diff options
Diffstat (limited to 'include/linux/rbtree_augmented.h')
| -rw-r--r-- | include/linux/rbtree_augmented.h | 115 |
1 files changed, 77 insertions, 38 deletions
diff --git a/include/linux/rbtree_augmented.h b/include/linux/rbtree_augmented.h index 0f902ccb48b0..fdd421b8d9ae 100644 --- a/include/linux/rbtree_augmented.h +++ b/include/linux/rbtree_augmented.h @@ -30,10 +30,9 @@ struct rb_augment_callbacks { void (*rotate)(struct rb_node *old, struct rb_node *new); }; -extern void __rb_insert_augmented(struct rb_node *node, - struct rb_root *root, - bool newleft, struct rb_node **leftmost, +extern void __rb_insert_augmented(struct rb_node *node, struct rb_root *root, void (*augment_rotate)(struct rb_node *old, struct rb_node *new)); + /* * Fixup the rbtree and update the augmented information when rebalancing. * @@ -48,7 +47,7 @@ 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, false, NULL, augment->rotate); + __rb_insert_augmented(node, root, augment->rotate); } static inline void @@ -56,45 +55,92 @@ rb_insert_augmented_cached(struct rb_node *node, struct rb_root_cached *root, bool newleft, const struct rb_augment_callbacks *augment) { - __rb_insert_augmented(node, &root->rb_root, - newleft, &root->rb_leftmost, augment->rotate); + if (newleft) + root->rb_leftmost = node; + rb_insert_augmented(node, &root->rb_root, augment); } -#define RB_DECLARE_CALLBACKS(rbstatic, rbname, rbstruct, rbfield, \ - rbtype, rbaugmented, rbcompute) \ +/* + * Template for declaring augmented rbtree callbacks (generic case) + * + * RBSTATIC: 'static' or empty + * RBNAME: name of the rb_augment_callbacks structure + * RBSTRUCT: struct type of the tree nodes + * RBFIELD: name of struct rb_node field within RBSTRUCT + * RBAUGMENTED: name of field within RBSTRUCT holding data for subtree + * RBCOMPUTE: name of function that recomputes the RBAUGMENTED data + */ + +#define RB_DECLARE_CALLBACKS(RBSTATIC, RBNAME, \ + RBSTRUCT, RBFIELD, RBAUGMENTED, RBCOMPUTE) \ static inline void \ -rbname ## _propagate(struct rb_node *rb, struct rb_node *stop) \ +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) \ + RBSTRUCT *node = rb_entry(rb, RBSTRUCT, RBFIELD); \ + if (RBCOMPUTE(node, true)) \ break; \ - node->rbaugmented = augmented; \ - rb = rb_parent(&node->rbfield); \ + rb = rb_parent(&node->RBFIELD); \ } \ } \ static inline void \ -rbname ## _copy(struct rb_node *rb_old, struct rb_node *rb_new) \ +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; \ + 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) \ +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); \ + RBSTRUCT *old = rb_entry(rb_old, RBSTRUCT, RBFIELD); \ + RBSTRUCT *new = rb_entry(rb_new, RBSTRUCT, RBFIELD); \ + new->RBAUGMENTED = old->RBAUGMENTED; \ + RBCOMPUTE(old, false); \ } \ -rbstatic const struct rb_augment_callbacks rbname = { \ - .propagate = rbname ## _propagate, \ - .copy = rbname ## _copy, \ - .rotate = rbname ## _rotate \ +RBSTATIC const struct rb_augment_callbacks RBNAME = { \ + .propagate = RBNAME ## _propagate, \ + .copy = RBNAME ## _copy, \ + .rotate = RBNAME ## _rotate \ }; +/* + * Template for declaring augmented rbtree callbacks, + * computing RBAUGMENTED scalar as max(RBCOMPUTE(node)) for all subtree nodes. + * + * RBSTATIC: 'static' or empty + * RBNAME: name of the rb_augment_callbacks structure + * RBSTRUCT: struct type of the tree nodes + * RBFIELD: name of struct rb_node field within RBSTRUCT + * RBTYPE: type of the RBAUGMENTED field + * RBAUGMENTED: name of RBTYPE field within RBSTRUCT holding data for subtree + * RBCOMPUTE: name of function that returns the per-node RBTYPE scalar + */ + +#define RB_DECLARE_CALLBACKS_MAX(RBSTATIC, RBNAME, RBSTRUCT, RBFIELD, \ + RBTYPE, RBAUGMENTED, RBCOMPUTE) \ +static inline bool RBNAME ## _compute_max(RBSTRUCT *node, bool exit) \ +{ \ + RBSTRUCT *child; \ + RBTYPE max = RBCOMPUTE(node); \ + if (node->RBFIELD.rb_left) { \ + child = rb_entry(node->RBFIELD.rb_left, RBSTRUCT, RBFIELD); \ + if (child->RBAUGMENTED > max) \ + max = child->RBAUGMENTED; \ + } \ + if (node->RBFIELD.rb_right) { \ + child = rb_entry(node->RBFIELD.rb_right, RBSTRUCT, RBFIELD); \ + if (child->RBAUGMENTED > max) \ + max = child->RBAUGMENTED; \ + } \ + if (exit && node->RBAUGMENTED == max) \ + return true; \ + node->RBAUGMENTED = max; \ + return false; \ +} \ +RB_DECLARE_CALLBACKS(RBSTATIC, RBNAME, \ + RBSTRUCT, RBFIELD, RBAUGMENTED, RBNAME ## _compute_max) + #define RB_RED 0 #define RB_BLACK 1 @@ -150,7 +196,6 @@ extern void __rb_erase_color(struct rb_node *parent, struct rb_root *root, static __always_inline struct rb_node * __rb_erase_augmented(struct rb_node *node, struct rb_root *root, - struct rb_node **leftmost, const struct rb_augment_callbacks *augment) { struct rb_node *child = node->rb_right; @@ -158,9 +203,6 @@ __rb_erase_augmented(struct rb_node *node, struct rb_root *root, struct rb_node *parent, *rebalance; unsigned long pc; - if (leftmost && node == *leftmost) - *leftmost = rb_next(node); - if (!tmp) { /* * Case 1: node to erase has no more than 1 child (easy!) @@ -260,8 +302,7 @@ static __always_inline void rb_erase_augmented(struct rb_node *node, struct rb_root *root, const struct rb_augment_callbacks *augment) { - struct rb_node *rebalance = __rb_erase_augmented(node, root, - NULL, augment); + struct rb_node *rebalance = __rb_erase_augmented(node, root, augment); if (rebalance) __rb_erase_color(rebalance, root, augment->rotate); } @@ -270,11 +311,9 @@ static __always_inline void rb_erase_augmented_cached(struct rb_node *node, struct rb_root_cached *root, const struct rb_augment_callbacks *augment) { - struct rb_node *rebalance = __rb_erase_augmented(node, &root->rb_root, - &root->rb_leftmost, - augment); - if (rebalance) - __rb_erase_color(rebalance, &root->rb_root, augment->rotate); + if (root->rb_leftmost == node) + root->rb_leftmost = rb_next(node); + rb_erase_augmented(node, &root->rb_root, augment); } #endif /* _LINUX_RBTREE_AUGMENTED_H */ |