MediaWiki  REL1_31
DBAccessObjectUtils.php
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1 <?php
35  public static function hasFlags( $bitfield, $flags ) {
36  return ( $bitfield & $flags ) == $flags;
37  }
38 
52  public static function getDBOptions( $bitfield ) {
53  if ( self::hasFlags( $bitfield, self::READ_LATEST_IMMUTABLE ) ) {
54  $index = DB_REPLICA; // override READ_LATEST if set
55  $fallbackIndex = DB_MASTER;
56  } elseif ( self::hasFlags( $bitfield, self::READ_LATEST ) ) {
57  $index = DB_MASTER;
58  $fallbackIndex = null;
59  } else {
60  $index = DB_REPLICA;
61  $fallbackIndex = null;
62  }
63 
64  $lockingOptions = [];
65  if ( self::hasFlags( $bitfield, self::READ_EXCLUSIVE ) ) {
66  $lockingOptions[] = 'FOR UPDATE';
67  } elseif ( self::hasFlags( $bitfield, self::READ_LOCKING ) ) {
68  $lockingOptions[] = 'LOCK IN SHARE MODE';
69  }
70 
71  if ( $fallbackIndex !== null ) {
72  $options = []; // locks on DB_REPLICA make no sense
73  $fallbackOptions = $lockingOptions;
74  } else {
75  $options = $lockingOptions;
76  $fallbackOptions = []; // no fallback
77  }
78 
79  return [ $index, $options, $fallbackIndex, $fallbackOptions ];
80  }
81 }
DBAccessObjectUtils\getDBOptions
static getDBOptions( $bitfield)
Get an appropriate DB index, options, and fallback DB index for a query.
Definition: DBAccessObjectUtils.php:52
IDBAccessObject
Interface for database access objects.
Definition: IDBAccessObject.php:55
php
injection txt This is an overview of how MediaWiki makes use of dependency injection The design described here grew from the discussion of RFC T384 The term dependency this means that anything an object needs to operate should be injected from the the object itself should only know narrow no concrete implementation of the logic it relies on The requirement to inject everything typically results in an architecture that based on two main types of and essentially stateless service objects that use other service objects to operate on the value objects As of the beginning MediaWiki is only starting to use the DI approach Much of the code still relies on global state or direct resulting in a highly cyclical dependency which acts as the top level factory for services in MediaWiki which can be used to gain access to default instances of various services MediaWikiServices however also allows new services to be defined and default services to be redefined Services are defined or redefined by providing a callback the instantiator that will return a new instance of the service When it will create an instance of MediaWikiServices and populate it with the services defined in the files listed by thereby bootstrapping the DI framework Per $wgServiceWiringFiles lists includes ServiceWiring php
Definition: injection.txt:37
DB_REPLICA
const DB_REPLICA
Definition: defines.php:25
DB_MASTER
const DB_MASTER
Definition: defines.php:29
DBAccessObjectUtils
Helper class for DAO classes.
Definition: DBAccessObjectUtils.php:29
$options
null means default in associative array with keys and values unescaped Should be merged with default with a value of false meaning to suppress the attribute in associative array with keys and values unescaped & $options
Definition: hooks.txt:2001
DBAccessObjectUtils\hasFlags
static hasFlags( $bitfield, $flags)
Definition: DBAccessObjectUtils.php:35