mru.c

   1 #include "cache.h"
   2 #include "mru.h"
   3
   4 void mru_append(struct mru *mru, void *item)
   5 {
   6         struct mru_entry *cur = xmalloc(sizeof(*cur));
   7         cur->item = item;
   8         cur->prev = mru->tail;
   9         cur->next = NULL;
  10
  11         if (mru->tail)
  12                 mru->tail->next = cur;
  13         else
  14                 mru->head = cur;
  15         mru->tail = cur;
  16 }
  17
  18 void mru_mark(struct mru *mru, struct mru_entry *entry)
  19 {
  20         /* If we're already at the front of the list, nothing to do */
  21         if (mru->head == entry)
  22                 return;
  23
  24         /* Otherwise, remove us from our current slot... */
  25         if (entry->prev)
  26                 entry->prev->next = entry->next;
  27         if (entry->next)
  28                 entry->next->prev = entry->prev;
  29         else
  30                 mru->tail = entry->prev;
  31
  32         /* And insert us at the beginning. */
  33         entry->prev = NULL;
  34         entry->next = mru->head;
  35         if (mru->head)
  36                 mru->head->prev = entry;
  37         mru->head = entry;
  38 }
  39
  40 void mru_clear(struct mru *mru)
  41 {
  42         struct mru_entry *p = mru->head;
  43
  44         while (p) {
  45                 struct mru_entry *to_free = p;
  46                 p = p->next;
  47                 free(to_free);
  48         }
  49         mru->head = mru->tail = NULL;
  50 }