src/Core/Cache/TraitMemcacheCommand.php

   1 <?php
   2
   3 namespace Friendica\Core\Cache;
   4
   5 use Friendica\Network\HTTPException\InternalServerErrorException;
   6
   7 /**
   8  * Trait for Memcache to add a custom version of the
   9  * method getAllKeys() since this isn't working anymore
  10  *
  11  * Adds the possibility to directly communicate with the memcache too
  12  */
  13 trait TraitMemcacheCommand
  14 {
  15         /**
  16          * @var string server address
  17          */
  18         protected $server;
  19
  20         /**
  21          * @var int server port
  22          */
  23         protected $port;
  24
  25         /**
  26          * Retrieves the stored keys of the memcache instance
  27          * Uses custom commands, which aren't bound to the used instance of the class
  28          *
  29          * @todo Due the fact that we use a custom command, there are race conditions possible:
  30          *       - $this->memcache(d) adds a key
  31          *       - $this->getMemcacheKeys is called directly "after"
  32          *       - But $this->memcache(d) isn't finished adding the key, so getMemcacheKeys doesn't find it
  33          *
  34          * @return array All keys of the memcache instance
  35          *
  36          * @throws InternalServerErrorException
  37          */
  38         protected function getMemcacheKeys()
  39         {
  40                 $string = $this->sendMemcacheCommand("stats items");
  41                 $lines  = explode("\r\n", $string);
  42                 $slabs  = [];
  43                 $keys   = [];
  44
  45                 foreach ($lines as $line) {
  46
  47                         if (preg_match("/STAT items:([\d]+):number ([\d]+)/", $line, $matches)) {
  48
  49                                 if (isset($matches[1])) {
  50                                         if (!in_array($matches[1], $keys)) {
  51                                                 $slabs[] = $matches[1];
  52                                                 $string  = $this->sendMemcacheCommand("stats cachedump " . $matches[1] . " " . $matches[2]);
  53                                                 preg_match_all("/ITEM (.*?) /", $string, $matches);
  54                                                 $keys = array_merge($keys, $matches[1]);
  55                                         }
  56                                 }
  57                         }
  58                 }
  59
  60                 return $keys;
  61         }
  62
  63         /**
  64          * Taken directly from memcache PECL source
  65          * Sends a command to the memcache instance and returns the result
  66          * as a string
  67          *
  68          * http://pecl.php.net/package/memcache
  69          *
  70          * @param string $command The command to send to the Memcache server
  71          *
  72          * @return string The returned buffer result
  73          *
  74          * @throws InternalServerErrorException In case the memcache server isn't available (anymore)
  75          */
  76         protected function sendMemcacheCommand(string $command)
  77         {
  78                 $s = @fsockopen($this->server, $this->port);
  79                 if (!$s) {
  80                         throw new InternalServerErrorException("Cant connect to:" . $this->server . ':' . $this->port);
  81                 }
  82
  83                 fwrite($s, $command . "\r\n");
  84                 $buf = '';
  85
  86                 while ((!feof($s))) {
  87
  88                         $buf .= fgets($s, 256);
  89
  90                         if (strpos($buf, "END\r\n") !== false) { // stat says end
  91                                 break;
  92                         }
  93
  94                         if (strpos($buf, "DELETED\r\n") !== false || strpos($buf, "NOT_FOUND\r\n") !== false) { // delete says these
  95                                 break;
  96                         }
  97
  98                         if (strpos($buf, "OK\r\n") !== false) { // flush_all says ok
  99                                 break;
 100                         }
 101                 }
 102
 103                 fclose($s);
 104                 return ($buf);
 105         }
 106 }