/* * Copyright (C) 2001 Sistina Software (UK) Limited. * * This file is released under the LGPL. */ #include "lib.h" #include "ttree.h" #include "pool.h" struct node { unsigned k; struct node *l, *m, *r; void *data; }; struct ttree { int klen; struct pool *mem; struct node *root; }; static struct node **_lookup_single(struct node **c, unsigned int k) { while (*c) { if (k < (*c)->k) c = &((*c)->l); else if (k > (*c)->k) c = &((*c)->r); else { c = &((*c)->m); break; } } return c; } void *ttree_lookup(struct ttree *tt, unsigned *key) { struct node **c = &tt->root; int count = tt->klen; while (*c && count) { c = _lookup_single(c, *key++); count--; } return *c ? (*c)->data : NULL; } static struct node *_node(struct pool *mem, unsigned int k) { struct node *n = pool_zalloc(mem, sizeof(*n)); if (n) n->k = k; return n; } int ttree_insert(struct ttree *tt, unsigned int *key, void *data) { struct node **c = &tt->root; int count = tt->klen; unsigned int k; do { k = *key++; c = _lookup_single(c, k); count--; } while (*c && count); if (!*c) { count++; while (count--) { if (!(*c = _node(tt->mem, k))) { stack; return 0; } k = *key++; if (count) c = &((*c)->m); } } (*c)->data = data; return 1; } struct ttree *ttree_create(struct pool *mem, unsigned int klen) { struct ttree *tt; if (!(tt = pool_zalloc(mem, sizeof(*tt)))) { stack; return NULL; } tt->klen = klen; tt->mem = mem; return tt; }