Interface for database access objects. More...
|const||READ_LOCKING = 3|
|Constants for object loading bitfield flags (higher => higher QoS) More...|
|const||READ_NONE = -1|
Interface for database access objects.
Classes using this support a set of constants in a bitfield argument to their data loading functions. In general, objects should assume READ_NORMAL if no flags are explicitly given, though certain objects may assume READ_LATEST for common use case or legacy reasons.
There are four types of reads:
A special constant READ_LATEST_IMMUTABLE can be used for fetching append-only data. Such data is either (a) on a replica DB and up-to-date or (b) not yet there, but on the master/quorum. Because the data is append-only, it can never be stale on a replica DB if present.
Callers should use READ_NORMAL (or pass in no flags) unless the read determines a write. In theory, such cases may require READ_LOCKING, though to avoid contention, READ_LATEST is often good enough. If UPDATE race condition checks are required on a row and expensive code must run after the row is fetched to determine the UPDATE, it may help to do something like:
|const IDBAccessObject::READ_LOCKING = 3|
Constants for object loading bitfield flags (higher => higher QoS)
Referenced by MediaWiki\Auth\AuthManager\beginAccountCreation(), MediaWiki\Auth\AuthManager\continueAccountCreation(), WikiPage\loadLastEdit(), MovePage\moveToInternal(), and MediaWiki\Auth\LegacyHookPreAuthenticationProviderTest\testTestUserForCreation().