diff options
Diffstat (limited to 'xpp/xtalk/xlist.c')
-rw-r--r-- | xpp/xtalk/xlist.c | 93 |
1 files changed, 93 insertions, 0 deletions
diff --git a/xpp/xtalk/xlist.c b/xpp/xtalk/xlist.c new file mode 100644 index 0000000..d28debd --- /dev/null +++ b/xpp/xtalk/xlist.c @@ -0,0 +1,93 @@ +#include <assert.h> +#include <stdlib.h> +#include <string.h> +#include <xlist.h> + +struct xlist_node *xlist_new(void *data) +{ + struct xlist_node *list; + + if((list = malloc(sizeof(*list))) == NULL) + return NULL; + list->next = list; + list->prev = list; + list->data = data; + return list; +} + +void xlist_destroy(struct xlist_node *list, xlist_destructor_t destructor) +{ + struct xlist_node *curr; + struct xlist_node *next; + + if (! list) + return; + curr = list->next; + while(curr != list) { + next = curr->next; + if(destructor) + destructor(curr->data); + memset(curr, 0, sizeof(*curr)); + free(curr); + curr = next; + } + memset(list, 0, sizeof(*list)); + free(list); +} + +void xlist_append_item(struct xlist_node *list, struct xlist_node *item) +{ + assert(list); + assert(xlist_empty(item)); + item->next = list; + item->prev = list->prev; + list->prev->next = item; + list->prev = item; +} + +void xlist_prepend_item(struct xlist_node *list, struct xlist_node *item) +{ + assert(list); + assert(xlist_empty(item)); + item->prev = list; + item->next = list->next; + list->next->prev = item; + list->next = item; +} + +void xlist_remove_item(struct xlist_node *item) +{ + assert(item); + item->prev->next = item->next; + item->next->prev = item->prev; + item->next = item->prev = item; +} + +struct xlist_node *xlist_shift(struct xlist_node *list) +{ + struct xlist_node *item; + + if(!list) + return NULL; + if(xlist_empty(list)) + return NULL; + item = list->next; + xlist_remove_item(item); + return item; +} + +int xlist_empty(const struct xlist_node *list) +{ + assert(list); + return list->next == list && list->prev == list; +} + +size_t xlist_length(const struct xlist_node *list) +{ + struct xlist_node *curr; + size_t count = 0; + + for(curr = list->next; curr != list; curr = curr->next) + count++; + return count; +} |