MediaWiki master
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Wrap any BagOStuff and add an in-process memory cache to it. More...
Inherits Wikimedia\ObjectCache\BagOStuff.
Public Member Functions | |
__construct (BagOStuff $backend, $params=[]) | |
add ( $key, $value, $exptime=0, $flags=0) | |
Insert an item if it does not already exist. | |
changeTTL ( $key, $exptime=0, $flags=0) | |
Change the expiration on an item. | |
changeTTLMulti (array $keys, $exptime, $flags=0) | |
Change the expiration of multiple items. | |
delete ( $key, $flags=0) | |
Delete an item if it exists. | |
deleteMulti (array $keys, $flags=0) | |
Delete a batch of items. | |
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. | |
getMulti (array $keys, $flags=0) | |
Get a batch of items. | |
incrWithInit ( $key, $exptime, $step=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='') | |
Acquire an advisory lock on a key string, exclusive to the caller. | |
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, $flags=0) | |
Set an item. | |
setMockTime (&$time) | |
setMulti (array $valueByKey, $exptime=0, $flags=0) | |
Set a batch of items. | |
unlock ( $key) | |
Release an advisory lock on a key string. | |
Public Member Functions inherited from Wikimedia\ObjectCache\BagOStuff | |
__construct (array $params=[]) | |
clearLastError () | |
Clear the "last error" registry. | |
getCurrentTime () | |
getLastError ( $watchPoint=0) | |
Get the "last error" registry. | |
getLogger () | |
getQoS ( $flag) | |
getScopedLock ( $key, $timeout=6, $exptime=30, $rclass='') | |
Get a lightweight exclusive self-unlocking lock. | |
getSegmentationSize () | |
getSegmentedValueMaxSize () | |
getWithSetCallback ( $key, $exptime, $callback, $flags=0) | |
Get an item, regenerating and setting it if not found. | |
isKeyGlobal ( $key) | |
Check whether a cache key is in the global keyspace. | |
makeGlobalKey ( $keygroup,... $components) | |
Make a cache key from the given components, in the "global" keyspace. | |
makeKey ( $keygroup,... $components) | |
Make a cache key from the given components, in the default keyspace. | |
setLogger (LoggerInterface $logger) | |
watchErrors () | |
Get a "watch point" token that can be used to get the "last error" to occur after now. | |
Protected Attributes | |
HashBagOStuff | $procCache |
BagOStuff | $store |
Protected Attributes inherited from Wikimedia\ObjectCache\BagOStuff | |
callable null | $asyncHandler |
int[] | $attrMap = [] |
Map of (BagOStuff:ATTR_* constant => BagOStuff:QOS_* constant) | |
string | $keyspace |
Default keyspace; used by makeKey() | |
int | $lastError = self::ERR_NONE |
BagOStuff:ERR_* constant of the last error that occurred. | |
int | $lastErrorId = 0 |
Error event sequence number of the last error that occurred. | |
LoggerInterface | $logger |
StatsFactory | $stats |
Additional Inherited Members | |
Public Attributes inherited from Wikimedia\ObjectCache\BagOStuff | |
const | MAX_CONFLICTS_ONE = 1 |
Abort after the first merge conflict. | |
const | READ_LATEST = 1 |
Bitfield constants for get()/getMulti(); these are only advisory. | |
const | READ_VERIFIED = 2 |
Promise that the caller handles detection of staleness. | |
const | WRITE_ALLOW_SEGMENTS = 16 |
Allow partitioning of the value if it is a large string. | |
const | WRITE_BACKGROUND = 64 |
If supported, do not block on write operation completion; instead, treat writes as succesful based on whether they could be buffered. | |
const | WRITE_CACHE_ONLY = 8 |
Bitfield constants for set()/merge(); these are only advisory. | |
const | WRITE_PRUNE_SEGMENTS = self::WRITE_ALLOW_SEGMENTS |
Delete all the segments if the value is partitioned. | |
Public Attributes inherited from Wikimedia\LightweightObjectStore\StorageAwareness | |
const | ATTR_DURABILITY = 2 |
Durability of writes; see QOS_DURABILITY_* (higher means stronger) | |
const | ATTR_EMULATION = 1 |
const | ERR_NO_RESPONSE = 1 |
Storage medium failed to yield a complete response to an operation. | |
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 to establish a connection. | |
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_UNKNOWN = INF |
Generic "unknown" value; useful for comparisons (always "good enough") | |
Protected Member Functions inherited from Wikimedia\ObjectCache\BagOStuff | |
fieldHasFlags ( $field, $flags) | |
makeKeyInternal ( $keyspace, $components) | |
Make a cache key for the given keyspace and components. | |
mergeFlagMaps (array $bags) | |
Merge the flag maps of one or more BagOStuff objects into a "lowest common denominator" map. | |
proxyCall (string $method, int $arg0Sig, int $resSig, array $genericArgs, BagOStuff $wrapper) | |
Call a method on behalf of wrapper BagOStuff instance. | |
requireConvertGenericKey () | |
Whether ::proxyCall() must re-encode cache keys before calling read/write methods. | |
setLastError ( $error) | |
Set the "last error" registry due to a problem encountered during an attempted operation. | |
Static Protected Attributes inherited from Wikimedia\ObjectCache\BagOStuff | |
static int | $nextErrorMonitorId = 1 |
Next sequence number to use for watch/error events. | |
Wrap any BagOStuff and add an in-process memory cache to it.
The differences between CachedBagOStuff and MultiWriteBagOStuff are:
Definition at line 35 of file CachedBagOStuff.php.
Wikimedia\ObjectCache\CachedBagOStuff::__construct | ( | BagOStuff | $backend, |
$params = [] ) |
BagOStuff | $backend | Permanent backend to use |
array | $params | Parameters for HashBagOStuff |
Definition at line 47 of file CachedBagOStuff.php.
References $params.
Wikimedia\ObjectCache\CachedBagOStuff::add | ( | $key, | |
$value, | |||
$exptime = 0, | |||
$flags = 0 ) |
Insert an item if it does not already exist.
string | $key | |
mixed | $value | |
int | $exptime | |
int | $flags | Bitfield of BagOStuff::WRITE_* constants (since 1.33) |
Reimplemented from Wikimedia\ObjectCache\BagOStuff.
Definition at line 132 of file CachedBagOStuff.php.
Wikimedia\ObjectCache\CachedBagOStuff::changeTTL | ( | $key, | |
$exptime = 0, | |||
$flags = 0 ) |
Change the expiration on an item.
If an expiry in the past is given then the key will immediately be expired
For large values written using WRITE_ALLOW_SEGMENTS, this only changes the TTL of the main segment list key. While lowering the TTL of the segment list key has the effect of functionally lowering the TTL of the key, it might leave unused blobs in cache for longer. Raising the TTL of such keys is not effective, since the expiration of a single segment key effectively expires the entire value.
string | $key | |
int | $exptime | TTL or UNIX timestamp |
int | $flags | Bitfield of BagOStuff::WRITE_* constants (since 1.33) |
Reimplemented from Wikimedia\ObjectCache\BagOStuff.
Definition at line 156 of file CachedBagOStuff.php.
Wikimedia\ObjectCache\CachedBagOStuff::changeTTLMulti | ( | array | $keys, |
$exptime, | |||
$flags = 0 ) |
Change the expiration of multiple items.
string[] | $keys | List of keys |
int | $exptime | TTL or UNIX timestamp |
int | $flags | Bitfield of BagOStuff::WRITE_* constants (since 1.33) |
Reimplemented from Wikimedia\ObjectCache\BagOStuff.
Definition at line 237 of file CachedBagOStuff.php.
References Wikimedia\ObjectCache\BagOStuff\fieldHasFlags().
Wikimedia\ObjectCache\CachedBagOStuff::delete | ( | $key, | |
$flags = 0 ) |
Delete an item if it exists.
For large values set with WRITE_ALLOW_SEGMENTS, this only deletes the placeholder key with the segment list. To delete the underlying blobs, include WRITE_ALLOW_SEGMENTS in the flags for delete() as well. While deleting the segment list key has the effect of functionally deleting the key, it leaves unused blobs in storage.
The reason that this is not done automatically, is that to delete underlying blobs, requires first fetching the current segment list. Given that 99% of keys don't use WRITE_ALLOW_SEGMENTS, this would be wasteful.
string | $key | |
int | $flags | Bitfield of BagOStuff::WRITE_* constants |
Reimplemented from Wikimedia\ObjectCache\BagOStuff.
Definition at line 116 of file CachedBagOStuff.php.
References Wikimedia\ObjectCache\BagOStuff\fieldHasFlags().
Wikimedia\ObjectCache\CachedBagOStuff::deleteMulti | ( | array | $keys, |
$flags = 0 ) |
Delete a batch of items.
This does not support WRITE_ALLOW_SEGMENTS to avoid excessive read I/O
WRITE_BACKGROUND can be used for bulk deletion where the response is not vital
string[] | $keys | List of keys |
int | $flags | Bitfield of BagOStuff::WRITE_* constants |
Reimplemented from Wikimedia\ObjectCache\BagOStuff.
Definition at line 221 of file CachedBagOStuff.php.
References Wikimedia\ObjectCache\BagOStuff\fieldHasFlags().
Wikimedia\ObjectCache\CachedBagOStuff::deleteObjectsExpiringBefore | ( | $timestamp, | |
callable | $progress = null, | ||
$limit = INF, | |||
string | $tag = null ) |
Delete all objects expiring before a certain date.
string | int | $timestamp | The reference date in MW or TS_UNIX format |
callable | null | $progress | Optional, a function which will be called regularly during long-running operations with the percentage progress as the first parameter. [optional] |
int | float | $limit | Maximum number of keys to delete [default: INF] |
string | null | $tag | Tag to purge a single shard only. This is only supported when server tags are used in configuration. |
Reimplemented from Wikimedia\ObjectCache\BagOStuff.
Definition at line 188 of file CachedBagOStuff.php.
Wikimedia\ObjectCache\CachedBagOStuff::get | ( | $key, | |
$flags = 0 ) |
Get an item.
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.
string | $key | |
int | $flags | Bitfield of BagOStuff::READ_* constants [optional] |
Reimplemented from Wikimedia\ObjectCache\BagOStuff.
Definition at line 57 of file CachedBagOStuff.php.
References Wikimedia\ObjectCache\BagOStuff\get(), and Wikimedia\ObjectCache\BagOStuff\WRITE_CACHE_ONLY.
Referenced by MediaWiki\Session\SessionBackend\__construct().
Wikimedia\ObjectCache\CachedBagOStuff::getMulti | ( | array | $keys, |
$flags = 0 ) |
Get a batch of items.
string[] | $keys | List of keys |
int | $flags | Bitfield; supports READ_LATEST [optional] |
Reimplemented from Wikimedia\ObjectCache\BagOStuff.
Definition at line 75 of file CachedBagOStuff.php.
References Wikimedia\ObjectCache\CachedBagOStuff\setMulti().
Wikimedia\ObjectCache\CachedBagOStuff::incrWithInit | ( | $key, | |
$exptime, | |||
$step = 1, | |||
$init = null, | |||
$flags = 0 ) |
Increase the value of the given key (no TTL change) if it exists or create it otherwise.
This will create the key with the value $init and TTL $exptime instead if not present. Callers should make sure that both ($init - $step) and $exptime are invariants for all operations to any given key. The value of $init should be at least that of $step.
The new value is returned, except if the WRITE_BACKGROUND flag is given, in which case the handler may choose to return true to indicate that the operation has been dispatched.
string | $key | Key built via makeKey() or makeGlobalKey() |
int | $exptime | Time-to-live (in seconds) or a UNIX timestamp expiration |
int | $step | Amount to increase the key value by [default: 1] |
int | null | $init | Value to initialize the key to if it does not exist [default: $step] |
int | $flags | Bit field of class WRITE_* constants [optional] |
Reimplemented from Wikimedia\ObjectCache\BagOStuff.
Definition at line 253 of file CachedBagOStuff.php.
Wikimedia\ObjectCache\CachedBagOStuff::lock | ( | $key, | |
$timeout = 6, | |||
$exptime = 6, | |||
$rclass = '' ) |
Acquire an advisory lock on a key string, exclusive to the caller.
string | $key | |
int | $timeout | Lock wait timeout; 0 for non-blocking [optional] |
int | $exptime | Lock time-to-live in seconds; 1 day maximum [optional] |
string | $rclass | If this thread already holds the lock, and the lock was acquired using the same value for this parameter, then return true and use reference counting so that only the unlock() call from the outermost lock() caller actually releases the lock (note that only the outermost time-to-live is used) [optional] |
Reimplemented from Wikimedia\ObjectCache\BagOStuff.
Definition at line 168 of file CachedBagOStuff.php.
Wikimedia\ObjectCache\CachedBagOStuff::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 overridden in the callback. Nothing is stored nor deleted if the callback returns false.
string | $key | |
callable | $callback | Callback method to be executed |
int | $exptime | Either an interval in seconds or a unix timestamp for expiry |
int | $attempts | The amount of times to attempt a merge in case of failure |
int | $flags | Bitfield of BagOStuff::WRITE_* constants |
Reimplemented from Wikimedia\ObjectCache\BagOStuff.
Definition at line 144 of file CachedBagOStuff.php.
Wikimedia\ObjectCache\CachedBagOStuff::set | ( | $key, | |
$value, | |||
$exptime = 0, | |||
$flags = 0 ) |
Set an item.
string | $key | |
mixed | $value | |
int | $exptime | Either an interval in seconds or a unix timestamp for expiry |
int | $flags | Bitfield of BagOStuff::WRITE_* constants If setting WRITE_ALLOW_SEGMENTS, remember to also set it in any delete() calls. |
Reimplemented from Wikimedia\ObjectCache\BagOStuff.
Definition at line 100 of file CachedBagOStuff.php.
References Wikimedia\ObjectCache\BagOStuff\fieldHasFlags().
Wikimedia\ObjectCache\CachedBagOStuff::setMockTime | ( | & | $time | ) |
float | null | &$time | Mock UNIX timestamp |
Reimplemented from Wikimedia\ObjectCache\BagOStuff.
Definition at line 265 of file CachedBagOStuff.php.
Wikimedia\ObjectCache\CachedBagOStuff::setMulti | ( | array | $valueByKey, |
$exptime = 0, | |||
$flags = 0 ) |
Set a batch of items.
This does not support WRITE_ALLOW_SEGMENTS to avoid excessive read I/O
WRITE_BACKGROUND can be used for bulk insertion where the response is not vital
mixed[] | $valueByKey | Map of (key => value) |
int | $exptime | Either an interval in seconds or a unix timestamp for expiry |
int | $flags | Bitfield of BagOStuff::WRITE_* constants (since 1.33) |
Reimplemented from Wikimedia\ObjectCache\BagOStuff.
Definition at line 205 of file CachedBagOStuff.php.
References Wikimedia\ObjectCache\BagOStuff\fieldHasFlags().
Referenced by Wikimedia\ObjectCache\CachedBagOStuff\getMulti().
Wikimedia\ObjectCache\CachedBagOStuff::unlock | ( | $key | ) |
Release an advisory lock on a key string.
string | $key |
Reimplemented from Wikimedia\ObjectCache\BagOStuff.
Definition at line 178 of file CachedBagOStuff.php.
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protected |
Definition at line 39 of file CachedBagOStuff.php.
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protected |
Definition at line 37 of file CachedBagOStuff.php.