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comparison program/lib/Roundcube/rcube_cache.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, The Roundcube Dev Team |
7 | Copyright (C) 2011, 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 | 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 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
30 {
31 /**
32 * Instance of database handler
33 *
34 * @var rcube_db|Memcache|bool
35 */
36 private $db;
37 private $type;
38 private $userid;
39 private $prefix;
40 private $table;
41 private $ttl;
42 private $packed;
43 private $index;
44 private $debug;
45 private $index_changed = false;
46 private $cache = array();
47 private $cache_changes = array();
48 private $cache_sums = array();
49 private $max_packet = -1;
50
51
52 /**
53 * Object constructor.
54 *
55 * @param string $type Engine type ('db' or 'memcache' or 'apc')
56 * @param int $userid User identifier
57 * @param string $prefix Key name prefix
58 * @param string $ttl Expiration time of memcache/apc items
59 * @param bool $packed Enables/disabled data serialization.
60 * It's possible to disable data serialization if you're sure
61 * stored data will be always a safe string
62 */
63 function __construct($type, $userid, $prefix='', $ttl=0, $packed=true)
64 {
65 $rcube = rcube::get_instance();
66 $type = strtolower($type);
67
68 if ($type == 'memcache') {
69 $this->type = 'memcache';
70 $this->db = $rcube->get_memcache();
71 $this->debug = $rcube->config->get('memcache_debug');
72 }
73 else if ($type == 'apc') {
74 $this->type = 'apc';
75 $this->db = function_exists('apc_exists'); // APC 3.1.4 required
76 $this->debug = $rcube->config->get('apc_debug');
77 }
78 else {
79 $this->type = 'db';
80 $this->db = $rcube->get_dbh();
81 $this->table = $this->db->table_name('cache', true);
82 }
83
84 // convert ttl string to seconds
85 $ttl = get_offset_sec($ttl);
86 if ($ttl > 2592000) $ttl = 2592000;
87
88 $this->userid = (int) $userid;
89 $this->ttl = $ttl;
90 $this->packed = $packed;
91 $this->prefix = $prefix;
92 }
93
94 /**
95 * Returns cached value.
96 *
97 * @param string $key Cache key name
98 *
99 * @return mixed Cached value
100 */
101 function get($key)
102 {
103 if (!array_key_exists($key, $this->cache)) {
104 return $this->read_record($key);
105 }
106
107 return $this->cache[$key];
108 }
109
110 /**
111 * Sets (add/update) value in cache.
112 *
113 * @param string $key Cache key name
114 * @param mixed $data Cache data
115 */
116 function set($key, $data)
117 {
118 $this->cache[$key] = $data;
119 $this->cache_changes[$key] = true;
120 }
121
122 /**
123 * Returns cached value without storing it in internal memory.
124 *
125 * @param string $key Cache key name
126 *
127 * @return mixed Cached value
128 */
129 function read($key)
130 {
131 if (array_key_exists($key, $this->cache)) {
132 return $this->cache[$key];
133 }
134
135 return $this->read_record($key, true);
136 }
137
138 /**
139 * Sets (add/update) value in cache and immediately saves
140 * it in the backend, no internal memory will be used.
141 *
142 * @param string $key Cache key name
143 * @param mixed $data Cache data
144 *
145 * @param boolean True on success, False on failure
146 */
147 function write($key, $data)
148 {
149 return $this->write_record($key, $this->serialize($data));
150 }
151
152 /**
153 * Clears the cache.
154 *
155 * @param string $key Cache key name or pattern
156 * @param boolean $prefix_mode Enable it to clear all keys starting
157 * with prefix specified in $key
158 */
159 function remove($key=null, $prefix_mode=false)
160 {
161 // Remove all keys
162 if ($key === null) {
163 $this->cache = array();
164 $this->cache_changes = array();
165 $this->cache_sums = array();
166 }
167 // Remove keys by name prefix
168 else if ($prefix_mode) {
169 foreach (array_keys($this->cache) as $k) {
170 if (strpos($k, $key) === 0) {
171 $this->cache[$k] = null;
172 $this->cache_changes[$k] = false;
173 unset($this->cache_sums[$k]);
174 }
175 }
176 }
177 // Remove one key by name
178 else {
179 $this->cache[$key] = null;
180 $this->cache_changes[$key] = false;
181 unset($this->cache_sums[$key]);
182 }
183
184 // Remove record(s) from the backend
185 $this->remove_record($key, $prefix_mode);
186 }
187
188 /**
189 * Remove cache records older than ttl
190 */
191 function expunge()
192 {
193 if ($this->type == 'db' && $this->db && $this->ttl) {
194 $this->db->query(
195 "DELETE FROM {$this->table}".
196 " WHERE `user_id` = ?".
197 " AND `cache_key` LIKE ?".
198 " AND `expires` < " . $this->db->now(),
199 $this->userid,
200 $this->prefix.'.%');
201 }
202 }
203
204 /**
205 * Remove expired records of all caches
206 */
207 static function gc()
208 {
209 $rcube = rcube::get_instance();
210 $db = $rcube->get_dbh();
211
212 $db->query("DELETE FROM " . $db->table_name('cache', true) . " WHERE `expires` < " . $db->now());
213 }
214
215 /**
216 * Writes the cache back to the DB.
217 */
218 function close()
219 {
220 foreach ($this->cache as $key => $data) {
221 // The key has been used
222 if ($this->cache_changes[$key]) {
223 // Make sure we're not going to write unchanged data
224 // by comparing current md5 sum with the sum calculated on DB read
225 $data = $this->serialize($data);
226
227 if (!$this->cache_sums[$key] || $this->cache_sums[$key] != md5($data)) {
228 $this->write_record($key, $data);
229 }
230 }
231 }
232
233 if ($this->index_changed) {
234 $this->write_index();
235 }
236
237 // reset internal cache index, thanks to this we can force index reload
238 $this->index = null;
239 $this->index_changed = false;
240 $this->cache = array();
241 $this->cache_sums = array();
242 $this->cache_changes = array();
243 }
244
245 /**
246 * Reads cache entry.
247 *
248 * @param string $key Cache key name
249 * @param boolean $nostore Enable to skip in-memory store
250 *
251 * @return mixed Cached value
252 */
253 private function read_record($key, $nostore=false)
254 {
255 if (!$this->db) {
256 return null;
257 }
258
259 if ($this->type != 'db') {
260 $this->load_index();
261
262 // Consistency check (#1490390)
263 if (!in_array($key, $this->index)) {
264 // we always check if the key exist in the index
265 // to have data in consistent state. Keeping the index consistent
266 // is needed for keys delete operation when we delete all keys or by prefix.
267 }
268 else {
269 $ckey = $this->ckey($key);
270
271 if ($this->type == 'memcache') {
272 $data = $this->db->get($ckey);
273 }
274 else if ($this->type == 'apc') {
275 $data = apc_fetch($ckey);
276 }
277
278 if ($this->debug) {
279 $this->debug('get', $ckey, $data);
280 }
281 }
282
283 if ($data !== false) {
284 $md5sum = md5($data);
285 $data = $this->unserialize($data);
286
287 if ($nostore) {
288 return $data;
289 }
290
291 $this->cache_sums[$key] = $md5sum;
292 $this->cache[$key] = $data;
293 }
294 else {
295 $this->cache[$key] = null;
296 }
297 }
298 else {
299 $sql_result = $this->db->query(
300 "SELECT `data`, `cache_key` FROM {$this->table}"
301 . " WHERE `user_id` = ? AND `cache_key` = ?",
302 $this->userid, $this->prefix.'.'.$key);
303
304 if ($sql_arr = $this->db->fetch_assoc($sql_result)) {
305 if (strlen($sql_arr['data']) > 0) {
306 $md5sum = md5($sql_arr['data']);
307 $data = $this->unserialize($sql_arr['data']);
308 }
309
310 $this->db->reset();
311
312 if ($nostore) {
313 return $data;
314 }
315
316 $this->cache[$key] = $data;
317 $this->cache_sums[$key] = $md5sum;
318 }
319 else {
320 $this->cache[$key] = null;
321 }
322 }
323
324 return $this->cache[$key];
325 }
326
327 /**
328 * Writes single cache record into DB.
329 *
330 * @param string $key Cache key name
331 * @param mixed $data Serialized cache data
332 *
333 * @param boolean True on success, False on failure
334 */
335 private function write_record($key, $data)
336 {
337 if (!$this->db) {
338 return false;
339 }
340
341 // don't attempt to write too big data sets
342 if (strlen($data) > $this->max_packet_size()) {
343 trigger_error("rcube_cache: max_packet_size ($this->max_packet) exceeded for key $key. Tried to write " . strlen($data) . " bytes", E_USER_WARNING);
344 return false;
345 }
346
347 if ($this->type == 'memcache' || $this->type == 'apc') {
348 $result = $this->add_record($this->ckey($key), $data);
349
350 // make sure index will be updated
351 if ($result) {
352 if (!array_key_exists($key, $this->cache_sums)) {
353 $this->cache_sums[$key] = true;
354 }
355
356 $this->load_index();
357
358 if (!$this->index_changed && !in_array($key, $this->index)) {
359 $this->index_changed = true;
360 }
361 }
362
363 return $result;
364 }
365
366 $db_key = $this->prefix . '.' . $key;
367
368 // Remove NULL rows (here we don't need to check if the record exist)
369 if ($data == 'N;') {
370 $result = $this->db->query(
371 "DELETE FROM {$this->table}".
372 " WHERE `user_id` = ? AND `cache_key` = ?",
373 $this->userid, $db_key);
374
375 return !$this->db->is_error($result);
376 }
377
378 $key_exists = array_key_exists($key, $this->cache_sums);
379 $expires = $this->ttl ? $this->db->now($this->ttl) : 'NULL';
380
381 if (!$key_exists) {
382 // Try INSERT temporarily ignoring "duplicate key" errors
383 $this->db->set_option('ignore_key_errors', true);
384
385 $result = $this->db->query(
386 "INSERT INTO {$this->table} (`expires`, `user_id`, `cache_key`, `data`)"
387 . " VALUES ($expires, ?, ?, ?)",
388 $this->userid, $db_key, $data);
389
390 $this->db->set_option('ignore_key_errors', false);
391 }
392
393 // otherwise try UPDATE
394 if (!isset($result) || !($count = $this->db->affected_rows($result))) {
395 $result = $this->db->query(
396 "UPDATE {$this->table} SET `expires` = $expires, `data` = ?"
397 . " WHERE `user_id` = ? AND `cache_key` = ?",
398 $data, $this->userid, $db_key);
399
400 $count = $this->db->affected_rows($result);
401 }
402
403 return $count > 0;
404 }
405
406 /**
407 * Deletes the cache record(s).
408 *
409 * @param string $key Cache key name or pattern
410 * @param boolean $prefix_mode Enable it to clear all keys starting
411 * with prefix specified in $key
412 */
413 private function remove_record($key=null, $prefix_mode=false)
414 {
415 if (!$this->db) {
416 return;
417 }
418
419 if ($this->type != 'db') {
420 $this->load_index();
421
422 // Remove all keys
423 if ($key === null) {
424 foreach ($this->index as $key) {
425 $this->delete_record($this->ckey($key));
426 }
427
428 $this->index = array();
429 }
430 // Remove keys by name prefix
431 else if ($prefix_mode) {
432 foreach ($this->index as $idx => $k) {
433 if (strpos($k, $key) === 0) {
434 $this->delete_record($this->ckey($k));
435 unset($this->index[$idx]);
436 }
437 }
438 }
439 // Remove one key by name
440 else {
441 $this->delete_record($this->ckey($key));
442 if (($idx = array_search($key, $this->index)) !== false) {
443 unset($this->index[$idx]);
444 }
445 }
446
447 $this->index_changed = true;
448
449 return;
450 }
451
452 // Remove all keys (in specified cache)
453 if ($key === null) {
454 $where = " AND `cache_key` LIKE " . $this->db->quote($this->prefix.'.%');
455 }
456 // Remove keys by name prefix
457 else if ($prefix_mode) {
458 $where = " AND `cache_key` LIKE " . $this->db->quote($this->prefix.'.'.$key.'%');
459 }
460 // Remove one key by name
461 else {
462 $where = " AND `cache_key` = " . $this->db->quote($this->prefix.'.'.$key);
463 }
464
465 $this->db->query(
466 "DELETE FROM {$this->table} WHERE `user_id` = ?" . $where,
467 $this->userid);
468 }
469
470 /**
471 * Adds entry into memcache/apc DB.
472 *
473 * @param string $key Cache key name
474 * @param mixed $data Serialized cache data
475 *
476 * @param boolean True on success, False on failure
477 */
478 private function add_record($key, $data)
479 {
480 if ($this->type == 'memcache') {
481 $result = $this->db->replace($key, $data, MEMCACHE_COMPRESSED, $this->ttl);
482
483 if (!$result) {
484 $result = $this->db->set($key, $data, MEMCACHE_COMPRESSED, $this->ttl);
485 }
486 }
487 else if ($this->type == 'apc') {
488 if (apc_exists($key)) {
489 apc_delete($key);
490 }
491
492 $result = apc_store($key, $data, $this->ttl);
493 }
494
495 if ($this->debug) {
496 $this->debug('set', $key, $data, $result);
497 }
498
499 return $result;
500 }
501
502 /**
503 * Deletes entry from memcache/apc DB.
504 *
505 * @param string $key Cache key name
506 *
507 * @param boolean True on success, False on failure
508 */
509 private function delete_record($key)
510 {
511 if ($this->type == 'memcache') {
512 // #1488592: use 2nd argument
513 $result = $this->db->delete($key, 0);
514 }
515 else {
516 $result = apc_delete($key);
517 }
518
519 if ($this->debug) {
520 $this->debug('delete', $key, null, $result);
521 }
522
523 return $result;
524 }
525
526 /**
527 * Writes the index entry into memcache/apc DB.
528 */
529 private function write_index()
530 {
531 if (!$this->db || $this->type == 'db') {
532 return;
533 }
534
535 $this->load_index();
536
537 // Make sure index contains new keys
538 foreach ($this->cache as $key => $value) {
539 if ($value !== null && !in_array($key, $this->index)) {
540 $this->index[] = $key;
541 }
542 }
543
544 // new keys added using self::write()
545 foreach ($this->cache_sums as $key => $value) {
546 if ($value === true && !in_array($key, $this->index)) {
547 $this->index[] = $key;
548 }
549 }
550
551 $data = serialize($this->index);
552 $this->add_record($this->ikey(), $data);
553 }
554
555 /**
556 * Gets the index entry from memcache/apc DB.
557 */
558 private function load_index()
559 {
560 if (!$this->db || $this->type == 'db') {
561 return;
562 }
563
564 if ($this->index !== null) {
565 return;
566 }
567
568 $index_key = $this->ikey();
569
570 if ($this->type == 'memcache') {
571 $data = $this->db->get($index_key);
572 }
573 else if ($this->type == 'apc') {
574 $data = apc_fetch($index_key);
575 }
576
577 if ($this->debug) {
578 $this->debug('get', $index_key, $data);
579 }
580
581 $this->index = $data ? unserialize($data) : array();
582 }
583
584 /**
585 * Creates per-user cache key name (for memcache and apc)
586 *
587 * @param string $key Cache key name
588 *
589 * @return string Cache key
590 */
591 private function ckey($key)
592 {
593 return sprintf('%d:%s:%s', $this->userid, $this->prefix, $key);
594 }
595
596 /**
597 * Creates per-user index cache key name (for memcache and apc)
598 *
599 * @return string Cache key
600 */
601 private function ikey()
602 {
603 // This way each cache will have its own index
604 return sprintf('%d:%s%s', $this->userid, $this->prefix, 'INDEX');
605 }
606
607 /**
608 * Serializes data for storing
609 */
610 private function serialize($data)
611 {
612 if ($this->type == 'db') {
613 return $this->db->encode($data, $this->packed);
614 }
615
616 return $this->packed ? serialize($data) : $data;
617 }
618
619 /**
620 * Unserializes serialized data
621 */
622 private function unserialize($data)
623 {
624 if ($this->type == 'db') {
625 return $this->db->decode($data, $this->packed);
626 }
627
628 return $this->packed ? @unserialize($data) : $data;
629 }
630
631 /**
632 * Determine the maximum size for cache data to be written
633 */
634 private function max_packet_size()
635 {
636 if ($this->max_packet < 0) {
637 $this->max_packet = 2097152; // default/max is 2 MB
638
639 if ($this->type == 'db') {
640 if ($value = $this->db->get_variable('max_allowed_packet', $this->max_packet)) {
641 $this->max_packet = $value;
642 }
643 $this->max_packet -= 2000;
644 }
645 else {
646 $max_packet = rcube::get_instance()->config->get($this->type . '_max_allowed_packet');
647 $this->max_packet = parse_bytes($max_packet) ?: $this->max_packet;
648 }
649 }
650
651 return $this->max_packet;
652 }
653
654 /**
655 * Write memcache/apc debug info to the log
656 */
657 private function debug($type, $key, $data = null, $result = null)
658 {
659 $line = strtoupper($type) . ' ' . $key;
660
661 if ($data !== null) {
662 $line .= ' ' . ($this->packed ? $data : serialize($data));
663 }
664
665 rcube::debug($this->type, $line, $result);
666 }
667 }