DBLockManager Class Reference

Version of LockManager based on using named/row DB locks. More...

Inheritance diagram for DBLockManager:

Collaboration diagram for DBLockManager:

List of all members.

Public Member Functions
	__construct (array $config)
	Construct a new instance from configuration.
	__destruct ()
	Make sure remaining locks get cleared for sanity.
Protected Member Functions
	cacheCheckFailures ($lockDb)
	Checks if the DB has not recently had connection/query errors.
	cacheRecordFailure ($lockDb)
	Log a lock request failure to the cache.
	freeLocksOnServer ($lockSrv, array $pathsByType)
	Get a connection to a lock server and release locks on $paths.
	getConnection ($lockDb)
	Get (or reuse) a connection to a lock DB.
	getLocksOnServer ($lockSrv, array $pathsByType)
	Get a connection to a lock server and acquire locks.
	getMissKey ($lockDb)
	Get a cache key for recent query misses for a DB.
	initConnection ($lockDb, DatabaseBase $db)
	Do additional initialization for new lock DB connection.
	isServerUp ($lockSrv)
Protected Attributes
Array	$conns = array()
	Map Database connections (DB name => Database) *.
Array	$dbServers
	Map of DB names to server config *.
	$lockExpiry
	$safeDelay
	$session = 0
BagOStuff	$statusCache
	*

---

Detailed Description

Version of LockManager based on using named/row DB locks.

This is meant for multi-wiki systems that may share files.

All lock requests for a resource, identified by a hash string, will map to one bucket. Each bucket maps to one or several peer DBs, each on their own server, all having the filelocks.sql tables (with row-level locking). A majority of peer DBs must agree for a lock to be acquired.

Caching is used to avoid hitting servers that are down.

Since:

1.19

Definition at line 39 of file DBLockManager.php.

---

Constructor & Destructor Documentation

DBLockManager::__construct

(

array $

config

)

Construct a new instance from configuration.

$config paramaters include:

• dbServers : Associative array of DB names to server configuration. Configuration is an associative array that includes:
  • host : DB server name
  • dbname : DB name
  • type : DB type (mysql,postgres,...)
  • user : DB user
  • password : DB user password
  • tablePrefix : DB table prefix
  • flags : DB flags (see DatabaseBase)
• dbsByBucket : Array of 1-16 consecutive integer keys, starting from 0, each having an odd-numbered list of DB names (peers) as values. Any DB named 'localDBMaster' will automatically use the DB master settings for this wiki (without the need for a dbServers entry). Only use 'localDBMaster' if the domain is a valid wiki ID.
• lockExpiry : Lock timeout (seconds) for dropped connections. [optional] This tells the DB server how long to wait before assuming connection failure and releasing all the locks for a session.

Parameters:

array

$config

Reimplemented from LockManager.

Definition at line 73 of file DBLockManager.php.

DBLockManager::__destruct

(

)

Make sure remaining locks get cleared for sanity.

Definition at line 227 of file DBLockManager.php.

---

Member Function Documentation

DBLockManager::cacheCheckFailures

(

$

lockDb

)

[protected]

Checks if the DB has not recently had connection/query errors.

This just avoids wasting time on doomed connection attempts.

Parameters:

$lockDb

string

Returns:

bool

Definition at line 195 of file DBLockManager.php.

DBLockManager::cacheRecordFailure

(

$

lockDb

)

[protected]

Log a lock request failure to the cache.

Parameters:

$lockDb

string

Returns:

bool Success

Definition at line 207 of file DBLockManager.php.

DBLockManager::freeLocksOnServer	(	$	lockSrv,
		array $	pathsByType
	)		[protected]

Get a connection to a lock server and release locks on $paths.

Subclasses must effectively implement this or releaseAllLocks().

Parameters:

	$lockSrv	string
array	$pathsByType	Map of LockManager::LOCK_* constants to lists of paths

Returns:

Status

Reimplemented from QuorumLockManager.

Definition at line 119 of file DBLockManager.php.

DBLockManager::getConnection

(

$

lockDb

)

[protected]

Get (or reuse) a connection to a lock DB.

Parameters:

$lockDb

string

Returns:

DatabaseBase

Exceptions:

DBError

Definition at line 147 of file DBLockManager.php.

DBLockManager::getLocksOnServer	(	$	lockSrv,
		array $	pathsByType
	)		[protected]

Get a connection to a lock server and acquire locks.

Parameters:

	$lockSrv	string
array	$pathsByType	Map of LockManager::LOCK_* constants to lists of paths

Returns:

Status

Reimplemented from QuorumLockManager.

Definition at line 111 of file DBLockManager.php.

DBLockManager::getMissKey

(

$

lockDb

)

[protected]

Get a cache key for recent query misses for a DB.

Parameters:

$lockDb

string

Returns:

string

Definition at line 219 of file DBLockManager.php.

DBLockManager::initConnection	(	$	lockDb,
		DatabaseBase $	db
	)		[protected]

Do additional initialization for new lock DB connection.

Parameters:

$lockDb	string
$db	DatabaseBase

Returns:

void

Exceptions:

DBError

Reimplemented in MySqlLockManager.

Definition at line 186 of file DBLockManager.php.

DBLockManager::isServerUp

(

$

lockSrv

)

[protected]

See also:

QuorumLockManager::isServerUp()

Returns:

bool

Reimplemented from QuorumLockManager.

Definition at line 127 of file DBLockManager.php.

---

Member Data Documentation

Array DBLockManager::$conns = array() [protected]

Map Database connections (DB name => Database) *.

Definition at line 47 of file DBLockManager.php.

Array DBLockManager::$dbServers [protected]

Map of DB names to server config *.

Definition at line 40 of file DBLockManager.php.

DBLockManager::$lockExpiry [protected]

Definition at line 43 of file DBLockManager.php.

DBLockManager::$safeDelay [protected]

Definition at line 44 of file DBLockManager.php.

DBLockManager::$session = 0 [protected]

Definition at line 46 of file DBLockManager.php.

BagOStuff DBLockManager::$statusCache [protected]

*

Definition at line 41 of file DBLockManager.php.

---

The documentation for this class was generated from the following file:

• includes/filebackend/lockmanager/DBLockManager.php