/*
  Copyright (c) 2008-2012 Red Hat, Inc. <http://www.redhat.com>
  This file is part of GlusterFS.

  This file is licensed to you under your choice of the GNU Lesser
  General Public License, version 3 or any later version (LGPLv3 or
  later), or the GNU General Public License, version 2 (GPLv2), in all
  cases as published by the Free Software Foundation.
*/

/*
 * This file contains functions to support dumping of
 * latencies of FOPs broken down by subvolumes.
 */

#include "glusterfs/glusterfs.h"
#include "glusterfs/xlator.h"
#include "glusterfs/common-utils.h"
#include "glusterfs/statedump.h"
#include "glusterfs/libglusterfs-messages.h"

void
gf_update_latency(call_frame_t *frame)
{
    double elapsed;
    struct timespec *begin, *end;

    fop_latency_t *lat;

    begin = &frame->begin;
    end = &frame->end;

    if (!(begin->tv_sec && end->tv_sec))
        goto out;

    elapsed = (end->tv_sec - begin->tv_sec) * 1e9 +
              (end->tv_nsec - begin->tv_nsec);

    if (frame->op < 0 || frame->op >= GF_FOP_MAXVALUE) {
        gf_log("[core]", GF_LOG_WARNING, "Invalid frame op value: %d",
               frame->op);
        return;
    }

    /* Can happen mostly at initiator xlator, as STACK_WIND/UNWIND macros
       set it right anyways for those frames */
    if (!frame->op)
        frame->op = frame->root->op;

    lat = &frame->this->stats.interval.latencies[frame->op];

    if (lat->max < elapsed)
        lat->max = elapsed;

    if (lat->min > elapsed)
        lat->min = elapsed;

    lat->total += elapsed;
    lat->count++;
out:
    return;
}

void
gf_proc_dump_latency_info(xlator_t *xl)
{
    char key_prefix[GF_DUMP_MAX_BUF_LEN];
    char key[GF_DUMP_MAX_BUF_LEN];
    int i;

    snprintf(key_prefix, GF_DUMP_MAX_BUF_LEN, "%s.latency", xl->name);
    gf_proc_dump_add_section("%s", key_prefix);

    for (i = 0; i < GF_FOP_MAXVALUE; i++) {
        gf_proc_dump_build_key(key, key_prefix, "%s", (char *)gf_fop_list[i]);

        fop_latency_t *lat = &xl->stats.interval.latencies[i];

        /* Doesn't make sense to continue if there are no fops
           came in the given interval */
        if (!lat->count)
            continue;

        gf_proc_dump_write(key, "%.03f,%" PRId64 ",%.03f",
                           (lat->total / lat->count), lat->count, lat->total);
    }

    memset(xl->stats.interval.latencies, 0,
           sizeof(xl->stats.interval.latencies));

    /* make sure 'min' is set to high value, so it would be
       properly set later */
    for (i = 0; i < GF_FOP_MAXVALUE; i++) {
        xl->stats.interval.latencies[i].min = 0xffffffff;
    }
}