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