cache/tests/store_test.php

   1 <?php
   2 // This file is part of Moodle - http://moodle.org/
   3 //
   4 // Moodle is free software: you can redistribute it and/or modify
   5 // it under the terms of the GNU General Public License as published by
   6 // the Free Software Foundation, either version 3 of the License, or
   7 // (at your option) any later version.
   8 //
   9 // Moodle is distributed in the hope that it will be useful,
  10 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 // GNU General Public License for more details.
  13 //
  14 // You should have received a copy of the GNU General Public License
  15 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
  16
  17 namespace core_cache;
  18
  19 /**
  20  * Unit tests for cache_store functionality.
  21  *
  22  * @package core_cache
  23  * @copyright 2021 The Open University
  24  * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  25  */
  26 class store_test extends \advanced_testcase {
  27
  28     /**
  29      * Tests the default implementation of cache_size_details, which does some
  30      * complicated statistics.
  31      */
  32     public function test_cache_size_details(): void {
  33         // Fill a store with 100 entries of varying size.
  34         $store = self::create_static_store();
  35         for ($i = 0; $i < 100; $i++) {
  36             $store->set('key' . $i, str_repeat('x', $i));
  37         }
  38
  39         // Do the statistics for 10 random picks.
  40         $details = $store->cache_size_details(10);
  41         $this->assertTrue($details->supported);
  42         $this->assertEquals(100, $details->items);
  43
  44         // Min/max possible means if it picks the smallest/largest 10.
  45         $this->assertGreaterThan(22, $details->mean);
  46         $this->assertLessThan(115, $details->mean);
  47         // Min/max possible SD.
  48         $this->assertLessThan(49, $details->sd);
  49         $this->assertGreaterThan(2.8, $details->sd);
  50         // Lowest possible confidence margin is about 1.74.
  51         $this->assertGreaterThan(1.7, $details->margin);
  52
  53         // Repeat the statistics for a pick of all 100 entries (exact).
  54         $details = $store->cache_size_details(100);
  55         $this->assertTrue($details->supported);
  56         $this->assertEquals(100, $details->items);
  57         $this->assertEqualsWithDelta(69.3, $details->mean, 0.1);
  58         $this->assertEqualsWithDelta(29.2, $details->sd, 0.1);
  59         $this->assertEquals(0, $details->margin);
  60     }
  61
  62     /**
  63      * Creates a static store for testing.
  64      *
  65      * @return \cachestore_static Store
  66      */
  67     protected static function create_static_store(): \cachestore_static {
  68         require_once(__DIR__ . '/../stores/static/lib.php');
  69         $store = new \cachestore_static('frog');
  70         $definition = \cache_definition::load('zombie', [
  71                 'mode' => \cache_store::MODE_REQUEST,
  72                 'component' => 'phpunit',
  73                 'area' => 'store_test',
  74                 'simplekeys' => true
  75         ]);
  76         $store->initialise($definition);
  77         return $store;
  78     }
  79 }