MediaWiki REL1_35
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Class representing a cache/ephemeral data store. More...
Public Member Functions | |
__construct (array $params=[]) | |
Parameters include: | |
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. | |
decr ( $key, $value=1, $flags=0) | |
Decrease stored value of $key by $value while preserving its TTL. | |
delete ( $key, $flags=0) | |
Delete an item. | |
deleteMulti (array $keys, $flags=0) | |
Batch deletion. | |
deleteObjectsExpiringBefore ( $timestamp, callable $progress=null, $limit=INF) | |
Delete all objects expiring before a certain date. | |
get ( $key, $flags=0) | |
Get an item with the given key. | |
getCurrentTime () | |
getLastError () | |
Get the "last error" registered; clearLastError() should be called manually. | |
getLogger () | |
getMulti (array $keys, $flags=0) | |
Get an associative array containing the item for each of the keys that have items. | |
getQoS ( $flag) | |
getScopedLock ( $key, $timeout=6, $expiry=30, $rclass='') | |
Get a lightweight exclusive self-unlocking lock. | |
getSegmentationSize () | |
getSegmentedValueMaxSize () | |
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. | |
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, $expiry=6, $rclass='') | |
Acquire an advisory lock on a key string. | |
makeGlobalKey ( $class,... $components) | |
Make a global cache key. | |
makeKey ( $class,... $components) | |
Make a cache key, scoped to this instance's keyspace. | |
makeKeyInternal ( $keyspace, $args) | |
Construct a cache key. | |
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. | |
setDebug ( $enabled) | |
setLogger (LoggerInterface $logger) | |
setMockTime (&$time) | |
setMulti (array $data, $exptime=0, $flags=0) | |
Batch insertion/replace. | |
setNewPreparedValues (array $valueByKey) | |
Prepare values for storage and get their serialized sizes, or, estimate those sizes. | |
unlock ( $key) | |
Release an advisory lock on a key string. | |
Public Attributes | |
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. | |
Protected Member Functions | |
fieldHasFlags ( $field, $flags) | |
mergeFlagMaps (array $bags) | |
Merge the flag maps of one or more BagOStuff objects into a "lowest common denominator" map. | |
Protected Attributes | |
callable null | $asyncHandler |
int[] | $attrMap = [] |
Map of (ATTR_* class constant => QOS_* class constant) | |
bool | $debugMode = false |
LoggerInterface | $logger |
Private Attributes | |
float null | $wallClockOverride |
Class representing a cache/ephemeral data store.
This interface is intended to be more or less compatible with the PHP memcached client.
Instances of this class should be created with an intended access scope, such as:
Callers should use the proper factory methods that yield BagOStuff instances. Site admins should make sure the configuration for those factory methods matches their access scope. BagOStuff subclasses have widely varying levels of support for replication features.
For any given instance, methods like lock(), unlock(), merge(), and set() with WRITE_SYNC should semantically operate over its entire access scope; any nodes/threads in that scope should serialize appropriately when using them. Likewise, a call to get() with READ_LATEST from one node in its access scope should reflect the prior changes of any other node its access scope. Any get() should reflect the changes of any prior set() with WRITE_SYNC.
Subclasses should override the default "segmentationSize" field with an appropriate value. The value should not be larger than what the storage backend (by default) supports. It also should be roughly informed by common performance bottlenecks (e.g. values over a certain size having poor scalability). The same goes for the "segmentedValueMaxSize" member, which limits the maximum size and chunk count (indirectly) of values.
Stable to extend
Definition at line 66 of file BagOStuff.php.
BagOStuff::__construct | ( | array | $params = [] | ) |
Parameters include:
array | $params | -param array{logger?:Psr\Log\LoggerInterface,asyncHandler?:callable} $params |
Reimplemented in MemcachedBagOStuff, APCUBagOStuff, EmptyBagOStuff, MediumSpecificBagOStuff, and WinCacheBagOStuff.
Definition at line 104 of file BagOStuff.php.
References setLogger().
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abstract |
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 in CachedBagOStuff, MediumSpecificBagOStuff, MultiWriteBagOStuff, and ReplicatedBagOStuff.
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abstract |
Let a callback be run to avoid wasting time on special blocking calls.
The callbacks may or may not be called ever, in any particular order. They are likely to be invoked when something WRITE_SYNC is used used. They should follow a caching pattern as shown below, so that any code using the work will get it's result no matter what happens.
callable | $workCallback |
Reimplemented in CachedBagOStuff, MediumSpecificBagOStuff, MultiWriteBagOStuff, and ReplicatedBagOStuff.
Referenced by Wikimedia\Rdbms\ChronologyProtector\shutdown().
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abstract |
Change the expiration on a key if it exists.
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 in CachedBagOStuff, MediumSpecificBagOStuff, MultiWriteBagOStuff, and ReplicatedBagOStuff.
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abstract |
Change the expiration of multiple keys that exist.
string[] | $keys | List of keys |
int | $exptime | TTL or UNIX timestamp |
int | $flags | Bitfield of BagOStuff::WRITE_* constants (since 1.33) |
Reimplemented in CachedBagOStuff, MediumSpecificBagOStuff, MultiWriteBagOStuff, RedisBagOStuff, ReplicatedBagOStuff, and SqlBagOStuff.
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abstract |
Clear the "last error" registry.
Reimplemented in CachedBagOStuff, MediumSpecificBagOStuff, MultiWriteBagOStuff, and ReplicatedBagOStuff.
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abstract |
Decrease stored value of $key by $value while preserving its TTL.
string | $key | |
int | $value | Value to subtract from $key (default: 1) [optional] |
int | $flags | Bit field of class WRITE_* constants [optional] |
Reimplemented in APCUBagOStuff, CachedBagOStuff, EmptyBagOStuff, HashBagOStuff, MemcachedPeclBagOStuff, MemcachedPhpBagOStuff, MultiWriteBagOStuff, RedisBagOStuff, ReplicatedBagOStuff, RESTBagOStuff, WinCacheBagOStuff, and SqlBagOStuff.
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abstract |
Delete an item.
For large values written using WRITE_ALLOW_SEGMENTS, this only deletes the main segment list key unless WRITE_PRUNE_SEGMENTS is in the flags. While deleting the segment list key has the effect of functionally deleting the key, it leaves unused blobs in cache.
string | $key |
int | $flags | Bitfield of BagOStuff::WRITE_* constants |
Reimplemented in CachedBagOStuff, MediumSpecificBagOStuff, MultiWriteBagOStuff, and ReplicatedBagOStuff.
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abstract |
Batch deletion.
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 in MultiWriteBagOStuff, CachedBagOStuff, MediumSpecificBagOStuff, and ReplicatedBagOStuff.
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abstract |
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 | $limit | Maximum number of keys to delete [default: INF] |
Reimplemented in CachedBagOStuff, MediumSpecificBagOStuff, MultiWriteBagOStuff, ReplicatedBagOStuff, and SqlBagOStuff.
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finalprotected |
int | $field | |
int | $flags |
Definition at line 509 of file BagOStuff.php.
Referenced by CachedBagOStuff\changeTTLMulti(), CachedBagOStuff\delete(), MediumSpecificBagOStuff\delete(), CachedBagOStuff\deleteMulti(), SqlBagOStuff\doCas(), MemcachedPeclBagOStuff\doDeleteMulti(), MemcachedPeclBagOStuff\doSetMulti(), MultiWriteBagOStuff\get(), ReplicatedBagOStuff\get(), ReplicatedBagOStuff\getMulti(), SqlBagOStuff\modifyMulti(), CachedBagOStuff\set(), CachedBagOStuff\setMulti(), and MultiWriteBagOStuff\usesAsyncWritesGivenFlags().
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abstract |
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.
string | $key | |
int | $flags | Bitfield of BagOStuff::READ_* constants [optional] |
Reimplemented in CachedBagOStuff, MediumSpecificBagOStuff, MultiWriteBagOStuff, and ReplicatedBagOStuff.
Referenced by McTest\execute(), and Wikimedia\Rdbms\ChronologyProtector\shutdown().
BagOStuff::getCurrentTime | ( | ) |
Definition at line 566 of file BagOStuff.php.
Referenced by HashBagOStuff\expire(), SqlBagOStuff\expireAll(), MemcachedBagOStuff\fixExpiry(), SqlBagOStuff\getConnection(), SqlBagOStuff\getMaxDateTime(), ReplicatedBagOStuff\hadRecentSessionWrite(), SqlBagOStuff\isExpired(), SqlBagOStuff\markServerDown(), SqlBagOStuff\occasionallyGarbageCollect(), and ReplicatedBagOStuff\remarkRecentSessionWrite().
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abstract |
Get the "last error" registered; clearLastError() should be called manually.
Reimplemented in CachedBagOStuff, MediumSpecificBagOStuff, MultiWriteBagOStuff, and ReplicatedBagOStuff.
BagOStuff::getLogger | ( | ) |
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abstract |
Get an associative array containing the item for each of the keys that have items.
string[] | $keys | List of keys |
int | $flags | Bitfield; supports READ_LATEST [optional] |
Reimplemented in CachedBagOStuff, MediumSpecificBagOStuff, MultiWriteBagOStuff, and ReplicatedBagOStuff.
BagOStuff::getQoS | ( | $flag | ) |
int | $flag | ATTR_* class constant |
Reimplemented in MediumSpecificBagOStuff.
Definition at line 483 of file BagOStuff.php.
Referenced by Wikimedia\Rdbms\ChronologyProtector\shutdown().
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final |
Get a lightweight exclusive self-unlocking lock.
Note that the same lock cannot be acquired twice.
This is useful for task de-duplication or to avoid obtrusive (though non-corrupting) DB errors like INSERT key conflicts or deadlocks when using LOCK IN SHARE MODE.
string | $key | |
int | $timeout | Lock wait timeout; 0 for non-blocking [optional] |
int | $expiry | Lock expiry [optional]; 1 day maximum |
string | $rclass | Allow reentry if set and the current lock used this value |
Definition at line 289 of file BagOStuff.php.
BagOStuff::getSegmentationSize | ( | ) |
Reimplemented in MediumSpecificBagOStuff.
Definition at line 491 of file BagOStuff.php.
BagOStuff::getSegmentedValueMaxSize | ( | ) |
Reimplemented in MediumSpecificBagOStuff.
Definition at line 499 of file BagOStuff.php.
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final |
Get an item with the given key, regenerating and setting it if not found.
The callback can take $exptime as argument by reference and modify it. Nothing is stored nor deleted if the callback returns false.
string | $key | |
int | $exptime | Time-to-live (seconds) |
callable | $callback | Callback that derives the new value |
int | $flags | Bitfield of BagOStuff::READ_* or BagOStuff::WRITE_* constants [optional] |
Definition at line 145 of file BagOStuff.php.
Referenced by Wikimedia\Rdbms\DatabaseMysqlBase\getServerVersion().
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abstract |
Increase stored value of $key by $value while preserving its TTL.
string | $key | Key to increase |
int | $value | Value to add to $key (default: 1) [optional] |
int | $flags | Bit field of class WRITE_* constants [optional] |
Reimplemented in SqlBagOStuff, APCUBagOStuff, CachedBagOStuff, EmptyBagOStuff, HashBagOStuff, MemcachedPeclBagOStuff, MemcachedPhpBagOStuff, MultiWriteBagOStuff, RedisBagOStuff, ReplicatedBagOStuff, RESTBagOStuff, and WinCacheBagOStuff.
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abstract |
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 - $value) and $exptime are invariants for all operations to any given key. The value of $init should be at least that of $value.
string | $key | Key built via makeKey() or makeGlobalKey() |
int | $exptime | Time-to-live (in seconds) or a UNIX timestamp expiration |
int | $value | Amount to increase the key value by [default: 1] |
int | null | $init | Value to initialize the key to if it does not exist [default: $value] |
int | $flags | Bit field of class WRITE_* constants [optional] |
Reimplemented in APCUBagOStuff, CachedBagOStuff, EmptyBagOStuff, MediumSpecificBagOStuff, MultiWriteBagOStuff, and ReplicatedBagOStuff.
Referenced by Wikimedia\UUID\GlobalIdGenerator\getSequentialPerNodeIDs().
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abstract |
Acquire an advisory lock on a key string.
Note that if reentry is enabled, duplicate calls ignore $expiry
string | $key | |
int | $timeout | Lock wait timeout; 0 for non-blocking [optional] |
int | $expiry | Lock expiry [optional]; 1 day maximum |
string | $rclass | Allow reentry if set and the current lock used this value |
Reimplemented in CachedBagOStuff, MediumSpecificBagOStuff, MultiWriteBagOStuff, ReplicatedBagOStuff, and SqlBagOStuff.
Referenced by Wikimedia\Rdbms\ChronologyProtector\shutdown().
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abstract |
Make a global cache key.
string | $class | Key class |
string|int | ...$components Key components (starting with a key collection name) |
Implements IStoreKeyEncoder.
Reimplemented in CachedBagOStuff, MediumSpecificBagOStuff, MultiWriteBagOStuff, and ReplicatedBagOStuff.
Referenced by Wikimedia\Rdbms\ChronologyProtector\__construct(), Wikimedia\Rdbms\DatabaseMysqlBase\getMasterServerInfo(), and Wikimedia\Rdbms\ChronologyProtector\getTouchedKey().
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abstract |
Make a cache key, scoped to this instance's keyspace.
string | $class | Key class |
string|int | ...$components Key components (starting with a key collection name) |
Implements IStoreKeyEncoder.
Reimplemented in CachedBagOStuff, MediumSpecificBagOStuff, MultiWriteBagOStuff, and ReplicatedBagOStuff.
Referenced by UploadBase\getUploadSessionKey().
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abstract |
Construct a cache key.
string | $keyspace | |
array | $args |
Reimplemented in CachedBagOStuff, MediumSpecificBagOStuff, MemcachedBagOStuff, MultiWriteBagOStuff, ReplicatedBagOStuff, WinCacheBagOStuff, and SqlBagOStuff.
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abstract |
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.
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 |
InvalidArgumentException |
Reimplemented in CachedBagOStuff, EmptyBagOStuff, MediumSpecificBagOStuff, MultiWriteBagOStuff, and ReplicatedBagOStuff.
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finalprotected |
Merge the flag maps of one or more BagOStuff objects into a "lowest common denominator" map.
BagOStuff[] | $bags |
Definition at line 519 of file BagOStuff.php.
Referenced by MultiWriteBagOStuff\__construct(), and ReplicatedBagOStuff\__construct().
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abstract |
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 |
Reimplemented in CachedBagOStuff, MediumSpecificBagOStuff, MultiWriteBagOStuff, and ReplicatedBagOStuff.
Referenced by Wikimedia\Rdbms\ChronologyProtector\shutdown().
BagOStuff::setDebug | ( | $enabled | ) |
bool | $enabled |
Reimplemented in CachedBagOStuff, MemcachedPhpBagOStuff, MultiWriteBagOStuff, and ReplicatedBagOStuff.
Definition at line 128 of file BagOStuff.php.
BagOStuff::setLogger | ( | LoggerInterface | $logger | ) |
LoggerInterface | $logger |
Reimplemented in RESTBagOStuff.
Definition at line 113 of file BagOStuff.php.
Referenced by __construct().
BagOStuff::setMockTime | ( | & | $time | ) |
Reimplemented in CachedBagOStuff, MultiWriteBagOStuff, and ReplicatedBagOStuff.
Definition at line 575 of file BagOStuff.php.
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abstract |
Batch insertion/replace.
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[] | $data | 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 in CachedBagOStuff, MediumSpecificBagOStuff, MultiWriteBagOStuff, and ReplicatedBagOStuff.
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abstract |
Prepare values for storage and get their serialized sizes, or, estimate those sizes.
All previously prepared values will be cleared. Each of the new prepared values will be individually cleared as they get used by write operations for that key. This is done to avoid unchecked growth in PHP memory usage.
Example usage:
This is only useful if the caller needs an estimate of the serialized object sizes. The caller cannot know the serialization format and even if it did, it could be expensive to serialize complex values twice just to get the size information before writing them to cache. This method solves both problems by making the cache instance do the serialization and having it reuse the result when the cache write happens.
array | $valueByKey | Map of (cache key => PHP variable value to serialize) |
Reimplemented in CachedBagOStuff, HashBagOStuff, MediumSpecificBagOStuff, MemcachedPeclBagOStuff, MultiWriteBagOStuff, and ReplicatedBagOStuff.
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abstract |
Release an advisory lock on a key string.
string | $key |
Reimplemented in CachedBagOStuff, MediumSpecificBagOStuff, MultiWriteBagOStuff, ReplicatedBagOStuff, and SqlBagOStuff.
Referenced by Wikimedia\Rdbms\ChronologyProtector\shutdown().
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protected |
Definition at line 76 of file BagOStuff.php.
Referenced by MultiWriteBagOStuff\doWrite(), and SqlBagOStuff\occasionallyGarbageCollect().
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protected |
Map of (ATTR_* class constant => QOS_* class constant)
Definition at line 78 of file BagOStuff.php.
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protected |
Definition at line 81 of file BagOStuff.php.
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protected |
Definition at line 73 of file BagOStuff.php.
Referenced by MultiWriteBagOStuff\doWrite(), and RESTBagOStuff\setLogger().
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private |
Definition at line 84 of file BagOStuff.php.
const BagOStuff::READ_LATEST = 1 |
Bitfield constants for get()/getMulti(); these are only advisory.
Definition at line 87 of file BagOStuff.php.
Referenced by RESTBagOStuff\incr().
const BagOStuff::READ_VERIFIED = 2 |
Definition at line 88 of file BagOStuff.php.
const BagOStuff::WRITE_ALLOW_SEGMENTS = 16 |
Definition at line 92 of file BagOStuff.php.
const BagOStuff::WRITE_BACKGROUND = 64 |
Definition at line 94 of file BagOStuff.php.
const BagOStuff::WRITE_CACHE_ONLY = 8 |
Definition at line 91 of file BagOStuff.php.
const BagOStuff::WRITE_PRUNE_SEGMENTS = 32 |
Definition at line 93 of file BagOStuff.php.
const BagOStuff::WRITE_SYNC = 4 |
Bitfield constants for set()/merge(); these are only advisory.
Definition at line 90 of file BagOStuff.php.