void (*dtor)(void*)) +{ + if (!lst) return; + + list_entry* entry = lst->head; + list_entry* tmp; + + while (entry != NULL) + { + if (dtor && entry->data) + (*dtor) (entry->data); + + tmp = entry->next; + delete (entry); + entry = tmp; + } + + delete (lst); +} + +/*! Adds a new element to the end of the list. + * Does *not* make a copy. + */ +bool list_append (list* lst, void* new_data) +{ + if (!lst) return false; + + list_entry* entry = 0; + + entry = t_calloc (1, list_entry); + if (!entry) return false; + + entry->data = new_data; + + if (0 == lst->num_entries) + { + lst->head = entry; + lst->tail = entry; + lst->cur = entry; + } + else + { + lst->tail->next = entry; + lst->tail = entry; + } + + lst->num_entries += 1; + return true; +} + +/*! Creates a NULL terminated array of pointers to list entries. + */ +void** list_normalize (const list *lst) +{ + void **nlst; + + if (!lst) return NULL; + + nlst = t_malloc (lst->num_entries + 1, void *); + if (nlst) + { + list *p = (list *) lst; + list_entry *cur = p->cur; + + void *entry; + int i = 0; + + list_reset (p); + while ((entry = list_next (p))) + { + nlst[i++] = entry; + } + nlst[i++] = NULL; + p->cur = cur; + } + return nlst; +} + +/*! Obtain the number of elements in the list + */ +size_t list_size (list* lst) +{ + if (!lst) return 0; + return lst->num_entries; +} + +/*! Reset iteration to start from the beginning of the list + */ +void list_reset (list* lst) +{ + if (!lst) return; + + lst->cur = lst->head; +} + +/*! Proceed to the next element in the list. + * Used to iterate over the list items. + */ +void* list_next (list* lst) +{ + if (!lst || !lst->cur) return 0; + + void* rv = lst->cur->data; + lst->cur = lst->cur->next; + + return rv; +} |