/*
 * 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 2002 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <synch.h>
#include <thread.h>
#include <memory.h>
#include <assert.h>
#include <libproc.h>
#include "ramdata.h"
#include "proto.h"
#include "htbl.h"


htbl_t *
init_hash(unsigned int size)
{
        htbl_t *htp;
        hashb_t *temp;
        int i;

        if ((size & (size - 1)) != 0)
                abend("Size must be power of two", NULL);

        htp = (htbl_t *)my_malloc(sizeof (htbl_t), NULL);
        htp->size = size;
        htp->tbl = (hashb_t *)
            my_calloc((size_t)size, sizeof (hashb_t), NULL);

        /* Init mutexes */
        for (i = 0; i < size; i++) {
                temp = &htp->tbl[i];
                (void) mutex_init(&temp->block, USYNC_THREAD, NULL);
        }

        return (htp);
}

void
destroy_hash(htbl_t *htp)
{
        int i;
        hentry_t *tmp;
        hentry_t *prev;
        hashb_t *cur;

        for (i = 0; i < htp->size; i++) {
                cur = &htp->tbl[i];
                (void) mutex_destroy(&cur->block);
                tmp = cur->first;

                while (tmp != NULL) {
                        prev = tmp;
                        tmp = tmp->next;

                        free(prev->key);
                        prev->key = NULL;
                        free(prev->lib);
                        prev->lib = NULL;

                        free((char *)prev);
                        if (tmp != NULL)
                                tmp->prev = NULL;
                }
        }
        free((char *)htp->tbl);
        htp->tbl = NULL;
        free(htp);
}

static unsigned int
hash_str(char *str, unsigned int sz)
{
        uint_t hash = 0;
        uint_t g;
        char *p;

        assert(str != NULL);
        for (p = str; *p != '\0'; p++) {
                hash = (hash << 4) + *p;
                if ((g = (hash & 0xf0000000)) != 0) {
                        hash ^= (g >> 24);
                        hash ^= g;
                }
        }

        return (hash & (sz - 1));
}


void
add_fcall(htbl_t *htp, char *lib, char *key, unsigned long cnt)
{
        unsigned int bucket;
        hentry_t *tmp;
        hentry_t *new;
        hashb_t *cur;

        bucket = hash_str(key, htp->size);
        cur = &htp->tbl[bucket];

        (void) mutex_lock(&cur->block);

        tmp = cur->first;
        while (tmp != NULL) {
                if (strcmp(tmp->key, key) == 0) {
                        if (strcmp(tmp->lib, lib) == 0) {
                                tmp->count += cnt;
                                (void) mutex_unlock(&cur->block);
                                return;
                        }
                }
                tmp = tmp->next;
        }

        /*
         * If we're still here, there was no such fcall recorded
         * so we make a new entry and add it to the table
         */

        new = (hentry_t *)my_malloc(sizeof (hentry_t), NULL);
        new->key = strdup(key);
        if (new->key == NULL)
                abend("Out of memory in htbl.c", NULL);
        new->lib = strdup(lib);
        if (new->lib == NULL)
                abend("Out of memory in htbl.c", NULL);
        new->count = cnt;
        new->prev = NULL;
        new->next = cur->first;
        tmp = new->next;
        if (tmp != NULL) {
                tmp->prev = new;
        }
        cur->first = new;

        (void) mutex_unlock(&cur->block);
}

/*
 * iterate_hash locks the table and returns an enumeration struct
 * using this it is possible to iterate through the entries of a hash table
 * once finished, use iter_free to unlock the table and free the struct
 */

hiter_t *
iterate_hash(htbl_t *tbl)
{
        int b;
        int i;
        hiter_t *new;
        hashb_t *cur;
        hentry_t *tmp = NULL;

        new = (hiter_t *)my_malloc(sizeof (hiter_t), NULL);
        new->table = tbl;

        for (i = 0; i < tbl->size; i++) {
                cur = &tbl->tbl[i];
                (void) mutex_lock(&cur->block);
                if (tmp == NULL) {
                        tmp = cur->first;
                        b = i;
                }
        }

        new->next = tmp;
        new->bucket = b;

        return (new);
}

void
iter_free(hiter_t *itr)
{
        int i;
        hashb_t *cur;
        htbl_t *tbl;

        tbl = itr->table;
        for (i = 0; i < tbl->size; i++) {
                cur = &tbl->tbl[i];
                (void) mutex_unlock(&cur->block);
        }

        free(itr);
}

hentry_t *
iter_next(hiter_t *itr)
{
        int i;
        hentry_t *tmp;
        hentry_t *ret;
        hashb_t *cur = NULL;
        htbl_t *hash;

        ret = itr->next;


        if (ret == NULL)
                return (ret);

        hash = itr->table;
        tmp = ret->next;
        i = itr->bucket;

        if (tmp == NULL) {
                for (i = i + 1; i < hash->size; i++) {
                        cur = &hash->tbl[i];
                        tmp = cur->first;
                        if (tmp != NULL)
                                break;
                }
        }

        itr->next = tmp;
        itr->bucket = i;

        return (ret);
}

size_t
elements_in_table(htbl_t *tbl)
{
        size_t elem = 0;
        hiter_t *itr = iterate_hash(tbl);
        hentry_t *tmp = iter_next(itr);
        while (tmp != NULL) {
                elem++;
                tmp = iter_next(itr);
        }
        iter_free(itr);
        return (elem);
}