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

class-sqlite-object-cache-statistics.php in SQLite Object Cache 1.3.0, 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	* Associative array with selected cache items names most frequent first.
19	*
20	* @var array
21	*/
22	public $selected_names;
23	/**
24	* Associative array with descriptive statistics.
25	*
26	* @var array
27	*/
28	public $descriptions;
29	/**
30	* Show the overrun message.
31	* @var bool Overrun detected, show message.
32	*/
33	private $overrun_message = false;
34	/**
35	* @var string
36	*/
37	private $start_time;
38	/**
39	* @var string
40	*/
41	private $end_time;
42	/**
43	* @var array
44	*/
45	private $options;
46
47	public function __construct( $options ) {
48	$this->options = $options;
49	}
50
51	/**
52	* Initialize and load data.
53	*
54	* @return void
55	* @throws Exception Announce database failure.
56	*/
57	public function init() {
58	global $wp_object_cache;
59
60	$first = PHP_INT_MAX;
61	$last = PHP_INT_MIN;
62
63	$selected_names = array();
64	$opens = array();
65	$selects = array();
66	$get_multiples = array();
67	$get_multiple_keys = array();
68	$inserts = array();
69	$deletes = array();
70	$RAMratios = array();
71	$RAMhits = 0;
72	$RAMmisses = 0;
73	$DISKratios = array();
74	$DISKLookupsPerRequest = array();
75	$SavesPerRequest = array();
76	$DBMSqueriesPerRequest = array();
77	$DISKhits = 0;
78	$DISKmisses = 0;
79
80	if ( ! method_exists( $wp_object_cache, 'sqlite_load_statistics' ) ) {
81	return;
82	}
83
84	if ( method_exists( $wp_object_cache, 'sqlite_remove_expired' ) ) {
85	$wp_object_cache->sqlite_remove_expired( true );
86	}
87
88	foreach ( $wp_object_cache->sqlite_load_statistics() as $data ) {
89	$first = min( $data->time, $first );
90	$last = max( $data->time, $last );
91	$RAMhits += $data->RAMhits;
92	$RAMmisses += $data->RAMmisses;
93	$DISKhits += $data->DISKhits;
94	$DISKmisses += $data->DISKmisses;
95	$DISKLookupsPerRequest[] = $data->DISKhits + $data->DISKmisses;
96	$RAMratio = $data->RAMhits / ( $data->RAMhits + $data->RAMmisses );
97	$RAMratios[] = $RAMratio;
98	$DISKratio = $data->DISKhits / ( $data->DISKhits + $data->DISKmisses );
99	$DISKratios[] = $DISKratio;
100	$opens [] = $data->open;
101	array_push( $selects, ...$data->selects );
102	array_push( $get_multiples, ...$data->get_multiples );
103	array_push( $get_multiple_keys, ...$data->get_multiple_keys );
104	array_push( $inserts, ...$data->inserts );
105	$SavesPerRequest [] = count( $data->inserts );
106	if ( property_exists( $data, 'DBMSqueries' ) && is_numeric( $data->DBMSqueries ) ) {
107	$DBMSqueriesPerRequest [] = $data->DBMSqueries;
108	}
109	array_push( $deletes, ...$data->deletes );
110
111	$this->truncate_if_too_long( $DISKLookupsPerRequest );
112	$this->truncate_if_too_long( $RAMratios );
113	$this->truncate_if_too_long( $DISKratios );
114	$this->truncate_if_too_long( $opens );
115	$this->truncate_if_too_long( $selects );
116	$this->truncate_if_too_long( $get_multiples );
117	$this->truncate_if_too_long( $get_multiple_keys );
118	$this->truncate_if_too_long( $inserts );
119	$this->truncate_if_too_long( $SavesPerRequest );
120	$this->truncate_if_too_long( $DBMSqueriesPerRequest );
121	$this->truncate_if_too_long( $deletes );
122
123	if ( property_exists( $data, 'select_names' ) && is_array( $data->select_names ) ) {
124	foreach ( $data->select_names as $name ) {
125	if ( ! array_key_exists( $name, $selected_names ) ) {
126	$selected_names[ $name ] = 0;
127	}
128	$selected_names[ $name ] ++;
129	}
130	}
131	}
132	$duration = $last - $first;
133	if ( $duration > 0 ) {
134	arsort( $selected_names );
135	$descriptions = array(
136	__( 'RAM hit ratio', 'sqlite-object-cache' ) => $this->descriptive_stats( $RAMratios ),
137	__( 'Disk hit ratio', 'sqlite-object-cache' ) => $this->descriptive_stats( $DISKratios ),
138	__( 'Disk lookups/request', 'sqlite-object-cache' ) => $this->descriptive_stats( $DISKLookupsPerRequest ),
139	__( 'Disk saves/request', 'sqlite-object-cache' ) => $this->descriptive_stats( $SavesPerRequest ),
140	__( 'MySQL queries/request', 'sqlite-object-cache' ) => $this->descriptive_stats( $DBMSqueriesPerRequest ),
141	__( 'Initialization times', 'sqlite-object-cache' ) => $this->descriptive_stats( $opens ),
142	__( 'Get times', 'sqlite-object-cache' ) => $this->descriptive_stats( $selects ),
143	__( 'GetMult times', 'sqlite-object-cache' ) => $this->descriptive_stats( $get_multiples ),
144	__( 'GetMult keys', 'sqlite-object-cache' ) => $this->descriptive_stats( $get_multiple_keys ),
145	__( 'Save times', 'sqlite-object-cache' ) => $this->descriptive_stats( $inserts ),
146	__( 'Delete times', 'sqlite-object-cache' ) => $this->descriptive_stats( $deletes ),
147	);
148
149	$this->descriptions = $descriptions;
150	$this->selected_names = $selected_names;
151	$this->start_time = $this->format_datestamp( $first );
152	$this->end_time = $this->format_datestamp( $last );
153	}
154	}
155
156	/**
157	* Truncate an array to a particular length.
158	*
159	* @param array $observations The array to truncate in place.
160	* @param int $limit Target array length.
161	*
162	* @return void
163	*/
164	public function truncate_if_too_long( &$observations, $limit = 999999 ) {
165	if ( count( $observations ) > $limit ) {
166	$this->overrun_message = true;
167	array_splice( $observations, $limit );
168	}
169	}
170
171	/**
172	* Descriptive statistics for an array of numbers.
173	*
174	* @param array $a The array.
175	*
176	* @return array
177	*/
178	public function descriptive_stats( array &$a ) {
179	sort( $a );
180	$min = $this->minimum( $a );
181	$max = $this->maximum( $a );
182
183	return array(
184	'n' => count( $a ),
185	'[min' => $min,
186	'p1' => $this->percentile( $a, 0.01 ),
187	'p5' => $this->percentile( $a, 0.05 ),
188	//'p33' => $this->percentile( $a, 0.33 ),
189	'median' => $this->percentile( $a, 0.5 ),
190	'mean' => $this->mean( $a ),
191	//'p67' => $this->percentile( $a, 0.67 ),
192	'p95' => $this->percentile( $a, 0.95 ),
193	'p99' => $this->percentile( $a, 0.99 ),
194	'max]' => $max,
195	'mad' => $this->mad( $a ),
196	'stdev' => $this->stdev( $a ),
197	'range' => $max - $min,
198	);
199	}
200
201	/**
202	* The smallest value in an array.
203	*
204	* @param array $a The array. Must be sorted.
205	*
206	* @return mixed\|null
207	*/
208	public function minimum( array $a ) {
209
210	return count( $a ) > 0 ? $a[0] : null;
211	}
212
213	/**
214	* The largest value in an array.
215	*
216	* @param array $a The array. Must be sorted.
217	*
218	* @return mixed\|null
219	*/
220	public function maximum( array $a ) {
221
222	return count( $a ) > 0 ? $a[ count( $a ) - 1 ] : null;
223	}
224
225	/** Percentile.
226	*
227	* @param array $a dataset. Must be sorted.
228	* @param number $p percentile as fraction 0-1.
229	*
230	* @return float
231	*/
232	public function percentile( array $a, $p ) {
233	$n = count( $a );
234	if ( ! $n ) {
235	return null;
236	}
237	$i = (int) floor( $n * $p );
238	if ( $i >= $n ) {
239	$i = $n - 1;
240	}
241
242	return $a[ $i ];
243	}
244
245	/**
246	* Arithmetic mean.
247	*
248	* @param array $a dataset.
249	*
250	* @return number
251	*/
252	public function mean( array $a ) {
253	$n = count( $a );
254	if ( ! $n ) {
255	return null;
256	}
257	if ( 1 === $n ) {
258	return $a[0];
259	}
260	$acc = 0;
261	foreach ( $a as $v ) {
262	$acc += $v;
263	}
264
265	return $acc / $n;
266	}
267
268	/**
269	* Mean absolute deviation.
270	*
271	* @param array $a dataset.
272	*
273	* @return float\|int\|null
274	*/
275	public function mad( array $a ) {
276	$n = count( $a );
277	if ( ! $n ) {
278	return null;
279	}
280	if ( 1 === $n ) {
281	return 0.0;
282	}
283	$acc = 0;
284	foreach ( $a as $v ) {
285	$acc += $v;
286	}
287	$mean = $acc / $n;
288	$acc = 0;
289	foreach ( $a as $v ) {
290	$acc += abs( $v - $mean );
291	}
292
293	return $acc / $n;
294	}
295
296	/**
297	* Standard deviation.
298	*
299	* @param array $a dataset.
300	*
301	* @return float\|null
302	*/
303	public function stdev( $a ) {
304	$n = count( $a );
305	if ( ! $n ) {
306	return null;
307	}
308	if ( 1 === $n ) {
309	return 0.0;
310	}
311	$sum = 0.0;
312	$sumsq = 0.0;
313	foreach ( $a as $v ) {
314	$sum += $v;
315	$sumsq += ( $v * $v );
316	}
317	$mean = $sum / $n;
318
319	return sqrt( ( $sumsq / $n ) - ( $mean * $mean ) );
320	}
321
322	/**
323	* Render the statistics display.
324	*
325	* @return void
326	*/
327	public function render() {
328
329	echo '<h3>' . esc_html__( 'Cache performance', 'sqlite-object-cache' ) . '</h3>';
330	if ( is_array( $this->descriptions ) ) {
331	echo '<p>' . esc_html( sprintf(
332	/* translators: 1 start time 2 end time both in localized format */
333	__( 'From %1$s to %2$s.', 'sqlite-object-cache' ),
334	$this->start_time, $this->end_time ) . ' ' . __( 'Times in microseconds.', 'sqlite-object-cache' ) ) . '</p>' . PHP_EOL;
335	echo '<table class="sql-object-cache-stats">' . PHP_EOL;
336	$first = true;
337	foreach ( $this->descriptions as $stat => $description ) {
338	if ( $first ) {
339	echo '<thead><tr>';
340	echo '<th scope="col"></th>';
341	foreach ( $description as $item => $value ) {
342	echo '<th scope="col" class="right">' . esc_html( $item ) . '</th>' . PHP_EOL;
343	}
344	echo '</tr></thead><tbody>' . PHP_EOL;
345	$first = false;
346	}
347	echo '<tr>';
348	echo '<th scope="row">' . esc_html( $stat ) . '</th>';
349	foreach ( $description as $value ) {
350	echo '<td>' . esc_html( round( $value, 2 ) ) . '</td>';
351	}
352	echo '</tr>' . PHP_EOL;
353	}
354	echo '</tr></tbody></table>' . PHP_EOL;
355	if ( $this->overrun_message ) {
356	echo '<p>';
357	esc_html_e( 'Some statistics were not processed. Processing them all uses too much RAM.', 'sqlite-object-cache' );
358	echo ' ';
359	esc_html_e( 'Try measuring a smaller random sample of requests.', 'sqlite-object-cache' );
360	echo '</p>' . PHP_EOL;
361	$this->overrun_message = false;
362	}
363	} else {
364	if ( is_array( $this->options ) && array_key_exists( 'capture', $this->options ) && 'on' === $this->options['capture'] ) {
365	echo '<p>' . esc_html__( 'No cache performance statistics have been captured.', 'sqlite-object-cache' ) . ' ';
366	$message =
367	/* translators: 1: a percentage */
368	__( 'The plugin is capturing a random sample of %s%% of requests. It is possible no samples have yet been captured.', 'sqlite-object-cache' );
369	$samplerate = is_numeric( $this->options['samplerate'] ) ? $this->options['samplerate'] : 1;
370	echo esc_html( sprintf( $message, $samplerate ) ) . '</p>';
371	} else {
372	echo '<p>' . esc_html__( 'Cache performance measurement is not enabled.', 'sqlite-object-cache' ) . ' ';
373	echo esc_html__( 'You may enable it on the Settings tab.', 'sqlite-object-cache' ) . '</p>';
374	}
375	}
376
377	if ( is_array( $this->selected_names ) && count( $this->selected_names ) > 0 ) {
378
379	$names = $this->selected_names;
380	uksort( $names, function ( $a, $b ) {
381	/* Descending order of frequency */
382	if ( $this->selected_names[ $a ] !== $this->selected_names[ $b ] ) {
383	return $this->selected_names[ $a ] > $this->selected_names[ $b ] ? - 1 : 1;
384	}
385	$as = explode( '\|', $a, 2 );
386	$bs = explode( '\|', $b, 2 );
387	/* Ascending order by group name */
388	if ( $as[0] !== $bs[0] ) {
389	return strnatcmp( $as[0], $bs[0] );
390	}
391	/* Ascending order by key name, handling numeric keys correctly. */
392	if ( is_numeric( $as[1] ) && is_numeric( $bs[1] ) ) {
393	if ( (float) $as[1] === (float) $bs[1] ) {
394	return 0;
395	}
396
397	return ( (float) $as[1] ) < ( (float) $bs[1] ) ? - 1 : 1;
398	}
399
400	return strnatcmp( $as[1], $bs[1] );
401	} );
402
403	echo '<h3>' . esc_html__( 'Most frequently looked up cache items', 'sqlite-object-cache' ) . '</h3>' . PHP_EOL;
404
405	echo '<table class="sql-object-cache-items">' . PHP_EOL;
406	$count_threshold = - 1;
407	$first = true;
408	foreach ( $names as $name => $count ) {
409	if ( $first ) {
410	echo '<thead><tr>';
411	echo '<th scope="col">' . esc_html__( "Cache Group", 'sqlite-object-cache' ) . '</th>';
412	echo '<th scope="col">' . esc_html__( "Cache Key", 'sqlite-object-cache' ) . '</th>';
413	echo '<th scope="col">' . esc_html__( "Count", 'sqlite-object-cache' ) . '</th>';
414	echo '</tr></thead><tbody>' . PHP_EOL;
415	$count_threshold = (int) ( $count * 0.7 );
416	$first = false;
417	}
418	if ( $count < $count_threshold ) {
419	break;
420	}
421	$splits = explode( '\|', $name, 2 );
422	echo '<tr>';
423	echo '<td>' . esc_html( $splits[0] ) . '</td>';
424	echo '<td>' . esc_html( $splits[1] ) . '</td>';
425	echo '<td>' . esc_html( $count ) . '</td>';
426	echo '</tr>' . PHP_EOL;
427	}
428	}
429	echo '</tbody></table>';
430	}
431
432	/**
433	* Render the usage display.
434	*
435	* @return void
436	*/
437	public function render_usage() {
438
439	global $wp_object_cache;
440	if ( ! method_exists( $wp_object_cache, 'sqlite_load_usages' ) ) {
441	return;
442	}
443	$filesize = null;
444	try {
445	if ( method_exists( $wp_object_cache, 'sqlite_files' ) ) {
446	foreach ( $wp_object_cache->sqlite_files() as $file ) {
447	ob_start();
448	$filesize = filesize( $file );
449	ob_end_clean();
450	break;
451	}
452	}
453	} catch ( Exception $ex ) {
454	$filesize = null;
455	}
456
457	echo '<h3>' . esc_html__( 'Cache usage', 'sqlite-object-cache' ) . '</h3>';
458	$grouplength = array();
459	$groupcount = array();
460	$length = 0;
461	$count = 0;
462	$earliest = PHP_INT_MAX;
463	$latest = PHP_INT_MIN;
464
465	try {
466
467	foreach ( $wp_object_cache->sqlite_load_usages( true ) as $item ) {
468	$length += $item->length;
469	$count ++;
470	$ts = $item->expires;
471	$earliest = min( $earliest, $ts );
472	$latest = max( $latest, $ts );
473	$splits = explode( '\|', $item->name, 2 );
474	$group = $splits[0];
475	$group = preg_replace( '/_[ 0-9._]+$/', '_*', $group );
476	if ( ! array_key_exists( $group, $grouplength ) ) {
477	$grouplength[ $group ] = 0;
478	$groupcount[ $group ] = 0;
479	}
480	$grouplength[ $group ] += $item->length;
481	$groupcount[ $group ] ++;
482	}
483	} catch ( Exception $ex ) {
484	echo '<p>' . esc_html__( 'Cannot load some or all cache items.', 'sqlite-object-cache' ) . '</p>';
485	}
486
487	if ( $count > 0 ) {
488	$groups = array_keys( $grouplength );
489	sort( $groups );
490
491	echo '<p>' . esc_html( sprintf(
492	/* translators: 1 start time 2 end time both in localized format */
493	__( 'Expirations from %1$s to %2$s.', 'sqlite-object-cache' ),
494	$this->format_datestamp( $earliest ), $this->format_datestamp( $latest ) ) . ' ' . __( 'Sizes in MiB.', 'sqlite-object-cache' ) ) . '</p>' . PHP_EOL;
495
496	echo '<table class="sql-object-cache-stats">' . PHP_EOL;
497	/* table headers */
498	echo '<thead><tr>';
499	echo '<th scope="col" class="right">' . esc_html__( 'Cache Group', 'sqlite-object-cache' ) . '</th>';
500	echo '<th scope="col" class="right">' . esc_html__( 'Items', 'sqlite-object-cache' ) . '</th>';
501	echo '<th scope="col" class="right">' . esc_html__( 'Size', 'sqlite-object-cache' ) . '</th>';
502	echo '</tr></thead><tbody>' . PHP_EOL;
503
504	/* filesize row */
505	if ( $filesize ) {
506	echo '<tr>';
507	echo '<th scope="row" class="right">' . esc_html__( 'Cache File Size', 'sqlite-object-cache' ) . '</th>';
508	echo '<td class="right total"></td>';
509	$sizemib = $filesize / ( 1024 * 1024 );
510	echo '<td class="right total">' . esc_html( number_format_i18n( $sizemib, 3 ) ) . '</td>';
511	echo '</tr>' . PHP_EOL;
512	}
513	/* totals row */
514	echo '<tr>';
515	echo '<th scope="row" class="right">' . esc_html__( 'All Groups', 'sqlite-object-cache' ) . '</th>';
516	echo '<td class="right total">' . esc_html( number_format_i18n( $count, 0 ) ) . '</td>';
517	$sizemib = $length / ( 1024 * 1024 );
518	echo '<td class="right total">' . esc_html( number_format_i18n( $sizemib, 3 ) ) . '</td>';
519	echo '</tr>' . PHP_EOL;
520	foreach ( $groups as $group ) {
521	/* detail row */
522	echo '<tr>';
523	echo '<th scope="row" class="right">' . esc_html( $group ) . '</th>';
524	echo '<td class="right">' . esc_html( number_format_i18n( $groupcount[ $group ], 0 ) ) . '</td>';
525	$sizemib = $grouplength[ $group ] / ( 1024 * 1024 );
526	echo '<td class="right">' . esc_html( number_format_i18n( $sizemib, 3 ) ) . '</td>';
527	echo '</tr>' . PHP_EOL;
528	}
529
530	echo '</tbody></table>' . PHP_EOL;
531	} else {
532	echo '<p>' . esc_html__( 'No cache items found.', 'sqlite-object-cache' ) . '</p>';
533	}
534	}
535
536	/**
537	* Format a UNIX timestamp using WP settings.
538	*
539	* @param $stamp
540	*
541	* @return false\|string
542	*/
543	private function format_datestamp( $stamp ) {
544	$date_format = get_option( 'date_format' ) . ' ' . get_option( 'time_format' );
545
546	return wp_date( $date_format, (int) $stamp );
547	}
548	}
549