Change lru from double to single linked list. Only the font cache uses LRU and it never searches in reverse. Saves 2 bytes per glyph.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@30818 a1c6a512-1295-4272-9138-f99709370657
This commit is contained in:
Fred Bauer 2011-10-21 20:23:21 +00:00
parent c032b9d083
commit 6f078c428f
2 changed files with 1 additions and 11 deletions

View file

@ -33,7 +33,7 @@ struct lru
void *_base;
};
#define LRU_SLOT_OVERHEAD (2 * sizeof(short))
#define LRU_SLOT_OVERHEAD (1 * sizeof(short))
/* Create LRU list with specified size from buf. */
void lru_create(struct lru* pl, void *buf, short size, short data_size);

View file

@ -48,11 +48,9 @@ void lru_create(struct lru* pl, void *buf, short size, short data_size)
for (i=0; i<pl->_size; i++)
{
lru_node_p(pl, i)->_next = i + 1;
lru_node_p(pl, i)->_prev = i - 1;
}
/* Fix up head and tail to form circular buffer */
lru_node_p(pl, 0)->_prev = pl->_tail;
lru_node_p(pl, pl->_tail)->_next = pl->_head;
}
@ -92,20 +90,12 @@ void lru_touch(struct lru* pl, short handle)
/* Remove current node from linked list */
struct lru_node* curr_node = lru_node_p(pl, handle);
struct lru_node* prev_node = lru_node_p(pl, curr_node->_prev);
struct lru_node* next_node = lru_node_p(pl, curr_node->_next);
prev_node->_next = curr_node->_next;
next_node->_prev = curr_node->_prev;
/* insert current node at tail */
struct lru_node* tail_node = lru_node_p(pl, pl->_tail);
short tail_node_next_handle = tail_node->_next; /* Bug fix */
struct lru_node* tail_node_next = lru_node_p(pl, tail_node_next_handle); /* Bug fix */
curr_node->_next = tail_node->_next;
curr_node->_prev = pl->_tail;
tail_node_next->_prev = handle; /* Bug fix */
tail_node->_next = handle;
pl->_tail = handle;