RedisBackend extends AbstractBackend implements TaggableBackendInterface
A caching backend which stores cache entries by using Redis with phpredis PHP module. Redis is a noSQL database with very good scaling characteristics in proportion to the amount of entries and data size.
Tags
Table of Contents
Interfaces
- TaggableBackendInterface
- A contract for a cache backend which supports tagging.
Constants
- DATETIME_EXPIRYTIME_UNLIMITED = '9999-12-31T23:59:59+0000'
- FAKED_UNLIMITED_LIFETIME = 31536000
- Faked unlimited lifetime = 31536000 (1 Year).
- IDENTIFIER_DATA_PREFIX = 'identData:'
- Key prefix for identifier->data entries
- IDENTIFIER_TAGS_PREFIX = 'identTags:'
- Key prefix for identifier->tags sets
- TAG_IDENTIFIERS_PREFIX = 'tagIdents:'
- Key prefix for tag->identifiers sets
- UNLIMITED_LIFETIME = 0
Properties
- $cache : FrontendInterface
- Reference to the cache which uses this backend
- $cacheIdentifier : string
- $compression : bool
- Indicates whether data is compressed or not (requires php zlib)
- $compressionLevel : int
- -1 to 9, indicates zlib compression level: -1 = default level 6, 0 = no compression, 9 maximum compression
- $connected : bool
- Indicates whether the server is connected
- $connectionTimeout : int
- limit in seconds (default is 0 meaning unlimited)
- $context : string
- The current application context
- $database : int
- Number of selected database, defaults to 0
- $defaultLifetime : int
- Default lifetime of a cache entry in seconds
- $hostname : string
- Hostname / IP of the Redis server, defaults to 127.0.0.1.
- $password : string
- Password for redis authentication
- $persistentConnection : bool
- Persistent connection
- $port : int
- Port of the Redis server, defaults to 6379
- $redis : Redis
Methods
- __construct() : mixed
- Construct this backend
- collectGarbage() : void
- With the current internal structure, only the identifier to data entries have a redis internal lifetime. If an entry expires, attached identifier to tags and tag to identifiers entries will be left over.
- findIdentifiersByTag() : array<string|int, mixed>
- Finds and returns all cache entry identifiers which are tagged by the specified tag.
- flush() : void
- Removes all cache entries of this cache.
- flushByTag() : void
- Removes all cache entries of this cache which are tagged with the specified tag.
- flushByTags() : mixed
- Backwards compatibility safeguard since re-introducing flushByTags as API.
- get() : mixed
- Loads data from the cache.
- has() : bool
- Checks if a cache entry with the specified identifier exists.
- initializeObject() : void
- Initializes the redis backend
- remove() : bool
- Removes all cache entries matching the specified identifier.
- set() : void
- Save data in the cache
- setCache() : mixed
- Sets a reference to the cache frontend which uses this backend
- setCompression() : void
- Enable data compression
- setCompressionLevel() : void
- Set data compression level.
- setConnectionTimeout() : void
- Set connection timeout.
- setDatabase() : void
- Setter for database number
- setDefaultLifetime() : mixed
- Sets the default lifetime for this cache backend
- setHostname() : void
- Setter for server hostname
- setPassword() : void
- Setter for authentication password
- setPersistentConnection() : void
- Setter for persistent connection
- setPort() : void
- Setter for server port
- calculateExpiryTime() : DateTime
- Calculates the expiry time by the given lifetime. If no lifetime is specified, the default lifetime is used.
- canBeUsedInStringContext() : bool
- Helper method to catch invalid identifiers and tags
- getDataIdentifier() : string
- getTagIdentifier() : string
- getTagsIdentifier() : string
- removeIdentifierEntriesAndRelations() : void
- Helper method for flushByTag() Gets list of identifiers and tags and removes all relations of those tags
Constants
DATETIME_EXPIRYTIME_UNLIMITED
public
mixed
DATETIME_EXPIRYTIME_UNLIMITED
= '9999-12-31T23:59:59+0000'
FAKED_UNLIMITED_LIFETIME
Faked unlimited lifetime = 31536000 (1 Year).
public
int
FAKED_UNLIMITED_LIFETIME
= 31536000
In redis an entry does not have a lifetime by default (it's not "volatile"). Entries can be made volatile either with EXPIRE after it has been SET, or with SETEX, which is a combined SET and EXPIRE command. But an entry can not be made "unvolatile" again. To set a volatile entry to not volatile again, it must be DELeted and SET without a following EXPIRE. To save these additional calls on every set(), we just make every entry volatile and treat a high number as "unlimited"
Faked unlimited lifetime
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IDENTIFIER_DATA_PREFIX
Key prefix for identifier->data entries
public
string
IDENTIFIER_DATA_PREFIX
= 'identData:'
IDENTIFIER_TAGS_PREFIX
Key prefix for identifier->tags sets
public
string
IDENTIFIER_TAGS_PREFIX
= 'identTags:'
TAG_IDENTIFIERS_PREFIX
Key prefix for tag->identifiers sets
public
string
TAG_IDENTIFIERS_PREFIX
= 'tagIdents:'
UNLIMITED_LIFETIME
public
mixed
UNLIMITED_LIFETIME
= 0
Properties
$cache
Reference to the cache which uses this backend
protected
FrontendInterface
$cache
$cacheIdentifier
protected
string
$cacheIdentifier
$compression
Indicates whether data is compressed or not (requires php zlib)
protected
bool
$compression
= false
$compressionLevel
-1 to 9, indicates zlib compression level: -1 = default level 6, 0 = no compression, 9 maximum compression
protected
int
$compressionLevel
= -1
$connected
Indicates whether the server is connected
protected
bool
$connected
= false
$connectionTimeout
limit in seconds (default is 0 meaning unlimited)
protected
int
$connectionTimeout
= 0
$context
The current application context
protected
string
$context
This variable is currently unused and set to "production" always. It is only kept to keep backwards compatibility.
$database
Number of selected database, defaults to 0
protected
int
$database
= 0
$defaultLifetime
Default lifetime of a cache entry in seconds
protected
int
$defaultLifetime
= 3600
$hostname
Hostname / IP of the Redis server, defaults to 127.0.0.1.
protected
string
$hostname
= '127.0.0.1'
$password
Password for redis authentication
protected
string
$password
= ''
$persistentConnection
Persistent connection
protected
bool
$persistentConnection
= false
$port
Port of the Redis server, defaults to 6379
protected
int
$port
= 6379
$redis
protected
Redis
$redis
Methods
__construct()
Construct this backend
public
__construct(string $context[, array<string|int, mixed> $options = [] ]) : mixed
Parameters
- $context : string
-
Unused, for backward compatibility only
- $options : array<string|int, mixed> = []
-
Configuration options
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collectGarbage()
With the current internal structure, only the identifier to data entries have a redis internal lifetime. If an entry expires, attached identifier to tags and tag to identifiers entries will be left over.
public
collectGarbage() : void
This method finds those entries and cleans them up.
Scales O(n*m) with number of cache entries (n) and number of tags (m)
findIdentifiersByTag()
Finds and returns all cache entry identifiers which are tagged by the specified tag.
public
findIdentifiersByTag(string $tag) : array<string|int, mixed>
Scales O(1) with number of cache entries Scales O(n) with number of tag entries
Parameters
- $tag : string
-
The tag to search for
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Return values
array<string|int, mixed> —An array of entries with all matching entries. An empty array if no entries matched
flush()
Removes all cache entries of this cache.
public
flush() : void
Scales O(1) with number of cache entries
flushByTag()
Removes all cache entries of this cache which are tagged with the specified tag.
public
flushByTag(string $tag) : void
Scales O(1) with number of cache entries Scales O(n^2) with number of tag entries
Parameters
- $tag : string
-
Tag the entries must have
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flushByTags()
Backwards compatibility safeguard since re-introducing flushByTags as API.
public
flushByTags(array<string|int, string> $tags) : mixed
See https://review.typo3.org/#/c/50537/ comments for patch set 14.
The method is here even though it is only required for TaggableBackendInterface. We add it here to ensure third party cache backends do not fail but instead delegate to a less efficient linear flushing behavior.
Parameters
- $tags : array<string|int, string>
get()
Loads data from the cache.
public
get(string $entryIdentifier) : mixed
Scales O(1) with number of cache entries
Parameters
- $entryIdentifier : string
-
An identifier which describes the cache entry to load
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Return values
mixed —The cache entry's content as a string or FALSE if the cache entry could not be loaded
has()
Checks if a cache entry with the specified identifier exists.
public
has(string $entryIdentifier) : bool
Scales O(1) with number of cache entries
Parameters
- $entryIdentifier : string
-
Identifier specifying the cache entry
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Return values
bool —TRUE if such an entry exists, FALSE if not
initializeObject()
Initializes the redis backend
public
initializeObject() : void
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remove()
Removes all cache entries matching the specified identifier.
public
remove(string $entryIdentifier) : bool
Scales O(1) with number of cache entries Scales O(n) with number of tags
Parameters
- $entryIdentifier : string
-
Specifies the cache entry to remove
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Return values
bool —TRUE if (at least) an entry could be removed or FALSE if no entry was found
set()
Save data in the cache
public
set(string $entryIdentifier, string $data[, array<string|int, mixed> $tags = [] ][, int $lifetime = null ]) : void
Scales O(1) with number of cache entries Scales O(n) with number of tags
Parameters
- $entryIdentifier : string
-
Identifier for this specific cache entry
- $data : string
-
Data to be stored
- $tags : array<string|int, mixed> = []
-
Tags to associate with this cache entry
- $lifetime : int = null
-
Lifetime of this cache entry in seconds. If NULL is specified, default lifetime is used. "0" means unlimited lifetime.
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setCache()
Sets a reference to the cache frontend which uses this backend
public
setCache(FrontendInterface $cache) : mixed
Parameters
- $cache : FrontendInterface
-
The frontend for this backend
setCompression()
Enable data compression
public
setCompression(bool $compression) : void
Parameters
- $compression : bool
-
TRUE to enable compression
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setCompressionLevel()
Set data compression level.
public
setCompressionLevel(int $compressionLevel) : void
If compression is enabled and this is not set, gzcompress default level will be used.
Parameters
- $compressionLevel : int
-
-1 to 9: Compression level
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setConnectionTimeout()
Set connection timeout.
public
setConnectionTimeout(int $connectionTimeout) : void
This value in seconds is used as a maximum number of seconds to wait if a connection can be established.
Parameters
- $connectionTimeout : int
-
limit in seconds, a value greater or equal than 0
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setDatabase()
Setter for database number
public
setDatabase(int $database) : void
Parameters
- $database : int
-
Database
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setDefaultLifetime()
Sets the default lifetime for this cache backend
public
setDefaultLifetime(int $defaultLifetime) : mixed
Parameters
- $defaultLifetime : int
-
Default lifetime of this cache backend in seconds. If NULL is specified, the default lifetime is used. "0" means unlimited lifetime.
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setHostname()
Setter for server hostname
public
setHostname(string $hostname) : void
Parameters
- $hostname : string
-
Hostname
setPassword()
Setter for authentication password
public
setPassword(string $password) : void
Parameters
- $password : string
-
Password
setPersistentConnection()
Setter for persistent connection
public
setPersistentConnection(bool $persistentConnection) : void
Parameters
- $persistentConnection : bool
setPort()
Setter for server port
public
setPort(int $port) : void
Parameters
- $port : int
-
Port
calculateExpiryTime()
Calculates the expiry time by the given lifetime. If no lifetime is specified, the default lifetime is used.
protected
calculateExpiryTime([int $lifetime = null ]) : DateTime
Parameters
- $lifetime : int = null
-
The lifetime in seconds
Return values
DateTime —The expiry time
canBeUsedInStringContext()
Helper method to catch invalid identifiers and tags
protected
canBeUsedInStringContext(mixed $variable) : bool
Parameters
- $variable : mixed
-
Variable to be checked
Return values
boolgetDataIdentifier()
protected
getDataIdentifier(string $identifier) : string
Parameters
- $identifier : string
Return values
stringgetTagIdentifier()
protected
getTagIdentifier(string $tag) : string
Parameters
- $tag : string
Return values
stringgetTagsIdentifier()
protected
getTagsIdentifier(string $identifier) : string
Parameters
- $identifier : string
Return values
stringremoveIdentifierEntriesAndRelations()
Helper method for flushByTag() Gets list of identifiers and tags and removes all relations of those tags
protected
removeIdentifierEntriesAndRelations(array<string|int, mixed> $identifiers, array<string|int, mixed> $tags) : void
Scales O(1) with number of cache entries Scales O(n^2) with number of tags
Parameters
- $identifiers : array<string|int, mixed>
-
List of identifiers to remove
- $tags : array<string|int, mixed>
-
List of tags to be handled