X-Git-Url: https://scm.lunaixsky.com/lunaix-os.git/blobdiff_plain/a5338b60e111972364a8bc6f07011c6defd213d2..270869139db617e29a35bb9ded41087bb702f9ac:/lunaix-os/kernel/ds/btrie.c?ds=sidebyside diff --git a/lunaix-os/kernel/ds/btrie.c b/lunaix-os/kernel/ds/btrie.c index fd173b9..72758fb 100644 --- a/lunaix-os/kernel/ds/btrie.c +++ b/lunaix-os/kernel/ds/btrie.c @@ -16,14 +16,17 @@ #define BTRIE_INSERT 1 struct btrie_node* -__btrie_traversal(struct btrie* root, uint32_t index, int options) +__btrie_traversal(struct btrie* root, unsigned long index, int options) { - index = index >> root->truncated; - uint32_t lz = index ? ROUNDDOWN(31 - __builtin_clz(index), BTRIE_BITS) : 0; - uint32_t bitmask = ((1 << BTRIE_BITS) - 1) << lz; - uint32_t i = 0; + unsigned long lz; + unsigned long bitmask; + unsigned long i = 0; struct btrie_node* tree = root->btrie_root; + lz = index ? ICEIL(msbitl - clzl(index), root->order) : 0; + lz = lz * root->order; + bitmask = ((1 << root->order) - 1) << lz; + // Time complexity: O(log_2(log_2(N))) where N is the index to lookup while (bitmask && tree) { i = (index & bitmask) >> lz; @@ -49,24 +52,24 @@ __btrie_traversal(struct btrie* root, uint32_t index, int options) } else { tree = subtree; } - bitmask = bitmask >> BTRIE_BITS; - lz -= BTRIE_BITS; + bitmask = bitmask >> root->order; + lz -= root->order; } return tree; } void -btrie_init(struct btrie* btrie, uint32_t trunc_bits) +btrie_init(struct btrie* btrie, unsigned int order) { btrie->btrie_root = vzalloc(sizeof(struct btrie_node)); llist_init_head(&btrie->btrie_root->nodes); llist_init_head(&btrie->btrie_root->children); - btrie->truncated = trunc_bits; + btrie->order = order; } void* -btrie_get(struct btrie* root, uint32_t index) +btrie_get(struct btrie* root, unsigned long index) { struct btrie_node* node = __btrie_traversal(root, index, 0); if (!node) { @@ -76,35 +79,40 @@ btrie_get(struct btrie* root, uint32_t index) } void -btrie_set(struct btrie* root, uint32_t index, void* data) +btrie_set(struct btrie* root, unsigned long index, void* data) { struct btrie_node* node = __btrie_traversal(root, index, BTRIE_INSERT); node->data = data; } void -__btrie_remove(struct btrie_node* node) +__btrie_rm_recursive(struct btrie_node* node) { struct btrie_node* parent = node->parent; + if (parent) { llist_delete(&node->siblings); llist_delete(&node->nodes); vfree(node); - if (llist_empty(&parent->children)) { - __btrie_remove(parent); + if (llist_empty(&parent->children) && !parent->data) { + __btrie_rm_recursive(parent); } } } void* -btrie_remove(struct btrie* root, uint32_t index) +btrie_remove(struct btrie* root, unsigned long index) { struct btrie_node* node = __btrie_traversal(root, index, 0); if (!node) { return 0; } void* data = node->data; - __btrie_remove(node); + if (!llist_empty(&node->children)) { + node->data = NULL; + } else { + __btrie_rm_recursive(node); + } return data; }