sqlite-object-cache / includes / lib / class-sqlite-object-cache-statistics.php

class-sqlite-object-cache-statistics.php in SQLite Object Cache 1.2.3, at includes/lib/class-sqlite-object-cache-statistics.php

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1	<?php
2	/**
3	* Statistics class file.
4	*
5	* @package SQLite Object Cache
6	*/
7
8	if ( ! defined( 'ABSPATH' ) ) {
9	exit;
10	}
11
12	/**
13	* statistics class.
14	*/
15	class SQLite_Object_Cache_Statistics {
16
17	/**
18	* Show the overrun message.
19	* @var bool Overrun detected, show message.
20	*/
21	private $overrun_message = false;
22	/**
23	* Associative array with selected cache items names most frequent first.
24	*
25	* @var array
26	*/
27	public $selected_names;
28
29	/**
30	* Associative array with descriptive statistics.
31	*
32	* @var array
33	*/
34	public $descriptions;
35	/**
36	* @var string
37	*/
38	private $start_time;
39	/**
40	* @var string
41	*/
42	private $end_time;
43	/**
44	* @var array
45	*/
46	private $options;
47
48	public function __construct( $options ) {
49	$this->options = $options;
50	}
51
52	/**
53	* Initialize and load data.
54	*
55	* @return void
56	* @throws Exception Announce database failure.
57	*/
58	public function init() {
59	global $wp_object_cache;
60
61	$first = PHP_INT_MAX;
62	$last = PHP_INT_MIN;
63
64	$selected_names = [];
65	$opens = [];
66	$selects = [];
67	$inserts = [];
68	$deletes = [];
69	$RAMratios = [];
70	$RAMhits = 0;
71	$RAMmisses = 0;
72	$DISKratios = [];
73	$DISKLookupsPerRequest = [];
74	$SavesPerRequest = [];
75	$DBMSqueriesPerRequest = [];
76	$DISKhits = 0;
77	$DISKmisses = 0;
78
79	if ( ! method_exists( $wp_object_cache, 'sqlite_load_statistics' ) ) {
80	return;
81	}
82
83	if ( method_exists( $wp_object_cache, 'sqlite_clean_up_cache' ) ) {
84	$wp_object_cache->sqlite_clean_up_cache();
85	}
86
87	foreach ( $wp_object_cache->sqlite_load_statistics() as $data ) {
88	$first = min( $data->time, $first );
89	$last = max( $data->time, $last );
90	$RAMhits += $data->RAMhits;
91	$RAMmisses += $data->RAMmisses;
92	$DISKhits += $data->DISKhits;
93	$DISKmisses += $data->DISKmisses;
94	$DISKLookupsPerRequest[] = $data->DISKhits + $data->DISKmisses;
95	$RAMratio = $data->RAMhits / ( $data->RAMhits + $data->RAMmisses );
96	$RAMratios[] = $RAMratio;
97	$DISKratio = $data->DISKhits / ( $data->DISKhits + $data->DISKmisses );
98	$DISKratios[] = $DISKratio;
99	$opens [] = $data->open;
100	array_push( $selects, ...$data->selects );
101	array_push( $inserts, ...$data->inserts );
102	$SavesPerRequest [] = count( $data->inserts );
103	if ( property_exists( $data, 'DBMSqueries' ) && is_numeric( $data->DBMSqueries ) ) {
104	$DBMSqueriesPerRequest [] = $data->DBMSqueries;
105	}
106	array_push( $deletes, ...$data->deletes );
107
108	$this->truncate_if_too_long( $DISKLookupsPerRequest );
109	$this->truncate_if_too_long( $RAMratios );
110	$this->truncate_if_too_long( $DISKratios );
111	$this->truncate_if_too_long( $opens );
112	$this->truncate_if_too_long( $selects );
113	$this->truncate_if_too_long( $inserts );
114	$this->truncate_if_too_long( $SavesPerRequest );
115	$this->truncate_if_too_long( $DBMSqueriesPerRequest );
116	$this->truncate_if_too_long( $deletes );
117
118	if ( property_exists( $data, 'select_names' ) && is_array( $data->select_names ) ) {
119	foreach ( $data->select_names as $name ) {
120	if ( ! array_key_exists( $name, $selected_names ) ) {
121	$selected_names[ $name ] = 0;
122	}
123	$selected_names[ $name ] ++;
124	}
125	}
126	}
127	$duration = $last - $first;
128	if ( $duration > 0 ) {
129	arsort( $selected_names );
130	$descriptions = [
131	__( 'RAM hit ratio', 'sqlite-object-cache' ) => $this->descriptive_stats( $RAMratios ),
132	__( 'Disk hit ratio', 'sqlite-object-cache' ) => $this->descriptive_stats( $DISKratios ),
133	__( 'Disk lookups/request', 'sqlite-object-cache' ) => $this->descriptive_stats( $DISKLookupsPerRequest ),
134	__( 'Disk saves/request', 'sqlite-object-cache' ) => $this->descriptive_stats( $SavesPerRequest ),
135	__( 'MySQL queries/request', 'sqlite-object-cache' ) => $this->descriptive_stats( $DBMSqueriesPerRequest ),
136	__( 'Initialization times', 'sqlite-object-cache' ) => $this->descriptive_stats( $opens ),
137	__( 'Lookup times', 'sqlite-object-cache' ) => $this->descriptive_stats( $selects ),
138	__( 'Save times', 'sqlite-object-cache' ) => $this->descriptive_stats( $inserts ),
139	__( 'Delete times', 'sqlite-object-cache' ) => $this->descriptive_stats( $deletes ),
140	];
141
142	$this->descriptions = $descriptions;
143	$this->selected_names = $selected_names;
144	$this->start_time = $this->format_datestamp( $first );
145	$this->end_time = $this->format_datestamp( $last );
146	}
147	}
148
149	/**
150	* Truncate an array to a particular length.
151	*
152	* @param array $observations The array to truncate in place.
153	* @param int $limit Target array length.
154	*
155	* @return void
156	*/
157	public function truncate_if_too_long( &$observations, $limit = 999999 ) {
158	if ( count( $observations ) > $limit ) {
159	$this->overrun_message = true;
160	array_splice( $observations, $limit );
161	}
162	}
163
164	/**
165	* Descriptive statistics for an array of numbers.
166	*
167	* @param array $a The array.
168	*
169	* @return array
170	*/
171	public function descriptive_stats( array &$a ) {
172	sort( $a );
173	$min = $this->minimum( $a );
174	$max = $this->maximum( $a );
175
176	return [
177	'n' => count( $a ),
178	'[min' => $min,
179	'p1' => $this->percentile( $a, 0.01 ),
180	'p5' => $this->percentile( $a, 0.05 ),
181	'median' => $this->percentile( $a, 0.5 ),
182	'mean' => $this->mean( $a ),
183	'p95' => $this->percentile( $a, 0.95 ),
184	'p99' => $this->percentile( $a, 0.99 ),
185	'max]' => $max,
186	'range' => $max - $min,
187	'mad' => $this->mad( $a ),
188	'stdev' => $this->stdev( $a ),
189	];
190	}
191
192	/**
193	* The smallest value in an array.
194	*
195	* @param array $a The array. Must be sorted.
196	*
197	* @return mixed\|null
198	*/
199	public function minimum( array $a ) {
200
201	return count( $a ) > 0 ? $a[0] : null;
202	}
203
204	/**
205	* The largest value in an array.
206	*
207	* @param array $a The array. Must be sorted.
208	*
209	* @return mixed\|null
210	*/
211	public function maximum( array $a ) {
212
213	return count( $a ) > 0 ? $a[ count( $a ) - 1 ] : null;
214	}
215
216	/** Percentile.
217	*
218	* @param array $a dataset. Must be sorted.
219	* @param number $p percentile as fraction 0-1.
220	*
221	* @return float
222	*/
223	public function percentile( array $a, $p ) {
224	$n = count( $a );
225	if ( ! $n ) {
226	return null;
227	}
228	$i = (int) floor( $n * $p );
229	if ( $i >= $n ) {
230	$i = $n - 1;
231	}
232
233	return $a[ $i ];
234	}
235
236	/**
237	* Arithmetic mean.
238	*
239	* @param array $a dataset.
240	*
241	* @return number
242	*/
243	public function mean( array $a ) {
244	$n = count( $a );
245	if ( ! $n ) {
246	return null;
247	}
248	if ( 1 === $n ) {
249	return $a[0];
250	}
251	$acc = 0;
252	foreach ( $a as $v ) {
253	$acc += $v;
254	}
255
256	return $acc / $n;
257	}
258
259	/**
260	* Mean absolute deviation.
261	*
262	* @param array $a dataset.
263	*
264	* @return float\|int\|null
265	*/
266	public function mad( array $a ) {
267	$n = count( $a );
268	if ( ! $n ) {
269	return null;
270	}
271	if ( 1 === $n ) {
272	return 0.0;
273	}
274	$acc = 0;
275	foreach ( $a as $v ) {
276	$acc += $v;
277	}
278	$mean = $acc / $n;
279	$acc = 0;
280	foreach ( $a as $v ) {
281	$acc += abs( $v - $mean );
282	}
283
284	return $acc / $n;
285	}
286
287	/**
288	* Standard deviation.
289	*
290	* @param array $a dataset.
291	*
292	* @return float\|null
293	*/
294	public function stdev( $a ) {
295	$n = count( $a );
296	if ( ! $n ) {
297	return null;
298	}
299	if ( 1 === $n ) {
300	return 0.0;
301	}
302	$sum = 0.0;
303	$sumsq = 0.0;
304	foreach ( $a as $v ) {
305	$sum += $v;
306	$sumsq += ( $v * $v );
307	}
308	$mean = $sum / $n;
309
310	return sqrt( ( $sumsq / $n ) - ( $mean * $mean ) );
311	}
312
313	/**
314	* Format a UNIX timestamp using WP settings.
315	*
316	* @param $stamp
317	*
318	* @return false\|string
319	*/
320	private function format_datestamp( $stamp ) {
321	$date_format = get_option( 'date_format' ) . ' ' . get_option( 'time_format' );
322
323	return wp_date( $date_format, (int) $stamp );
324	}
325
326	/**
327	* Render the statistics display.
328	*
329	* @return void
330	*/
331	public function render() {
332
333	echo '<h3>' . esc_html__( 'Cache performance', 'sqlite-object-cache' ) . '</h3>';
334	if ( is_array( $this->descriptions ) ) {
335	echo '<p>' . esc_html( sprintf(
336	/* translators: 1 start time 2 end time both in localized format */
337	__( 'From %1$s to %2$s.', 'sqlite-object-cache' ),
338	$this->start_time, $this->end_time ) . ' ' . __( 'Times in microseconds.', 'sqlite-object-cache' ) ) . '</p>' . PHP_EOL;
339	echo '<table class="sql-object-cache-stats">' . PHP_EOL;
340	$first = true;
341	foreach ( $this->descriptions as $stat => $description ) {
342	if ( $first ) {
343	echo '<thead><tr>';
344	echo '<th scope="col"></th>';
345	foreach ( $description as $item => $value ) {
346	echo '<th scope="col" class="right">' . esc_html( $item ) . '</th>' . PHP_EOL;
347	}
348	echo '</tr></thead><tbody>' . PHP_EOL;
349	$first = false;
350	}
351	echo '<tr>';
352	echo '<th scope="row">' . esc_html( $stat ) . '</th>';
353	foreach ( $description as $value ) {
354	echo '<td>' . esc_html( round( $value, 2 ) ) . '</td>';
355	}
356	echo '</tr>' . PHP_EOL;
357	}
358	echo '</tr></tbody></table>' . PHP_EOL;
359	if ($this->overrun_message) {
360	echo '<p>';
361	esc_html_e ( 'Some statistics were not processed. Processing them all uses too much RAM.', 'sqlite-object-cache');
362	echo ' ';
363	esc_html_e ( 'Try measuring a smaller random sample of requests.', 'sqlite-object-cache');
364	echo '</p>'. PHP_EOL;
365	$this->overrun_message = false;
366	}
367	} else {
368	if ( is_array( $this->options ) && array_key_exists( 'capture', $this->options ) && 'on' === $this->options['capture'] ) {
369	echo '<p>' . esc_html__( 'No cache performance statistics have been captured.', 'sqlite-object-cache' ) . ' ';
370	$message =
371	/* translators: 1: a percentage */
372	__( 'The plugin is capturing a random sample of %s%% of requests. It is possible no samples have yet been captured.', 'sqlite-object-cache' );
373	$samplerate = is_numeric( $this->options['samplerate'] ) ? $this->options['samplerate'] : 1;
374	echo esc_html( sprintf( $message, $samplerate ) ) . '</p>';
375	} else {
376	echo '<p>' . esc_html__( 'Cache performance measurement is not enabled.', 'sqlite-object-cache' ) . ' ';
377	echo esc_html__( 'You may enable it on the Settings tab.', 'sqlite-object-cache' ) . '</p>';
378	}
379	}
380
381	if ( is_array( $this->selected_names ) && count( $this->selected_names ) > 0 ) {
382
383	$names = $this->selected_names;
384	uksort( $names, function ( $a, $b ) {
385	/* Descending order of frequency */
386	if ( $this->selected_names[ $a ] !== $this->selected_names[ $b ] ) {
387	return $this->selected_names[ $a ] > $this->selected_names[ $b ] ? - 1 : 1;
388	}
389	$as = explode( '\|', $a, 2 );
390	$bs = explode( '\|', $b, 2 );
391	/* Ascending order by group name */
392	if ( $as[0] !== $bs[0] ) {
393	return strnatcmp( $as[0], $bs[0] );
394	}
395	/* Ascending order by key name, handling numeric keys correctly. */
396	if ( is_numeric( $as[1] ) && is_numeric( $bs[1] ) ) {
397	if ( (float) $as[1] === (float) $bs[1] ) {
398	return 0;
399	}
400
401	return ( (float) $as[1] ) < ( (float) $bs[1] ) ? - 1 : 1;
402	}
403
404	return strnatcmp( $as[1], $bs[1] );
405	} );
406
407	echo '<h3>' . esc_html__( 'Most frequently looked up cache items', 'sqlite-object-cache' ) . '</h3>' . PHP_EOL;
408
409	echo '<table class="sql-object-cache-items">' . PHP_EOL;
410	$count_threshold = - 1;
411	$first = true;
412	foreach ( $names as $name => $count ) {
413	if ( $first ) {
414	echo '<thead><tr>';
415	echo '<th scope="col">' . esc_html__( "Cache Group", 'sqlite-object-cache' ) . '</th>';
416	echo '<th scope="col">' . esc_html__( "Cache Key", 'sqlite-object-cache' ) . '</th>';
417	echo '<th scope="col">' . esc_html__( "Count", 'sqlite-object-cache' ) . '</th>';
418	echo '</tr></thead><tbody>' . PHP_EOL;
419	$count_threshold = (int) ( $count * 0.7 );
420	$first = false;
421	}
422	if ( $count < $count_threshold ) {
423	break;
424	}
425	$splits = explode( '\|', $name, 2 );
426	echo '<tr>';
427	echo '<td>' . esc_html( $splits[0] ) . '</td>';
428	echo '<td>' . esc_html( $splits[1] ) . '</td>';
429	echo '<td>' . esc_html( $count ) . '</td>';
430	echo '</tr>' . PHP_EOL;
431	}
432	}
433	echo '</tbody></table>';
434	}
435
436	/**
437	* Render the usage display.
438	*
439	* @return void
440	*/
441	public function render_usage() {
442
443	global $wp_object_cache;
444	if ( ! method_exists( $wp_object_cache, 'sqlite_load_usages' ) ) {
445	return;
446	}
447	$filesize = null;
448	try {
449	if ( method_exists( $wp_object_cache, 'sqlite_files' ) ) {
450	foreach ( $wp_object_cache->sqlite_files() as $file ) {
451	ob_start();
452	$filesize = filesize( $file );
453	ob_end_clean();
454	break;
455	}
456	}
457	} catch ( Exception $ex ) {
458	$filesize = null;
459	}
460
461	echo '<h3>' . esc_html__( 'Cache usage', 'sqlite-object-cache' ) . '</h3>';
462	$grouplength = [];
463	$groupcount = [];
464	$length = 0;
465	$count = 0;
466	$earliest = PHP_INT_MAX;
467	$latest = PHP_INT_MIN;
468
469	try {
470
471	foreach ( $wp_object_cache->sqlite_load_usages( true ) as $item ) {
472	$length += $item->length;
473	$count ++;
474	$ts = $item->expires;
475	$earliest = min( $earliest, $ts );
476	$latest = max( $latest, $ts );
477	$splits = explode( '\|', $item->name, 2 );
478	$group = $splits[0];
479	$group = preg_replace( '/_[ 0-9._]+$/', '_*', $group );
480	if ( ! array_key_exists( $group, $grouplength ) ) {
481	$grouplength[ $group ] = 0;
482	$groupcount[ $group ] = 0;
483	}
484	$grouplength[ $group ] += $item->length;
485	$groupcount[ $group ] ++;
486	}
487	} catch ( Exception $ex ) {
488	echo '<p>' . esc_html__( 'Cannot load some or all cache items.', 'sqlite-object-cache' ) . '</p>';
489	}
490
491	if ( $count > 0 ) {
492	$groups = array_keys( $grouplength );
493	sort( $groups );
494
495	echo '<p>' . esc_html( sprintf(
496	/* translators: 1 start time 2 end time both in localized format */
497	__( 'Expirations from %1$s to %2$s.', 'sqlite-object-cache' ),
498	$this->format_datestamp( $earliest ), $this->format_datestamp( $latest ) ) . ' ' . __( 'Sizes in MiB.', 'sqlite-object-cache' ) ) . '</p>' . PHP_EOL;
499
500	echo '<table class="sql-object-cache-stats">' . PHP_EOL;
501	/* table headers */
502	echo '<thead><tr>';
503	echo '<th scope="col" class="right">' . esc_html__( 'Cache Group', 'sqlite-object-cache' ) . '</th>';
504	echo '<th scope="col" class="right">' . esc_html__( 'Items', 'sqlite-object-cache' ) . '</th>';
505	echo '<th scope="col" class="right">' . esc_html__( 'Size', 'sqlite-object-cache' ) . '</th>';
506	echo '</tr></thead><tbody>' . PHP_EOL;
507
508	/* filesize row */
509	if ( $filesize ) {
510	echo '<tr>';
511	echo '<th scope="row" class="right">' . esc_html__( 'Cache File Size', 'sqlite-object-cache' ) . '</th>';
512	echo '<td class="right total"></td>';
513	$sizemib = $filesize / ( 1024 * 1024 );
514	echo '<td class="right total">' . esc_html( number_format_i18n( $sizemib, 3 ) ) . '</td>';
515	echo '</tr>' . PHP_EOL;
516	}
517	/* totals row */
518	echo '<tr>';
519	echo '<th scope="row" class="right">' . esc_html__( 'All Groups', 'sqlite-object-cache' ) . '</th>';
520	echo '<td class="right total">' . esc_html( number_format_i18n( $count, 0 ) ) . '</td>';
521	$sizemib = $length / ( 1024 * 1024 );
522	echo '<td class="right total">' . esc_html( number_format_i18n( $sizemib, 3 ) ) . '</td>';
523	echo '</tr>' . PHP_EOL;
524	foreach ( $groups as $group ) {
525	/* detail row */
526	echo '<tr>';
527	echo '<th scope="row" class="right">' . esc_html( $group ) . '</th>';
528	echo '<td class="right">' . esc_html( number_format_i18n( $groupcount[ $group ], 0 ) ) . '</td>';
529	$sizemib = $grouplength[ $group ] / ( 1024 * 1024 );
530	echo '<td class="right">' . esc_html( number_format_i18n( $sizemib, 3 ) ) . '</td>';
531	echo '</tr>' . PHP_EOL;
532	}
533
534	echo '</tbody></table>' . PHP_EOL;
535	} else {
536	echo '<p>' . esc_html__( 'No cache items found.', 'sqlite-object-cache' ) . '</p>';
537	}
538	}
539	}
540