includes/libs/rdbms/connectionmanager/ConnectionManager.php

   1 <?php
   2
   3 namespace Wikimedia\Rdbms;
   4
   5 use InvalidArgumentException;
   6
   7 /**
   8  * Database connection manager.
   9  *
  10  * This manages access to master and replica databases.
  11  *
  12  * @since 1.29
  13  *
  14  * @license GPL-2.0+
  15  * @author Addshore
  16  */
  17 class ConnectionManager {
  18
  19         /**
  20          * @var LoadBalancer
  21          */
  22         private $loadBalancer;
  23
  24         /**
  25          * The symbolic name of the target database, or false for the local wiki's database.
  26          *
  27          * @var string|false
  28          */
  29         private $domain;
  30
  31         /**
  32          * @var string[]
  33          */
  34         private $groups = [];
  35
  36         /**
  37          * @param LoadBalancer $loadBalancer
  38          * @param string|bool $domain Optional logical DB name, defaults to current wiki.
  39          *        This follows the convention for database names used by $loadBalancer.
  40          * @param string[] $groups see LoadBalancer::getConnection
  41          *
  42          * @throws InvalidArgumentException
  43          */
  44         public function __construct( LoadBalancer $loadBalancer, $domain = false, array $groups = [] ) {
  45                 if ( !is_string( $domain ) && $domain !== false ) {
  46                         throw new InvalidArgumentException( '$dbName must be a string, or false.' );
  47                 }
  48
  49                 $this->loadBalancer = $loadBalancer;
  50                 $this->domain = $domain;
  51                 $this->groups = $groups;
  52         }
  53
  54         /**
  55          * @param int $i
  56          * @param string[]|null $groups
  57          *
  58          * @return Database
  59          */
  60         private function getConnection( $i, array $groups = null ) {
  61                 $groups = $groups === null ? $this->groups : $groups;
  62                 return $this->loadBalancer->getConnection( $i, $groups, $this->domain );
  63         }
  64
  65         /**
  66          * @param int $i
  67          * @param string[]|null $groups
  68          *
  69          * @return DBConnRef
  70          */
  71         private function getConnectionRef( $i, array $groups = null ) {
  72                 $groups = $groups === null ? $this->groups : $groups;
  73                 return $this->loadBalancer->getConnectionRef( $i, $groups, $this->domain );
  74         }
  75
  76         /**
  77          * Returns a connection to the master DB, for updating. The connection should later be released
  78          * by calling releaseConnection().
  79          *
  80          * @since 1.29
  81          *
  82          * @return Database
  83          */
  84         public function getWriteConnection() {
  85                 return $this->getConnection( DB_MASTER );
  86         }
  87
  88         /**
  89          * Returns a database connection for reading. The connection should later be released by
  90          * calling releaseConnection().
  91          *
  92          * @since 1.29
  93          *
  94          * @param string[]|null $groups
  95          *
  96          * @return Database
  97          */
  98         public function getReadConnection( array $groups = null ) {
  99                 $groups = $groups === null ? $this->groups : $groups;
 100                 return $this->getConnection( DB_REPLICA, $groups );
 101         }
 102
 103         /**
 104          * @since 1.29
 105          *
 106          * @param IDatabase $db
 107          */
 108         public function releaseConnection( IDatabase $db ) {
 109                 $this->loadBalancer->reuseConnection( $db );
 110         }
 111
 112         /**
 113          * Returns a connection ref to the master DB, for updating.
 114          *
 115          * @since 1.29
 116          *
 117          * @return DBConnRef
 118          */
 119         public function getWriteConnectionRef() {
 120                 return $this->getConnectionRef( DB_MASTER );
 121         }
 122
 123         /**
 124          * Returns a database connection ref for reading.
 125          *
 126          * @since 1.29
 127          *
 128          * @param string[]|null $groups
 129          *
 130          * @return DBConnRef
 131          */
 132         public function getReadConnectionRef( array $groups = null ) {
 133                 $groups = $groups === null ? $this->groups : $groups;
 134                 return $this->getConnectionRef( DB_REPLICA, $groups );
 135         }
 136
 137 }