src/rate_ctr.c

   1 /* utility routines for keeping conters about events and the event rates */
   2
   3 /* (C) 2009-2010 by Harald Welte <laforge@gnumonks.org>
   4  *
   5  * All Rights Reserved
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License along
  18  * with this program; if not, write to the Free Software Foundation, Inc.,
  19  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  */
  22
  23 /*! \addtogroup rate_ctr
  24  *  @{
  25  */
  26
  27 /*! \file rate_ctr.c */
  28
  29
  30 #include <stdint.h>
  31 #include <string.h>
  32
  33 #include <osmocom/core/utils.h>
  34 #include <osmocom/core/linuxlist.h>
  35 #include <osmocom/core/talloc.h>
  36 #include <osmocom/core/timer.h>
  37 #include <osmocom/core/rate_ctr.h>
  38
  39 static LLIST_HEAD(rate_ctr_groups);
  40
  41 static void *tall_rate_ctr_ctx;
  42
  43 /*! \brief Allocate a new group of counters according to description
  44  *  \param[in] ctx \ref talloc context
  45  *  \param[in] desc Rate counter group description
  46  *  \param[in] idx Index of new counter group
  47  */
  48 struct rate_ctr_group *rate_ctr_group_alloc(void *ctx,
  49                                             const struct rate_ctr_group_desc *desc,
  50                                             unsigned int idx)
  51 {
  52         unsigned int size;
  53         struct rate_ctr_group *group;
  54
  55         size = sizeof(struct rate_ctr_group) +
  56                         desc->num_ctr * sizeof(struct rate_ctr);
  57
  58         if (!ctx)
  59                 ctx = tall_rate_ctr_ctx;
  60
  61         group = talloc_zero_size(ctx, size);
  62         if (!group)
  63                 return NULL;
  64
  65         group->desc = desc;
  66         group->idx = idx;
  67
  68         llist_add(&group->list, &rate_ctr_groups);
  69
  70         return group;
  71 }
  72
  73 /*! \brief Free the memory for the specified group of counters */
  74 void rate_ctr_group_free(struct rate_ctr_group *grp)
  75 {
  76         llist_del(&grp->list);
  77         talloc_free(grp);
  78 }
  79
  80 /*! \brief Add a number to the counter */
  81 void rate_ctr_add(struct rate_ctr *ctr, int inc)
  82 {
  83         ctr->current += inc;
  84 }
  85
  86 static void interval_expired(struct rate_ctr *ctr, enum rate_ctr_intv intv)
  87 {
  88         /* calculate rate over last interval */
  89         ctr->intv[intv].rate = ctr->current - ctr->intv[intv].last;
  90         /* save current counter for next interval */
  91         ctr->intv[intv].last = ctr->current;
  92
  93         /* update the rate of the next bigger interval.  This will
  94          * be overwritten when that next larger interval expires */
  95         if (intv + 1 < ARRAY_SIZE(ctr->intv))
  96                 ctr->intv[intv+1].rate += ctr->intv[intv].rate;
  97 }
  98
  99 static struct osmo_timer_list rate_ctr_timer;
 100 static uint64_t timer_ticks;
 101
 102 /* The one-second interval has expired */
 103 static void rate_ctr_group_intv(struct rate_ctr_group *grp)
 104 {
 105         unsigned int i;
 106
 107         for (i = 0; i < grp->desc->num_ctr; i++) {
 108                 struct rate_ctr *ctr = &grp->ctr[i];
 109
 110                 interval_expired(ctr, RATE_CTR_INTV_SEC);
 111                 if ((timer_ticks % 60) == 0)
 112                         interval_expired(ctr, RATE_CTR_INTV_MIN);
 113                 if ((timer_ticks % (60*60)) == 0)
 114                         interval_expired(ctr, RATE_CTR_INTV_HOUR);
 115                 if ((timer_ticks % (24*60*60)) == 0)
 116                         interval_expired(ctr, RATE_CTR_INTV_DAY);
 117         }
 118 }
 119
 120 static void rate_ctr_timer_cb(void *data)
 121 {
 122         struct rate_ctr_group *ctrg;
 123
 124         /* Increment number of ticks before we calculate intervals,
 125          * as a counter value of 0 would already wrap all counters */
 126         timer_ticks++;
 127
 128         llist_for_each_entry(ctrg, &rate_ctr_groups, list)
 129                 rate_ctr_group_intv(ctrg);
 130
 131         osmo_timer_schedule(&rate_ctr_timer, 1, 0);
 132 }
 133
 134 /*! \brief Initialize the counter module */
 135 int rate_ctr_init(void *tall_ctx)
 136 {
 137         tall_rate_ctr_ctx = tall_ctx;
 138         rate_ctr_timer.cb = rate_ctr_timer_cb;
 139         osmo_timer_schedule(&rate_ctr_timer, 1, 0);
 140
 141         return 0;
 142 }
 143
 144 /*! \brief Search for counter group based on group name and index */
 145 struct rate_ctr_group *rate_ctr_get_group_by_name_idx(const char *name, const unsigned int idx)
 146 {
 147         struct rate_ctr_group *ctrg;
 148
 149         llist_for_each_entry(ctrg, &rate_ctr_groups, list) {
 150                 if (!ctrg->desc)
 151                         continue;
 152
 153                 if (!strcmp(ctrg->desc->group_name_prefix, name) &&
 154                                 ctrg->idx == idx) {
 155                         return ctrg;
 156                 }
 157         }
 158         return NULL;
 159 }
 160
 161 /*! \brief Search for counter group based on group name */
 162 const struct rate_ctr *rate_ctr_get_by_name(const struct rate_ctr_group *ctrg, const char *name)
 163 {
 164         int i;
 165         const struct rate_ctr_desc *ctr_desc;
 166
 167         if (!ctrg->desc)
 168                 return NULL;
 169
 170         for (i = 0; i < ctrg->desc->num_ctr; i++) {
 171                 ctr_desc = &ctrg->desc->ctr_desc[i];
 172
 173                 if (!strcmp(ctr_desc->name, name)) {
 174                         return &ctrg->ctr[i];
 175                 }
 176         }
 177         return NULL;
 178 }
 179
 180 /*! @} */