/*

 * Copyright (c) 2004-2006 Maxim Sobolev <sobomax@FreeBSD.org>

 * Copyright (c) 2006-2015 Sippy Software, Inc., http://www.sippysoft.com

 * All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in the

 *    documentation and/or other materials provided with the distribution.

 *

 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND

 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE

 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL

 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS

 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)

 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT

 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY

 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF

 * SUCH DAMAGE.

 *

 */

#include <assert.h>

#include <stdatomic.h>

#include <stddef.h>

#include <stdbool.h>

#include <stdint.h>

#include <stdlib.h>

#include <string.h>

#include "config.h"

#include "rtpp_types.h"

#include "rtpp_mallocs.h"

#include "rtpp_refcnt.h"

#include "rtpp_codeptr.h"

#include "rtpp_log.h"

#include "rtpp_log_obj.h"

#include "rtpp_pcount.h"

#include "rtpp_pcount_fin.h"

struct _rtpps_pcount {

    _Atomic(unsigned long) nrelayed;

    _Atomic(unsigned long) ndropped;

    _Atomic(unsigned long) nignored;

};

#define TOP_DROPS_SIZE 4

struct rtpp_pcount_loc {

    _Atomic(const struct rtpp_codeptr *) ptr __attribute__((aligned(CACHELINE_SIZE)));

    _Atomic(unsigned long) cnt;

};

struct rtpp_pcount_priv {

    struct rtpp_pcount pub;

    struct _rtpps_pcount cnt;

    struct rtpp_pcount_loc top_drop_locs[TOP_DROPS_SIZE];

};

static void rtpp_pcount_dtor(struct rtpp_pcount_priv *);

static void rtpp_pcount_reg_reld(struct rtpp_pcount *);

static void rtpp_pcount_reg_drop(struct rtpp_pcount *, HERETYPE);

static void rtpp_pcount_reg_ignr(struct rtpp_pcount *);

static void rtpp_pcount_get_stats(struct rtpp_pcount *, struct rtpps_pcount *);

static void rtpp_pcount_log_drops(struct rtpp_pcount *, struct rtpp_log *);

DEFINE_SMETHODS(rtpp_pcount,

    .reg_reld = &rtpp_pcount_reg_reld,

    .reg_drop = &rtpp_pcount_reg_drop,

    .reg_ignr = &rtpp_pcount_reg_ignr,

    .get_stats = &rtpp_pcount_get_stats,

    .log_drops = &rtpp_pcount_log_drops

);

struct rtpp_pcount *

rtpp_pcount_ctor(void)

{

    struct rtpp_pcount_priv *pvt;

    pvt = rtpp_rzmalloc(sizeof(struct rtpp_pcount_priv), PVT_RCOFFS(pvt));

    if (pvt == NULL) {

        goto e0;

    }

    atomic_init(&(pvt->cnt.nrelayed), 0);

    atomic_init(&(pvt->cnt.ndropped), 0);

    atomic_init(&(pvt->cnt.nignored), 0);

    for (int i = 0; i < TOP_DROPS_SIZE; i++) {

        atomic_init(&(pvt->top_drop_locs[i].ptr), NULL);

        atomic_init(&(pvt->top_drop_locs[i].cnt), 0);

    }

    PUBINST_FININIT(&pvt->pub, pvt, rtpp_pcount_dtor);

    return ((&pvt->pub));

e0:

    return (NULL);

}

static void

rtpp_pcount_dtor(struct rtpp_pcount_priv *pvt)

{

    rtpp_pcount_fin(&(pvt->pub));

}

static void

rtpp_pcount_reg_reld(struct rtpp_pcount *self)

{

    struct rtpp_pcount_priv *pvt;

    PUB2PVT(self, pvt);

    atomic_fetch_add_explicit(&pvt->cnt.nrelayed, 1, memory_order_relaxed);

}

static void

rtpp_pcount_reg_drop(struct rtpp_pcount *self, HERETYPEARG)

{

    struct rtpp_pcount_priv *pvt;

    PUB2PVT(self, pvt);

    atomic_fetch_add_explicit(&pvt->cnt.ndropped, 1, memory_order_relaxed);

    assert(mlp != NULL);

    for (int i = 0; i < TOP_DROPS_SIZE; i++) {

        const struct rtpp_codeptr *old_ptr;

retry:

        old_ptr = atomic_load_explicit(&pvt->top_drop_locs[i].ptr, memory_order_relaxed);

        if (old_ptr == NULL) {

            if (atomic_compare_exchange_strong(&pvt->top_drop_locs[i].ptr, &old_ptr, mlp) != true) {

                goto retry;

            }

        }

        if (old_ptr != NULL && old_ptr != mlp)

            continue;

        atomic_fetch_add_explicit(&pvt->top_drop_locs[i].cnt, 1, memory_order_relaxed);

        break;

    }

}

static void rtpp_pcount_log_drops(struct rtpp_pcount *self, struct rtpp_log *log)

{

    struct rtpp_pcount_priv *pvt;

    PUB2PVT(self, pvt);

    for (int i = 0; i < TOP_DROPS_SIZE; i++) {

        const struct rtpp_codeptr *mlp;

        unsigned long cnt;

        mlp = atomic_load_explicit(&pvt->top_drop_locs[i].ptr, memory_order_relaxed);

        if (mlp == NULL)

            break;

        cnt = atomic_load_explicit(&pvt->top_drop_locs[i].cnt, memory_order_relaxed);

        if (cnt == 0)

            continue;

        RTPP_LOG(log, RTPP_LOG_INFO, CODEPTR_FMT(": %lu packets dropped here", mlp, cnt));

    }

}

static void

rtpp_pcount_reg_ignr(struct rtpp_pcount *self)

{

    struct rtpp_pcount_priv *pvt;

    PUB2PVT(self, pvt);

    atomic_fetch_add_explicit(&pvt->cnt.nignored, 1, memory_order_relaxed);

}

static void

rtpp_pcount_get_stats(struct rtpp_pcount *self, struct rtpps_pcount *ocnt)

{

    struct rtpp_pcount_priv *pvt;

    PUB2PVT(self, pvt);

    ocnt->nrelayed = atomic_load_explicit((&pvt->cnt.nrelayed), memory_order_relaxed);

    ocnt->ndropped = atomic_load_explicit((&pvt->cnt.ndropped), memory_order_relaxed);

    ocnt->nignored = atomic_load_explicit((&pvt->cnt.nignored), memory_order_relaxed);

}