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#ifndef MRU_H
#define MRU_H
/**
* A simple most-recently-used cache, backed by a doubly-linked list.
*
* Usage is roughly:
*
* // Create a list. Zero-initialization is required.
* static struct mru cache;
* mru_append(&cache, item);
* ...
*
* // Iterate in MRU order.
* struct mru_entry *p;
* for (p = cache.head; p; p = p->next) {
* if (matches(p->item))
* break;
* }
*
* // Mark an item as used, moving it to the front of the list.
* mru_mark(&cache, p);
*
* // Reset the list to empty, cleaning up all resources.
* mru_clear(&cache);
*
* Note that you SHOULD NOT call mru_mark() and then continue traversing the
* list; it reorders the marked item to the front of the list, and therefore
* you will begin traversing the whole list again.
*/
struct mru_entry {
void *item;
struct mru_entry *prev, *next;
};
struct mru {
struct mru_entry *head, *tail;
};
void mru_append(struct mru *mru, void *item);
void mru_mark(struct mru *mru, struct mru_entry *entry);
void mru_clear(struct mru *mru);
#endif /* MRU_H */
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