src/utils/latency/latency_test.c

   1 /**
   2  * collectd - src/utils_latency_test.c
   3  * Copyright (C) 2015       Florian octo Forster
   4  *
   5  * Permission is hereby granted, free of charge, to any person obtaining a
   6  * copy of this software and associated documentation files (the "Software"),
   7  * to deal in the Software without restriction, including without limitation
   8  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   9  * and/or sell copies of the Software, and to permit persons to whom the
  10  * Software is furnished to do so, subject to the following conditions:
  11  *
  12  * The above copyright notice and this permission notice shall be included in
  13  * all copies or substantial portions of the Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  18  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  21  * DEALINGS IN THE SOFTWARE.
  22  *
  23  * Authors:
  24  *   Florian octo Forster <octo at collectd.org>
  25  */
  26
  27 #define DBL_PRECISION 1e-6
  28
  29 #include "collectd.h"
  30 #include "utils/common/common.h" /* for STATIC_ARRAY_SIZE */
  31
  32 #include "testing.h"
  33 #include "utils/latency/latency.h"
  34 #include "utils_time.h"
  35
  36 DEF_TEST(simple) {
  37   struct {
  38     double val;
  39     double min;
  40     double max;
  41     double sum;
  42     double avg;
  43   } cases[] = {
  44       /* val  min  max  sum   avg */
  45       {0.5, 0.5, 0.5, 0.5, 0.5}, {0.3, 0.3, 0.5, 0.8, 0.4},
  46       {0.7, 0.3, 0.7, 1.5, 0.5}, {2.5, 0.3, 2.5, 4.0, 1.0},
  47       {99, 0.3, 99, 103, 20.6},
  48       /* { -1, 0.3,  99, 103, 20.6}, see issue #1139 */
  49   };
  50   latency_counter_t *l;
  51
  52   CHECK_NOT_NULL(l = latency_counter_create());
  53
  54   for (size_t i = 0; i < STATIC_ARRAY_SIZE(cases); i++) {
  55     printf("# case %" PRIsz ": DOUBLE_TO_CDTIME_T(%g) = %" PRIu64 "\n", i,
  56            cases[i].val, DOUBLE_TO_CDTIME_T(cases[i].val));
  57     latency_counter_add(l, DOUBLE_TO_CDTIME_T(cases[i].val));
  58
  59     EXPECT_EQ_DOUBLE(cases[i].min,
  60                      CDTIME_T_TO_DOUBLE(latency_counter_get_min(l)));
  61     EXPECT_EQ_DOUBLE(cases[i].max,
  62                      CDTIME_T_TO_DOUBLE(latency_counter_get_max(l)));
  63     EXPECT_EQ_DOUBLE(cases[i].sum,
  64                      CDTIME_T_TO_DOUBLE(latency_counter_get_sum(l)));
  65     EXPECT_EQ_DOUBLE(cases[i].avg,
  66                      CDTIME_T_TO_DOUBLE(latency_counter_get_average(l)));
  67   }
  68
  69   latency_counter_destroy(l);
  70   return 0;
  71 }
  72
  73 DEF_TEST(percentile) {
  74   latency_counter_t *l;
  75
  76   CHECK_NOT_NULL(l = latency_counter_create());
  77
  78   for (size_t i = 0; i < 100; i++) {
  79     latency_counter_add(l, TIME_T_TO_CDTIME_T(((time_t)i) + 1));
  80   }
  81
  82   EXPECT_EQ_DOUBLE(1.0, CDTIME_T_TO_DOUBLE(latency_counter_get_min(l)));
  83   EXPECT_EQ_DOUBLE(100.0, CDTIME_T_TO_DOUBLE(latency_counter_get_max(l)));
  84   EXPECT_EQ_DOUBLE(100.0 * 101.0 / 2.0,
  85                    CDTIME_T_TO_DOUBLE(latency_counter_get_sum(l)));
  86   EXPECT_EQ_DOUBLE(50.5, CDTIME_T_TO_DOUBLE(latency_counter_get_average(l)));
  87
  88   EXPECT_EQ_DOUBLE(50.0,
  89                    CDTIME_T_TO_DOUBLE(latency_counter_get_percentile(l, 50.0)));
  90   EXPECT_EQ_DOUBLE(80.0,
  91                    CDTIME_T_TO_DOUBLE(latency_counter_get_percentile(l, 80.0)));
  92   EXPECT_EQ_DOUBLE(95.0,
  93                    CDTIME_T_TO_DOUBLE(latency_counter_get_percentile(l, 95.0)));
  94   EXPECT_EQ_DOUBLE(99.0,
  95                    CDTIME_T_TO_DOUBLE(latency_counter_get_percentile(l, 99.0)));
  96
  97   CHECK_ZERO(latency_counter_get_percentile(l, -1.0));
  98   CHECK_ZERO(latency_counter_get_percentile(l, 101.0));
  99
 100   latency_counter_destroy(l);
 101   return 0;
 102 }
 103
 104 DEF_TEST(get_rate) {
 105   /* We re-declare the struct here so we can inspect its content. */
 106   struct {
 107     cdtime_t start_time;
 108     cdtime_t sum;
 109     size_t num;
 110     cdtime_t min;
 111     cdtime_t max;
 112     cdtime_t bin_width;
 113     int histogram[HISTOGRAM_NUM_BINS];
 114   } * peek;
 115   latency_counter_t *l;
 116
 117   CHECK_NOT_NULL(l = latency_counter_create());
 118   peek = (void *)l;
 119
 120   for (time_t i = 1; i <= 125; i++) {
 121     latency_counter_add(l, TIME_T_TO_CDTIME_T(i));
 122   }
 123
 124   /* We expect a bucket width of 125ms. */
 125   EXPECT_EQ_UINT64(DOUBLE_TO_CDTIME_T(0.125), peek->bin_width);
 126
 127   struct {
 128     size_t index;
 129     int want;
 130   } bucket_cases[] = {
 131       {0, 0},  /* (0.000-0.125] */
 132       {1, 0},  /* (0.125-0.250] */
 133       {2, 0},  /* (0.250-0.375] */
 134       {3, 0},  /* (0.375-0.500] */
 135       {4, 0},  /* (0.500-0.625] */
 136       {5, 0},  /* (0.625-0.750] */
 137       {6, 0},  /* (0.750-0.875] */
 138       {7, 1},  /* (0.875-1.000] */
 139       {8, 0},  /* (1.000-1.125] */
 140       {9, 0},  /* (1.125-1.250] */
 141       {10, 0}, /* (1.250-1.375] */
 142       {11, 0}, /* (1.375-1.500] */
 143       {12, 0}, /* (1.500-1.625] */
 144       {13, 0}, /* (1.625-1.750] */
 145       {14, 0}, /* (1.750-1.875] */
 146       {15, 1}, /* (1.875-2.000] */
 147       {16, 0}, /* (2.000-2.125] */
 148   };
 149
 150   for (size_t i = 0; i < STATIC_ARRAY_SIZE(bucket_cases); i++) {
 151     size_t index = bucket_cases[i].index;
 152     EXPECT_EQ_INT(bucket_cases[i].want, peek->histogram[index]);
 153   }
 154
 155   struct {
 156     cdtime_t lower_bound;
 157     cdtime_t upper_bound;
 158     double want;
 159   } cases[] = {
 160       {
 161           // bucket 6 is zero
 162           DOUBLE_TO_CDTIME_T_STATIC(0.750),
 163           DOUBLE_TO_CDTIME_T_STATIC(0.875),
 164           0.00,
 165       },
 166       {
 167           // bucket 7 contains the t=1 update
 168           DOUBLE_TO_CDTIME_T_STATIC(0.875),
 169           DOUBLE_TO_CDTIME_T_STATIC(1.000),
 170           1.00,
 171       },
 172       {
 173           // range: bucket 7 - bucket 15; contains the t=1 and t=2 updates
 174           DOUBLE_TO_CDTIME_T_STATIC(0.875),
 175           DOUBLE_TO_CDTIME_T_STATIC(2.000),
 176           2.00,
 177       },
 178       {
 179           // lower bucket is only partially applied
 180           DOUBLE_TO_CDTIME_T_STATIC(0.875 + (0.125 / 4)),
 181           DOUBLE_TO_CDTIME_T_STATIC(2.000),
 182           1.75,
 183       },
 184       {
 185           // upper bucket is only partially applied
 186           DOUBLE_TO_CDTIME_T_STATIC(0.875),
 187           DOUBLE_TO_CDTIME_T_STATIC(2.000 - (0.125 / 4)),
 188           1.75,
 189       },
 190       {
 191           // both buckets are only partially applied
 192           DOUBLE_TO_CDTIME_T_STATIC(0.875 + (0.125 / 4)),
 193           DOUBLE_TO_CDTIME_T_STATIC(2.000 - (0.125 / 4)),
 194           1.50,
 195       },
 196       {
 197           // lower bound is unspecified
 198           0,
 199           DOUBLE_TO_CDTIME_T_STATIC(2.000),
 200           2.00,
 201       },
 202       {
 203           // upper bound is unspecified
 204           DOUBLE_TO_CDTIME_T_STATIC(125.000 - 0.125),
 205           0,
 206           1.00,
 207       },
 208       {
 209           // overflow test: upper >> longest latency
 210           DOUBLE_TO_CDTIME_T_STATIC(1.000),
 211           DOUBLE_TO_CDTIME_T_STATIC(999999),
 212           124.00,
 213       },
 214       {
 215           // overflow test: lower > longest latency
 216           DOUBLE_TO_CDTIME_T_STATIC(130),
 217           0,
 218           0.00,
 219       },
 220       {
 221           // lower > upper => error
 222           DOUBLE_TO_CDTIME_T_STATIC(10),
 223           DOUBLE_TO_CDTIME_T_STATIC(9),
 224           NAN,
 225       },
 226       {
 227           // lower == upper => zero
 228           DOUBLE_TO_CDTIME_T_STATIC(9),
 229           DOUBLE_TO_CDTIME_T_STATIC(9),
 230           0.00,
 231       },
 232   };
 233
 234   for (size_t i = 0; i < STATIC_ARRAY_SIZE(cases); i++) {
 235     cdtime_t now = peek->start_time + TIME_T_TO_CDTIME_T(1);
 236     EXPECT_EQ_DOUBLE(cases[i].want,
 237                      latency_counter_get_rate(l, cases[i].lower_bound,
 238                                               cases[i].upper_bound, now));
 239   }
 240
 241   latency_counter_destroy(l);
 242   return 0;
 243 }
 244
 245 int main(void) {
 246   RUN_TEST(simple);
 247   RUN_TEST(percentile);
 248   RUN_TEST(get_rate);
 249
 250   END_TEST;
 251 }