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/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2007 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*
* lut.c -- simple lookup table module
*
* this file contains a very simple lookup table (lut) implementation.
* the tables only support insert & lookup, no delete, and can
* only be walked in one order. if the key already exists
* for something being inserted, the previous entry is simply
* replaced.
*/
#pragma ident "%Z%%M% %I% %E% SMI"
#include <stdio.h>
#include "alloc.h"
#include "out.h"
#include "stats.h"
#include "lut.h"
#include "lut_impl.h"
#include "tree.h"
static struct stats *Addtotal;
static struct stats *Lookuptotal;
static struct stats *Freetotal;
void
lut_init(void)
{
Addtotal = stats_new_counter("lut.adds", "total adds", 1);
Lookuptotal = stats_new_counter("lut.lookup", "total lookups", 1);
Freetotal = stats_new_counter("lut.frees", "total frees", 1);
}
void
lut_fini(void)
{
stats_delete(Addtotal);
stats_delete(Lookuptotal);
stats_delete(Freetotal);
}
/*
* lut_add -- add an entry to the table
*
* use it like this:
* struct lut *root = NULL;
* root = lut_add(root, key, value, cmp_func);
*
* the cmp_func can be strcmp(). pass in NULL and instead of
* calling a cmp_func the routine will just look at the difference
* between key pointers (useful when all strings are kept in a
* string table so they are equal if their pointers are equal).
*
*/
struct lut *
lut_add(struct lut *root, void *lhs, void *rhs, lut_cmp cmp_func)
{
int diff;
struct lut **tmp_hdl = &root, *parent = NULL, *tmp = root;
while (tmp) {
if (cmp_func)
diff = (*cmp_func)(tmp->lut_lhs, lhs);
else
diff = (const char *)lhs - (const char *)tmp->lut_lhs;
if (diff == 0) {
/* already in tree, replace node */
tmp->lut_rhs = rhs;
return (root);
} else if (diff > 0) {
tmp_hdl = &(tmp->lut_left);
parent = tmp;
tmp = tmp->lut_left;
} else {
tmp_hdl = &(tmp->lut_right);
parent = tmp;
tmp = tmp->lut_right;
}
}
/* either empty tree or not in tree, so create new node */
*tmp_hdl = MALLOC(sizeof (*root));
(*tmp_hdl)->lut_lhs = lhs;
(*tmp_hdl)->lut_rhs = rhs;
(*tmp_hdl)->lut_parent = parent;
(*tmp_hdl)->lut_left = (*tmp_hdl)->lut_right = NULL;
stats_counter_bump(Addtotal);
return (root);
}
void *
lut_lookup(struct lut *root, void *lhs, lut_cmp cmp_func)
{
int diff;
stats_counter_bump(Lookuptotal);
while (root) {
if (cmp_func)
diff = (*cmp_func)(root->lut_lhs, lhs);
else
diff = (const char *)lhs - (const char *)root->lut_lhs;
if (diff == 0)
return (root->lut_rhs);
else if (diff > 0)
root = root->lut_left;
else
root = root->lut_right;
}
return (NULL);
}
void *
lut_lookup_lhs(struct lut *root, void *lhs, lut_cmp cmp_func)
{
int diff;
stats_counter_bump(Lookuptotal);
while (root) {
if (cmp_func)
diff = (*cmp_func)(root->lut_lhs, lhs);
else
diff = (const char *)lhs - (const char *)root->lut_lhs;
if (diff == 0)
return (root->lut_lhs);
else if (diff > 0)
root = root->lut_left;
else
root = root->lut_right;
}
return (NULL);
}
/*
* lut_walk -- walk the table in lexical order
*/
void
lut_walk(struct lut *root, lut_cb callback, void *arg)
{
struct lut *tmp = root;
struct lut *prev_child = NULL;
if (root == NULL)
return;
while (tmp->lut_left != NULL)
tmp = tmp->lut_left;
/* do callback on leftmost node */
(*callback)(tmp->lut_lhs, tmp->lut_rhs, arg);
for (;;) {
if (tmp->lut_right != NULL && tmp->lut_right != prev_child) {
tmp = tmp->lut_right;
while (tmp->lut_left != NULL)
tmp = tmp->lut_left;
/* do callback on leftmost node */
(*callback)(tmp->lut_lhs, tmp->lut_rhs, arg);
} else if (tmp->lut_parent != NULL) {
prev_child = tmp;
tmp = tmp->lut_parent;
/*
* do callback on parent only if we're coming up
* from the left
*/
if (tmp->lut_right != prev_child)
(*callback)(tmp->lut_lhs, tmp->lut_rhs, arg);
} else
return;
}
}
/*
* lut_free -- free the lut
*/
void
lut_free(struct lut *root, lut_cb callback, void *arg)
{
struct lut *tmp = root;
struct lut *prev_child = NULL;
if (root == NULL)
return;
while (tmp->lut_left != NULL)
tmp = tmp->lut_left;
/* do callback on leftmost node */
if (callback)
(*callback)(tmp->lut_lhs, tmp->lut_rhs, arg);
for (;;) {
if (tmp->lut_right != NULL && tmp->lut_right != prev_child) {
tmp = tmp->lut_right;
while (tmp->lut_left != NULL)
tmp = tmp->lut_left;
/* do callback on leftmost node */
if (callback)
(*callback)(tmp->lut_lhs, tmp->lut_rhs, arg);
} else if (tmp->lut_parent != NULL) {
prev_child = tmp;
tmp = tmp->lut_parent;
FREE(prev_child);
/*
* do callback on parent only if we're coming up
* from the left
*/
if (tmp->lut_right != prev_child && callback)
(*callback)(tmp->lut_lhs, tmp->lut_rhs, arg);
} else {
/*
* free the root node and then we're done
*/
FREE(tmp);
return;
}
}
}
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