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Diffstat (limited to 'vcs-svn/trp.h')
| -rw-r--r-- | vcs-svn/trp.h | 236 |
1 files changed, 236 insertions, 0 deletions
diff --git a/vcs-svn/trp.h b/vcs-svn/trp.h new file mode 100644 index 0000000000..ee35c688a0 --- /dev/null +++ b/vcs-svn/trp.h @@ -0,0 +1,236 @@ +/* + * C macro implementation of treaps. + * + * Usage: + * #include <stdint.h> + * #include "trp.h" + * trp_gen(...) + * + * Licensed under a two-clause BSD-style license. + * See LICENSE for details. + */ + +#ifndef TRP_H_ +#define TRP_H_ + +#define MAYBE_UNUSED __attribute__((__unused__)) + +/* Node structure. */ +struct trp_node { + uint32_t trpn_left; + uint32_t trpn_right; +}; + +/* Root structure. */ +struct trp_root { + uint32_t trp_root; +}; + +/* Pointer/Offset conversion. */ +#define trpn_pointer(a_base, a_offset) (a_base##_pointer(a_offset)) +#define trpn_offset(a_base, a_pointer) (a_base##_offset(a_pointer)) +#define trpn_modify(a_base, a_offset) \ + do { \ + if ((a_offset) < a_base##_pool.committed) { \ + uint32_t old_offset = (a_offset);\ + (a_offset) = a_base##_alloc(1); \ + *trpn_pointer(a_base, a_offset) = \ + *trpn_pointer(a_base, old_offset); \ + } \ + } while (0) + +/* Left accessors. */ +#define trp_left_get(a_base, a_field, a_node) \ + (trpn_pointer(a_base, a_node)->a_field.trpn_left) +#define trp_left_set(a_base, a_field, a_node, a_left) \ + do { \ + trpn_modify(a_base, a_node); \ + trp_left_get(a_base, a_field, a_node) = (a_left); \ + } while (0) + +/* Right accessors. */ +#define trp_right_get(a_base, a_field, a_node) \ + (trpn_pointer(a_base, a_node)->a_field.trpn_right) +#define trp_right_set(a_base, a_field, a_node, a_right) \ + do { \ + trpn_modify(a_base, a_node); \ + trp_right_get(a_base, a_field, a_node) = (a_right); \ + } while (0) + +/* + * Fibonacci hash function. + * The multiplier is the nearest prime to (2^32 times (√5 - 1)/2). + * See Knuth §6.4: volume 3, 3rd ed, p518. + */ +#define trpn_hash(a_node) (uint32_t) (2654435761u * (a_node)) + +/* Priority accessors. */ +#define trp_prio_get(a_node) trpn_hash(a_node) + +/* Node initializer. */ +#define trp_node_new(a_base, a_field, a_node) \ + do { \ + trp_left_set(a_base, a_field, (a_node), ~0); \ + trp_right_set(a_base, a_field, (a_node), ~0); \ + } while (0) + +/* Internal utility macros. */ +#define trpn_first(a_base, a_field, a_root, r_node) \ + do { \ + (r_node) = (a_root); \ + if ((r_node) == ~0) \ + return NULL; \ + while (~trp_left_get(a_base, a_field, (r_node))) \ + (r_node) = trp_left_get(a_base, a_field, (r_node)); \ + } while (0) + +#define trpn_rotate_left(a_base, a_field, a_node, r_node) \ + do { \ + (r_node) = trp_right_get(a_base, a_field, (a_node)); \ + trp_right_set(a_base, a_field, (a_node), \ + trp_left_get(a_base, a_field, (r_node))); \ + trp_left_set(a_base, a_field, (r_node), (a_node)); \ + } while (0) + +#define trpn_rotate_right(a_base, a_field, a_node, r_node) \ + do { \ + (r_node) = trp_left_get(a_base, a_field, (a_node)); \ + trp_left_set(a_base, a_field, (a_node), \ + trp_right_get(a_base, a_field, (r_node))); \ + trp_right_set(a_base, a_field, (r_node), (a_node)); \ + } while (0) + +#define trp_gen(a_attr, a_pre, a_type, a_field, a_base, a_cmp) \ +a_attr a_type MAYBE_UNUSED *a_pre##first(struct trp_root *treap) \ +{ \ + uint32_t ret; \ + trpn_first(a_base, a_field, treap->trp_root, ret); \ + return trpn_pointer(a_base, ret); \ +} \ +a_attr a_type MAYBE_UNUSED *a_pre##next(struct trp_root *treap, a_type *node) \ +{ \ + uint32_t ret; \ + uint32_t offset = trpn_offset(a_base, node); \ + if (~trp_right_get(a_base, a_field, offset)) { \ + trpn_first(a_base, a_field, \ + trp_right_get(a_base, a_field, offset), ret); \ + } else { \ + uint32_t tnode = treap->trp_root; \ + ret = ~0; \ + while (1) { \ + int cmp = (a_cmp)(trpn_pointer(a_base, offset), \ + trpn_pointer(a_base, tnode)); \ + if (cmp < 0) { \ + ret = tnode; \ + tnode = trp_left_get(a_base, a_field, tnode); \ + } else if (cmp > 0) { \ + tnode = trp_right_get(a_base, a_field, tnode); \ + } else { \ + break; \ + } \ + } \ + } \ + return trpn_pointer(a_base, ret); \ +} \ +a_attr a_type MAYBE_UNUSED *a_pre##search(struct trp_root *treap, a_type *key) \ +{ \ + int cmp; \ + uint32_t ret = treap->trp_root; \ + while (~ret && (cmp = (a_cmp)(key, trpn_pointer(a_base, ret)))) { \ + if (cmp < 0) { \ + ret = trp_left_get(a_base, a_field, ret); \ + } else { \ + ret = trp_right_get(a_base, a_field, ret); \ + } \ + } \ + return trpn_pointer(a_base, ret); \ +} \ +a_attr a_type MAYBE_UNUSED *a_pre##nsearch(struct trp_root *treap, a_type *key) \ +{ \ + int cmp; \ + uint32_t ret = treap->trp_root; \ + while (~ret && (cmp = (a_cmp)(key, trpn_pointer(a_base, ret)))) { \ + if (cmp < 0) { \ + if (!~trp_left_get(a_base, a_field, ret)) \ + break; \ + ret = trp_left_get(a_base, a_field, ret); \ + } else { \ + ret = trp_right_get(a_base, a_field, ret); \ + } \ + } \ + return trpn_pointer(a_base, ret); \ +} \ +a_attr uint32_t MAYBE_UNUSED a_pre##insert_recurse(uint32_t cur_node, uint32_t ins_node) \ +{ \ + if (cur_node == ~0) { \ + return ins_node; \ + } else { \ + uint32_t ret; \ + int cmp = (a_cmp)(trpn_pointer(a_base, ins_node), \ + trpn_pointer(a_base, cur_node)); \ + if (cmp < 0) { \ + uint32_t left = a_pre##insert_recurse( \ + trp_left_get(a_base, a_field, cur_node), ins_node); \ + trp_left_set(a_base, a_field, cur_node, left); \ + if (trp_prio_get(left) < trp_prio_get(cur_node)) \ + trpn_rotate_right(a_base, a_field, cur_node, ret); \ + else \ + ret = cur_node; \ + } else { \ + uint32_t right = a_pre##insert_recurse( \ + trp_right_get(a_base, a_field, cur_node), ins_node); \ + trp_right_set(a_base, a_field, cur_node, right); \ + if (trp_prio_get(right) < trp_prio_get(cur_node)) \ + trpn_rotate_left(a_base, a_field, cur_node, ret); \ + else \ + ret = cur_node; \ + } \ + return ret; \ + } \ +} \ +a_attr void MAYBE_UNUSED a_pre##insert(struct trp_root *treap, a_type *node) \ +{ \ + uint32_t offset = trpn_offset(a_base, node); \ + trp_node_new(a_base, a_field, offset); \ + treap->trp_root = a_pre##insert_recurse(treap->trp_root, offset); \ +} \ +a_attr uint32_t MAYBE_UNUSED a_pre##remove_recurse(uint32_t cur_node, uint32_t rem_node) \ +{ \ + int cmp = a_cmp(trpn_pointer(a_base, rem_node), \ + trpn_pointer(a_base, cur_node)); \ + if (cmp == 0) { \ + uint32_t ret; \ + uint32_t left = trp_left_get(a_base, a_field, cur_node); \ + uint32_t right = trp_right_get(a_base, a_field, cur_node); \ + if (left == ~0) { \ + if (right == ~0) \ + return ~0; \ + } else if (right == ~0 || trp_prio_get(left) < trp_prio_get(right)) { \ + trpn_rotate_right(a_base, a_field, cur_node, ret); \ + right = a_pre##remove_recurse(cur_node, rem_node); \ + trp_right_set(a_base, a_field, ret, right); \ + return ret; \ + } \ + trpn_rotate_left(a_base, a_field, cur_node, ret); \ + left = a_pre##remove_recurse(cur_node, rem_node); \ + trp_left_set(a_base, a_field, ret, left); \ + return ret; \ + } else if (cmp < 0) { \ + uint32_t left = a_pre##remove_recurse( \ + trp_left_get(a_base, a_field, cur_node), rem_node); \ + trp_left_set(a_base, a_field, cur_node, left); \ + return cur_node; \ + } else { \ + uint32_t right = a_pre##remove_recurse( \ + trp_right_get(a_base, a_field, cur_node), rem_node); \ + trp_right_set(a_base, a_field, cur_node, right); \ + return cur_node; \ + } \ +} \ +a_attr void MAYBE_UNUSED a_pre##remove(struct trp_root *treap, a_type *node) \ +{ \ + treap->trp_root = a_pre##remove_recurse(treap->trp_root, \ + trpn_offset(a_base, node)); \ +} \ + +#endif |