vikbooking / admin / helpers / src / cron / tracker / array.php

array.php in VikBooking Hotel Booking Engine & PMS trunk, at admin/helpers/src/cron/tracker/array.php

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1	<?php
2	/**
3	* @package VikBooking
4	* @subpackage core
5	* @author E4J s.r.l.
6	* @copyright Copyright (C) 2021 E4J s.r.l. All Rights Reserved.
7	* @license http://www.gnu.org/licenses/gpl-2.0.html GNU/GPL
8	* @link https://vikwp.com
9	*/
10
11	// No direct access
12	defined('ABSPATH') or die('No script kiddies please!');
13
14	/**
15	* VikBooking cron job scalar-elements array tracker.
16	*
17	* @since 1.5.10
18	*/
19	trait VBOCronTrackerArray
20	{
21	/**
22	* Defines the maximum number of characters that can occupy the list
23	* containing all the tracked elements. Children classes can alter
24	* this value according to their needs.
25	*
26	* @var int
27	*/
28	protected $maximumCharsTrackableElements = 10000;
29
30	/**
31	* Helper method used to flag the specified element as tracked. This is really helpful to easily
32	* check whether a specific record has been already parsed, which can be done by passing the same
33	* element argument to the `isTracked` method.
34	*
35	* It is recommended to register only scalar values in order to prevent an uncontrolled increase of the
36	* total length, which can arrive up to 2^16-1 characters (65535). It's up to the sub-classes to take care of
37	* this limit, which should clean the flag_char property in order to always have less than 65536 characters.
38	*
39	* @param mixed $element The element to track.
40	*
41	* @return boolean True on success, false otherwise.
42	*/
43	protected function track($element)
44	{
45	if ($this->isTracked($element) \|\| !is_scalar($element))
46	{
47	// element already tracked, avoid duplicate registration
48	return false;
49	}
50
51	if (is_numeric($element))
52	{
53	// cast to number to save some space occupied by json_encode for strings
54	$element = is_float($element) ? (float) $element : (int) $element;
55	}
56
57	// make sure this trait has been attached only to a cron job instance
58	if (!$this instanceof VBOCronJob)
59	{
60	throw new Exception('This tracker can be attached only to a VBOCronJob instance', 500);
61	}
62
63	// register the element at the beginning of the list
64	$data = $this->getData();
65	array_unshift($data->flag_char, $element);
66
67	// sanitize the elements contained within the cache in order
68	// avoid a length exceeding the maximum threshold
69	$this->sanitizeFlagCache($data);
70
71	return true;
72	}
73
74	/**
75	* Checks whether the specified element has been already processed.
76	*
77	* @param mixed $element The element to check.
78	*
79	* @return boolean True if already processed, false otherwise.
80	*/
81	protected function isTracked($element)
82	{
83	// make sure this trait has been attached only to a cron job instance
84	if (!$this instanceof VBOCronJob)
85	{
86	throw new Exception('This tracker can be attached only to a VBOCronJob instance', 500);
87	}
88
89	return in_array($element, $this->getData()->flag_char);
90	}
91
92	/**
93	* Ensures the array with the tracked elements doesn't exceed the maximum limit.
94	*
95	* @param object $data The cron job data.
96	*
97	* @return void
98	*/
99	private function sanitizeFlagCache($data)
100	{
101	// count the total number of characters that occupy the cache
102	$len = 0;
103
104	foreach ($data->flag_char as $element)
105	{
106	// sum value with the total number of characters
107	$len += strlen((string) $element);
108
109	if (!is_numeric($element))
110	{
111	// we have a string element, we need to include other 2 characters reserved for wrapping
112	$len += 2;
113	}
114
115	// increase the length by 1 to include also the elements separator (,)
116	$len++;
117	}
118
119	if ($data->flag_char)
120	{
121	// remove the trailing comma separator
122	$len--;
123	}
124
125	// sum also the initial and trailing brackets
126	$len += 2;
127
128	// even if the maximum number of allowed characters is 65535, we prefer to always stay under
129	// 10000 elements, since json_encode may use a specific encoding for some characters
130	if ($len > $this->maximumCharsTrackableElements)
131	{
132	// it is enough to pop the last 2 items from the list in order to stay under the desired limit,
133	// since this method always triggers while registering a new element
134	array_pop($data->flag_char);
135	array_pop($data->flag_char);
136	}
137	}
138	}
139