ctf/cvt/hash.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (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 2004 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#pragma ident   "%Z%%M% %I% %E% SMI"

/*
 * Routines for manipulating hash tables
 */

#include <stdio.h>
#include <stdlib.h>
#include <strings.h>
#include <sys/types.h>
#include <sys/sysmacros.h>

#include "hash.h"
#include "memory.h"
#include "list.h"

struct hash {
    int h_nbuckets;
    list_t **h_buckets;

    int (*h_hashfn)(int, void *);
    int (*h_cmp)(void *, void *);
};

struct hash_data {
    hash_t *hd_hash;
    int (*hd_fun)();
    void *hd_key;
    void *hd_private;

    void *hd_ret;
};

static int
hash_def_hash(int nbuckets, uintptr_t data)
{
    return (data % nbuckets);
}

static int
hash_def_cmp(uintptr_t d1, uintptr_t d2)
{
    return (d1 != d2);
}


int
hash_name(int nbuckets, const char *name)
{
    const char *c;
    ulong_t g;
    int h = 0;

    for (c = name; *c; c++) {
        h = (h << 4) + *c;
        if ((g = (h & 0xf0000000)) != 0) {
            h ^= (g >> 24);
            h ^= g;
        }
    }

    return (h % nbuckets);
}

hash_t *
hash_new(int nbuckets, int (*hashfn)(int, void *), int (*cmp)(void *, void *))
{
    hash_t *hash;

    hash = xmalloc(sizeof (hash_t));
    hash->h_buckets = xcalloc(sizeof (list_t *) * nbuckets);
    hash->h_nbuckets = nbuckets;
    hash->h_hashfn = hashfn ? hashfn : (int (*)())hash_def_hash;
    hash->h_cmp = cmp ? cmp : (int (*)())hash_def_cmp;

    return (hash);
}

void
hash_add(hash_t *hash, void *key)
{
    int bucket = hash->h_hashfn(hash->h_nbuckets, key);

    list_add(&hash->h_buckets[bucket], key);
}

static int
hash_add_cb(void *node, void *private)
{
    hash_add((hash_t *)private, node);
    return (0);
}

void
hash_merge(hash_t *to, hash_t *from)
{
    (void) hash_iter(from, hash_add_cb, to);
}

static int
hash_remove_cb(void *key1, void *key2, hash_t *hash)
{
    return (hash->h_cmp(key1, key2));
}

void
hash_remove(hash_t *hash, void *key)
{
    int bucket = hash->h_hashfn(hash->h_nbuckets, key);

    (void) list_remove(&hash->h_buckets[bucket], key,
        (int (*)())hash_remove_cb, hash);
}

int
hash_match(hash_t *hash, void *key, int (*fun)(void *, void *),
    void *private)
{
    int bucket = hash->h_hashfn(hash->h_nbuckets, key);

    return (list_iter(hash->h_buckets[bucket], fun, private) < 0);
}

static int
hash_find_list_cb(void *node, struct hash_data *hd)
{
    int cbrc;
    int rc = 0;

    if (hd->hd_hash->h_cmp(hd->hd_key, node) == 0) {
        if ((cbrc = hd->hd_fun(node, hd->hd_private)) < 0)
            return (cbrc);
        rc += cbrc;
    }

    return (rc);
}

int
hash_find_iter(hash_t *hash, void *key, int (*fun)(void *, void *),
    void *private)
{
    int bucket = hash->h_hashfn(hash->h_nbuckets, key);
    struct hash_data hd;

    hd.hd_hash = hash;
    hd.hd_fun = fun;
    hd.hd_key = key;
    hd.hd_private = private;

    return (list_iter(hash->h_buckets[bucket], (int (*)())hash_find_list_cb,
        &hd));
}

/* stop on first match */
static int
hash_find_first_cb(void *node, struct hash_data *hd)
{
    if (hd->hd_hash->h_cmp(hd->hd_key, node) == 0) {
        hd->hd_ret = node;
        return (-1);
    }

    return (0);
}

int
hash_find(hash_t *hash, void *key, void **value)
{
    int ret;
    struct hash_data hd;

    hd.hd_hash = hash;
    hd.hd_fun = hash_find_first_cb;
    hd.hd_key = key;

    ret = hash_match(hash, key, (int (*)())hash_find_first_cb, &hd);
    if (ret && value)
        *value = hd.hd_ret;

    return (ret);
}

int
hash_iter(hash_t *hash, int (*fun)(void *, void *), void *private)
{
    int cumrc = 0;
    int cbrc;
    int i;

    for (i = 0; i < hash->h_nbuckets; i++) {
        if (hash->h_buckets[i] != NULL) {
            if ((cbrc = list_iter(hash->h_buckets[i], fun,
                private)) < 0)
                return (cbrc);
            cumrc += cbrc;
        }
    }

    return (cumrc);
}

int
hash_count(hash_t *hash)
{
    int num, i;

    for (num = 0, i = 0; i < hash->h_nbuckets; i++)
        num += list_count(hash->h_buckets[i]);

    return (num);
}

void
hash_free(hash_t *hash, void (*datafree)(void *, void *), void *private)
{
    int i;

    if (hash == NULL)
        return;

    for (i = 0; i < hash->h_nbuckets; i++)
        list_free(hash->h_buckets[i], datafree, private);
    free(hash->h_buckets);
    free(hash);
}

void
hash_stats(hash_t *hash, int verbose)
{
    int min = list_count(hash->h_buckets[0]);
    int minidx = 0;
    int max = min;
    int maxidx = 0;
    int tot = min;
    int count;
    int i;

    if (min && verbose)
        printf("%3d: %d\n", 0, min);
    for (i = 1; i < hash->h_nbuckets; i++) {
        count = list_count(hash->h_buckets[i]);
        if (min > count) {
            min = count;
            minidx = i;
        }
        if (max < count) {
            max = count;
            maxidx = i;
        }
        if (count && verbose)
            printf("%3d: %d\n", i, count);
        tot += count;
    }

    printf("Hash statistics:\n");
    printf(" Buckets: %d\n", hash->h_nbuckets);
    printf(" Items  : %d\n", tot);
    printf(" Min/Max: %d in #%d, %d in #%d\n", min, minidx, max, maxidx);
    printf(" Average: %5.2f\n", (float)tot / (float)hash->h_nbuckets);
}