MediaWiki  1.33.0
ReplicatedBagOStuff Class Reference

A cache class that directs writes to one set of servers and reads to another. More...

Inheritance diagram for ReplicatedBagOStuff:
Collaboration diagram for ReplicatedBagOStuff:

Public Member Functions

 __construct ( $params)
 Constructor. More...
 
 add ( $key, $value, $exptime=0, $flags=0)
 Insert an item if it does not already exist. More...
 
 changeTTL ( $key, $exptime=0, $flags=0)
 Change the expiration on a key if it exists. More...
 
 clearLastError ()
 Clear the "last error" registry. More...
 
 decr ( $key, $value=1)
 Decrease stored value of $key by $value while preserving its TTL. More...
 
 delete ( $key, $flags=0)
 Delete an item. More...
 
 deleteMulti (array $keys, $flags=0)
 Batch deletion. More...
 
 deleteObjectsExpiringBefore ( $date, $progressCallback=false)
 Delete all objects expiring before a certain date. More...
 
 get ( $key, $flags=0)
 Get an item with the given key. More...
 
 getLastError ()
 Get the "last error" registered; clearLastError() should be called manually. More...
 
 getMulti (array $keys, $flags=0)
 Get an associative array containing the item for each of the keys that have items. More...
 
 incr ( $key, $value=1)
 Increase stored value of $key by $value while preserving its TTL. More...
 
 incrWithInit ( $key, $ttl, $value=1, $init=1)
 Increase stored value of $key by $value while preserving its TTL. More...
 
 lock ( $key, $timeout=6, $expiry=6, $rclass='')
 Acquire an advisory lock on a key string. More...
 
 makeGlobalKey ( $class, $component=null)
 Make a global cache key. More...
 
 makeKey ( $class, $component=null)
 Make a cache key, scoped to this instance's keyspace. More...
 
 makeKeyInternal ( $keyspace, $args)
 Construct a cache key. More...
 
 merge ( $key, callable $callback, $exptime=0, $attempts=10, $flags=0)
 Merge changes into the existing cache value (possibly creating a new one) More...
 
 set ( $key, $value, $exptime=0, $flags=0)
 Set an item. More...
 
 setDebug ( $debug)
 
 setMulti (array $data, $exptime=0, $flags=0)
 Batch insertion/replace. More...
 
 unlock ( $key)
 Release an advisory lock on a key string. More...
 
- Public Member Functions inherited from BagOStuff
 __construct (array $params=[])
 $params include: More...
 
 addBusyCallback (callable $workCallback)
 Let a callback be run to avoid wasting time on special blocking calls. More...
 
 getQoS ( $flag)
 
 getScopedLock ( $key, $timeout=6, $expiry=30, $rclass='')
 Get a lightweight exclusive self-unlocking lock. More...
 
 getWithSetCallback ( $key, $ttl, $callback, $flags=0)
 Get an item with the given key, regenerating and setting it if not found. More...
 
 setLogger (LoggerInterface $logger)
 
 setMockTime (&$time)
 

Protected Member Functions

 doGet ( $key, $flags=0, &$casToken=null)
 
- Protected Member Functions inherited from BagOStuff
 cas ( $casToken, $key, $value, $exptime=0, $flags=0)
 Check and set an item. More...
 
 convertToExpiry ( $exptime)
 Convert an optionally relative time to an absolute time. More...
 
 convertToRelative ( $exptime)
 Convert an optionally absolute expiry time to a relative time. More...
 
 debug ( $text)
 
 expiryIsRelative ( $exptime)
 
 getCurrentTime ()
 
 isInteger ( $value)
 Check if a value is an integer. More...
 
 mergeFlagMaps (array $bags)
 Merge the flag maps of one or more BagOStuff objects into a "lowest common denominator" map. More...
 
 mergeViaCas ( $key, $callback, $exptime=0, $attempts=10, $flags=0)
 
 setLastError ( $err)
 Set the "last error" registry. More...
 

Protected Attributes

BagOStuff $readStore
 
BagOStuff $writeStore
 
- Protected Attributes inherited from BagOStuff
callable null $asyncHandler
 
int[] $attrMap = []
 Map of (ATTR_* class constant => QOS_* class constant) More...
 
callable[] $busyCallbacks = []
 
string $keyspace = 'local'
 
int $lastError = self::ERR_NONE
 ERR_* class constant. More...
 
array[] $locks = []
 Lock tracking. More...
 
LoggerInterface $logger
 
int $syncTimeout
 Seconds. More...
 

Additional Inherited Members

- Public Attributes inherited from BagOStuff
const READ_LATEST = 1
 Bitfield constants for get()/getMulti() More...
 
const READ_VERIFIED = 2
 
const WRITE_CACHE_ONLY = 8
 
const WRITE_SYNC = 4
 Bitfield constants for set()/merge() More...
 
- Public Attributes inherited from IExpiringStore
const ATTR_EMULATION = 1
 
const ATTR_SYNCWRITES = 2
 
const ERR_NO_RESPONSE = 1
 
const ERR_NONE = 0
 
const ERR_UNEXPECTED = 3
 
const ERR_UNREACHABLE = 2
 
const QOS_EMULATION_SQL = 1
 
const QOS_SYNCWRITES_BE = 2
 
const QOS_SYNCWRITES_NONE = 1
 
const QOS_SYNCWRITES_QC = 3
 
const QOS_SYNCWRITES_SS = 4
 
const QOS_UNKNOWN = INF
 
const TTL_DAY = 86400
 
const TTL_HOUR = 3600
 
const TTL_INDEFINITE = 0
 
const TTL_MINUTE = 60
 
const TTL_MONTH = 2592000
 
const TTL_PROC_LONG = 30
 
const TTL_PROC_SHORT = 3
 
const TTL_SECOND = 1
 
const TTL_WEEK = 604800
 
const TTL_YEAR = 31536000
 

Detailed Description

A cache class that directs writes to one set of servers and reads to another.

This assumes that the servers used for reads are setup to replica DB those that writes go to. This can easily be used with redis for example.

In the WAN scenario (e.g. multi-datacenter case), this is useful when writes are rare or they usually take place in the primary datacenter.

Since
1.26

Definition at line 34 of file ReplicatedBagOStuff.php.

Constructor & Destructor Documentation

◆ __construct()

ReplicatedBagOStuff::__construct (   $params)

Constructor.

Parameters are:

  • writeFactory : ObjectFactory::getObjectFromSpec array yeilding BagOStuff. This object will be used for writes (e.g. the master DB).
  • readFactory : ObjectFactory::getObjectFromSpec array yeilding BagOStuff. This object will be used for reads (e.g. a replica DB).
Parameters
array$params
Exceptions
InvalidArgumentException

Definition at line 50 of file ReplicatedBagOStuff.php.

References $params, false, and BagOStuff\mergeFlagMaps().

Member Function Documentation

◆ add()

ReplicatedBagOStuff::add (   $key,
  $value,
  $exptime = 0,
  $flags = 0 
)

Insert an item if it does not already exist.

Parameters
string$key
mixed$value
int$exptime
int$flagsBitfield of BagOStuff::WRITE_* constants (since 1.33)
Returns
bool Success

Reimplemented from BagOStuff.

Definition at line 91 of file ReplicatedBagOStuff.php.

References $value.

◆ changeTTL()

ReplicatedBagOStuff::changeTTL (   $key,
  $expiry = 0,
  $flags = 0 
)

Change the expiration on a key if it exists.

If an expiry in the past is given then the key will immediately be expired

Parameters
string$key
int$expiryTTL or UNIX timestamp
int$flagsBitfield of BagOStuff::WRITE_* constants (since 1.33)
Returns
bool Success Returns false on failure or if the item does not exist
Since
1.28

Reimplemented from BagOStuff.

Definition at line 99 of file ReplicatedBagOStuff.php.

◆ clearLastError()

ReplicatedBagOStuff::clearLastError ( )

Clear the "last error" registry.

Since
1.23

Reimplemented from BagOStuff.

Definition at line 147 of file ReplicatedBagOStuff.php.

◆ decr()

ReplicatedBagOStuff::decr (   $key,
  $value = 1 
)

Decrease stored value of $key by $value while preserving its TTL.

Parameters
string$key
int$valueValue to subtract from $key (default: 1) [optional]
Returns
int|bool New value or false on failure

Reimplemented from BagOStuff.

Definition at line 133 of file ReplicatedBagOStuff.php.

References $value.

◆ delete()

ReplicatedBagOStuff::delete (   $key,
  $flags = 0 
)

Delete an item.

Parameters
string$key
Returns
bool True if the item was deleted or not found, false on failure
Parameters
int$flagsBitfield of BagOStuff::WRITE_* constants

Reimplemented from BagOStuff.

Definition at line 87 of file ReplicatedBagOStuff.php.

◆ deleteMulti()

ReplicatedBagOStuff::deleteMulti ( array  $keys,
  $flags = 0 
)

Batch deletion.

Parameters
string[]$keysList of keys
int$flagsBitfield of BagOStuff::WRITE_* constants
Returns
bool Success
Since
1.33

Reimplemented from BagOStuff.

Definition at line 125 of file ReplicatedBagOStuff.php.

References $keys.

◆ deleteObjectsExpiringBefore()

ReplicatedBagOStuff::deleteObjectsExpiringBefore (   $date,
  $progressCallback = false 
)

Delete all objects expiring before a certain date.

Parameters
string$dateThe reference date in MW format
callable | bool$progressCallbackOptional, a function which will be called regularly during long-running operations with the percentage progress as the first parameter.
Returns
bool Success, false if unimplemented

Reimplemented from BagOStuff.

Definition at line 111 of file ReplicatedBagOStuff.php.

◆ doGet()

ReplicatedBagOStuff::doGet (   $key,
  $flags = 0,
$casToken = null 
)
protected
Parameters
string$key
int$flagsBitfield of BagOStuff::READ_* constants [optional]
mixed | null&$casTokenToken to use for check-and-set comparisons
Returns
mixed Returns false on failure or if the item does not exist

Reimplemented from BagOStuff.

Definition at line 164 of file ReplicatedBagOStuff.php.

◆ get()

ReplicatedBagOStuff::get (   $key,
  $flags = 0 
)

Get an item with the given key.

If the key includes a deterministic input hash (e.g. the key can only have the correct value) or complete staleness checks are handled by the caller (e.g. nothing relies on the TTL), then the READ_VERIFIED flag should be set. This lets tiered backends know they can safely upgrade a cached value to higher tiers using standard TTLs.

Parameters
string$key
int$flagsBitfield of BagOStuff::READ_* constants [optional]
Returns
mixed Returns false on failure or if the item does not exist

Reimplemented from BagOStuff.

Definition at line 77 of file ReplicatedBagOStuff.php.

◆ getLastError()

ReplicatedBagOStuff::getLastError ( )

Get the "last error" registered; clearLastError() should be called manually.

Returns
int ERR_* constant for the "last error" registry
Since
1.23

Reimplemented from BagOStuff.

Definition at line 141 of file ReplicatedBagOStuff.php.

References IExpiringStore\ERR_NONE.

◆ getMulti()

ReplicatedBagOStuff::getMulti ( array  $keys,
  $flags = 0 
)

Get an associative array containing the item for each of the keys that have items.

Parameters
string[]$keysList of keys
int$flagsBitfield; supports READ_LATEST [optional]
Returns
array

Reimplemented from BagOStuff.

Definition at line 115 of file ReplicatedBagOStuff.php.

References $keys.

◆ incr()

ReplicatedBagOStuff::incr (   $key,
  $value = 1 
)

Increase stored value of $key by $value while preserving its TTL.

Parameters
string$keyKey to increase
int$valueValue to add to $key (default: 1) [optional]
Returns
int|bool New value or false on failure

Reimplemented from BagOStuff.

Definition at line 129 of file ReplicatedBagOStuff.php.

References $value.

◆ incrWithInit()

ReplicatedBagOStuff::incrWithInit (   $key,
  $ttl,
  $value = 1,
  $init = 1 
)

Increase stored value of $key by $value while preserving its TTL.

This will create the key with value $init and TTL $ttl instead if not present

Parameters
string$key
int$ttl
int$value
int$init
Returns
int|bool New value or false on failure
Since
1.24

Reimplemented from BagOStuff.

Definition at line 137 of file ReplicatedBagOStuff.php.

References $value.

◆ lock()

ReplicatedBagOStuff::lock (   $key,
  $timeout = 6,
  $expiry = 6,
  $rclass = '' 
)

Acquire an advisory lock on a key string.

Note that if reentry is enabled, duplicate calls ignore $expiry

Parameters
string$key
int$timeoutLock wait timeout; 0 for non-blocking [optional]
int$expiryLock expiry [optional]; 1 day maximum
string$rclassAllow reentry if set and the current lock used this value
Returns
bool Success

Reimplemented from BagOStuff.

Definition at line 103 of file ReplicatedBagOStuff.php.

◆ makeGlobalKey()

ReplicatedBagOStuff::makeGlobalKey (   $class,
  $component = null 
)

Make a global cache key.

Since
1.27
Parameters
string$classKey class
string | null$component[optional] Key component (starting with a key collection name)
Returns
string Colon-delimited list of $keyspace followed by escaped components of $args

Reimplemented from BagOStuff.

Definition at line 160 of file ReplicatedBagOStuff.php.

◆ makeKey()

ReplicatedBagOStuff::makeKey (   $class,
  $component = null 
)

Make a cache key, scoped to this instance's keyspace.

Since
1.27
Parameters
string$classKey class
string | null$component[optional] Key component (starting with a key collection name)
Returns
string Colon-delimited list of $keyspace followed by escaped components of $args

Reimplemented from BagOStuff.

Definition at line 156 of file ReplicatedBagOStuff.php.

◆ makeKeyInternal()

ReplicatedBagOStuff::makeKeyInternal (   $keyspace,
  $args 
)

Construct a cache key.

Since
1.27
Parameters
string$keyspace
array$args
Returns
string Colon-delimited list of $keyspace followed by escaped components of $args

Reimplemented from BagOStuff.

Definition at line 152 of file ReplicatedBagOStuff.php.

◆ merge()

ReplicatedBagOStuff::merge (   $key,
callable  $callback,
  $exptime = 0,
  $attempts = 10,
  $flags = 0 
)

Merge changes into the existing cache value (possibly creating a new one)

The callback function returns the new value given the current value (which will be false if not present), and takes the arguments: (this BagOStuff, cache key, current value, TTL). The TTL parameter is reference set to $exptime. It can be overriden in the callback. Nothing is stored nor deleted if the callback returns false.

Parameters
string$key
callable$callbackCallback method to be executed
int$exptimeEither an interval in seconds or a unix timestamp for expiry
int$attemptsThe amount of times to attempt a merge in case of failure
int$flagsBitfield of BagOStuff::WRITE_* constants
Returns
bool Success
Exceptions
InvalidArgumentException

Reimplemented from BagOStuff.

Definition at line 95 of file ReplicatedBagOStuff.php.

◆ set()

ReplicatedBagOStuff::set (   $key,
  $value,
  $exptime = 0,
  $flags = 0 
)

Set an item.

Parameters
string$key
mixed$value
int$exptimeEither an interval in seconds or a unix timestamp for expiry
int$flagsBitfield of BagOStuff::WRITE_* constants
Returns
bool Success

Reimplemented from BagOStuff.

Definition at line 83 of file ReplicatedBagOStuff.php.

References $value.

◆ setDebug()

ReplicatedBagOStuff::setDebug (   $bool)
Parameters
bool$bool

Reimplemented from BagOStuff.

Definition at line 72 of file ReplicatedBagOStuff.php.

References $debug.

◆ setMulti()

ReplicatedBagOStuff::setMulti ( array  $data,
  $exptime = 0,
  $flags = 0 
)

Batch insertion/replace.

Parameters
mixed[]$dataMap of (key => value)
int$exptimeEither an interval in seconds or a unix timestamp for expiry
int$flagsBitfield of BagOStuff::WRITE_* constants (since 1.33)
Returns
bool Success
Since
1.24

Reimplemented from BagOStuff.

Definition at line 121 of file ReplicatedBagOStuff.php.

References $data.

◆ unlock()

ReplicatedBagOStuff::unlock (   $key)

Release an advisory lock on a key string.

Parameters
string$key
Returns
bool Success

Reimplemented from BagOStuff.

Definition at line 107 of file ReplicatedBagOStuff.php.

Member Data Documentation

◆ $readStore

BagOStuff ReplicatedBagOStuff::$readStore
protected

Definition at line 38 of file ReplicatedBagOStuff.php.

◆ $writeStore

BagOStuff ReplicatedBagOStuff::$writeStore
protected

Definition at line 36 of file ReplicatedBagOStuff.php.


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