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/*
* 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;
};
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;
}
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