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comparison program/lib/Roundcube/rcube_cache_shared.php @ 0:4681f974d28b

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vanilla 1.3.3 distro, I hope
author Charlie Root
date Thu, 04 Jan 2018 15:52:31 -0500
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-1:000000000000 0:4681f974d28b
1 <?php
2
3 /**
4 +-----------------------------------------------------------------------+
5 | This file is part of the Roundcube Webmail client |
6 | Copyright (C) 2011-2013, The Roundcube Dev Team |
7 | Copyright (C) 2011-2013, Kolab Systems AG |
8 | |
9 | Licensed under the GNU General Public License version 3 or |
10 | any later version with exceptions for skins & plugins. |
11 | See the README file for a full license statement. |
12 | |
13 | PURPOSE: |
14 | Shared (cross-user) caching engine |
15 +-----------------------------------------------------------------------+
16 | Author: Thomas Bruederli <roundcube@gmail.com> |
17 | Author: Aleksander Machniak <alec@alec.pl> |
18 +-----------------------------------------------------------------------+
19 */
20
21 /**
22 * Interface class for accessing Roundcube shared cache
23 *
24 * @package Framework
25 * @subpackage Cache
26 * @author Thomas Bruederli <roundcube@gmail.com>
27 * @author Aleksander Machniak <alec@alec.pl>
28 */
29 class rcube_cache_shared
30 {
31 /**
32 * Instance of database handler
33 *
34 * @var rcube_db|Memcache|bool
35 */
36 private $db;
37 private $type;
38 private $prefix;
39 private $ttl;
40 private $packed;
41 private $index;
42 private $table;
43 private $debug;
44 private $index_changed = false;
45 private $cache = array();
46 private $cache_changes = array();
47 private $cache_sums = array();
48 private $max_packet = -1;
49
50
51 /**
52 * Object constructor.
53 *
54 * @param string $type Engine type ('db' or 'memcache' or 'apc')
55 * @param string $prefix Key name prefix
56 * @param string $ttl Expiration time of memcache/apc items
57 * @param bool $packed Enables/disabled data serialization.
58 * It's possible to disable data serialization if you're sure
59 * stored data will be always a safe string
60 */
61 function __construct($type, $prefix='', $ttl=0, $packed=true)
62 {
63 $rcube = rcube::get_instance();
64 $type = strtolower($type);
65
66 if ($type == 'memcache') {
67 $this->type = 'memcache';
68 $this->db = $rcube->get_memcache();
69 $this->debug = $rcube->config->get('memcache_debug');
70 }
71 else if ($type == 'apc') {
72 $this->type = 'apc';
73 $this->db = function_exists('apc_exists'); // APC 3.1.4 required
74 $this->debug = $rcube->config->get('apc_debug');
75 }
76 else {
77 $this->type = 'db';
78 $this->db = $rcube->get_dbh();
79 $this->table = $this->db->table_name('cache_shared', true);
80 }
81
82 // convert ttl string to seconds
83 $ttl = get_offset_sec($ttl);
84 if ($ttl > 2592000) $ttl = 2592000;
85
86 $this->ttl = $ttl;
87 $this->packed = $packed;
88 $this->prefix = $prefix;
89 }
90
91 /**
92 * Returns cached value.
93 *
94 * @param string $key Cache key name
95 *
96 * @return mixed Cached value
97 */
98 function get($key)
99 {
100 if (!array_key_exists($key, $this->cache)) {
101 return $this->read_record($key);
102 }
103
104 return $this->cache[$key];
105 }
106
107 /**
108 * Sets (add/update) value in cache.
109 *
110 * @param string $key Cache key name
111 * @param mixed $data Cache data
112 */
113 function set($key, $data)
114 {
115 $this->cache[$key] = $data;
116 $this->cache_changes[$key] = true;
117 }
118
119 /**
120 * Returns cached value without storing it in internal memory.
121 *
122 * @param string $key Cache key name
123 *
124 * @return mixed Cached value
125 */
126 function read($key)
127 {
128 if (array_key_exists($key, $this->cache)) {
129 return $this->cache[$key];
130 }
131
132 return $this->read_record($key, true);
133 }
134
135 /**
136 * Sets (add/update) value in cache and immediately saves
137 * it in the backend, no internal memory will be used.
138 *
139 * @param string $key Cache key name
140 * @param mixed $data Cache data
141 *
142 * @param boolean True on success, False on failure
143 */
144 function write($key, $data)
145 {
146 return $this->write_record($key, $this->serialize($data));
147 }
148
149 /**
150 * Clears the cache.
151 *
152 * @param string $key Cache key name or pattern
153 * @param boolean $prefix_mode Enable it to clear all keys starting
154 * with prefix specified in $key
155 */
156 function remove($key=null, $prefix_mode=false)
157 {
158 // Remove all keys
159 if ($key === null) {
160 $this->cache = array();
161 $this->cache_changes = array();
162 $this->cache_sums = array();
163 }
164 // Remove keys by name prefix
165 else if ($prefix_mode) {
166 foreach (array_keys($this->cache) as $k) {
167 if (strpos($k, $key) === 0) {
168 $this->cache[$k] = null;
169 $this->cache_changes[$k] = false;
170 unset($this->cache_sums[$k]);
171 }
172 }
173 }
174 // Remove one key by name
175 else {
176 $this->cache[$key] = null;
177 $this->cache_changes[$key] = false;
178 unset($this->cache_sums[$key]);
179 }
180
181 // Remove record(s) from the backend
182 $this->remove_record($key, $prefix_mode);
183 }
184
185 /**
186 * Remove cache records older than ttl
187 */
188 function expunge()
189 {
190 if ($this->type == 'db' && $this->db && $this->ttl) {
191 $this->db->query(
192 "DELETE FROM {$this->table}"
193 . " WHERE `cache_key` LIKE ?"
194 . " AND `expires` < " . $this->db->now(),
195 $this->prefix . '.%');
196 }
197 }
198
199 /**
200 * Remove expired records of all caches
201 */
202 static function gc()
203 {
204 $rcube = rcube::get_instance();
205 $db = $rcube->get_dbh();
206
207 $db->query("DELETE FROM " . $db->table_name('cache_shared', true) . " WHERE `expires` < " . $db->now());
208 }
209
210 /**
211 * Writes the cache back to the DB.
212 */
213 function close()
214 {
215 foreach ($this->cache as $key => $data) {
216 // The key has been used
217 if ($this->cache_changes[$key]) {
218 // Make sure we're not going to write unchanged data
219 // by comparing current md5 sum with the sum calculated on DB read
220 $data = $this->serialize($data);
221
222 if (!$this->cache_sums[$key] || $this->cache_sums[$key] != md5($data)) {
223 $this->write_record($key, $data);
224 }
225 }
226 }
227
228 if ($this->index_changed) {
229 $this->write_index();
230 }
231
232 // reset internal cache index, thanks to this we can force index reload
233 $this->index = null;
234 $this->index_changed = false;
235 $this->cache = array();
236 $this->cache_sums = array();
237 $this->cache_changes = array();
238 }
239
240 /**
241 * Reads cache entry.
242 *
243 * @param string $key Cache key name
244 * @param boolean $nostore Enable to skip in-memory store
245 *
246 * @return mixed Cached value
247 */
248 private function read_record($key, $nostore=false)
249 {
250 if (!$this->db) {
251 return null;
252 }
253
254 if ($this->type != 'db') {
255 $this->load_index();
256
257 // Consistency check (#1490390)
258 if (!in_array($key, $this->index)) {
259 // we always check if the key exist in the index
260 // to have data in consistent state. Keeping the index consistent
261 // is needed for keys delete operation when we delete all keys or by prefix.
262 }
263 else {
264 $ckey = $this->ckey($key);
265
266 if ($this->type == 'memcache') {
267 $data = $this->db->get($ckey);
268 }
269 else if ($this->type == 'apc') {
270 $data = apc_fetch($ckey);
271 }
272
273 if ($this->debug) {
274 $this->debug('get', $ckey, $data);
275 }
276 }
277
278 if ($data !== false) {
279 $md5sum = md5($data);
280 $data = $this->unserialize($data);
281
282 if ($nostore) {
283 return $data;
284 }
285
286 $this->cache_sums[$key] = $md5sum;
287 $this->cache[$key] = $data;
288 }
289 else {
290 $this->cache[$key] = null;
291 }
292 }
293 else {
294 $sql_result = $this->db->query(
295 "SELECT `data`, `cache_key` FROM {$this->table}"
296 . " WHERE `cache_key` = ?",
297 $this->prefix . '.' . $key);
298
299 if ($sql_arr = $this->db->fetch_assoc($sql_result)) {
300 if (strlen($sql_arr['data']) > 0) {
301 $md5sum = md5($sql_arr['data']);
302 $data = $this->unserialize($sql_arr['data']);
303 }
304
305 $this->db->reset();
306
307 if ($nostore) {
308 return $data;
309 }
310
311 $this->cache[$key] = $data;
312 $this->cache_sums[$key] = $md5sum;
313 }
314 else {
315 $this->cache[$key] = null;
316 }
317 }
318
319 return $this->cache[$key];
320 }
321
322 /**
323 * Writes single cache record into DB.
324 *
325 * @param string $key Cache key name
326 * @param mixed $data Serialized cache data
327 *
328 * @param boolean True on success, False on failure
329 */
330 private function write_record($key, $data)
331 {
332 if (!$this->db) {
333 return false;
334 }
335
336 // don't attempt to write too big data sets
337 if (strlen($data) > $this->max_packet_size()) {
338 trigger_error("rcube_cache: max_packet_size ($this->max_packet) exceeded for key $key. Tried to write " . strlen($data) . " bytes", E_USER_WARNING);
339 return false;
340 }
341
342 if ($this->type == 'memcache' || $this->type == 'apc') {
343 $result = $this->add_record($this->ckey($key), $data);
344
345 // make sure index will be updated
346 if ($result) {
347 if (!array_key_exists($key, $this->cache_sums)) {
348 $this->cache_sums[$key] = true;
349 }
350
351 $this->load_index();
352
353 if (!$this->index_changed && !in_array($key, $this->index)) {
354 $this->index_changed = true;
355 }
356 }
357
358 return $result;
359 }
360
361 $db_key = $this->prefix . '.' . $key;
362
363 // Remove NULL rows (here we don't need to check if the record exist)
364 if ($data == 'N;') {
365 $result = $this->db->query("DELETE FROM {$this->table} WHERE `cache_key` = ?", $db_key);
366
367 return !$this->db->is_error($result);
368 }
369
370 $key_exists = array_key_exists($key, $this->cache_sums);
371 $expires = $this->ttl ? $this->db->now($this->ttl) : 'NULL';
372
373 if (!$key_exists) {
374 // Try INSERT temporarily ignoring "duplicate key" errors
375 $this->db->set_option('ignore_key_errors', true);
376
377 $result = $this->db->query(
378 "INSERT INTO {$this->table} (`expires`, `cache_key`, `data`)"
379 . " VALUES ($expires, ?, ?)",
380 $db_key, $data);
381
382 $this->db->set_option('ignore_key_errors', false);
383 }
384
385 // otherwise try UPDATE
386 if (!isset($result) || !($count = $this->db->affected_rows($result))) {
387 $result = $this->db->query(
388 "UPDATE {$this->table} SET `expires` = $expires, `data` = ?"
389 . " WHERE `cache_key` = ?",
390 $data, $db_key);
391
392 $count = $this->db->affected_rows($result);
393 }
394
395 return $count > 0;
396 }
397
398 /**
399 * Deletes the cache record(s).
400 *
401 * @param string $key Cache key name or pattern
402 * @param boolean $prefix_mode Enable it to clear all keys starting
403 * with prefix specified in $key
404 */
405 private function remove_record($key=null, $prefix_mode=false)
406 {
407 if (!$this->db) {
408 return;
409 }
410
411 if ($this->type != 'db') {
412 $this->load_index();
413
414 // Remove all keys
415 if ($key === null) {
416 foreach ($this->index as $key) {
417 $this->delete_record($this->ckey($key));
418 }
419
420 $this->index = array();
421 }
422 // Remove keys by name prefix
423 else if ($prefix_mode) {
424 foreach ($this->index as $idx => $k) {
425 if (strpos($k, $key) === 0) {
426 $this->delete_record($this->ckey($k));
427 unset($this->index[$idx]);
428 }
429 }
430 }
431 // Remove one key by name
432 else {
433 $this->delete_record($this->ckey($key));
434 if (($idx = array_search($key, $this->index)) !== false) {
435 unset($this->index[$idx]);
436 }
437 }
438
439 $this->index_changed = true;
440
441 return;
442 }
443
444 // Remove all keys (in specified cache)
445 if ($key === null) {
446 $where = " WHERE `cache_key` LIKE " . $this->db->quote($this->prefix.'.%');
447 }
448 // Remove keys by name prefix
449 else if ($prefix_mode) {
450 $where = " WHERE `cache_key` LIKE " . $this->db->quote($this->prefix.'.'.$key.'%');
451 }
452 // Remove one key by name
453 else {
454 $where = " WHERE `cache_key` = " . $this->db->quote($this->prefix.'.'.$key);
455 }
456
457 $this->db->query("DELETE FROM " . $this->table . $where);
458 }
459
460 /**
461 * Adds entry into memcache/apc DB.
462 *
463 * @param string $key Cache internal key name
464 * @param mixed $data Serialized cache data
465 *
466 * @param boolean True on success, False on failure
467 */
468 private function add_record($key, $data)
469 {
470 if ($this->type == 'memcache') {
471 $result = $this->db->replace($key, $data, MEMCACHE_COMPRESSED, $this->ttl);
472
473 if (!$result) {
474 $result = $this->db->set($key, $data, MEMCACHE_COMPRESSED, $this->ttl);
475 }
476 }
477 else if ($this->type == 'apc') {
478 if (apc_exists($key)) {
479 apc_delete($key);
480 }
481
482 $result = apc_store($key, $data, $this->ttl);
483 }
484
485 if ($this->debug) {
486 $this->debug('set', $key, $data, $result);
487 }
488
489 return $result;
490 }
491
492 /**
493 * Deletes entry from memcache/apc DB.
494 *
495 * @param string $key Cache internal key name
496 *
497 * @param boolean True on success, False on failure
498 */
499 private function delete_record($key)
500 {
501 if ($this->type == 'memcache') {
502 // #1488592: use 2nd argument
503 $result = $this->db->delete($key, 0);
504 }
505 else {
506 $result = apc_delete($key);
507 }
508
509 if ($this->debug) {
510 $this->debug('delete', $key, null, $result);
511 }
512
513 return $result;
514 }
515
516 /**
517 * Writes the index entry into memcache/apc DB.
518 */
519 private function write_index()
520 {
521 if (!$this->db || $this->type == 'db') {
522 return;
523 }
524
525 $this->load_index();
526
527 // Make sure index contains new keys
528 foreach ($this->cache as $key => $value) {
529 if ($value !== null && !in_array($key, $this->index)) {
530 $this->index[] = $key;
531 }
532 }
533
534 // new keys added using self::write()
535 foreach ($this->cache_sums as $key => $value) {
536 if ($value === true && !in_array($key, $this->index)) {
537 $this->index[] = $key;
538 }
539 }
540
541 $data = serialize($this->index);
542 $this->add_record($this->ikey(), $data);
543 }
544
545 /**
546 * Gets the index entry from memcache/apc DB.
547 */
548 private function load_index()
549 {
550 if (!$this->db || $this->type == 'db') {
551 return;
552 }
553
554 if ($this->index !== null) {
555 return;
556 }
557
558 $index_key = $this->ikey();
559
560 if ($this->type == 'memcache') {
561 $data = $this->db->get($index_key);
562 }
563 else if ($this->type == 'apc') {
564 $data = apc_fetch($index_key);
565 }
566
567 if ($this->debug) {
568 $this->debug('get', $index_key, $data);
569 }
570
571 $this->index = $data ? unserialize($data) : array();
572 }
573
574 /**
575 * Creates cache key name (for memcache and apc)
576 *
577 * @param string $key Cache key name
578 *
579 * @return string Cache key
580 */
581 private function ckey($key)
582 {
583 return $this->prefix . ':' . $key;
584 }
585
586 /**
587 * Creates index cache key name (for memcache and apc)
588 *
589 * @return string Cache key
590 */
591 private function ikey()
592 {
593 // This way each cache will have its own index
594 return $this->prefix . 'INDEX';
595 }
596
597 /**
598 * Serializes data for storing
599 */
600 private function serialize($data)
601 {
602 if ($this->type == 'db') {
603 return $this->db->encode($data, $this->packed);
604 }
605
606 return $this->packed ? serialize($data) : $data;
607 }
608
609 /**
610 * Unserializes serialized data
611 */
612 private function unserialize($data)
613 {
614 if ($this->type == 'db') {
615 return $this->db->decode($data, $this->packed);
616 }
617
618 return $this->packed ? @unserialize($data) : $data;
619 }
620
621 /**
622 * Determine the maximum size for cache data to be written
623 */
624 private function max_packet_size()
625 {
626 if ($this->max_packet < 0) {
627 $this->max_packet = 2097152; // default/max is 2 MB
628
629 if ($this->type == 'db') {
630 if ($value = $this->db->get_variable('max_allowed_packet', $this->max_packet)) {
631 $this->max_packet = $value;
632 }
633 $this->max_packet -= 2000;
634 }
635 else {
636 $max_packet = rcube::get_instance()->config->get($this->type . '_max_allowed_packet');
637 $this->max_packet = parse_bytes($max_packet) ?: $this->max_packet;
638 }
639 }
640
641 return $this->max_packet;
642 }
643
644 /**
645 * Write memcache/apc debug info to the log
646 */
647 private function debug($type, $key, $data = null, $result = null)
648 {
649 $line = strtoupper($type) . ' ' . $key;
650
651 if ($data !== null) {
652 $line .= ' ' . ($this->packed ? $data : serialize($data));
653 }
654
655 rcube::debug($this->type, $line, $result);
656 }
657 }