Search moodle.org's
Developer Documentation

See Release Notes
Long Term Support Release

  • Bug fixes for general core bugs in 3.9.x will end* 10 May 2021 (12 months).
  • Bug fixes for security issues in 3.9.x will end* 8 May 2023 (36 months).
  • PHP version: minimum PHP 7.2.0 Note: minimum PHP version has increased since Moodle 3.8. PHP 7.3.x and 7.4.x are supported too.

Differences Between: [Versions 39 and 311] [Versions 39 and 400] [Versions 39 and 401] [Versions 39 and 402] [Versions 39 and 403]

The library file for the file cache store. This file is part of the file cache store, it contains the API for interacting with an instance of the store. This is used as a default cache store within the Cache API. It should never be deleted.

Copyright: 2012 Sam Hemelryk
License: http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
File Size: 787 lines (26 kb)
Included or required:0 times
Referenced: 0 times
Includes or requires: 0 files

Defines 1 class


Class: cachestore_file  - X-Ref

The file store class.

Configuration options
path:           string: path to the cache directory, if left empty one will be created in the cache directory
autocreate:     true, false
prescan:        true, false

__construct($name, array $configuration = array()   X-Ref
Constructs the store instance.

Noting that this function is not an initialisation. It is used to prepare the store for use.
The store will be initialised when required and will be provided with a cache_definition at that time.

param: string $name
param: array $configuration

instance_created()   X-Ref
Performs any necessary operation when the file store instance has been created.


is_ready()   X-Ref
Returns true if this store instance is ready to be used.

return: bool

is_initialised()   X-Ref
Returns true once this instance has been initialised.

return: bool

get_supported_features(array $configuration = array()   X-Ref
Returns the supported features as a combined int.

param: array $configuration
return: int

supports_multiple_identifiers()   X-Ref
Returns false as this store does not support multiple identifiers.
(This optional function is a performance optimisation; it must be
consistent with the value from get_supported_features.)

return: bool False

get_supported_modes(array $configuration = array()   X-Ref
Returns the supported modes as a combined int.

param: array $configuration
return: int

are_requirements_met()   X-Ref
Returns true if the store requirements are met.

return: bool

is_supported_mode($mode)   X-Ref
Returns true if the given mode is supported by this store.

param: int $mode One of cache_store::MODE_*
return: bool

initialise(cache_definition $definition)   X-Ref
Initialises the cache.

Once this has been done the cache is all set to be used.

param: cache_definition $definition

prescan_keys()   X-Ref
Pre-scan the cache to see which keys are present.


glob_keys_pattern($prefix = '')   X-Ref
Gets a pattern suitable for use with glob to find all keys in the cache.

param: string $prefix A prefix to use.
return: string The pattern.

file_path_for_key($key, $create = false)   X-Ref
Returns the file path to use for the given key.

param: string $key The key to generate a file path for.
param: bool $create If set to the true the directory structure the key requires will be created.
return: string The full path to the file that stores a particular cache key.

get($key)   X-Ref
Retrieves an item from the cache store given its key.

param: string $key The key to retrieve
return: mixed The data that was associated with the key, or false if the key did not exist.

get_many($keys)   X-Ref
Retrieves several items from the cache store in a single transaction.

If not all of the items are available in the cache then the data value for those that are missing will be set to false.

param: array $keys The array of keys to retrieve
return: array An array of items from the cache. There will be an item for each key, those that were not in the store will

delete($key)   X-Ref
Deletes an item from the cache store.

param: string $key The key to delete.
return: bool Returns true if the operation was a success, false otherwise.

delete_many(array $keys)   X-Ref
Deletes several keys from the cache in a single action.

param: array $keys The keys to delete
return: int The number of items successfully deleted.

set($key, $data)   X-Ref
Sets an item in the cache given its key and data value.

param: string $key The key to use.
param: mixed $data The data to set.
return: bool True if the operation was a success false otherwise.

prep_data_before_save($data)   X-Ref
Prepares data to be stored in a file.

param: mixed $data
return: string

prep_data_after_read($data)   X-Ref
Prepares the data it has been read from the cache. Undoing what was done in prep_data_before_save.

param: string $data
return: mixed

set_many(array $keyvaluearray)   X-Ref
Sets many items in the cache in a single transaction.

param: array $keyvaluearray An array of key value pairs. Each item in the array will be an associative array with two
return: int The number of items successfully set. It is up to the developer to check this matches the number of items

has($key)   X-Ref
Checks if the store has a record for the given key and returns true if so.

param: string $key
return: bool

has_all(array $keys)   X-Ref
Returns true if the store contains records for all of the given keys.

param: array $keys
return: bool

has_any(array $keys)   X-Ref
Returns true if the store contains records for any of the given keys.

param: array $keys
return: bool

purge()   X-Ref
Purges the cache definition deleting all the items within it.

return: boolean True on success. False otherwise.

purge_all_definitions()   X-Ref
Purges all the cache definitions deleting all items within them.

return: boolean True on success. False otherwise.

config_get_configuration_array($data)   X-Ref
Given the data from the add instance form this function creates a configuration array.

param: stdClass $data
return: array

config_set_edit_form_data(moodleform $editform, array $config)   X-Ref
Allows the cache store to set its data against the edit form before it is shown to the user.

param: moodleform $editform
param: array $config

ensure_path_exists()   X-Ref
Checks to make sure that the path for the file cache exists.

return: bool

instance_deleted()   X-Ref
Performs any necessary clean up when the file store instance is being deleted.

1. Purges the cache directory.
2. Deletes the directory we created for the given definition.

initialise_test_instance(cache_definition $definition)   X-Ref
Generates an instance of the cache store that can be used for testing.

Returns an instance of the cache store, or false if one cannot be created.

param: cache_definition $definition
return: cachestore_file

unit_test_configuration()   X-Ref
Generates the appropriate configuration required for unit testing.

return: array Array of unit test configuration data to be used by initialise().

write_file($file, $content)   X-Ref
Writes your madness to a file.

There are several things going on in this function to try to ensure what we don't end up with partial writes etc.
1. Files for writing are opened with the mode xb, the file must be created and can not already exist.
2. Renaming, data is written to a temporary file, where it can be verified using md5 and is then renamed.

param: string $file Absolute file path
param: string $content The content to write.
return: bool

my_name()   X-Ref
Returns the name of this instance.

return: string

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

return: array

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

param: string $prefix