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 // +---------------------------------------------------------------------------+
40 * This is the PHP client for memcached - a distributed memory cache daemon.
41 * More information is available at http://www.danga.com/memcached/
45 * require_once 'memcached.php';
47 * $mc = new memcached(array(
48 * 'servers' => array('127.0.0.1:10000',
49 * array('192.0.0.1:10010', 2),
52 * 'compress_threshold' => 10240,
53 * 'persistant' => true));
55 * $mc->add('key', array('some', 'array'));
56 * $mc->replace('key', 'some random string');
57 * $val = $mc->get('key');
59 * @author Ryan T. Dean <rtdean@cytherianage.net>
60 * @package memcached-client
67 // {{{ class memcached
69 * memcached client class implemented using (p)fsockopen()
71 * @author Ryan T. Dean <rtdean@cytherianage.net>
83 * Flag: indicates data is serialized
88 * Flag: indicates data is compressed
95 * Minimum savings to store data compressed
97 const COMPRESSION_SAVINGS
= 0.20;
114 * Cached Sockets that are connected
122 * Current debug status; 0 - none to 9 - profiling
130 * Dead hosts, assoc array, 'host'=>'unixtime when ok to check again'
138 * Is compression available?
146 * Do we want to use compression?
151 var $_compress_enable;
154 * At how many bytes should we compress?
159 var $_compress_threshold;
162 * Are we using persistant links?
170 * If only using one server; contains ip:port to connect to
178 * Array containing ip:port or array(ip:port, weight)
194 * Total # of bit buckets we have
202 * # of total servers we have
210 * Stream timeout in seconds. Applies for example to fread()
215 var $_timeout_seconds;
218 * Stream timeout in microseconds
223 var $_timeout_microseconds;
226 * Connect timeout in seconds
228 var $_connect_timeout;
231 * Number of connection attempts for each server
233 var $_connect_attempts;
238 // {{{ public functions
242 * Memcache initializer
244 * @param array $args Associative array of settings
249 function memcached ($args)
251 $this->set_servers(@$args['servers']);
252 $this->_debug
= @$args['debug'];
253 $this->stats
= array();
254 $this->_compress_threshold
= @$args['compress_threshold'];
255 $this->_persistant
= array_key_exists('persistant', $args) ?
(@$args['persistant']) : false;
256 $this->_compress_enable
= true;
257 $this->_have_zlib
= function_exists("gzcompress");
259 $this->_cache_sock
= array();
260 $this->_host_dead
= array();
262 $this->_timeout_seconds
= 1;
263 $this->_timeout_microseconds
= 0;
265 $this->_connect_timeout
= 0.01;
266 $this->_connect_attempts
= 3;
273 * Adds a key/value to the memcache server if one isn't already set with
276 * @param string $key Key to set with data
277 * @param mixed $val Value to store
278 * @param integer $exp (optional) Time to expire data at
283 function add ($key, $val, $exp = 0)
285 return $this->_set('add', $key, $val, $exp);
292 * Decriment a value stored on the memcache server
294 * @param string $key Key to decriment
295 * @param integer $amt (optional) Amount to decriment
297 * @return mixed FALSE on failure, value on success
300 function decr ($key, $amt=1)
302 return $this->_incrdecr('decr', $key, $amt);
309 * Deletes a key from the server, optionally after $time
311 * @param string $key Key to delete
312 * @param integer $time (optional) How long to wait before deleting
314 * @return boolean TRUE on success, FALSE on failure
317 function delete ($key, $time = 0)
322 $sock = $this->get_sock($key);
323 if (!is_resource($sock))
326 $key = is_array($key) ?
$key[1] : $key;
328 @$this->stats
['delete']++
;
329 $cmd = "delete $key $time\r\n";
330 if(!$this->_safe_fwrite($sock, $cmd, strlen($cmd)))
332 $this->_dead_sock($sock);
335 $res = trim(fgets($sock));
338 $this->_debugprint(sprintf("MemCache: delete %s (%s)\n", $key, $res));
340 if ($res == "DELETED")
346 // {{{ disconnect_all()
349 * Disconnects all connected sockets
353 function disconnect_all ()
355 foreach ($this->_cache_sock
as $sock)
358 $this->_cache_sock
= array();
362 // {{{ enable_compress()
365 * Enable / Disable compression
367 * @param boolean $enable TRUE to enable, FALSE to disable
371 function enable_compress ($enable)
373 $this->_compress_enable
= $enable;
377 // {{{ forget_dead_hosts()
380 * Forget about all of the dead hosts
384 function forget_dead_hosts ()
386 $this->_host_dead
= array();
393 * Retrieves the value associated with the key from the memcache server
395 * @param string $key Key to retrieve
402 $fname = 'memcached::get';
403 wfProfileIn( $fname );
405 if (!$this->_active
) {
406 wfProfileOut( $fname );
410 $sock = $this->get_sock($key);
412 if (!is_resource($sock)) {
413 wfProfileOut( $fname );
417 @$this->stats
['get']++
;
419 $cmd = "get $key\r\n";
420 if (!$this->_safe_fwrite($sock, $cmd, strlen($cmd)))
422 $this->_dead_sock($sock);
423 wfProfileOut( $fname );
428 $this->_load_items($sock, $val);
431 foreach ($val as $k => $v)
432 $this->_debugprint(@sprintf
("MemCache: sock %s got %s => %s\r\n", serialize($sock), $k, $v));
434 wfProfileOut( $fname );
442 * Get multiple keys from the server(s)
444 * @param array $keys Keys to retrieve
449 function get_multi ($keys)
454 $this->stats
['get_multi']++
;
455 $sock_keys = array();
457 foreach ($keys as $key)
459 $sock = $this->get_sock($key);
460 if (!is_resource($sock)) continue;
461 $key = is_array($key) ?
$key[1] : $key;
462 if (!isset($sock_keys[$sock]))
464 $sock_keys[$sock] = array();
467 $sock_keys[$sock][] = $key;
470 // Send out the requests
471 foreach ($socks as $sock)
474 foreach ($sock_keys[$sock] as $key)
480 if ($this->_safe_fwrite($sock, $cmd, strlen($cmd)))
485 $this->_dead_sock($sock);
491 foreach ($gather as $sock)
493 $this->_load_items($sock, $val);
497 foreach ($val as $k => $v)
498 $this->_debugprint(sprintf("MemCache: got %s => %s\r\n", $k, $v));
507 * Increments $key (optionally) by $amt
509 * @param string $key Key to increment
510 * @param integer $amt (optional) amount to increment
512 * @return integer New key value?
515 function incr ($key, $amt=1)
517 return $this->_incrdecr('incr', $key, $amt);
524 * Overwrites an existing value for key; only works if key is already set
526 * @param string $key Key to set value as
527 * @param mixed $value Value to store
528 * @param integer $exp (optional) Experiation time
533 function replace ($key, $value, $exp=0)
535 return $this->_set('replace', $key, $value, $exp);
542 * Passes through $cmd to the memcache server connected by $sock; returns
543 * output as an array (null array if no output)
545 * NOTE: due to a possible bug in how PHP reads while using fgets(), each
546 * line may not be terminated by a \r\n. More specifically, my testing
547 * has shown that, on FreeBSD at least, each line is terminated only
548 * with a \n. This is with the PHP flag auto_detect_line_endings set
549 * to falase (the default).
551 * @param resource $sock Socket to send command on
552 * @param string $cmd Command to run
554 * @return array Output array
557 function run_command ($sock, $cmd)
559 if (!is_resource($sock))
562 if (!$this->_safe_fwrite($sock, $cmd, strlen($cmd)))
569 if (preg_match('/^END/', $res))
571 if (strlen($res) == 0)
581 * Unconditionally sets a key to a given value in the memcache. Returns true
582 * if set successfully.
584 * @param string $key Key to set value as
585 * @param mixed $value Value to set
586 * @param integer $exp (optional) Experiation time
588 * @return boolean TRUE on success
591 function set ($key, $value, $exp=0)
593 return $this->_set('set', $key, $value, $exp);
597 // {{{ set_compress_threshold()
600 * Sets the compression threshold
602 * @param integer $thresh Threshold to compress if larger than
606 function set_compress_threshold ($thresh)
608 $this->_compress_threshold
= $thresh;
615 * Sets the debug flag
617 * @param boolean $dbg TRUE for debugging, FALSE otherwise
621 * @see memcahced::memcached
623 function set_debug ($dbg)
625 $this->_debug
= $dbg;
632 * Sets the server list to distribute key gets and puts between
634 * @param array $list Array of servers to connect to
638 * @see memcached::memcached()
640 function set_servers ($list)
642 $this->_servers
= $list;
643 $this->_active
= count($list);
644 $this->_buckets
= null;
645 $this->_bucketcount
= 0;
647 $this->_single_sock
= null;
648 if ($this->_active
== 1)
649 $this->_single_sock
= $this->_servers
[0];
653 * Sets the timeout for new connections
655 * @param integer $seconds Number of seconds
656 * @param integer $microseconds Number of microseconds
660 function set_timeout ($seconds, $microseconds)
662 $this->_timeout_seconds
= $seconds;
663 $this->_timeout_microseconds
= $microseconds;
668 // {{{ private methods
672 * Close the specified socket
674 * @param string $sock Socket to close
678 function _close_sock ($sock)
680 $host = array_search($sock, $this->_cache_sock
);
681 fclose($this->_cache_sock
[$host]);
682 unset($this->_cache_sock
[$host]);
686 // {{{ _connect_sock()
689 * Connects $sock to $host, timing out after $timeout
691 * @param integer $sock Socket to connect
692 * @param string $host Host:IP to connect to
697 function _connect_sock (&$sock, $host)
699 list ($ip, $port) = explode(":", $host);
701 $timeout = $this->_connect_timeout
;
702 $errno = $errstr = null;
703 for ($i = 0; !$sock && $i < $this->_connect_attempts
; $i++
) {
705 # Sleep until the timeout, in case it failed fast
706 $elapsed = microtime(true) - $t;
707 if ( $elapsed < $timeout ) {
708 usleep(($timeout - $elapsed) * 1e6
);
712 $t = microtime(true);
713 if ($this->_persistant
== 1)
715 $sock = @pfsockopen
($ip, $port, $errno, $errstr, $timeout);
718 $sock = @fsockopen
($ip, $port, $errno, $errstr, $timeout);
723 $this->_debugprint( "Error connecting to $host: $errstr\n" );
727 // Initialise timeout
728 stream_set_timeout($sock, $this->_timeout_seconds
, $this->_timeout_microseconds
);
737 * Marks a host as dead until 30-40 seconds in the future
739 * @param string $sock Socket to mark as dead
743 function _dead_sock ($sock)
745 $host = array_search($sock, $this->_cache_sock
);
746 @list
($ip, /* $port */) = explode(":", $host);
747 $this->_host_dead
[$ip] = time() +
30 +
intval(rand(0, 10));
748 $this->_host_dead
[$host] = $this->_host_dead
[$ip];
749 unset($this->_cache_sock
[$host]);
758 * @param string $key Key to retrieve value for;
760 * @return mixed resource on success, false on failure
763 function get_sock ($key)
768 if ($this->_single_sock
!== null) {
769 $this->_flush_read_buffer($this->_single_sock
);
770 return $this->sock_to_host($this->_single_sock
);
773 $hv = is_array($key) ?
intval($key[0]) : $this->_hashfunc($key);
775 if ($this->_buckets
=== null)
777 foreach ($this->_servers
as $v)
781 for ($i=0; $i<$v[1]; $i++
)
788 $this->_buckets
= $bu;
789 $this->_bucketcount
= count($bu);
792 $realkey = is_array($key) ?
$key[1] : $key;
793 for ($tries = 0; $tries<20; $tries++
)
795 $host = $this->_buckets
[$hv %
$this->_bucketcount
];
796 $sock = $this->sock_to_host($host);
797 if (is_resource($sock)) {
798 $this->_flush_read_buffer($sock);
801 $hv +
= $this->_hashfunc($tries . $realkey);
811 * Creates a hash integer based on the $key
813 * @param string $key Key to hash
815 * @return integer Hash value
818 function _hashfunc ($key)
820 # Hash function must on [0,0x7ffffff]
821 # We take the first 31 bits of the MD5 hash, which unlike the hash
822 # function used in a previous version of this client, works
823 return hexdec(substr(md5($key),0,8)) & 0x7fffffff;
830 * Perform increment/decriment on $key
832 * @param string $cmd Command to perform
833 * @param string $key Key to perform it on
834 * @param integer $amt Amount to adjust
836 * @return integer New value of $key
839 function _incrdecr ($cmd, $key, $amt=1)
844 $sock = $this->get_sock($key);
845 if (!is_resource($sock))
848 $key = is_array($key) ?
$key[1] : $key;
849 @$this->stats
[$cmd]++
;
850 if (!$this->_safe_fwrite($sock, "$cmd $key $amt\r\n"))
851 return $this->_dead_sock($sock);
853 stream_set_timeout($sock, 1, 0);
854 $line = fgets($sock);
856 if (!preg_match('/^(\d+)/', $line, $match))
865 * Load items into $ret from $sock
867 * @param resource $sock Socket to read from
868 * @param array $ret Returned values
872 function _load_items ($sock, &$ret)
876 $decl = fgets($sock);
877 if ($decl == "END\r\n")
880 } elseif (preg_match('/^VALUE (\S+) (\d+) (\d+)\r\n$/', $decl, $match))
882 list($rkey, $flags, $len) = array($match[1], $match[2], $match[3]);
888 $data = fread($sock, $bneed);
894 @$ret[$rkey] .= $data;
897 if ($offset != $len+
2)
899 // Something is borked!
901 $this->_debugprint(sprintf("Something is borked! key %s expecting %d got %d length\n", $rkey, $len+
2, $offset));
904 $this->_close_sock($sock);
908 if ($this->_have_zlib
&& $flags & memcached
::COMPRESSED
)
909 $ret[$rkey] = gzuncompress($ret[$rkey]);
911 $ret[$rkey] = rtrim($ret[$rkey]);
913 if ($flags & memcached
::SERIALIZED
)
914 $ret[$rkey] = unserialize($ret[$rkey]);
918 $this->_debugprint("Error parsing memcached response\n");
928 * Performs the requested storage operation to the memcache server
930 * @param string $cmd Command to perform
931 * @param string $key Key to act on
932 * @param mixed $val What we need to store
933 * @param integer $exp When it should expire
938 function _set ($cmd, $key, $val, $exp)
943 $sock = $this->get_sock($key);
944 if (!is_resource($sock))
947 @$this->stats
[$cmd]++
;
951 if (!is_scalar($val))
953 $val = serialize($val);
954 $flags |
= memcached
::SERIALIZED
;
956 $this->_debugprint(sprintf("client: serializing data as it is not scalar\n"));
961 if ($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 - memcached
::COMPRESSION_SAVINGS
))
970 $this->_debugprint(sprintf("client: compressing data; was %d bytes is now %d bytes\n", $len, $c_len));
973 $flags |
= memcached
::COMPRESSED
;
976 if (!$this->_safe_fwrite($sock, "$cmd $key $flags $exp $len\r\n$val\r\n"))
977 return $this->_dead_sock($sock);
979 $line = trim(fgets($sock));
983 if ($flags & memcached
::COMPRESSED
)
984 $val = 'compressed data';
985 $this->_debugprint(sprintf("MemCache: %s %s => %s (%s)\n", $cmd, $key, $val, $line));
987 if ($line == "STORED")
993 // {{{ sock_to_host()
996 * Returns the socket for the host
998 * @param string $host Host:IP to get socket for
1000 * @return mixed IO Stream or false
1003 function sock_to_host ($host)
1005 if (isset($this->_cache_sock
[$host]))
1006 return $this->_cache_sock
[$host];
1010 list ($ip, /* $port */) = explode (":", $host);
1011 if (isset($this->_host_dead
[$host]) && $this->_host_dead
[$host] > $now ||
1012 isset($this->_host_dead
[$ip]) && $this->_host_dead
[$ip] > $now)
1015 if (!$this->_connect_sock($sock, $host))
1016 return $this->_dead_sock($host);
1018 // Do not buffer writes
1019 stream_set_write_buffer($sock, 0);
1021 $this->_cache_sock
[$host] = $sock;
1023 return $this->_cache_sock
[$host];
1026 function _debugprint($str){
1031 * Write to a stream, timing out after the correct amount of time
1033 * @return bool false on failure, true on success
1036 function _safe_fwrite($f, $buf, $len = false) {
1037 stream_set_blocking($f, 0);
1039 if ($len === false) {
1040 wfDebug("Writing " . strlen( $buf ) . " bytes\n");
1041 $bytesWritten = fwrite($f, $buf);
1043 wfDebug("Writing $len bytes\n");
1044 $bytesWritten = fwrite($f, $buf, $len);
1046 $n = stream_select($r=NULL, $w = array($f), $e = NULL, 10, 0);
1047 # $this->_timeout_seconds, $this->_timeout_microseconds);
1049 wfDebug("stream_select returned $n\n");
1050 stream_set_blocking($f, 1);
1052 return $bytesWritten;
1056 * Original behaviour
1058 function _safe_fwrite($f, $buf, $len = false) {
1059 if ($len === false) {
1060 $bytesWritten = fwrite($f, $buf);
1062 $bytesWritten = fwrite($f, $buf, $len);
1064 return $bytesWritten;
1068 * Flush the read buffer of a stream
1070 function _flush_read_buffer($f) {
1071 if (!is_resource($f)) {
1074 $n = stream_select($r=array($f), $w = NULL, $e = NULL, 0, 0);
1075 while ($n == 1 && !feof($f)) {
1077 $n = stream_select($r=array($f), $w = NULL, $e = NULL, 0, 0);
1086 // vim: sts=3 sw=3 et