MediaWiki REL1_37
Public Member Functions | Protected Member Functions | Protected Attributes | List of all members
MemcachedBagOStuff Class Reference
Cache

Base class for memcached clients. More...

Inheritance diagram for MemcachedBagOStuff:
Inheritance graph
[legend]
Collaboration diagram for MemcachedBagOStuff:
Collaboration graph
[legend]

Public Member Functions

 __construct (array $params)
 
 makeKeyInternal ( $keyspace, $components)
 Construct a cache key.
 
 validateKeyEncoding ( $key)
 Ensure that a key is safe to use (contains no control characters and no characters above the ASCII range.)
 
- Public Member Functions inherited from MediumSpecificBagOStuff
 add ( $key, $value, $exptime=0, $flags=0)
 Insert an item if it does not already exist.
 
 addBusyCallback (callable $workCallback)
 Let a callback be run to avoid wasting time on special blocking calls.
 
 changeTTL ( $key, $exptime=0, $flags=0)
 Change the expiration on a key if it exists.
 
 changeTTLMulti (array $keys, $exptime, $flags=0)
 Change the expiration of multiple keys that exist.
 
 clearLastError ()
 Clear the "last error" registry.
 
 delete ( $key, $flags=0)
 Delete an item.
 
 deleteMulti (array $keys, $flags=0)
 Batch deletion.
 
 deleteObjectsExpiringBefore ( $timestamp, callable $progress=null, $limit=INF, string $tag=null)
 Delete all objects expiring before a certain date.
 
 get ( $key, $flags=0)
 Get an item with the given key.
 
 getLastError ()
 Get the "last error" registered; clearLastError() should be called manually.
 
 getMulti (array $keys, $flags=0)
 Get an associative array containing the item for each of the keys that have items.
 
 getQoS ( $flag)
 
 getSegmentationSize ()
 
 getSegmentedValueMaxSize ()
 
 incrWithInit ( $key, $exptime, $value=1, $init=null, $flags=0)
 Increase the value of the given key (no TTL change) if it exists or create it otherwise.
 
 lock ( $key, $timeout=6, $exptime=6, $rclass='')
 
 makeGlobalKey ( $collection,... $components)
 Make a cache key for the default keyspace and given components.
 
 makeKey ( $collection,... $components)
 Make a cache key for the global keyspace and given components.
 
 merge ( $key, callable $callback, $exptime=0, $attempts=10, $flags=0)
 Merge changes into the existing cache value (possibly creating a new one)
 
 set ( $key, $value, $exptime=0, $flags=0)
 Set an item.
 
 setMulti (array $valueByKey, $exptime=0, $flags=0)
 Batch insertion/replace.
 
 setNewPreparedValues (array $valueByKey)
 Make a "generic" reversible cache key from the given components.
 
 unlock ( $key)
 Release an advisory lock on a key string.
 
- Public Member Functions inherited from BagOStuff
 decr ( $key, $value=1, $flags=0)
 Decrease stored value of $key by $value while preserving its TTL.
 
 getCurrentTime ()
 
 getLogger ()
 
 getScopedLock ( $key, $timeout=6, $expiry=30, $rclass='')
 Get a lightweight exclusive self-unlocking lock.
 
 getWithSetCallback ( $key, $exptime, $callback, $flags=0)
 Get an item with the given key, regenerating and setting it if not found.
 
 incr ( $key, $value=1, $flags=0)
 Increase stored value of $key by $value while preserving its TTL.
 
 isKeyGlobal ( $key)
 Check whether a cache key is in the global keyspace.
 
 registerWrapperInfoForStats (string $prefixComponent, string $statsGroup, callable $collectionCallback)
 Register info about a caching layer class that uses BagOStuff as a backing store.
 
 setDebug ( $enabled)
 
 setLogger (LoggerInterface $logger)
 
 setMockTime (&$time)
 

Protected Member Functions

 fixExpiry ( $exptime)
 
 stripRouteFromKey ( $key)
 
 validateKeyAndPrependRoute ( $key)
 
- Protected Member Functions inherited from MediumSpecificBagOStuff
 cas ( $casToken, $key, $value, $exptime=0, $flags=0)
 Check and set an item.
 
 convertGenericKey ( $key)
 Convert a "generic" reversible cache key into one for this cache.
 
 debug ( $text)
 
 doAdd ( $key, $value, $exptime=0, $flags=0)
 Insert an item if it does not already exist.
 
 doCas ( $casToken, $key, $value, $exptime=0, $flags=0)
 Check and set an item.
 
 doChangeTTL ( $key, $exptime, $flags)
 
 doChangeTTLMulti (array $keys, $exptime, $flags=0)
 
 doDelete ( $key, $flags=0)
 Delete an item.
 
 doDeleteMulti (array $keys, $flags=0)
 
 doGet ( $key, $flags=0, &$casToken=null)
 
 doGetMulti (array $keys, $flags=0)
 Get an associative array containing the item for each of the keys that have items.
 
 doLock ( $key, $timeout, $exptime)
 
 doSet ( $key, $value, $exptime=0, $flags=0)
 Set an item.
 
 doSetMulti (array $data, $exptime=0, $flags=0)
 
 doUnlock ( $key)
 
 getExpirationAsTimestamp ( $exptime)
 Convert an optionally relative timestamp to an absolute time.
 
 getExpirationAsTTL ( $exptime)
 Convert an optionally absolute expiry time to a relative time.
 
 getSerialized ( $value, $key)
 Get the serialized form a value, using any applicable prepared value.
 
 guessSerialValueSize ( $value, $depth=0, &$loops=0)
 Estimate the size of a variable once serialized.
 
 isInteger ( $value)
 Check if a value is an integer.
 
 isRelativeExpiration ( $exptime)
 
 makeLockKey ( $key)
 
 makeValueOrSegmentList ( $key, $value, $exptime, $flags)
 Determine the entry (inline or segment list) to store under a key to save the value.
 
 mergeViaCas ( $key, callable $callback, $exptime, $attempts, $flags)
 
 resolveSegments ( $key, $mainValue)
 Get and reassemble the chunks of blob at the given key.
 
 serialize ( $value)
 
 setLastError ( $err)
 Set the "last error" registry.
 
 unserialize ( $value)
 
 updateOpStats (string $op, array $keyInfo)
 
- Protected Member Functions inherited from BagOStuff
 componentsFromGenericKey ( $key)
 Extract the components from a "generic" reversible cache key.
 
 determineKeyPrefixForStats ( $key)
 
 fieldHasFlags ( $field, $flags)
 
 genericKeyFromComponents (... $components)
 At a minimum, there must be a keyspace and collection name component.
 
 mergeFlagMaps (array $bags)
 Merge the flag maps of one or more BagOStuff objects into a "lowest common denominator" map.
 
 proxyCall ( $method, $arg0Sig, $resSig, array $genericArgs)
 Call a method on behalf of wrapper BagOStuff instance that uses "generic" keys.
 

Protected Attributes

string $routingPrefix
 Routing prefix appended to keys during operations.
 
- Protected Attributes inherited from MediumSpecificBagOStuff
callable[] $busyCallbacks = []
 
int $lastError = self::ERR_NONE
 ERR_* class constant.
 
array< string, array > $locks = []
 Map of (key => (class, depth, expiry)
 
array[] $preparedValues = []
 Map of (key => (PHP variable value, serialized value))
 
int $segmentationSize
 Bytes; chunk size of segmented cache values.
 
int $segmentedValueMaxSize
 Bytes; maximum total size of a segmented cache value.
 
int $syncTimeout
 Seconds.
 
const LOCK_DEPTH = 1
 
const LOCK_EXPIRY = 3
 
const LOCK_RCLASS = 0
 
const LOCK_TIME = 2
 
const METRIC_OP_ADD = 'add'
 
const METRIC_OP_CAS = 'cas'
 
const METRIC_OP_CHANGE_TTL = 'change_ttl'
 
const METRIC_OP_DECR = 'decr'
 
const METRIC_OP_DELETE = 'delete'
 
const METRIC_OP_GET = 'get'
 
const METRIC_OP_INCR = 'incr'
 
const METRIC_OP_SET = 'set'
 
- Protected Attributes inherited from BagOStuff
callable null $asyncHandler
 
int[] $attrMap = []
 Map of (ATTR_* class constant => QOS_* class constant)
 
bool $debugMode = true
 Whether to send debug log entries to the SPI logger instance.
 
string $keyspace
 Default keyspace; used by makeKey()
 
LoggerInterface $logger
 
StatsdDataFactoryInterface $stats
 
array< string, array > $wrapperInfoByPrefix = []
 Cache key processing callbacks and info for metrics.
 

Additional Inherited Members

- Public Attributes inherited from BagOStuff
const READ_LATEST = 1
 Bitfield constants for get()/getMulti(); these are only advisory.
 
const READ_VERIFIED = 2
 
const WRITE_ALLOW_SEGMENTS = 16
 
const WRITE_BACKGROUND = 64
 
const WRITE_CACHE_ONLY = 8
 
const WRITE_PRUNE_SEGMENTS = 32
 
const WRITE_SYNC = 4
 Bitfield constants for set()/merge(); these are only advisory.
 
- Public Attributes inherited from Wikimedia\LightweightObjectStore\StorageAwareness
const ATTR_DURABILITY = 2
 Durability of writes; see QOS_DURABILITY_* (higher means stronger)
 
const ATTR_EMULATION = 1
 Emulation/fallback mode; see QOS_EMULATION_*; higher is better.
 
const ERR_NO_RESPONSE = 1
 Storage medium failed to yield a response.
 
const ERR_NONE = 0
 No storage medium error.
 
const ERR_UNEXPECTED = 3
 Storage medium operation failed due to usage limitations or an I/O error.
 
const ERR_UNREACHABLE = 2
 Storage medium could not be reached.
 
const QOS_DURABILITY_DISK = 4
 Data is saved to disk and writes do not usually block on fsync()
 
const QOS_DURABILITY_NONE = 1
 Data is never saved to begin with (blackhole store)
 
const QOS_DURABILITY_RDBMS = 5
 Data is saved to disk and writes usually block on fsync(), like a standard RDBMS.
 
const QOS_DURABILITY_SCRIPT = 2
 Data is lost at the end of the current web request or CLI script.
 
const QOS_DURABILITY_SERVICE = 3
 Data is lost once the service storing the data restarts.
 
const QOS_EMULATION_SQL = 1
 Fallback disk-based SQL store.
 
const QOS_UNKNOWN = INF
 Generic "unknown" value; useful for comparisons (always "good enough")
 

Detailed Description

Base class for memcached clients.

Definition at line 29 of file MemcachedBagOStuff.php.

Constructor & Destructor Documentation

◆ __construct()

MemcachedBagOStuff::__construct ( array  $params)
Parameters
array$paramsAdditional parameters include:
  • routingPrefix: a routing prefix of the form "<datacenter>/<cluster>/" used to convey the location/strategy to use for handling keys accessed from this instance. The prefix is prepended to keys during cache operations. The memcached proxy must preserve these prefixes in any responses that include requested keys (e.g. get/gets). The proxy is also assumed to strip the routing prefix from the stored key name, which allows for unprefixed access. This can be used with mcrouter. [optional]

Reimplemented from MediumSpecificBagOStuff.

Definition at line 42 of file MemcachedBagOStuff.php.

References Wikimedia\LightweightObjectStore\StorageAwareness\ATTR_DURABILITY, and Wikimedia\LightweightObjectStore\StorageAwareness\QOS_DURABILITY_SERVICE.

Member Function Documentation

◆ fixExpiry()

MemcachedBagOStuff::fixExpiry (   $exptime)
protected
Parameters
int | float$exptime
Returns
int

Definition at line 149 of file MemcachedBagOStuff.php.

References BagOStuff\getCurrentTime(), and MediumSpecificBagOStuff\isRelativeExpiration().

Referenced by MemcachedPeclBagOStuff\doAdd(), MemcachedPhpBagOStuff\doAdd(), MemcachedPeclBagOStuff\doCas(), MemcachedPhpBagOStuff\doCas(), MemcachedPeclBagOStuff\doChangeTTL(), MemcachedPhpBagOStuff\doChangeTTL(), MemcachedPeclBagOStuff\doSet(), MemcachedPhpBagOStuff\doSet(), and MemcachedPeclBagOStuff\doSetMulti().

◆ makeKeyInternal()

MemcachedBagOStuff::makeKeyInternal (   $keyspace,
  $components 
)

Construct a cache key.

Since
1.27
Parameters
string$keyspace
array$components
Returns
string

Reimplemented from BagOStuff.

Definition at line 60 of file MemcachedBagOStuff.php.

References BagOStuff\$keyspace.

◆ stripRouteFromKey()

MemcachedBagOStuff::stripRouteFromKey (   $key)
protected
Parameters
string$key
Returns
string

Definition at line 132 of file MemcachedBagOStuff.php.

Referenced by MemcachedPeclBagOStuff\doGetMulti(), and MemcachedPhpBagOStuff\doGetMulti().

◆ validateKeyAndPrependRoute()

MemcachedBagOStuff::validateKeyAndPrependRoute (   $key)
protected
Parameters
string$key
Returns
string

Definition at line 114 of file MemcachedBagOStuff.php.

References validateKeyEncoding().

Referenced by MemcachedPeclBagOStuff\decr(), MemcachedPhpBagOStuff\decr(), MemcachedPeclBagOStuff\doAdd(), MemcachedPhpBagOStuff\doAdd(), MemcachedPeclBagOStuff\doCas(), MemcachedPhpBagOStuff\doCas(), MemcachedPeclBagOStuff\doChangeTTL(), MemcachedPhpBagOStuff\doChangeTTL(), MemcachedPeclBagOStuff\doDelete(), MemcachedPhpBagOStuff\doDelete(), MemcachedPeclBagOStuff\doDeleteMulti(), MemcachedPeclBagOStuff\doGet(), MemcachedPhpBagOStuff\doGet(), MemcachedPeclBagOStuff\doGetMulti(), MemcachedPhpBagOStuff\doGetMulti(), MemcachedPeclBagOStuff\doSet(), MemcachedPhpBagOStuff\doSet(), MemcachedPeclBagOStuff\doSetMulti(), MemcachedPeclBagOStuff\incr(), and MemcachedPhpBagOStuff\incr().

◆ validateKeyEncoding()

MemcachedBagOStuff::validateKeyEncoding (   $key)

Ensure that a key is safe to use (contains no control characters and no characters above the ASCII range.)

Parameters
string$key
Returns
string
Exceptions
Exception

Definition at line 102 of file MemcachedBagOStuff.php.

Referenced by validateKeyAndPrependRoute().

Member Data Documentation

◆ $routingPrefix

string MemcachedBagOStuff::$routingPrefix
protected

Routing prefix appended to keys during operations.

Definition at line 31 of file MemcachedBagOStuff.php.

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