Redis Cache Store. More...

Inheritance diagram for cachestore_redis:

Public Member Functions
	__construct ($name, array $configuration=array())
	Constructs an instance of this type of store.

	acquire_lock ($key, $ownerid)
	Tries to acquire a lock with a given name.

	cache_size_details (int $samplekeys=50)
	Gets the amount of memory used by this specific cache within the store, if known.

	check_lock_state ($key, $ownerid)
	Checks a lock with a given name and owner information.

	cleanup ()

	create_clone (array $details=array())
	Creates a clone of this store instance ready to be initialised.

	delete ($key)
	Delete the given key.

	delete_many (array $keys)
	Delete many keys.

	estimate_stored_size ($key, $value)
	Estimates the stored size, taking into account whether compression is turned on.

	expire_ttl ()
	Runs TTL expiry process for this cache.

	find_all ()
	Finds all of the keys being used by this cache store instance.

	find_by_prefix ($prefix)
	Finds all of the keys whose keys start with the given prefix.

	get ($key)
	Get the value associated with a given key.

	get_last_io_bytes ()
	Gets the number of bytes read from or written to cache as a result of the last action.

	get_many ($keys)
	Get the values associated with a list of keys.

	get_warnings ()
	Can be overridden to return any warnings this store instance should make to the admin.

	has ($key)
	Determines if the store has a given key.

	has_all (array $keys)
	Determines if the store has all of the keys in a list.

	has_any (array $keys)
	Determines if the store has any of the keys in a list.

	initialise (cache_definition $definition)
	Initialize the store.

	instance_created ()
	Performs any necessary operation when the store instance has been created.

	instance_deleted ()
	Cleans up after an instance of the store.

	is_initialised ()
	Determine if the store is initialized.

	is_ready ()
	Determine if the store is ready for use.

	is_searchable ()
	Returns true if the store instance is searchable.

	my_name ()
	Get the name of the store.

	purge ()
	Purges all keys from the store.

	release_lock ($key, $ownerid)
	Releases a given lock if the owner information matches.

	set ($key, $value)
	Set the value of a key.

	set_many (array $keyvaluearray)
	Set the values of many keys.

	shutdown_release_locks ()
	Releases any locks when the system shuts down, in case there is a crash or somebody forgets to use 'try-finally'.

	store_total_size ()
	Gets Redis reported memory usage.

	supports_data_guarantee ()
	Returns true if the store instance guarantees data.

	supports_dereferencing_objects ()
	Returns true if the store automatically dereferences objects.

	supports_multiple_identifiers ()
	Returns true if the store instance supports multiple identifiers.

	supports_native_ttl ()
	Returns true if the store instance supports native ttl.

Static Public Member Functions
static	are_requirements_met ()
	Determines if the requirements for this type of store are met.

static	can_add_instance ()
	Returns true if the user can add an instance of the store plugin.

static	config_get_compressor_options ()
	Gets an array of options to use as the compressor.

static	config_get_configuration_array ($data)
	Creates a configuration array from given 'add instance' form data.

static	config_get_serializer_options ()
	Gets an array of options to use as the serialiser.

static	config_set_edit_form_data (moodleform $editform, array $config)
	Sets form data from a configuration array.

static	get_supported_features (array $configuration=array())
	Get the features of this type of cache store.

static	get_supported_modes (array $configuration=array())
	Get the supported modes of this type of cache store.

static	initialise_test_instance (cache_definition $definition)
	Creates an instance of the store for testing.

static	is_supported_mode ($mode)
	Determines if this type of store supports a given mode.

static	ready_to_be_used_for_testing ()
	Returns true if this cache store instance is both suitable for testing, and ready for testing.

static	set_phpunit_time (int $time=0)
	Sets the current time (within unit test) for TTL functionality.

static	unit_test_configuration ()
	Return configuration to use when unit testing.

Public Attributes
const	COMPRESSOR_NONE = 0
	Compressor: none.

const	COMPRESSOR_PHP_GZIP = 1
	Compressor: PHP GZip.

const	COMPRESSOR_PHP_ZSTD = 2
	Compressor: PHP Zstandard.

const	DEREFERENCES_OBJECTS = 16
	The cache store dereferences objects.

const	IO_BYTES_NOT_SUPPORTED = -1
	Returned from get_last_io_bytes if this cache store doesn't support counting bytes read/sent.

const	IS_SEARCHABLE = 8
	The cache is searchable by key.

const	MODE_APPLICATION = 1
	Application caches.

const	MODE_REQUEST = 4
	Request caches.

const	MODE_SESSION = 2
	Session caches.

const	STATIC_ACCEL = ' static accel. '
	Static caches.

const	SUPPORTS_DATA_GUARANTEE = 2
	Ensures data remains in the cache once set.

const	SUPPORTS_MULTIPLE_IDENTIFIERS = 1
	Supports multi-part keys.

const	SUPPORTS_NATIVE_TTL = 4
	Supports a native ttl system.

int const	TTL_EXPIRE_BATCH = 10000
	Number of items to delete from cache in one batch when expiring old TTL data.

string const	TTL_SUFFIX = '_ttl'
	Suffix used on key name (for hash) to store the TTL sorted list.

Protected Member Functions
	new_redis (array $configuration)
	Create a new Redis instance and connect to the server.

	ping (Redis $redis)
	See if we can ping Redis server.

Static Protected Member Functions
static	get_time ()
	Gets the current time for TTL functionality.

Protected Attributes
int	$compressor = self::COMPRESSOR_NONE
	Compressor for this store.

array	$currentlocks = null
	Array of current locks, or null if we haven't registered shutdown function.

cache_definition	$definition = null
	Cache definition for this store.

string	$hash
	The definition hash, used for hash key.

boolean	$isready = false
	Flag for readiness!

int	$lastiobytes = 0
	Bytes read or written by last call to set()/get() or set_many()/get_many().

int	$locktimeout = 600
	Timeout before lock is automatically released (in case of crashes)

int	$lockwait = 60
	Maximum number of seconds to wait for a lock before giving up.

string	$name
	Name of this store.

Redis	$redis
	Connection to Redis for this store.

int	$serializer = Redis::SERIALIZER_PHP
	Serializer for this store.

Detailed Description

Redis Cache Store.

To allow separation of definitions in Moodle and faster purging, each cache is implemented as a Redis hash. That is a trade-off between having functionality of TTL and being able to manage many caches in a single redis instance. Given the recommendation not to use TTL if at all possible and the benefits of having many stores in Redis using the hash configuration, the hash implementation has been used.

Copyright: 2013 Adam Durana

License: http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later

Constructor & Destructor Documentation

◆ __construct()

cachestore_redis::__construct	(		$name,
		array	$configuration = array() )

Constructs an instance of this type of store.

Parameters

string	$name
array	$configuration

Reimplemented from cache_store.

Member Function Documentation

◆ acquire_lock()

cachestore_redis::acquire_lock	(		$key,
			$ownerid )

Tries to acquire a lock with a given name.

See also: cache_is_lockable

Parameters

string	$key	Name of the lock to acquire.
string	$ownerid	Information to identify owner of lock if acquired.

Return values

bool	True if the lock was acquired, false if it was not.

Implements cache_is_lockable.

◆ are_requirements_met()

static cachestore_redis::are_requirements_met ( )

static

Determines if the requirements for this type of store are met.

Return values

bool

Implements cache_store_interface.

◆ cache_size_details()

cache_store::cache_size_details ( int $samplekeys = 50 )

inherited

Gets the amount of memory used by this specific cache within the store, if known.

This function may be slow and should not be called in normal usage, only for administration pages. The value is usually an estimate, and may not be available at all.

When estimating, a number of sample items will be used for the estimate. If set to 50 (default), then this function will retrieve 50 random items and use that to estimate the total size.

The return value has the following fields:

supported (true if any other values are completed)
items (number of items)
mean (mean size of one item in bytes)
sd (standard deviation of item size in bytes, based on sample)
margin (95% confidence margin for mean - will be 0 if exactly computed)

Parameters

int $samplekeys Number of samples to use

Return values

stdClass Object with information about the store size

Reimplemented in cachestore_file.

◆ can_add_instance()

static cache_store::can_add_instance ( )

staticinherited

Returns true if the user can add an instance of the store plugin.

Return values

bool

Reimplemented in cachestore_dummy, cachestore_session, and cachestore_static.

◆ check_lock_state()

cachestore_redis::check_lock_state	(		$key,
			$ownerid )

Checks a lock with a given name and owner information.

See also: cache_is_lockable

Parameters

string	$key	Name of the lock to check.
string	$ownerid	Owner information to check existing lock against.

Return values

mixed True if the lock exists and the owner information matches, null if the lock does not exist, and false otherwise.

Implements cache_is_lockable.

◆ cleanup()

cache_store::cleanup ( )

inherited

Deprecated: since 2.5

See also: cache_store\instance_deleted()

Reimplemented in cachestore_dummy.

◆ config_get_compressor_options()

static cachestore_redis::config_get_compressor_options ( )

static

Gets an array of options to use as the compressor.

Return values

array

◆ config_get_configuration_array()

static cachestore_redis::config_get_configuration_array ( $data )

static

Creates a configuration array from given 'add instance' form data.

See also: cache_is_configurable

Parameters

stdClass $data

Return values

array

Implements cache_is_configurable.

◆ config_get_serializer_options()

static cachestore_redis::config_get_serializer_options ( )

static

Gets an array of options to use as the serialiser.

Return values

array

◆ config_set_edit_form_data()

static cachestore_redis::config_set_edit_form_data	(	moodleform	$editform,
		array	$config )

static

Sets form data from a configuration array.

See also: cache_is_configurable

Parameters

moodleform	$editform
array	$config

Implements cache_is_configurable.

◆ create_clone()

cache_store::create_clone ( array $details = array() )

inherited

Creates a clone of this store instance ready to be initialised.

This method is used so that a cache store needs only be constructed once. Future requests for an instance of the store will be given a cloned instance.

If you are writing a cache store that isn't compatible with the clone operation you can override this method to handle any situations you want before cloning.

Parameters

array $details An array containing the details of the store from the cache config.

Return values

cache_store

◆ delete()

cachestore_redis::delete ( $key )

Delete the given key.

Parameters

string $key The key to delete.

Return values

bool	True if the delete operation succeeds, false otherwise.

Reimplemented from cache_store.

◆ delete_many()

cachestore_redis::delete_many ( array $keys )

Delete many keys.

Parameters

array $keys The keys to delete.

Return values

int	The number of keys successfully deleted.

Reimplemented from cache_store.

◆ estimate_stored_size()

cachestore_redis::estimate_stored_size	(		$key,
			$value )

Estimates the stored size, taking into account whether compression is turned on.

Parameters

mixed	$key	Key name
mixed	$value	Value

Return values

int	Approximate stored size

Reimplemented from cache_store.

◆ expire_ttl()

cachestore_redis::expire_ttl ( )

Runs TTL expiry process for this cache.

This is not part of the standard cache API and is intended for use by the scheduled task cachestore_redis\ttl.

Return values

array Various keys with information about how the expiry went

◆ find_all()

cachestore_redis::find_all ( )

Finds all of the keys being used by this cache store instance.

Return values

array of all keys in the hash as a numbered array.

Implements cache_is_searchable.

◆ find_by_prefix()

cachestore_redis::find_by_prefix ( $prefix )

Finds all of the keys whose keys start with the given prefix.

Parameters

string $prefix

Return values

array List of keys that match this prefix.

Implements cache_is_searchable.

◆ get()

cachestore_redis::get ( $key )

Get the value associated with a given key.

Parameters

string $key The key to get the value of.

Return values

mixed The value of the key, or false if there is no value associated with the key.

Reimplemented from cache_store.

◆ get_last_io_bytes()

cachestore_redis::get_last_io_bytes ( )

Gets the number of bytes read from or written to cache as a result of the last action.

If compression is not enabled, this function always returns IO_BYTES_NOT_SUPPORTED. The reason is that when compression is not enabled, data sent to the cache is not serialized, and we would need to serialize it to compute the size, which would have a significant performance cost.

Return values

int	Bytes read or written

Since: Moodle 4.0

Reimplemented from cache_store.

◆ get_many()

cachestore_redis::get_many ( $keys )

Get the values associated with a list of keys.

Parameters

array $keys The keys to get the values of.

Return values

array An array of the values of the given keys.

Reimplemented from cache_store.

◆ get_supported_features()

static cachestore_redis::get_supported_features ( array $configuration = array() )

static

Get the features of this type of cache store.

Parameters

array $configuration

Return values

int

Implements cache_store_interface.

◆ get_supported_modes()

static cachestore_redis::get_supported_modes ( array $configuration = array() )

static

Get the supported modes of this type of cache store.

Parameters

array $configuration

Return values

int

Implements cache_store_interface.

◆ get_time()

static cachestore_redis::get_time ( )

staticprotected

Gets the current time for TTL functionality.

This wrapper makes it easier to unit-test the TTL behaviour.

Return values

int	Current time

◆ get_warnings()

cache_store::get_warnings ( )

inherited

Can be overridden to return any warnings this store instance should make to the admin.

This should be used to notify things like configuration conflicts etc. The warnings returned here will be displayed on the cache configuration screen.

Return values

string[] An array of warning strings from the store instance.

◆ has()

cachestore_redis::has ( $key )

Determines if the store has a given key.

See also: cache_is_key_aware

Parameters

string $key The key to check for.

Return values

bool	True if the key exists, false if it does not.

Implements cache_is_key_aware.

◆ has_all()

cachestore_redis::has_all ( array $keys )

Determines if the store has all of the keys in a list.

See also: cache_is_key_aware

Parameters

array $keys The keys to check for.

Return values

bool	True if all of the keys are found, false otherwise.

Implements cache_is_key_aware.

◆ has_any()

cachestore_redis::has_any ( array $keys )

Determines if the store has any of the keys in a list.

See also: cache_is_key_aware

Parameters

array $keys The keys to check for.

Return values

bool	True if any of the keys are found, false none of the keys are found.

Implements cache_is_key_aware.

◆ initialise()

cachestore_redis::initialise ( cache_definition $definition )

Initialize the store.

Parameters

cache_definition $definition

Return values

bool

Reimplemented from cache_store.

◆ initialise_test_instance()

static cachestore_redis::initialise_test_instance ( cache_definition $definition )

static

Creates an instance of the store for testing.

Parameters

cache_definition $definition

Return values

mixed An instance of the store, or false if an instance cannot be created.

Implements cache_store_interface.

◆ instance_created()

cache_store::instance_created ( )

inherited

Performs any necessary operation when the store instance has been created.

Since: Moodle 2.5

Reimplemented in cachestore_file.

◆ instance_deleted()

cachestore_redis::instance_deleted ( )

Cleans up after an instance of the store.

Reimplemented from cache_store.

◆ is_initialised()

cachestore_redis::is_initialised ( )

Determine if the store is initialized.

Return values

bool

Reimplemented from cache_store.

◆ is_ready()

cachestore_redis::is_ready ( )

Determine if the store is ready for use.

Return values

bool

Reimplemented from cache_store.

◆ is_searchable()

cache_store::is_searchable ( )

inherited

Returns true if the store instance is searchable.

Return values

bool

◆ is_supported_mode()

static cachestore_redis::is_supported_mode ( $mode )

static

Determines if this type of store supports a given mode.

Parameters

int $mode

Return values

bool

Implements cache_store_interface.

◆ my_name()

cachestore_redis::my_name ( )

Get the name of the store.

Return values

string

Reimplemented from cache_store.

◆ new_redis()

cachestore_redis::new_redis ( array $configuration )

protected

Create a new Redis instance and connect to the server.

Parameters

array $configuration The server configuration

Return values

Redis

◆ ping()

cachestore_redis::ping ( Redis $redis )

protected

See if we can ping Redis server.

Parameters

Redis $redis

Return values

bool

◆ purge()

cachestore_redis::purge ( )

Purges all keys from the store.

Return values

bool

Reimplemented from cache_store.

◆ ready_to_be_used_for_testing()

static cachestore_redis::ready_to_be_used_for_testing ( )

static

Returns true if this cache store instance is both suitable for testing, and ready for testing.

When TEST_CACHESTORE_REDIS_TESTSERVERS is set, then we are ready to be use d for testing.

Return values

bool

Reimplemented from cache_store.

◆ release_lock()

cachestore_redis::release_lock	(		$key,
			$ownerid )

Releases a given lock if the owner information matches.

See also: cache_is_lockable

Parameters

string	$key	Name of the lock to release.
string	$ownerid	Owner information to use.

Return values

bool	True if the lock is released, false if it is not.

Implements cache_is_lockable.

◆ set()

cachestore_redis::set	(		$key,
			$value )

Set the value of a key.

Parameters

string	$key	The key to set the value of.
mixed	$value	The value.

Return values

bool	True if the operation succeeded, false otherwise.

Reimplemented from cache_store.

◆ set_many()

cachestore_redis::set_many ( array $keyvaluearray )

Set the values of many keys.

Parameters

array $keyvaluearray An array of key/value pairs. Each item in the array is an associative array with two keys, 'key' and 'value'.

Return values

int	The number of key/value pairs successfuly set.

Reimplemented from cache_store.

◆ set_phpunit_time()

static cachestore_redis::set_phpunit_time ( int $time = 0 )

static

Sets the current time (within unit test) for TTL functionality.

This setting is stored in $CFG so will be automatically reset if you use resetAfterTest.

Parameters

int $time Current time (set 0 to start using real time).

◆ shutdown_release_locks()

cachestore_redis::shutdown_release_locks ( )

Releases any locks when the system shuts down, in case there is a crash or somebody forgets to use 'try-finally'.

Do not call this function manually (except from unit test).

◆ store_total_size()

cachestore_redis::store_total_size ( )

Gets Redis reported memory usage.

Return values

int|null Memory used by Redis or null if we don't know

Reimplemented from cache_store.

◆ supports_data_guarantee()

cache_store::supports_data_guarantee ( )

inherited

Returns true if the store instance guarantees data.

Return values

bool

◆ supports_dereferencing_objects()

cache_store::supports_dereferencing_objects ( )

inherited

Returns true if the store automatically dereferences objects.

Return values

bool

◆ supports_multiple_identifiers()

cache_store::supports_multiple_identifiers ( )

inherited

Returns true if the store instance supports multiple identifiers.

Return values

bool

Reimplemented in cachestore_file, cachestore_session, and cachestore_static.

◆ supports_native_ttl()

cache_store::supports_native_ttl ( )

inherited

Returns true if the store instance supports native ttl.

Return values

bool

◆ unit_test_configuration()

static cachestore_redis::unit_test_configuration ( )

static

Return configuration to use when unit testing.

Return values

array

Implements cache_store_interface.

Member Data Documentation

◆ DEREFERENCES_OBJECTS

const cache_store::DEREFERENCES_OBJECTS = 16

inherited

The cache store dereferences objects.

When set, loaders will assume that all data coming from this store has already had all references resolved. So even for complex object structures it will not try to remove references again.

◆ MODE_APPLICATION

const cache_store::MODE_APPLICATION = 1

inherited

Application caches.

These are shared caches.

◆ MODE_REQUEST

const cache_store::MODE_REQUEST = 4

inherited

Request caches.

Static caches really.

◆ MODE_SESSION

const cache_store::MODE_SESSION = 2

inherited

Session caches.

Just access to the PHP session.

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

cache/stores/redis/lib.php

Public Member Functions

Static Public Member Functions

Public Attributes

Protected Member Functions

Static Protected Member Functions

Protected Attributes

Detailed Description

Constructor & Destructor Documentation

◆ __construct()

Member Function Documentation

◆ acquire_lock()

◆ are_requirements_met()

◆ cache_size_details()

◆ can_add_instance()

◆ check_lock_state()

◆ cleanup()

◆ config_get_compressor_options()

◆ config_get_configuration_array()

◆ config_get_serializer_options()

◆ config_set_edit_form_data()

◆ create_clone()

◆ delete()

◆ delete_many()

◆ estimate_stored_size()

◆ expire_ttl()

◆ find_all()

◆ find_by_prefix()

◆ get()

◆ get_last_io_bytes()

◆ get_many()

◆ get_supported_features()

◆ get_supported_modes()

◆ get_time()

◆ get_warnings()

◆ has()

◆ has_all()

◆ has_any()

◆ initialise()

◆ initialise_test_instance()

◆ instance_created()

◆ instance_deleted()

◆ is_initialised()

◆ is_ready()

◆ is_searchable()

◆ is_supported_mode()

◆ my_name()

◆ new_redis()

◆ ping()

◆ purge()

◆ ready_to_be_used_for_testing()

◆ release_lock()

◆ set()

◆ set_many()

◆ set_phpunit_time()

◆ shutdown_release_locks()

◆ store_total_size()

◆ supports_data_guarantee()

◆ supports_dereferencing_objects()

◆ supports_multiple_identifiers()

◆ supports_native_ttl()

◆ unit_test_configuration()

Member Data Documentation

◆ DEREFERENCES_OBJECTS

◆ MODE_APPLICATION

◆ MODE_REQUEST

◆ MODE_SESSION