/*
 * 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 2006 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 *
 * stats.c -- simple stats tracking table module
 *
 */

#include <sys/types.h>
#include <strings.h>
#include "stats.h"
#include "alloc.h"
#include "out.h"

struct stats {
        struct stats *next;
        const char *name;
        const char *desc;
        enum stats_type {
                STATS_COUNTER = 3000,
                STATS_ELAPSE,
                STATS_STRING
        } t;
        union {
                int counter;
                struct {
                        hrtime_t start;
                        hrtime_t stop;
                } elapse;
                const char *string;
        } u;
};

static int Ext;                 /* true if extended stats are enabled */
static struct stats *Statslist;
static struct stats *Laststats;


/*
 * stats_init -- initialize the stats module
 *
 */

void
stats_init(int ext)
{
        Ext = ext;
}

void
stats_fini(void)
{
}

static struct stats *
stats_new(const char *name, const char *desc, enum stats_type t)
{
        struct stats *ret = MALLOC(sizeof (*ret));

        bzero(ret, sizeof (*ret));
        ret->t = t;
        ret->name = STRDUP(name);
        ret->desc = STRDUP(desc);

        if (Laststats == NULL)
                Statslist = ret;
        else
                Laststats->next = ret;
        Laststats = ret;

        return (ret);
}

void
stats_delete(struct stats *sp)
{
        struct stats *p, *s;

        if (sp == NULL)
                return;

        for (p = NULL, s = Statslist; s != NULL; s = s->next)
                if (s == sp)
                        break;

        if (s == NULL)
                return;

        if (p == NULL)
                Statslist = s->next;
        else
                p->next = s->next;

        if (s == Laststats)
                Laststats = p;

        FREE((void *)sp->name);
        FREE((void *)sp->desc);
        FREE(sp);
}

struct stats *
stats_new_counter(const char *name, const char *desc, int ext)
{
        if (ext && !Ext)
                return (NULL);          /* extended stats not enabled */

        return (stats_new(name, desc, STATS_COUNTER));
}

void
stats_counter_bump(struct stats *sp)
{
        if (sp == NULL)
                return;

        ASSERT(sp->t == STATS_COUNTER);

        sp->u.counter++;
}

void
stats_counter_add(struct stats *sp, int n)
{
        if (sp == NULL)
                return;

        ASSERT(sp->t == STATS_COUNTER);

        sp->u.counter += n;
}

void
stats_counter_reset(struct stats *sp)
{
        if (sp == NULL)
                return;

        ASSERT(sp->t == STATS_COUNTER);

        sp->u.counter = 0;
}

int
stats_counter_value(struct stats *sp)
{
        if (sp == NULL)
                return (0);

        ASSERT(sp->t == STATS_COUNTER);

        return (sp->u.counter);
}

struct stats *
stats_new_elapse(const char *name, const char *desc, int ext)
{
        if (ext && !Ext)
                return (NULL);          /* extended stats not enabled */

        return (stats_new(name, desc, STATS_ELAPSE));
}

void
stats_elapse_start(struct stats *sp)
{
        if (sp == NULL)
                return;

        ASSERT(sp->t == STATS_ELAPSE);

        sp->u.elapse.start = gethrtime();
}

void
stats_elapse_stop(struct stats *sp)
{
        if (sp == NULL)
                return;

        ASSERT(sp->t == STATS_ELAPSE);

        sp->u.elapse.stop = gethrtime();
}

struct stats *
stats_new_string(const char *name, const char *desc, int ext)
{
        if (ext && !Ext)
                return (NULL);          /* extended stats not enabled */

        return (stats_new(name, desc, STATS_STRING));
}

void
stats_string_set(struct stats *sp, const char *s)
{
        if (sp == NULL)
                return;

        ASSERT(sp->t == STATS_STRING);

        sp->u.string = s;
}

/*
 * stats_publish -- spew all stats
 *
 */

void
stats_publish(void)
{
        struct stats *sp;

        for (sp = Statslist; sp; sp = sp->next)
                switch (sp->t) {
                case STATS_COUNTER:
                        out(O_OK, "%32s %13d %s", sp->name,
                            sp->u.counter, sp->desc);
                        break;

                case STATS_ELAPSE:
                        if (sp->u.elapse.start && sp->u.elapse.stop) {
                                hrtime_t delta =
                                    sp->u.elapse.stop - sp->u.elapse.start;

                                out(O_OK, "%32s %11lldns %s", sp->name,
                                    delta, sp->desc);
                        }
                        break;

                case STATS_STRING:
                        out(O_OK, "%32s %13s %s", sp->name, sp->u.string,
                            sp->desc);
                        break;

                default:
                        out(O_DIE, "stats_publish: unknown type %d", sp->t);
                }
}