includes/memcached-client.php

   1 <?php
   2 //
   3 // +---------------------------------------------------------------------------+
   4 // | memcached client, PHP                                                     |
   5 // +---------------------------------------------------------------------------+
   6 // | Copyright (c) 2003 Ryan T. Dean <rtdean@cytherianage.net>                 |
   7 // | All rights reserved.                                                      |
   8 // |                                                                           |
   9 // | Redistribution and use in source and binary forms, with or without        |
  10 // | modification, are permitted provided that the following conditions        |
  11 // | are met:                                                                  |
  12 // |                                                                           |
  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.   |
  18 // |                                                                           |
  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 // +---------------------------------------------------------------------------+
  35 //
  36 // $TCAnet$
  37 //
  38
  39 /**
  40  * This is the PHP client for memcached - a distributed memory cache daemon.
  41  * More information is available at http://www.danga.com/memcached/
  42  *
  43  * Usage example:
  44  *
  45  * require_once 'memcached.php';
  46  *
  47  * $mc = new memcached(array(
  48  *              'servers' => array('127.0.0.1:10000',
  49  *                                 array('192.0.0.1:10010', 2),
  50  *                                 '127.0.0.1:10020'),
  51  *              'debug'   => false,
  52  *              'compress_threshold' => 10240,
  53  *              'persistant' => true));
  54  *
  55  * $mc->add('key', array('some', 'array'));
  56  * $mc->replace('key', 'some random string');
  57  * $val = $mc->get('key');
  58  *
  59  * @author  Ryan T. Dean <rtdean@cytherianage.net>
  60  * @package memcached-client
  61  * @version 0.1.2
  62  */
  63
  64 // {{{ requirements
  65 // }}}
  66
  67 // {{{ constants
  68 // {{{ flags
  69
  70 /**
  71  * Flag: indicates data is serialized
  72  */
  73 define("MEMCACHE_SERIALIZED", 1<<0);
  74
  75 /**
  76  * Flag: indicates data is compressed
  77  */
  78 define("MEMCACHE_COMPRESSED", 1<<1);
  79
  80 // }}}
  81
  82 /**
  83  * Minimum savings to store data compressed
  84  */
  85 define("COMPRESSION_SAVINGS", 0.20);
  86
  87 // }}}
  88
  89 // {{{ class memcached
  90 /**
  91  * memcached client class implemented using (p)fsockopen()
  92  *
  93  * @author  Ryan T. Dean <rtdean@cytherianage.net>
  94  * @package memcached-client
  95  */
  96 class memcached
  97 {
  98    // {{{ properties
  99    // {{{ public
 100
 101    /**
 102     * Command statistics
 103     *
 104     * @var     array
 105     * @access  public
 106     */
 107    var $stats;
 108
 109    // }}}
 110    // {{{ private
 111
 112    /**
 113     * Cached Sockets that are connected
 114     *
 115     * @var     array
 116     * @access  private
 117     */
 118    var $_cache_sock;
 119
 120    /**
 121     * Current debug status; 0 - none to 9 - profiling
 122     *
 123     * @var     boolean
 124     * @access  private
 125     */
 126    var $_debug;
 127
 128    /**
 129     * Dead hosts, assoc array, 'host'=>'unixtime when ok to check again'
 130     *
 131     * @var     array
 132     * @access  private
 133     */
 134    var $_host_dead;
 135
 136    /**
 137     * Is compression available?
 138     *
 139     * @var     boolean
 140     * @access  private
 141     */
 142    var $_have_zlib;
 143
 144    /**
 145     * Do we want to use compression?
 146     *
 147     * @var     boolean
 148     * @access  private
 149     */
 150    var $_compress_enable;
 151
 152    /**
 153     * At how many bytes should we compress?
 154     *
 155     * @var     interger
 156     * @access  private
 157     */
 158    var $_compress_threshold;
 159
 160    /**
 161     * Are we using persistant links?
 162     *
 163     * @var     boolean
 164     * @access  private
 165     */
 166    var $_persistant;
 167
 168    /**
 169     * If only using one server; contains ip:port to connect to
 170     *
 171     * @var     string
 172     * @access  private
 173     */
 174    var $_single_sock;
 175
 176    /**
 177     * Array containing ip:port or array(ip:port, weight)
 178     *
 179     * @var     array
 180     * @access  private
 181     */
 182    var $_servers;
 183
 184    /**
 185     * Our bit buckets
 186     *
 187     * @var     array
 188     * @access  private
 189     */
 190    var $_buckets;
 191
 192    /**
 193     * Total # of bit buckets we have
 194     *
 195     * @var     interger
 196     * @access  private
 197     */
 198    var $_bucketcount;
 199
 200    /**
 201     * # of total servers we have
 202     *
 203     * @var     interger
 204     * @access  private
 205     */
 206    var $_active;
 207
 208    /**
 209     * Stream timeout in seconds. Applies for example to fread()
 210     *
 211     * @var     integer
 212     * @access  private
 213     */
 214    var $_timeout_seconds;
 215
 216    /**
 217     * Stream timeout in microseconds
 218     *
 219     * @var     integer
 220     * @access  private
 221     */
 222    var $_timeout_microseconds;
 223
 224    /**
 225     * Connect timeout in seconds
 226     */
 227    var $_connect_timeout;
 228
 229    /**
 230     * Number of connection attempts for each server
 231     */
 232    var $_connect_attempts;
 233
 234    // }}}
 235    // }}}
 236    // {{{ methods
 237    // {{{ public functions
 238    // {{{ memcached()
 239
 240    /**
 241     * Memcache initializer
 242     *
 243     * @param   array    $args    Associative array of settings
 244     *
 245     * @return  mixed
 246     * @access  public
 247     */
 248    function memcached ($args)
 249    {
 250       $this->set_servers(@$args['servers']);
 251       $this->_debug = @$args['debug'];
 252       $this->stats = array();
 253       $this->_compress_threshold = @$args['compress_threshold'];
 254       $this->_persistant = array_key_exists('persistant', $args) ? (@$args['persistant']) : false;
 255       $this->_compress_enable = true;
 256       $this->_have_zlib = function_exists("gzcompress");
 257
 258       $this->_cache_sock = array();
 259       $this->_host_dead = array();
 260
 261       $this->_timeout_seconds = 1;
 262       $this->_timeout_microseconds = 0;
 263
 264       $this->_connect_timeout = 0.01;
 265       $this->_connect_attempts = 3;
 266    }
 267
 268    // }}}
 269    // {{{ add()
 270
 271    /**
 272     * Adds a key/value to the memcache server if one isn't already set with
 273     * that key
 274     *
 275     * @param   string   $key     Key to set with data
 276     * @param   mixed    $val     Value to store
 277     * @param   interger $exp     (optional) Time to expire data at
 278     *
 279     * @return  boolean
 280     * @access  public
 281     */
 282    function add ($key, $val, $exp = 0)
 283    {
 284       return $this->_set('add', $key, $val, $exp);
 285    }
 286
 287    // }}}
 288    // {{{ decr()
 289
 290    /**
 291     * Decriment a value stored on the memcache server
 292     *
 293     * @param   string   $key     Key to decriment
 294     * @param   interger $amt     (optional) Amount to decriment
 295     *
 296     * @return  mixed    FALSE on failure, value on success
 297     * @access  public
 298     */
 299    function decr ($key, $amt=1)
 300    {
 301       return $this->_incrdecr('decr', $key, $amt);
 302    }
 303
 304    // }}}
 305    // {{{ delete()
 306
 307    /**
 308     * Deletes a key from the server, optionally after $time
 309     *
 310     * @param   string   $key     Key to delete
 311     * @param   interger $time    (optional) How long to wait before deleting
 312     *
 313     * @return  boolean  TRUE on success, FALSE on failure
 314     * @access  public
 315     */
 316    function delete ($key, $time = 0)
 317    {
 318       if (!$this->_active)
 319          return false;
 320
 321       $sock = $this->get_sock($key);
 322       if (!is_resource($sock))
 323          return false;
 324
 325       $key = is_array($key) ? $key[1] : $key;
 326
 327       @$this->stats['delete']++;
 328       $cmd = "delete $key $time\r\n";
 329       if(!$this->_safe_fwrite($sock, $cmd, strlen($cmd)))
 330       {
 331          $this->_dead_sock($sock);
 332          return false;
 333       }
 334       $res = trim(fgets($sock));
 335
 336       if ($this->_debug)
 337          $this->_debugprint(sprintf("MemCache: delete %s (%s)\n", $key, $res));
 338
 339       if ($res == "DELETED")
 340          return true;
 341       return false;
 342    }
 343
 344    // }}}
 345    // {{{ disconnect_all()
 346
 347    /**
 348     * Disconnects all connected sockets
 349     *
 350     * @access  public
 351     */
 352    function disconnect_all ()
 353    {
 354       foreach ($this->_cache_sock as $sock)
 355          fclose($sock);
 356
 357       $this->_cache_sock = array();
 358    }
 359
 360    // }}}
 361    // {{{ enable_compress()
 362
 363    /**
 364     * Enable / Disable compression
 365     *
 366     * @param   boolean  $enable  TRUE to enable, FALSE to disable
 367     *
 368     * @access  public
 369     */
 370    function enable_compress ($enable)
 371    {
 372       $this->_compress_enable = $enable;
 373    }
 374
 375    // }}}
 376    // {{{ forget_dead_hosts()
 377
 378    /**
 379     * Forget about all of the dead hosts
 380     *
 381     * @access  public
 382     */
 383    function forget_dead_hosts ()
 384    {
 385       $this->_host_dead = array();
 386    }
 387
 388    // }}}
 389    // {{{ get()
 390
 391    /**
 392     * Retrieves the value associated with the key from the memcache server
 393     *
 394     * @param  string   $key     Key to retrieve
 395     *
 396     * @return  mixed
 397     * @access  public
 398     */
 399    function get ($key)
 400    {
 401       $fname = 'memcached::get';
 402       wfProfileIn( $fname );
 403
 404       if (!$this->_active) {
 405          wfProfileOut( $fname );
 406          return false;
 407       }
 408
 409       $sock = $this->get_sock($key);
 410
 411       if (!is_resource($sock)) {
 412          wfProfileOut( $fname );
 413          return false;
 414       }
 415
 416       @$this->stats['get']++;
 417
 418       $cmd = "get $key\r\n";
 419       if (!$this->_safe_fwrite($sock, $cmd, strlen($cmd)))
 420       {
 421          $this->_dead_sock($sock);
 422          wfProfileOut( $fname );
 423          return false;
 424       }
 425
 426       $val = array();
 427       $this->_load_items($sock, $val);
 428
 429       if ($this->_debug)
 430          foreach ($val as $k => $v)
 431             $this->_debugprint(@sprintf("MemCache: sock %s got %s => %s\r\n", serialize($sock), $k, $v));
 432
 433       wfProfileOut( $fname );
 434       return @$val[$key];
 435    }
 436
 437    // }}}
 438    // {{{ get_multi()
 439
 440    /**
 441     * Get multiple keys from the server(s)
 442     *
 443     * @param   array    $keys    Keys to retrieve
 444     *
 445     * @return  array
 446     * @access  public
 447     */
 448    function get_multi ($keys)
 449    {
 450       if (!$this->_active)
 451          return false;
 452
 453       $this->stats['get_multi']++;
 454
 455       foreach ($keys as $key)
 456       {
 457          $sock = $this->get_sock($key);
 458          if (!is_resource($sock)) continue;
 459          $key = is_array($key) ? $key[1] : $key;
 460          if (!isset($sock_keys[$sock]))
 461          {
 462             $sock_keys[$sock] = array();
 463             $socks[] = $sock;
 464          }
 465          $sock_keys[$sock][] = $key;
 466       }
 467
 468       // Send out the requests
 469       foreach ($socks as $sock)
 470       {
 471          $cmd = "get";
 472          foreach ($sock_keys[$sock] as $key)
 473          {
 474             $cmd .= " ". $key;
 475          }
 476          $cmd .= "\r\n";
 477
 478          if ($this->_safe_fwrite($sock, $cmd, strlen($cmd)))
 479          {
 480             $gather[] = $sock;
 481          } else
 482          {
 483             $this->_dead_sock($sock);
 484          }
 485       }
 486
 487       // Parse responses
 488       $val = array();
 489       foreach ($gather as $sock)
 490       {
 491          $this->_load_items($sock, $val);
 492       }
 493
 494       if ($this->_debug)
 495          foreach ($val as $k => $v)
 496             $this->_debugprint(sprintf("MemCache: got %s => %s\r\n", $k, $v));
 497
 498       return $val;
 499    }
 500
 501    // }}}
 502    // {{{ incr()
 503
 504    /**
 505     * Increments $key (optionally) by $amt
 506     *
 507     * @param   string   $key     Key to increment
 508     * @param   interger $amt     (optional) amount to increment
 509     *
 510     * @return  interger New key value?
 511     * @access  public
 512     */
 513    function incr ($key, $amt=1)
 514    {
 515       return $this->_incrdecr('incr', $key, $amt);
 516    }
 517
 518    // }}}
 519    // {{{ replace()
 520
 521    /**
 522     * Overwrites an existing value for key; only works if key is already set
 523     *
 524     * @param   string   $key     Key to set value as
 525     * @param   mixed    $value   Value to store
 526     * @param   interger $exp     (optional) Experiation time
 527     *
 528     * @return  boolean
 529     * @access  public
 530     */
 531    function replace ($key, $value, $exp=0)
 532    {
 533       return $this->_set('replace', $key, $value, $exp);
 534    }
 535
 536    // }}}
 537    // {{{ run_command()
 538
 539    /**
 540     * Passes through $cmd to the memcache server connected by $sock; returns
 541     * output as an array (null array if no output)
 542     *
 543     * NOTE: due to a possible bug in how PHP reads while using fgets(), each
 544     *       line may not be terminated by a \r\n.  More specifically, my testing
 545     *       has shown that, on FreeBSD at least, each line is terminated only
 546     *       with a \n.  This is with the PHP flag auto_detect_line_endings set
 547     *       to falase (the default).
 548     *
 549     * @param   resource $sock    Socket to send command on
 550     * @param   string   $cmd     Command to run
 551     *
 552     * @return  array    Output array
 553     * @access  public
 554     */
 555    function run_command ($sock, $cmd)
 556    {
 557       if (!is_resource($sock))
 558          return array();
 559
 560       if (!$this->_safe_fwrite($sock, $cmd, strlen($cmd)))
 561          return array();
 562
 563       while (true)
 564       {
 565          $res = fgets($sock);
 566          $ret[] = $res;
 567          if (preg_match('/^END/', $res))
 568             break;
 569          if (strlen($res) == 0)
 570             break;
 571       }
 572       return $ret;
 573    }
 574
 575    // }}}
 576    // {{{ set()
 577
 578    /**
 579     * Unconditionally sets a key to a given value in the memcache.  Returns true
 580     * if set successfully.
 581     *
 582     * @param   string   $key     Key to set value as
 583     * @param   mixed    $value   Value to set
 584     * @param   interger $exp     (optional) Experiation time
 585     *
 586     * @return  boolean  TRUE on success
 587     * @access  public
 588     */
 589    function set ($key, $value, $exp=0)
 590    {
 591       return $this->_set('set', $key, $value, $exp);
 592    }
 593
 594    // }}}
 595    // {{{ set_compress_threshold()
 596
 597    /**
 598     * Sets the compression threshold
 599     *
 600     * @param   interger $thresh  Threshold to compress if larger than
 601     *
 602     * @access  public
 603     */
 604    function set_compress_threshold ($thresh)
 605    {
 606       $this->_compress_threshold = $thresh;
 607    }
 608
 609    // }}}
 610    // {{{ set_debug()
 611
 612    /**
 613     * Sets the debug flag
 614     *
 615     * @param   boolean  $dbg     TRUE for debugging, FALSE otherwise
 616     *
 617     * @access  public
 618     *
 619     * @see     memcahced::memcached
 620     */
 621    function set_debug ($dbg)
 622    {
 623       $this->_debug = $dbg;
 624    }
 625
 626    // }}}
 627    // {{{ set_servers()
 628
 629    /**
 630     * Sets the server list to distribute key gets and puts between
 631     *
 632     * @param   array    $list    Array of servers to connect to
 633     *
 634     * @access  public
 635     *
 636     * @see     memcached::memcached()
 637     */
 638    function set_servers ($list)
 639    {
 640       $this->_servers = $list;
 641       $this->_active = count($list);
 642       $this->_buckets = null;
 643       $this->_bucketcount = 0;
 644
 645       $this->_single_sock = null;
 646       if ($this->_active == 1)
 647          $this->_single_sock = $this->_servers[0];
 648    }
 649
 650    /**
 651     * Sets the timeout for new connections
 652     *
 653     * @param   integer  $seconds Number of seconds
 654     * @param   integer  $microseconds  Number of microseconds
 655     *
 656     * @access  public
 657     */
 658    function set_timeout ($seconds, $microseconds)
 659    {
 660       $this->_timeout_seconds = $seconds;
 661       $this->_timeout_microseconds = $microseconds;
 662    }
 663
 664    // }}}
 665    // }}}
 666    // {{{ private methods
 667    // {{{ _close_sock()
 668
 669    /**
 670     * Close the specified socket
 671     *
 672     * @param   string   $sock    Socket to close
 673     *
 674     * @access  private
 675     */
 676    function _close_sock ($sock)
 677    {
 678       $host = array_search($sock, $this->_cache_sock);
 679       fclose($this->_cache_sock[$host]);
 680       unset($this->_cache_sock[$host]);
 681    }
 682
 683    // }}}
 684    // {{{ _connect_sock()
 685
 686    /**
 687     * Connects $sock to $host, timing out after $timeout
 688     *
 689     * @param   interger $sock    Socket to connect
 690     * @param   string   $host    Host:IP to connect to
 691     *
 692     * @return  boolean
 693     * @access  private
 694     */
 695    function _connect_sock (&$sock, $host)
 696    {
 697       list ($ip, $port) = explode(":", $host);
 698       $sock = false;
 699       $timeout = $this->_connect_timeout;
 700       for ($i = 0; !$sock && $i < $this->_connect_attempts; $i++) {
 701          if ($i > 0) {
 702             # Sleep until the timeout, in case it failed fast
 703             $elapsed = microtime(true) - $t;
 704             if ( $elapsed < $timeout ) {
 705                usleep(($timeout - $elapsed) * 1e6);
 706             }
 707             $timeout *= 2;
 708          }
 709          $t = microtime(true);
 710          if ($this->_persistant == 1)
 711          {
 712             $sock = @pfsockopen($ip, $port, $errno, $errstr, $timeout);
 713          } else
 714          {
 715             $sock = @fsockopen($ip, $port, $errno, $errstr, $timeout);
 716          }
 717       }
 718       if (!$sock) {
 719          if ($this->_debug)
 720             $this->_debugprint( "Error connecting to $host: $errstr\n" );
 721          return false;
 722       }
 723
 724       // Initialise timeout
 725       stream_set_timeout($sock, $this->_timeout_seconds, $this->_timeout_microseconds);
 726
 727       return true;
 728    }
 729
 730    // }}}
 731    // {{{ _dead_sock()
 732
 733    /**
 734     * Marks a host as dead until 30-40 seconds in the future
 735     *
 736     * @param   string   $sock    Socket to mark as dead
 737     *
 738     * @access  private
 739     */
 740    function _dead_sock ($sock)
 741    {
 742       $host = array_search($sock, $this->_cache_sock);
 743       @list ($ip, $port) = explode(":", $host);
 744       $this->_host_dead[$ip] = time() + 30 + intval(rand(0, 10));
 745       $this->_host_dead[$host] = $this->_host_dead[$ip];
 746       unset($this->_cache_sock[$host]);
 747    }
 748
 749    // }}}
 750    // {{{ get_sock()
 751
 752    /**
 753     * get_sock
 754     *
 755     * @param   string   $key     Key to retrieve value for;
 756     *
 757     * @return  mixed    resource on success, false on failure
 758     * @access  private
 759     */
 760    function get_sock ($key)
 761    {
 762       if (!$this->_active)
 763          return false;
 764
 765       if ($this->_single_sock !== null) {
 766          $this->_flush_read_buffer($this->_single_sock);
 767          return $this->sock_to_host($this->_single_sock);
 768       }
 769
 770       $hv = is_array($key) ? intval($key[0]) : $this->_hashfunc($key);
 771
 772       if ($this->_buckets === null)
 773       {
 774          foreach ($this->_servers as $v)
 775          {
 776             if (is_array($v))
 777             {
 778                for ($i=0; $i<$v[1]; $i++)
 779                   $bu[] = $v[0];
 780             } else
 781             {
 782                $bu[] = $v;
 783             }
 784          }
 785          $this->_buckets = $bu;
 786          $this->_bucketcount = count($bu);
 787       }
 788
 789       $realkey = is_array($key) ? $key[1] : $key;
 790       for ($tries = 0; $tries<20; $tries++)
 791       {
 792          $host = $this->_buckets[$hv % $this->_bucketcount];
 793          $sock = $this->sock_to_host($host);
 794          if (is_resource($sock)) {
 795             $this->_flush_read_buffer($sock);
 796             return $sock;
 797          }
 798          $hv += $this->_hashfunc($tries . $realkey);
 799       }
 800
 801       return false;
 802    }
 803
 804    // }}}
 805    // {{{ _hashfunc()
 806
 807    /**
 808     * Creates a hash interger based on the $key
 809     *
 810     * @param   string   $key     Key to hash
 811     *
 812     * @return  interger Hash value
 813     * @access  private
 814     */
 815    function _hashfunc ($key)
 816    {
 817       # Hash function must on [0,0x7ffffff]
 818       # We take the first 31 bits of the MD5 hash, which unlike the hash
 819       # function used in a previous version of this client, works
 820       return hexdec(substr(md5($key),0,8)) & 0x7fffffff;
 821    }
 822
 823    // }}}
 824    // {{{ _incrdecr()
 825
 826    /**
 827     * Perform increment/decriment on $key
 828     *
 829     * @param   string   $cmd     Command to perform
 830     * @param   string   $key     Key to perform it on
 831     * @param   interger $amt     Amount to adjust
 832     *
 833     * @return  interger    New value of $key
 834     * @access  private
 835     */
 836    function _incrdecr ($cmd, $key, $amt=1)
 837    {
 838       if (!$this->_active)
 839          return null;
 840
 841       $sock = $this->get_sock($key);
 842       if (!is_resource($sock))
 843          return null;
 844
 845       $key = is_array($key) ? $key[1] : $key;
 846       @$this->stats[$cmd]++;
 847       if (!$this->_safe_fwrite($sock, "$cmd $key $amt\r\n"))
 848          return $this->_dead_sock($sock);
 849
 850       stream_set_timeout($sock, 1, 0);
 851       $line = fgets($sock);
 852       if (!preg_match('/^(\d+)/', $line, $match))
 853          return null;
 854       return $match[1];
 855    }
 856
 857    // }}}
 858    // {{{ _load_items()
 859
 860    /**
 861     * Load items into $ret from $sock
 862     *
 863     * @param   resource $sock    Socket to read from
 864     * @param   array    $ret     Returned values
 865     *
 866     * @access  private
 867     */
 868    function _load_items ($sock, &$ret)
 869    {
 870       while (1)
 871       {
 872          $decl = fgets($sock);
 873          if ($decl == "END\r\n")
 874          {
 875             return true;
 876          } elseif (preg_match('/^VALUE (\S+) (\d+) (\d+)\r\n$/', $decl, $match))
 877          {
 878             list($rkey, $flags, $len) = array($match[1], $match[2], $match[3]);
 879             $bneed = $len+2;
 880             $offset = 0;
 881
 882             while ($bneed > 0)
 883             {
 884                $data = fread($sock, $bneed);
 885                $n = strlen($data);
 886                if ($n == 0)
 887                   break;
 888                $offset += $n;
 889                $bneed -= $n;
 890                @$ret[$rkey] .= $data;
 891             }
 892
 893             if ($offset != $len+2)
 894             {
 895                // Something is borked!
 896                if ($this->_debug)
 897                   $this->_debugprint(sprintf("Something is borked!  key %s expecting %d got %d length\n", $rkey, $len+2, $offset));
 898
 899                unset($ret[$rkey]);
 900                $this->_close_sock($sock);
 901                return false;
 902             }
 903
 904             if ($this->_have_zlib && $flags & MEMCACHE_COMPRESSED)
 905                $ret[$rkey] = gzuncompress($ret[$rkey]);
 906
 907             $ret[$rkey] = rtrim($ret[$rkey]);
 908
 909             if ($flags & MEMCACHE_SERIALIZED)
 910                $ret[$rkey] = unserialize($ret[$rkey]);
 911
 912          } else
 913          {
 914             $this->_debugprint("Error parsing memcached response\n");
 915             return 0;
 916          }
 917       }
 918    }
 919
 920    // }}}
 921    // {{{ _set()
 922
 923    /**
 924     * Performs the requested storage operation to the memcache server
 925     *
 926     * @param   string   $cmd     Command to perform
 927     * @param   string   $key     Key to act on
 928     * @param   mixed    $val     What we need to store
 929     * @param   interger $exp     When it should expire
 930     *
 931     * @return  boolean
 932     * @access  private
 933     */
 934    function _set ($cmd, $key, $val, $exp)
 935    {
 936       if (!$this->_active)
 937          return false;
 938
 939       $sock = $this->get_sock($key);
 940       if (!is_resource($sock))
 941          return false;
 942
 943       @$this->stats[$cmd]++;
 944
 945       $flags = 0;
 946
 947       if (!is_scalar($val))
 948       {
 949          $val = serialize($val);
 950          $flags |= MEMCACHE_SERIALIZED;
 951          if ($this->_debug)
 952             $this->_debugprint(sprintf("client: serializing data as it is not scalar\n"));
 953       }
 954
 955       $len = strlen($val);
 956
 957       if ($this->_have_zlib && $this->_compress_enable &&
 958           $this->_compress_threshold && $len >= $this->_compress_threshold)
 959       {
 960          $c_val = gzcompress($val, 9);
 961          $c_len = strlen($c_val);
 962
 963          if ($c_len < $len*(1 - COMPRESSION_SAVINGS))
 964          {
 965             if ($this->_debug)
 966                $this->_debugprint(sprintf("client: compressing data; was %d bytes is now %d bytes\n", $len, $c_len));
 967             $val = $c_val;
 968             $len = $c_len;
 969             $flags |= MEMCACHE_COMPRESSED;
 970          }
 971       }
 972       if (!$this->_safe_fwrite($sock, "$cmd $key $flags $exp $len\r\n$val\r\n"))
 973          return $this->_dead_sock($sock);
 974
 975       $line = trim(fgets($sock));
 976
 977       if ($this->_debug)
 978       {
 979          if ($flags & MEMCACHE_COMPRESSED)
 980             $val = 'compressed data';
 981          $this->_debugprint(sprintf("MemCache: %s %s => %s (%s)\n", $cmd, $key, $val, $line));
 982       }
 983       if ($line == "STORED")
 984          return true;
 985       return false;
 986    }
 987
 988    // }}}
 989    // {{{ sock_to_host()
 990
 991    /**
 992     * Returns the socket for the host
 993     *
 994     * @param   string   $host    Host:IP to get socket for
 995     *
 996     * @return  mixed    IO Stream or false
 997     * @access  private
 998     */
 999    function sock_to_host ($host)
1000    {
1001       if (isset($this->_cache_sock[$host]))
1002          return $this->_cache_sock[$host];
1003
1004       $now = time();
1005       list ($ip, $port) = explode (":", $host);
1006       if (isset($this->_host_dead[$host]) && $this->_host_dead[$host] > $now ||
1007           isset($this->_host_dead[$ip]) && $this->_host_dead[$ip] > $now)
1008          return null;
1009
1010       if (!$this->_connect_sock($sock, $host))
1011          return $this->_dead_sock($host);
1012
1013       // Do not buffer writes
1014       stream_set_write_buffer($sock, 0);
1015
1016       $this->_cache_sock[$host] = $sock;
1017
1018       return $this->_cache_sock[$host];
1019    }
1020
1021    function _debugprint($str){
1022       print($str);
1023    }
1024
1025    /**
1026     * Write to a stream, timing out after the correct amount of time
1027     *
1028     * @return bool false on failure, true on success
1029     */
1030     /*
1031    function _safe_fwrite($f, $buf, $len = false) {
1032       stream_set_blocking($f, 0);
1033
1034       if ($len === false) {
1035          wfDebug("Writing " . strlen( $buf ) . " bytes\n");
1036          $bytesWritten = fwrite($f, $buf);
1037       } else {
1038          wfDebug("Writing $len bytes\n");
1039          $bytesWritten = fwrite($f, $buf, $len);
1040       }
1041       $n = stream_select($r=NULL, $w = array($f), $e = NULL, 10, 0);
1042       #   $this->_timeout_seconds, $this->_timeout_microseconds);
1043
1044       wfDebug("stream_select returned $n\n");
1045       stream_set_blocking($f, 1);
1046       return $n == 1;
1047       return $bytesWritten;
1048    }*/
1049
1050    /**
1051     * Original behaviour
1052     */
1053    function _safe_fwrite($f, $buf, $len = false) {
1054       if ($len === false) {
1055          $bytesWritten = fwrite($f, $buf);
1056       } else {
1057          $bytesWritten = fwrite($f, $buf, $len);
1058       }
1059       return $bytesWritten;
1060    }
1061
1062    /**
1063     * Flush the read buffer of a stream
1064     */
1065    function _flush_read_buffer($f) {
1066       if (!is_resource($f)) {
1067          return;
1068       }
1069       $n = stream_select($r=array($f), $w = NULL, $e = NULL, 0, 0);
1070       while ($n == 1 && !feof($f)) {
1071          fread($f, 1024);
1072          $n = stream_select($r=array($f), $w = NULL, $e = NULL, 0, 0);
1073       }
1074    }
1075
1076    // }}}
1077    // }}}
1078    // }}}
1079 }
1080
1081 // vim: sts=3 sw=3 et
1082
1083 // }}}
1084 ?>