add rbtree
This commit is contained in:
Nick Peng
@@ -13,6 +13,8 @@ struct cache_head *cache_new(int hashsize, void (*item_free)(struct cache_head *
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int cache_add(struct cache_head *head, struct cache_node *node, void *key, int key_len);
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int cache_del(struct cache_node *node);
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struct cache_node *cache_lookup(struct cache_head *head, void *key, int key_len);
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int cache_update(struct cache_head *head, void *key, int key_len);
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287
src/include/rbtree.h
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287
src/include/rbtree.h
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@@ -0,0 +1,287 @@
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#ifndef _GENERIC_RBTREE_H
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#define _GENERIC_RBTREE_H
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#include <stddef.h>
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struct rb_node {
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unsigned long __rb_parent_color;
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struct rb_node *rb_right;
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struct rb_node *rb_left;
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} __attribute__((aligned(sizeof(long))));
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/* The alignment might seem pointless, but allegedly CRIS needs it */
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struct rb_root {
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struct rb_node *rb_node;
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};
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#define rb_parent(r) ((struct rb_node *)((r)->__rb_parent_color & ~3))
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#define RB_ROOT \
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(struct rb_root) \
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{ \
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NULL, \
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}
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#define rb_entry(ptr, type, member) container_of(ptr, type, member)
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#define RB_EMPTY_ROOT(root) ((root)->rb_node == NULL)
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/* 'empty' nodes are nodes that are known not to be inserted in an rbtree */
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#define RB_EMPTY_NODE(node) ((node)->__rb_parent_color == (unsigned long)(node))
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#define RB_CLEAR_NODE(node) ((node)->__rb_parent_color = (unsigned long)(node))
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extern void rb_insert_color(struct rb_node *, struct rb_root *);
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extern void rb_erase(struct rb_node *, struct rb_root *);
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/* Find logical next and previous nodes in a tree */
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extern struct rb_node *rb_next(const struct rb_node *);
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extern struct rb_node *rb_prev(const struct rb_node *);
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extern struct rb_node *rb_first(const struct rb_root *);
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extern struct rb_node *rb_last(const struct rb_root *);
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/* Postorder iteration - always visit the parent after its children */
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extern struct rb_node *rb_first_postorder(const struct rb_root *);
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extern struct rb_node *rb_next_postorder(const struct rb_node *);
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/* Fast replacement of a single node without remove/rebalance/add/rebalance */
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extern void rb_replace_node(struct rb_node *victim, struct rb_node *new_node, struct rb_root *root);
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static inline void rb_link_node(struct rb_node *node, struct rb_node *parent, struct rb_node **rb_link)
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{
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node->__rb_parent_color = (unsigned long)parent;
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node->rb_left = node->rb_right = NULL;
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*rb_link = node;
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}
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#define rb_entry_safe(ptr, type, member) \
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({ \
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typeof(ptr) ____ptr = (ptr); \
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____ptr ? rb_entry(____ptr, type, member) : NULL; \
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})
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/*
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* Handy for checking that we are not deleting an entry that is
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* already in a list, found in block/{blk-throttle,cfq-iosched}.c,
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* probably should be moved to lib/rbtree.c...
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*/
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static inline void rb_erase_init(struct rb_node *n, struct rb_root *root)
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{
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rb_erase(n, root);
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RB_CLEAR_NODE(n);
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}
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/*
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* Please note - only struct rb_augment_callbacks and the prototypes for
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* rb_insert_augmented() and rb_erase_augmented() are intended to be public.
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* The rest are implementation details you are not expected to depend on.
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*
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* See Documentation/rbtree.txt for documentation and samples.
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*/
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struct rb_augment_callbacks {
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void (*propagate)(struct rb_node *node, struct rb_node *stop);
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void (*copy)(struct rb_node *old_node, struct rb_node *new_node);
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void (*rotate)(struct rb_node *old_node, struct rb_node *new_node);
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};
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extern void __rb_insert_augmented(struct rb_node *node, struct rb_root *root,
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void (*augment_rotate)(struct rb_node *old_node, struct rb_node *new_node));
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/*
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* Fixup the rbtree and update the augmented information when rebalancing.
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*
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* On insertion, the user must update the augmented information on the path
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* leading to the inserted node, then call rb_link_node() as usual and
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* rb_augment_inserted() instead of the usual rb_insert_color() call.
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* If rb_augment_inserted() rebalances the rbtree, it will callback into
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* a user provided function to update the augmented information on the
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* affected subtrees.
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*/
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static inline void
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rb_insert_augmented(struct rb_node *node, struct rb_root *root,
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const struct rb_augment_callbacks *augment)
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{
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__rb_insert_augmented(node, root, augment->rotate);
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}
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#define RB_DECLARE_CALLBACKS(rbstatic, rbname, rbstruct, rbfield, \
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rbtype, rbaugmented, rbcompute) \
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static inline void \
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rbname ## _propagate(struct rb_node *rb, struct rb_node *stop) \
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{ \
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while (rb != stop) { \
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rbstruct *node = rb_entry(rb, rbstruct, rbfield); \
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rbtype augmented = rbcompute(node); \
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if (node->rbaugmented == augmented) \
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break; \
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node->rbaugmented = augmented; \
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rb = rb_parent(&node->rbfield); \
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} \
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} \
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static inline void \
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rbname ## _copy(struct rb_node *rb_old, struct rb_node *rb_new) \
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{ \
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rbstruct *old_node = rb_entry(rb_old, rbstruct, rbfield); \
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rbstruct *new_node = rb_entry(rb_new, rbstruct, rbfield); \
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new_node->rbaugmented = old_node->rbaugmented; \
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} \
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static void \
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rbname ## _rotate(struct rb_node *rb_old, struct rb_node *rb_new) \
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{ \
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rbstruct *old_node = rb_entry(rb_old, rbstruct, rbfield); \
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rbstruct *new_node = rb_entry(rb_new, rbstruct, rbfield); \
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new_node->rbaugmented = old_node->rbaugmented; \
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old_node->rbaugmented = rbcompute(old_node); \
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} \
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rbstatic const struct rb_augment_callbacks rbname = { \
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rbname ## _propagate, rbname ## _copy, rbname ## _rotate \
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};
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#define RB_RED 0
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#define RB_BLACK 1
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#define __rb_parent(pc) ((struct rb_node *)(pc & ~3))
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#define __rb_color(pc) ((pc) & 1)
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#define __rb_is_black(pc) __rb_color(pc)
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#define __rb_is_red(pc) (!__rb_color(pc))
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#define rb_color(rb) __rb_color((rb)->__rb_parent_color)
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#define rb_is_red(rb) __rb_is_red((rb)->__rb_parent_color)
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#define rb_is_black(rb) __rb_is_black((rb)->__rb_parent_color)
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static inline void rb_set_parent(struct rb_node *rb, struct rb_node *p)
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{
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rb->__rb_parent_color = rb_color(rb) | (unsigned long)p;
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}
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static inline void rb_set_parent_color(struct rb_node *rb,
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struct rb_node *p, int color)
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{
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rb->__rb_parent_color = (unsigned long)p | color;
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}
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static inline void
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__rb_change_child(struct rb_node *old_node, struct rb_node *new_node,
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struct rb_node *parent, struct rb_root *root)
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{
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if (parent) {
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if (parent->rb_left == old_node)
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parent->rb_left = new_node;
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else
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parent->rb_right = new_node;
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} else
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root->rb_node = new_node;
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}
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extern void __rb_erase_color(struct rb_node *parent, struct rb_root *root,
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void (*augment_rotate)(struct rb_node *old_node, struct rb_node *new_node));
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static inline struct rb_node *
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__rb_erase_augmented(struct rb_node *node, struct rb_root *root,
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const struct rb_augment_callbacks *augment)
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{
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struct rb_node *child = node->rb_right, *tmp = node->rb_left;
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struct rb_node *parent, *rebalance;
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unsigned long pc;
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if (!tmp) {
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/*
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* Case 1: node to erase has no more than 1 child (easy!)
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*
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* Note that if there is one child it must be red due to 5)
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* and node must be black due to 4). We adjust colors locally
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* so as to bypass __rb_erase_color() later on.
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*/
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pc = node->__rb_parent_color;
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parent = __rb_parent(pc);
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__rb_change_child(node, child, parent, root);
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if (child) {
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child->__rb_parent_color = pc;
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rebalance = NULL;
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} else
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rebalance = __rb_is_black(pc) ? parent : NULL;
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tmp = parent;
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} else if (!child) {
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/* Still case 1, but this time the child is node->rb_left */
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tmp->__rb_parent_color = pc = node->__rb_parent_color;
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parent = __rb_parent(pc);
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__rb_change_child(node, tmp, parent, root);
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rebalance = NULL;
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tmp = parent;
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} else {
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struct rb_node *successor = child, *child2;
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tmp = child->rb_left;
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if (!tmp) {
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/*
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* Case 2: node's successor is its right child
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*
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* (n) (s)
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* / \ / \
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* (x) (s) -> (x) (c)
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* \
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* (c)
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*/
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parent = successor;
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child2 = successor->rb_right;
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augment->copy(node, successor);
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} else {
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/*
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* Case 3: node's successor is leftmost under
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* node's right child subtree
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*
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* (n) (s)
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* / \ / \
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* (x) (y) -> (x) (y)
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* / /
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* (p) (p)
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* / /
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* (s) (c)
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* \
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* (c)
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*/
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do {
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parent = successor;
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successor = tmp;
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tmp = tmp->rb_left;
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} while (tmp);
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parent->rb_left = child2 = successor->rb_right;
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successor->rb_right = child;
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rb_set_parent(child, successor);
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augment->copy(node, successor);
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augment->propagate(parent, successor);
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}
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successor->rb_left = tmp = node->rb_left;
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rb_set_parent(tmp, successor);
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pc = node->__rb_parent_color;
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tmp = __rb_parent(pc);
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__rb_change_child(node, successor, tmp, root);
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if (child2) {
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successor->__rb_parent_color = pc;
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rb_set_parent_color(child2, parent, RB_BLACK);
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rebalance = NULL;
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} else {
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unsigned long pc2 = successor->__rb_parent_color;
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successor->__rb_parent_color = pc;
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rebalance = __rb_is_black(pc2) ? parent : NULL;
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}
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tmp = successor;
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}
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augment->propagate(tmp, NULL);
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return rebalance;
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}
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static inline void
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rb_erase_augmented(struct rb_node *node, struct rb_root *root,
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const struct rb_augment_callbacks *augment)
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{
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struct rb_node *rebalance = __rb_erase_augmented(node, root, augment);
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if (rebalance)
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__rb_erase_color(rebalance, root, augment->rotate);
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}
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#endif /* _GENERIC_RBTREE_H */
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