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- #include <unistd.h>
- #include <stdbool.h>
- struct rb_node {
- unsigned long __rb_parent_color;
- struct rb_node *rb_right;
- struct rb_node *rb_left;
- } __attribute__((aligned(sizeof(long))));
- struct rb_root {
- struct rb_node *rb_node;
- };
- #define rb_parent(r) ((struct rb_node *)((r)->__rb_parent_color & ~3))
- #define RB_ROOT (struct rb_root) { NULL, }
- #define rb_entry(ptr, type, member) container_of(ptr, type, member)
- #define RB_EMPTY_ROOT(root) ((root)->rb_node == NULL)
- #define RB_EMPTY_NODE(node) \
- ((node)->__rb_parent_color == (unsigned long)(node))
- #define RB_CLEAR_NODE(node) \
- ((node)->__rb_parent_color = (unsigned long)(node))
- extern void rb_insert_color(struct rb_node *, struct rb_root *);
- extern void rb_erase(struct rb_node *, struct rb_root *);
- extern struct rb_node *rb_next(const struct rb_node *);
- extern struct rb_node *rb_prev(const struct rb_node *);
- extern struct rb_node *rb_first(const struct rb_root *);
- extern struct rb_node *rb_last(const struct rb_root *);
- extern struct rb_node *rb_first_postorder(const struct rb_root *);
- extern struct rb_node *rb_next_postorder(const struct rb_node *);
- extern void rb_replace_node(struct rb_node *victim, struct rb_node *nw, struct rb_root *root);
- static inline void rb_link_node(struct rb_node * node, struct rb_node * parent, struct rb_node ** rb_link)
- {
- node->__rb_parent_color = (unsigned long)parent;
- node->rb_left = node->rb_right = NULL;
- *rb_link = node;
- }
- #define rb_entry_safe(ptr, type, member) ({ typeof(ptr) ____ptr = (ptr); ____ptr ? rb_entry(____ptr, type, member) : NULL; })
- #define rbtree_postorder_for_each_entry_safe(pos, n, root, field) for (pos = rb_entry_safe(rb_first_postorder(root), typeof(*pos), field); pos && ({ n = rb_entry_safe(rb_next_postorder(&pos->field), typeof(*pos), field); 1; });
- struct rb_augment_callbacks {
- void (*propagate)(struct rb_node *node, struct rb_node *stop);
- void (*copy)(struct rb_node *old, struct rb_node *nw);
- void (*rotate)(struct rb_node *old, struct rb_node *nw);
- };
- extern void __rb_insert_augmented(struct rb_node *node, struct rb_root *root,
- void (*augment_rotate)(struct rb_node *old, struct rb_node *nw));
- static inline void
- rb_insert_augmented(struct rb_node *node, struct rb_root *root,
- const struct rb_augment_callbacks *augment)
- {
- __rb_insert_augmented(node, root, augment->rotate);
- }
- #define RB_DECLARE_CALLBACKS(rbstatic, rbname, rbstruct, rbfield, rbtype, rbaugmented, rbcompute) \
- static inline void \
- rbname ## _propagate(struct rb_node *rb, struct rb_node *stop) \
- { \
- while (rb != stop) { \
- rbstruct *node = rb_entry(rb, rbstruct, rbfield); \
- rbtype augmented = rbcompute(node); \
- if (node->rbaugmented == augmented) \
- break; \
- node->rbaugmented = augmented; \
- rb = rb_parent(&node->rbfield); \
- } \
- } \
- static inline void \
- rbname ## _copy(struct rb_node *rb_old, struct rb_node *rb_new) \
- { \
- rbstruct *old = rb_entry(rb_old, rbstruct, rbfield); \
- rbstruct *new = rb_entry(rb_new, rbstruct, rbfield); \
- new->rbaugmented = old->rbaugmented; \
- } \
- static void \
- rbname ## _rotate(struct rb_node *rb_old, struct rb_node *rb_new) \
- { \
- rbstruct *old = rb_entry(rb_old, rbstruct, rbfield); \
- rbstruct *new = rb_entry(rb_new, rbstruct, rbfield); \
- new->rbaugmented = old->rbaugmented; \
- old->rbaugmented = rbcompute(old); \
- } \
- rbstatic const struct rb_augment_callbacks rbname = { \
- rbname ## _propagate, rbname ## _copy, rbname ## _rotate \
- };
- #define RB_RED 0
- #define RB_BLACK 1
- #define __rb_parent(pc) ((struct rb_node *)(pc & ~3))
- #define __rb_color(pc) ((pc) & 1)
- #define __rb_is_black(pc) __rb_color(pc)
- #define __rb_is_red(pc) (!__rb_color(pc))
- #define rb_color(rb) __rb_color((rb)->__rb_parent_color)
- #define rb_is_red(rb) __rb_is_red((rb)->__rb_parent_color)
- #define rb_is_black(rb) __rb_is_black((rb)->__rb_parent_color)
- static inline void rb_set_parent(struct rb_node *rb, struct rb_node *p)
- {
- rb->__rb_parent_color = rb_color(rb) | (unsigned long)p;
- }
- static inline void rb_set_parent_color(struct rb_node *rb,
- struct rb_node *p, int color)
- {
- rb->__rb_parent_color = (unsigned long)p | color;
- }
- static inline void
- __rb_change_child(struct rb_node *old, struct rb_node *nw,
- struct rb_node *parent, struct rb_root *root)
- {
- if (parent) {
- if (parent->rb_left == old)
- parent->rb_left = nw;
- else
- parent->rb_right = nw;
- } else
- root->rb_node = nw;
- }
- extern void __rb_erase_color(struct rb_node *parent, struct rb_root *root,
- void (*augment_rotate)(struct rb_node *old, struct rb_node *nw));
- static __always_inline struct rb_node *
- __rb_erase_augmented(struct rb_node *node, struct rb_root *root,
- const struct rb_augment_callbacks *augment)
- {
- struct rb_node *child = node->rb_right, *tmp = node->rb_left;
- struct rb_node *parent, *rebalance;
- unsigned long pc;
- if (!tmp) {
- /*
- * Case 1: node to erase has no more than 1 child (easy!)
- *
- * Note that if there is one child it must be red due to 5)
- * and node must be black due to 4). We adjust colors locally
- * so as to bypass __rb_erase_color() later on.
- */
- pc = node->__rb_parent_color;
- parent = __rb_parent(pc);
- __rb_change_child(node, child, parent, root);
- if (child) {
- child->__rb_parent_color = pc;
- rebalance = NULL;
- } else
- rebalance = __rb_is_black(pc) ? parent : NULL;
- tmp = parent;
- } else if (!child) {
- /* Still case 1, but this time the child is node->rb_left */
- tmp->__rb_parent_color = pc = node->__rb_parent_color;
- parent = __rb_parent(pc);
- __rb_change_child(node, tmp, parent, root);
- rebalance = NULL;
- tmp = parent;
- } else {
- struct rb_node *successor = child, *child2;
- tmp = child->rb_left;
- if (!tmp) {
- /*
- * Case 2: node's successor is its right child
- *
- * (n) (s)
- * / \ / \
- * (x) (s) -> (x) (c)
- * \
- * (c)
- */
- parent = successor;
- child2 = successor->rb_right;
- augment->copy(node, successor);
- } else {
- /*
- * Case 3: node's successor is leftmost under
- * node's right child subtree
- *
- * (n) (s)
- * / \ / \
- * (x) (y) -> (x) (y)
- * / /
- * (p) (p)
- * / /
- * (s) (c)
- * \
- * (c)
- */
- do {
- parent = successor;
- successor = tmp;
- tmp = tmp->rb_left;
- } while (tmp);
- parent->rb_left = child2 = successor->rb_right;
- successor->rb_right = child;
- rb_set_parent(child, successor);
- augment->copy(node, successor);
- augment->propagate(parent, successor);
- }
- successor->rb_left = tmp = node->rb_left;
- rb_set_parent(tmp, successor);
- pc = node->__rb_parent_color;
- tmp = __rb_parent(pc);
- __rb_change_child(node, successor, tmp, root);
- if (child2) {
- successor->__rb_parent_color = pc;
- rb_set_parent_color(child2, parent, RB_BLACK);
- rebalance = NULL;
- } else {
- unsigned long pc2 = successor->__rb_parent_color;
- successor->__rb_parent_color = pc;
- rebalance = __rb_is_black(pc2) ? parent : NULL;
- }
- tmp = successor;
- }
- augment->propagate(tmp, NULL);
- return rebalance;
- }
- #define RB_RED 0
- #define RB_BLACK 1
- static inline void rb_set_black(struct rb_node *rb)
- {
- rb->__rb_parent_color |= RB_BLACK;
- }
- static inline struct rb_node *rb_red_parent(struct rb_node *red)
- {
- return (struct rb_node *)red->__rb_parent_color;
- }
- static inline void
- __rb_rotate_set_parents(struct rb_node *old, struct rb_node *nw,
- struct rb_root *root, int color)
- {
- struct rb_node *parent = rb_parent(old);
- nw->__rb_parent_color = old->__rb_parent_color;
- rb_set_parent_color(old, nw, color);
- __rb_change_child(old, nw, parent, root);
- }
- static __always_inline void
- __rb_insert(struct rb_node *node, struct rb_root *root,
- void (*augment_rotate)(struct rb_node *old, struct rb_node *nw))
- {
- struct rb_node *parent = rb_red_parent(node), *gparent, *tmp;
- while (true) {
- /*
- * Loop invariant: node is red
- *
- * If there is a black parent, we are done.
- * Otherwise, take some corrective action as we don't
- * want a red root or two consecutive red nodes.
- */
- if (!parent) {
- rb_set_parent_color(node, NULL, RB_BLACK);
- break;
- } else if (rb_is_black(parent))
- break;
- gparent = rb_red_parent(parent);
- tmp = gparent->rb_right;
- if (parent != tmp) { /* parent == gparent->rb_left */
- if (tmp && rb_is_red(tmp)) {
- /*
- * Case 1 - color flips
- *
- * G g
- * / \ / \
- * p u --> P U
- * / /
- * n n
- *
- * However, since g's parent might be red, and
- * 4) does not allow this, we need to recurse
- * at g.
- */
- rb_set_parent_color(tmp, gparent, RB_BLACK);
- rb_set_parent_color(parent, gparent, RB_BLACK);
- node = gparent;
- parent = rb_parent(node);
- rb_set_parent_color(node, parent, RB_RED);
- continue;
- }
- tmp = parent->rb_right;
- if (node == tmp) {
- /*
- * Case 2 - left rotate at parent
- *
- * G G
- * / \ / \
- * p U --> n U
- * \ /
- * n p
- *
- * This still leaves us in violation of 4), the
- * continuation into Case 3 will fix that.
- */
- parent->rb_right = tmp = node->rb_left;
- node->rb_left = parent;
- if (tmp)
- rb_set_parent_color(tmp, parent,
- RB_BLACK);
- rb_set_parent_color(parent, node, RB_RED);
- augment_rotate(parent, node);
- parent = node;
- tmp = node->rb_right;
- }
- /*
- * Case 3 - right rotate at gparent
- *
- * G P
- * / \ / \
- * p U --> n g
- * / \
- * n U
- */
- gparent->rb_left = tmp; /* == parent->rb_right */
- parent->rb_right = gparent;
- if (tmp)
- rb_set_parent_color(tmp, gparent, RB_BLACK);
- __rb_rotate_set_parents(gparent, parent, root, RB_RED);
- augment_rotate(gparent, parent);
- break;
- } else {
- tmp = gparent->rb_left;
- if (tmp && rb_is_red(tmp)) {
- /* Case 1 - color flips */
- rb_set_parent_color(tmp, gparent, RB_BLACK);
- rb_set_parent_color(parent, gparent, RB_BLACK);
- node = gparent;
- parent = rb_parent(node);
- rb_set_parent_color(node, parent, RB_RED);
- continue;
- }
- tmp = parent->rb_left;
- if (node == tmp) {
- /* Case 2 - right rotate at parent */
- parent->rb_left = tmp = node->rb_right;
- node->rb_right = parent;
- if (tmp)
- rb_set_parent_color(tmp, parent,
- RB_BLACK);
- rb_set_parent_color(parent, node, RB_RED);
- augment_rotate(parent, node);
- parent = node;
- tmp = node->rb_left;
- }
- /* Case 3 - left rotate at gparent */
- gparent->rb_right = tmp; /* == parent->rb_left */
- parent->rb_left = gparent;
- if (tmp)
- rb_set_parent_color(tmp, gparent, RB_BLACK);
- __rb_rotate_set_parents(gparent, parent, root, RB_RED);
- augment_rotate(gparent, parent);
- break;
- }
- }
- }
- static __always_inline void
- ____rb_erase_color(struct rb_node *parent, struct rb_root *root,
- void (*augment_rotate)(struct rb_node *old,
- struct rb_node *nw))
- {
- struct rb_node *node = NULL, *sibling, *tmp1, *tmp2;
- while (true) {
- /*
- * Loop invariants:
- * - node is black (or NULL on first iteration)
- * - node is not the root (parent is not NULL)
- * - All leaf paths going through parent and node have a
- * black node count that is 1 lower than other leaf paths.
- */
- sibling = parent->rb_right;
- if (node != sibling) { /* node == parent->rb_left */
- if (rb_is_red(sibling)) {
- /*
- * Case 1 - left rotate at parent
- *
- * P S
- * / \ / \
- * N s --> p Sr
- * / \ / \
- * Sl Sr N Sl
- */
- parent->rb_right = tmp1 = sibling->rb_left;
- sibling->rb_left = parent;
- rb_set_parent_color(tmp1, parent, RB_BLACK);
- __rb_rotate_set_parents(parent, sibling, root,
- RB_RED);
- augment_rotate(parent, sibling);
- sibling = tmp1;
- }
- tmp1 = sibling->rb_right;
- if (!tmp1 || rb_is_black(tmp1)) {
- tmp2 = sibling->rb_left;
- if (!tmp2 || rb_is_black(tmp2)) {
- /*
- * Case 2 - sibling color flip
- * (p could be either color here)
- *
- * (p) (p)
- * / \ / \
- * N S --> N s
- * / \ / \
- * Sl Sr Sl Sr
- *
- * This leaves us violating 5) which
- * can be fixed by flipping p to black
- * if it was red, or by recursing at p.
- * p is red when coming from Case 1.
- */
- rb_set_parent_color(sibling, parent,
- RB_RED);
- if (rb_is_red(parent))
- rb_set_black(parent);
- else {
- node = parent;
- parent = rb_parent(node);
- if (parent)
- continue;
- }
- break;
- }
- /*
- * Case 3 - right rotate at sibling
- * (p could be either color here)
- *
- * (p) (p)
- * / \ / \
- * N S --> N Sl
- * / \ \
- * sl Sr s
- * \
- * Sr
- */
- sibling->rb_left = tmp1 = tmp2->rb_right;
- tmp2->rb_right = sibling;
- parent->rb_right = tmp2;
- if (tmp1)
- rb_set_parent_color(tmp1, sibling,
- RB_BLACK);
- augment_rotate(sibling, tmp2);
- tmp1 = sibling;
- sibling = tmp2;
- }
- /*
- * Case 4 - left rotate at parent + color flips
- * (p and sl could be either color here.
- * After rotation, p becomes black, s acquires
- * p's color, and sl keeps its color)
- *
- * (p) (s)
- * / \ / \
- * N S --> P Sr
- * / \ / \
- * (sl) sr N (sl)
- */
- parent->rb_right = tmp2 = sibling->rb_left;
- sibling->rb_left = parent;
- rb_set_parent_color(tmp1, sibling, RB_BLACK);
- if (tmp2)
- rb_set_parent(tmp2, parent);
- __rb_rotate_set_parents(parent, sibling, root,
- RB_BLACK);
- augment_rotate(parent, sibling);
- break;
- } else {
- sibling = parent->rb_left;
- if (rb_is_red(sibling)) {
- /* Case 1 - right rotate at parent */
- parent->rb_left = tmp1 = sibling->rb_right;
- sibling->rb_right = parent;
- rb_set_parent_color(tmp1, parent, RB_BLACK);
- __rb_rotate_set_parents(parent, sibling, root,
- RB_RED);
- augment_rotate(parent, sibling);
- sibling = tmp1;
- }
- tmp1 = sibling->rb_left;
- if (!tmp1 || rb_is_black(tmp1)) {
- tmp2 = sibling->rb_right;
- if (!tmp2 || rb_is_black(tmp2)) {
- /* Case 2 - sibling color flip */
- rb_set_parent_color(sibling, parent,
- RB_RED);
- if (rb_is_red(parent))
- rb_set_black(parent);
- else {
- node = parent;
- parent = rb_parent(node);
- if (parent)
- continue;
- }
- break;
- }
- /* Case 3 - right rotate at sibling */
- sibling->rb_right = tmp1 = tmp2->rb_left;
- tmp2->rb_left = sibling;
- parent->rb_left = tmp2;
- if (tmp1)
- rb_set_parent_color(tmp1, sibling,
- RB_BLACK);
- augment_rotate(sibling, tmp2);
- tmp1 = sibling;
- sibling = tmp2;
- }
- /* Case 4 - left rotate at parent + color flips */
- parent->rb_left = tmp2 = sibling->rb_right;
- sibling->rb_right = parent;
- rb_set_parent_color(tmp1, sibling, RB_BLACK);
- if (tmp2)
- rb_set_parent(tmp2, parent);
- __rb_rotate_set_parents(parent, sibling, root,
- RB_BLACK);
- augment_rotate(parent, sibling);
- break;
- }
- }
- }
- void __rb_erase_color(struct rb_node *parent, struct rb_root *root,
- void (*augment_rotate)(struct rb_node *old, struct rb_node *nw))
- {
- ____rb_erase_color(parent, root, augment_rotate);
- }
- static inline void dummy_propagate(struct rb_node *node, struct rb_node *stop) {}
- static inline void dummy_copy(struct rb_node *old, struct rb_node *nw) {}
- static inline void dummy_rotate(struct rb_node *old, struct rb_node *nw) {}
- static const struct rb_augment_callbacks dummy_callbacks = {
- dummy_propagate, dummy_copy, dummy_rotate
- };
- void rb_insert_color(struct rb_node *node, struct rb_root *root)
- {
- __rb_insert(node, root, dummy_rotate);
- }
- void rb_erase(struct rb_node *node, struct rb_root *root)
- {
- struct rb_node *rebalance;
- rebalance = __rb_erase_augmented(node, root, &dummy_callbacks);
- if (rebalance)
- ____rb_erase_color(rebalance, root, dummy_rotate);
- }
- void __rb_insert_augmented(struct rb_node *node, struct rb_root *root,
- void (*augment_rotate)(struct rb_node *old,
- struct rb_node *nw))
- {
- __rb_insert(node, root, augment_rotate);
- }
- struct rb_node *rb_first(const struct rb_root *root)
- {
- struct rb_node *n;
- n = root->rb_node;
- if (!n)
- return NULL;
- while (n->rb_left)
- n = n->rb_left;
- return n;
- }
- struct rb_node *rb_last(const struct rb_root *root)
- {
- struct rb_node *n;
- n = root->rb_node;
- if (!n)
- return NULL;
- while (n->rb_right)
- n = n->rb_right;
- return n;
- }
- struct rb_node *rb_next(const struct rb_node *node)
- {
- struct rb_node *parent;
- if (RB_EMPTY_NODE(node))
- return NULL;
- /*
- * If we have a right-hand child, go down and then left as far
- * as we can.
- */
- if (node->rb_right) {
- node = node->rb_right;
- while (node->rb_left)
- node=node->rb_left;
- return (struct rb_node *)node;
- }
- /*
- * No right-hand children. Everything down and left is smaller than us,
- * so any 'next' node must be in the general direction of our parent.
- * Go up the tree; any time the ancestor is a right-hand child of its
- * parent, keep going up. First time it's a left-hand child of its
- * parent, said parent is our 'next' node.
- */
- while ((parent = rb_parent(node)) && node == parent->rb_right)
- node = parent;
- return parent;
- }
- struct rb_node *rb_prev(const struct rb_node *node)
- {
- struct rb_node *parent;
- if (RB_EMPTY_NODE(node))
- return NULL;
- /*
- * If we have a left-hand child, go down and then right as far
- * as we can.
- */
- if (node->rb_left) {
- node = node->rb_left;
- while (node->rb_right)
- node=node->rb_right;
- return (struct rb_node *)node;
- }
- /*
- * No left-hand children. Go up till we find an ancestor which
- * is a right-hand child of its parent.
- */
- while ((parent = rb_parent(node)) && node == parent->rb_left)
- node = parent;
- return parent;
- }
- void rb_replace_node(struct rb_node *victim, struct rb_node *nw,
- struct rb_root *root)
- {
- struct rb_node *parent = rb_parent(victim);
- /* Set the surrounding nodes to point to the replacement */
- __rb_change_child(victim, nw, parent, root);
- if (victim->rb_left)
- rb_set_parent(victim->rb_left, nw);
- if (victim->rb_right)
- rb_set_parent(victim->rb_right, nw);
- /* Copy the pointers/colour from the victim to the replacement */
- *nw = *victim;
- }
- static struct rb_node *rb_left_deepest_node(const struct rb_node *node)
- {
- for (;;) {
- if (node->rb_left)
- node = node->rb_left;
- else if (node->rb_right)
- node = node->rb_right;
- else
- return (struct rb_node *)node;
- }
- }
- struct rb_node *rb_next_postorder(const struct rb_node *node)
- {
- const struct rb_node *parent;
- if (!node)
- return NULL;
- parent = rb_parent(node);
- /* If we're sitting on node, we've already seen our children */
- if (parent && node == parent->rb_left && parent->rb_right) {
- /* If we are the parent's left node, go to the parent's right
- * node then all the way down to the left */
- return rb_left_deepest_node(parent->rb_right);
- } else
- /* Otherwise we are the parent's right node, and the parent
- * should be next */
- return (struct rb_node *)parent;
- }
- struct rb_node *rb_first_postorder(const struct rb_root *root)
- {
- if (!root->rb_node)
- return NULL;
- return rb_left_deepest_node(root->rb_node);
- }
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