3 * +---------------------------------------------------------------------------+
4 * | memcached client, PHP |
5 * +---------------------------------------------------------------------------+
6 * | Copyright (c) 2003 Ryan T. Dean <rtdean@cytherianage.net> |
7 * | All rights reserved. |
9 * | Redistribution and use in source and binary forms, with or without |
10 * | modification, are permitted provided that the following conditions |
13 * | 1. Redistributions of source code must retain the above copyright |
14 * | notice, this list of conditions and the following disclaimer. |
15 * | 2. Redistributions in binary form must reproduce the above copyright |
16 * | notice, this list of conditions and the following disclaimer in the |
17 * | documentation and/or other materials provided with the distribution. |
19 * | THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
20 * | IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
21 * | OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
22 * | IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
23 * | INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
24 * | NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
25 * | DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
26 * | THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
27 * | (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
28 * | THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
29 * +---------------------------------------------------------------------------+
30 * | Author: Ryan T. Dean <rtdean@cytherianage.net> |
31 * | Heavily influenced by the Perl memcached client by Brad Fitzpatrick. |
32 * | Permission granted by Brad Fitzpatrick for relicense of ported Perl |
33 * | client logic under 2-clause BSD license. |
34 * +---------------------------------------------------------------------------+
41 * This is the PHP client for memcached - a distributed memory cache daemon.
42 * More information is available at http://www.danga.com/memcached/
46 * require_once 'memcached.php';
48 * $mc = new MWMemcached(array(
49 * 'servers' => array('127.0.0.1:10000',
50 * array('192.0.0.1:10010', 2),
53 * 'compress_threshold' => 10240,
54 * 'persistant' => true));
56 * $mc->add('key', array('some', 'array'));
57 * $mc->replace('key', 'some random string');
58 * $val = $mc->get('key');
60 * @author Ryan T. Dean <rtdean@cytherianage.net>
67 // {{{ class MWMemcached
69 * memcached client class implemented using (p)fsockopen()
71 * @author Ryan T. Dean <rtdean@cytherianage.net>
82 * Flag: indicates data is serialized
87 * Flag: indicates data is compressed
94 * Minimum savings to store data compressed
96 const COMPRESSION_SAVINGS
= 0.20;
113 * Cached Sockets that are connected
121 * Current debug status; 0 - none to 9 - profiling
129 * Dead hosts, assoc array, 'host'=>'unixtime when ok to check again'
137 * Is compression available?
145 * Do we want to use compression?
150 var $_compress_enable;
153 * At how many bytes should we compress?
158 var $_compress_threshold;
161 * Are we using persistant links?
169 * If only using one server; contains ip:port to connect to
177 * Array containing ip:port or array(ip:port, weight)
193 * Total # of bit buckets we have
201 * # of total servers we have
209 * Stream timeout in seconds. Applies for example to fread()
214 var $_timeout_seconds;
217 * Stream timeout in microseconds
222 var $_timeout_microseconds;
225 * Connect timeout in seconds
227 var $_connect_timeout;
230 * Number of connection attempts for each server
232 var $_connect_attempts;
237 // {{{ public functions
241 * Memcache initializer
243 * @param $args Array Associative array of settings
247 public function __construct( $args ) {
248 global $wgMemCachedTimeout;
249 $this->set_servers( isset( $args['servers'] ) ?
$args['servers'] : array() );
250 $this->_debug
= isset( $args['debug'] ) ?
$args['debug'] : false;
251 $this->stats
= array();
252 $this->_compress_threshold
= isset( $args['compress_threshold'] ) ?
$args['compress_threshold'] : 0;
253 $this->_persistant
= isset( $args['persistant'] ) ?
$args['persistant'] : false;
254 $this->_compress_enable
= true;
255 $this->_have_zlib
= function_exists( 'gzcompress' );
257 $this->_cache_sock
= array();
258 $this->_host_dead
= array();
260 $this->_timeout_seconds
= 0;
261 $this->_timeout_microseconds
= $wgMemCachedTimeout;
263 $this->_connect_timeout
= 0.01;
264 $this->_connect_attempts
= 2;
271 * Adds a key/value to the memcache server if one isn't already set with
274 * @param $key String: key to set with data
275 * @param $val Mixed: value to store
276 * @param $exp Integer: (optional) Expiration time. This can be a number of seconds
277 * to cache for (up to 30 days inclusive). Any timespans of 30 days + 1 second or
278 * longer must be the timestamp of the time at which the mapping should expire. It
279 * is safe to use timestamps in all cases, regardless of exipration
280 * eg: strtotime("+3 hour")
284 public function add( $key, $val, $exp = 0 ) {
285 return $this->_set( 'add', $key, $val, $exp );
292 * Decrease a value stored on the memcache server
294 * @param $key String: key to decrease
295 * @param $amt Integer: (optional) amount to decrease
297 * @return Mixed: FALSE on failure, value on success
299 public function decr( $key, $amt = 1 ) {
300 return $this->_incrdecr( 'decr', $key, $amt );
307 * Deletes a key from the server, optionally after $time
309 * @param $key String: key to delete
310 * @param $time Integer: (optional) how long to wait before deleting
312 * @return Boolean: TRUE on success, FALSE on failure
314 public function delete( $key, $time = 0 ) {
315 if ( !$this->_active
) {
319 $sock = $this->get_sock( $key );
320 if ( !is_resource( $sock ) ) {
324 $key = is_array( $key ) ?
$key[1] : $key;
326 if ( isset( $this->stats
['delete'] ) ) {
327 $this->stats
['delete']++
;
329 $this->stats
['delete'] = 1;
331 $cmd = "delete $key $time\r\n";
332 if( !$this->_safe_fwrite( $sock, $cmd, strlen( $cmd ) ) ) {
333 $this->_dead_sock( $sock );
336 $res = trim( fgets( $sock ) );
338 if ( $this->_debug
) {
339 $this->_debugprint( sprintf( "MemCache: delete %s (%s)\n", $key, $res ) );
342 if ( $res == "DELETED" ) {
349 // {{{ disconnect_all()
352 * Disconnects all connected sockets
354 public function disconnect_all() {
355 foreach ( $this->_cache_sock
as $sock ) {
359 $this->_cache_sock
= array();
363 // {{{ enable_compress()
366 * Enable / Disable compression
368 * @param $enable Boolean: TRUE to enable, FALSE to disable
370 public function enable_compress( $enable ) {
371 $this->_compress_enable
= $enable;
375 // {{{ forget_dead_hosts()
378 * Forget about all of the dead hosts
380 public function forget_dead_hosts() {
381 $this->_host_dead
= array();
388 * Retrieves the value associated with the key from the memcache server
390 * @param $key Mixed: key to retrieve
394 public function get( $key ) {
395 wfProfileIn( __METHOD__
);
397 if ( $this->_debug
) {
398 $this->_debugprint( "get($key)\n" );
401 if ( !$this->_active
) {
402 wfProfileOut( __METHOD__
);
406 $sock = $this->get_sock( $key );
408 if ( !is_resource( $sock ) ) {
409 wfProfileOut( __METHOD__
);
413 if ( isset( $this->stats
['get'] ) ) {
414 $this->stats
['get']++
;
416 $this->stats
['get'] = 1;
419 $cmd = "get $key\r\n";
420 if ( !$this->_safe_fwrite( $sock, $cmd, strlen( $cmd ) ) ) {
421 $this->_dead_sock( $sock );
422 wfProfileOut( __METHOD__
);
427 $this->_load_items( $sock, $val );
429 if ( $this->_debug
) {
430 foreach ( $val as $k => $v ) {
431 $this->_debugprint( sprintf( "MemCache: sock %s got %s\n", serialize( $sock ), $k ) );
435 wfProfileOut( __METHOD__
);
443 * Get multiple keys from the server(s)
445 * @param $keys Array: keys to retrieve
449 public function get_multi( $keys ) {
450 if ( !$this->_active
) {
454 if ( isset( $this->stats
['get_multi'] ) ) {
455 $this->stats
['get_multi']++
;
457 $this->stats
['get_multi'] = 1;
459 $sock_keys = array();
461 foreach ( $keys as $key ) {
462 $sock = $this->get_sock( $key );
463 if ( !is_resource( $sock ) ) {
466 $key = is_array( $key ) ?
$key[1] : $key;
467 if ( !isset( $sock_keys[$sock] ) ) {
468 $sock_keys[$sock] = array();
471 $sock_keys[$sock][] = $key;
474 // Send out the requests
475 foreach ( $socks as $sock ) {
477 foreach ( $sock_keys[$sock] as $key ) {
482 if ( $this->_safe_fwrite( $sock, $cmd, strlen( $cmd ) ) ) {
485 $this->_dead_sock( $sock );
491 foreach ( $gather as $sock ) {
492 $this->_load_items( $sock, $val );
495 if ( $this->_debug
) {
496 foreach ( $val as $k => $v ) {
497 $this->_debugprint( sprintf( "MemCache: got %s\n", $k ) );
508 * Increments $key (optionally) by $amt
510 * @param $key String: key to increment
511 * @param $amt Integer: (optional) amount to increment
513 * @return Integer: null if the key does not exist yet (this does NOT
514 * create new mappings if the key does not exist). If the key does
515 * exist, this returns the new value for that key.
517 public function incr( $key, $amt = 1 ) {
518 return $this->_incrdecr( 'incr', $key, $amt );
525 * Overwrites an existing value for key; only works if key is already set
527 * @param $key String: key to set value as
528 * @param $value Mixed: value to store
529 * @param $exp Integer: (optional) Expiration time. This can be a number of seconds
530 * to cache for (up to 30 days inclusive). Any timespans of 30 days + 1 second or
531 * longer must be the timestamp of the time at which the mapping should expire. It
532 * is safe to use timestamps in all cases, regardless of exipration
533 * eg: strtotime("+3 hour")
537 public function replace( $key, $value, $exp = 0 ) {
538 return $this->_set( 'replace', $key, $value, $exp );
545 * Passes through $cmd to the memcache server connected by $sock; returns
546 * output as an array (null array if no output)
548 * NOTE: due to a possible bug in how PHP reads while using fgets(), each
549 * line may not be terminated by a \r\n. More specifically, my testing
550 * has shown that, on FreeBSD at least, each line is terminated only
551 * with a \n. This is with the PHP flag auto_detect_line_endings set
552 * to falase (the default).
554 * @param $sock Ressource: socket to send command on
555 * @param $cmd String: command to run
557 * @return Array: output array
559 public function run_command( $sock, $cmd ) {
560 if ( !is_resource( $sock ) ) {
564 if ( !$this->_safe_fwrite( $sock, $cmd, strlen( $cmd ) ) ) {
569 $res = fgets( $sock );
571 if ( preg_match( '/^END/', $res ) ) {
574 if ( strlen( $res ) == 0 ) {
585 * Unconditionally sets a key to a given value in the memcache. Returns true
586 * if set successfully.
588 * @param $key String: key to set value as
589 * @param $value Mixed: value to set
590 * @param $exp Integer: (optional) Expiration time. This can be a number of seconds
591 * to cache for (up to 30 days inclusive). Any timespans of 30 days + 1 second or
592 * longer must be the timestamp of the time at which the mapping should expire. It
593 * is safe to use timestamps in all cases, regardless of exipration
594 * eg: strtotime("+3 hour")
596 * @return Boolean: TRUE on success
598 public function set( $key, $value, $exp = 0 ) {
599 return $this->_set( 'set', $key, $value, $exp );
603 // {{{ set_compress_threshold()
606 * Sets the compression threshold
608 * @param $thresh Integer: threshold to compress if larger than
610 public function set_compress_threshold( $thresh ) {
611 $this->_compress_threshold
= $thresh;
618 * Sets the debug flag
620 * @param $dbg Boolean: TRUE for debugging, FALSE otherwise
622 * @see MWMemcached::__construct
624 public function set_debug( $dbg ) {
625 $this->_debug
= $dbg;
632 * Sets the server list to distribute key gets and puts between
634 * @param $list Array of servers to connect to
636 * @see MWMemcached::__construct()
638 public function set_servers( $list ) {
639 $this->_servers
= $list;
640 $this->_active
= count( $list );
641 $this->_buckets
= null;
642 $this->_bucketcount
= 0;
644 $this->_single_sock
= null;
645 if ( $this->_active
== 1 ) {
646 $this->_single_sock
= $this->_servers
[0];
651 * Sets the timeout for new connections
653 * @param $seconds Integer: number of seconds
654 * @param $microseconds Integer: number of microseconds
656 public function set_timeout( $seconds, $microseconds ) {
657 $this->_timeout_seconds
= $seconds;
658 $this->_timeout_microseconds
= $microseconds;
663 // {{{ private methods
667 * Close the specified socket
669 * @param $sock String: socket to close
673 function _close_sock( $sock ) {
674 $host = array_search( $sock, $this->_cache_sock
);
675 fclose( $this->_cache_sock
[$host] );
676 unset( $this->_cache_sock
[$host] );
680 // {{{ _connect_sock()
683 * Connects $sock to $host, timing out after $timeout
685 * @param $sock Integer: socket to connect
686 * @param $host String: Host:IP to connect to
691 function _connect_sock( &$sock, $host ) {
692 list( $ip, $port ) = explode( ':', $host );
694 $timeout = $this->_connect_timeout
;
695 $errno = $errstr = null;
696 for( $i = 0; !$sock && $i < $this->_connect_attempts
; $i++
) {
697 wfSuppressWarnings();
698 if ( $this->_persistant
== 1 ) {
699 $sock = pfsockopen( $ip, $port, $errno, $errstr, $timeout );
701 $sock = fsockopen( $ip, $port, $errno, $errstr, $timeout );
706 if ( $this->_debug
) {
707 $this->_debugprint( "Error connecting to $host: $errstr\n" );
712 // Initialise timeout
713 stream_set_timeout( $sock, $this->_timeout_seconds
, $this->_timeout_microseconds
);
722 * Marks a host as dead until 30-40 seconds in the future
724 * @param $sock String: socket to mark as dead
728 function _dead_sock( $sock ) {
729 $host = array_search( $sock, $this->_cache_sock
);
730 $this->_dead_host( $host );
733 function _dead_host( $host ) {
734 $parts = explode( ':', $host );
736 $this->_host_dead
[$ip] = time() +
30 +
intval( rand( 0, 10 ) );
737 $this->_host_dead
[$host] = $this->_host_dead
[$ip];
738 unset( $this->_cache_sock
[$host] );
747 * @param $key String: key to retrieve value for;
749 * @return Mixed: resource on success, false on failure
752 function get_sock( $key ) {
753 if ( !$this->_active
) {
757 if ( $this->_single_sock
!== null ) {
758 $this->_flush_read_buffer( $this->_single_sock
);
759 return $this->sock_to_host( $this->_single_sock
);
762 $hv = is_array( $key ) ?
intval( $key[0] ) : $this->_hashfunc( $key );
764 if ( $this->_buckets
=== null ) {
765 foreach ( $this->_servers
as $v ) {
766 if ( is_array( $v ) ) {
767 for( $i = 0; $i < $v[1]; $i++
) {
774 $this->_buckets
= $bu;
775 $this->_bucketcount
= count( $bu );
778 $realkey = is_array( $key ) ?
$key[1] : $key;
779 for( $tries = 0; $tries < 20; $tries++
) {
780 $host = $this->_buckets
[$hv %
$this->_bucketcount
];
781 $sock = $this->sock_to_host( $host );
782 if ( is_resource( $sock ) ) {
783 $this->_flush_read_buffer( $sock );
786 $hv = $this->_hashfunc( $hv . $realkey );
796 * Creates a hash integer based on the $key
798 * @param $key String: key to hash
800 * @return Integer: hash value
803 function _hashfunc( $key ) {
804 # Hash function must on [0,0x7ffffff]
805 # We take the first 31 bits of the MD5 hash, which unlike the hash
806 # function used in a previous version of this client, works
807 return hexdec( substr( md5( $key ), 0, 8 ) ) & 0x7fffffff;
814 * Perform increment/decriment on $key
816 * @param $cmd String: command to perform
817 * @param $key String: key to perform it on
818 * @param $amt Integer: amount to adjust
820 * @return Integer: new value of $key
823 function _incrdecr( $cmd, $key, $amt = 1 ) {
824 if ( !$this->_active
) {
828 $sock = $this->get_sock( $key );
829 if ( !is_resource( $sock ) ) {
833 $key = is_array( $key ) ?
$key[1] : $key;
834 if ( isset( $this->stats
[$cmd] ) ) {
835 $this->stats
[$cmd]++
;
837 $this->stats
[$cmd] = 1;
839 if ( !$this->_safe_fwrite( $sock, "$cmd $key $amt\r\n" ) ) {
840 return $this->_dead_sock( $sock );
843 $line = fgets( $sock );
845 if ( !preg_match( '/^(\d+)/', $line, $match ) ) {
855 * Load items into $ret from $sock
857 * @param $sock Ressource: socket to read from
858 * @param $ret Array: returned values
862 function _load_items( $sock, &$ret ) {
864 $decl = fgets( $sock );
865 if ( $decl == "END\r\n" ) {
867 } elseif ( preg_match( '/^VALUE (\S+) (\d+) (\d+)\r\n$/', $decl, $match ) ) {
868 list( $rkey, $flags, $len ) = array( $match[1], $match[2], $match[3] );
872 while ( $bneed > 0 ) {
873 $data = fread( $sock, $bneed );
874 $n = strlen( $data );
880 if ( isset( $ret[$rkey] ) ) {
881 $ret[$rkey] .= $data;
887 if ( $offset != $len +
2 ) {
888 // Something is borked!
889 if ( $this->_debug
) {
890 $this->_debugprint( sprintf( "Something is borked! key %s expecting %d got %d length\n", $rkey, $len +
2, $offset ) );
893 unset( $ret[$rkey] );
894 $this->_close_sock( $sock );
898 if ( $this->_have_zlib
&& $flags & self
::COMPRESSED
) {
899 $ret[$rkey] = gzuncompress( $ret[$rkey] );
902 $ret[$rkey] = rtrim( $ret[$rkey] );
904 if ( $flags & self
::SERIALIZED
) {
905 $ret[$rkey] = unserialize( $ret[$rkey] );
909 $this->_debugprint( "Error parsing memcached response\n" );
919 * Performs the requested storage operation to the memcache server
921 * @param $cmd String: command to perform
922 * @param $key String: key to act on
923 * @param $val Mixed: what we need to store
924 * @param $exp Integer: (optional) Expiration time. This can be a number of seconds
925 * to cache for (up to 30 days inclusive). Any timespans of 30 days + 1 second or
926 * longer must be the timestamp of the time at which the mapping should expire. It
927 * is safe to use timestamps in all cases, regardless of exipration
928 * eg: strtotime("+3 hour")
933 function _set( $cmd, $key, $val, $exp ) {
934 if ( !$this->_active
) {
938 $sock = $this->get_sock( $key );
939 if ( !is_resource( $sock ) ) {
943 if ( isset( $this->stats
[$cmd] ) ) {
944 $this->stats
[$cmd]++
;
946 $this->stats
[$cmd] = 1;
951 if ( !is_scalar( $val ) ) {
952 $val = serialize( $val );
953 $flags |
= self
::SERIALIZED
;
954 if ( $this->_debug
) {
955 $this->_debugprint( sprintf( "client: serializing data as it is not scalar\n" ) );
959 $len = strlen( $val );
961 if ( $this->_have_zlib
&& $this->_compress_enable
&&
962 $this->_compress_threshold
&& $len >= $this->_compress_threshold
)
964 $c_val = gzcompress( $val, 9 );
965 $c_len = strlen( $c_val );
967 if ( $c_len < $len * ( 1 - self
::COMPRESSION_SAVINGS
) ) {
968 if ( $this->_debug
) {
969 $this->_debugprint( sprintf( "client: compressing data; was %d bytes is now %d bytes\n", $len, $c_len ) );
973 $flags |
= self
::COMPRESSED
;
976 if ( !$this->_safe_fwrite( $sock, "$cmd $key $flags $exp $len\r\n$val\r\n" ) ) {
977 return $this->_dead_sock( $sock );
980 $line = trim( fgets( $sock ) );
982 if ( $this->_debug
) {
983 $this->_debugprint( sprintf( "%s %s (%s)\n", $cmd, $key, $line ) );
985 if ( $line == "STORED" ) {
992 // {{{ sock_to_host()
995 * Returns the socket for the host
997 * @param $host String: Host:IP to get socket for
999 * @return Mixed: IO Stream or false
1002 function sock_to_host( $host ) {
1003 if ( isset( $this->_cache_sock
[$host] ) ) {
1004 return $this->_cache_sock
[$host];
1009 list( $ip, /* $port */) = explode( ':', $host );
1010 if ( isset( $this->_host_dead
[$host] ) && $this->_host_dead
[$host] > $now ||
1011 isset( $this->_host_dead
[$ip] ) && $this->_host_dead
[$ip] > $now
1016 if ( !$this->_connect_sock( $sock, $host ) ) {
1017 return $this->_dead_host( $host );
1020 // Do not buffer writes
1021 stream_set_write_buffer( $sock, 0 );
1023 $this->_cache_sock
[$host] = $sock;
1025 return $this->_cache_sock
[$host];
1028 function _debugprint( $str ) {
1033 * Write to a stream, timing out after the correct amount of time
1035 * @return Boolean: false on failure, true on success
1038 function _safe_fwrite( $f, $buf, $len = false ) {
1039 stream_set_blocking( $f, 0 );
1041 if ( $len === false ) {
1042 wfDebug( "Writing " . strlen( $buf ) . " bytes\n" );
1043 $bytesWritten = fwrite( $f, $buf );
1045 wfDebug( "Writing $len bytes\n" );
1046 $bytesWritten = fwrite( $f, $buf, $len );
1048 $n = stream_select( $r = null, $w = array( $f ), $e = null, 10, 0 );
1049 # $this->_timeout_seconds, $this->_timeout_microseconds );
1051 wfDebug( "stream_select returned $n\n" );
1052 stream_set_blocking( $f, 1 );
1054 return $bytesWritten;
1058 * Original behaviour
1060 function _safe_fwrite( $f, $buf, $len = false ) {
1061 if ( $len === false ) {
1062 $bytesWritten = fwrite( $f, $buf );
1064 $bytesWritten = fwrite( $f, $buf, $len );
1066 return $bytesWritten;
1070 * Flush the read buffer of a stream
1072 function _flush_read_buffer( $f ) {
1073 if ( !is_resource( $f ) ) {
1076 $n = stream_select( $r = array( $f ), $w = null, $e = null, 0, 0 );
1077 while ( $n == 1 && !feof( $f ) ) {
1079 $n = stream_select( $r = array( $f ), $w = null, $e = null, 0, 0 );
1088 // vim: sts=3 sw=3 et
1092 class MemCachedClientforWiki
extends MWMemcached
{
1093 function _debugprint( $text ) {
1094 wfDebug( "memcached: $text" );