RedisCache

Distributed cache that stores values in Redis in-memory database.

Implements: ICache, IReferenceable, IConfigurable, IOpenable

Description

The RedisCache class allows you to create distributed caches that store values in Redis in-memory database.

Configuration parameters

  • connection(s):
    • discovery_key: (optional) key to retrieve the connection from IDiscovery
    • host: host name or IP address
    • port: port number
    • uri: resource URI or connection string with all parameters in it
  • credential(s):
    • store_key: key to retrieve parameters from ICredentialStore
    • username: username (currently is not used)
    • password: user’s password
  • options:
    • retries: number of retries (default: 3)
    • timeout: default caching timeout in milliseconds (default: 1 minute)
    • max_size: maximum number of values stored in this cache (default: 1000)

References

  • *:discovery:*:*:1.0 - (optional) IDiscovery services
  • *:credential-store:*:*:1.0 - (optional) ICredentialStore stores to resolve credentials

Constructors

Creates a new instance of this cache.

RedisCache()

Instance methods

close

Closes a component and frees used resources.

close(context: Optional[IContext])

  • context: IContext - (optional) a context to trace execution through a call chain.

configure

Configures a component by passing its configuration parameters.

configure(config: ConfigParams)

  • config: ConfigParams - configuration parameters to be set.

is_open

Checks if the component is open.

is_open(): bool

  • returns: bool - true if the component is open and false otherwise.

open

Opens the component.

open(context: Optional[IContext])

  • context: IContext - (optional) a context to trace execution through a call chain.

remove

Removes a value from the cache by its key.

remove(context: Optional[IContext], key: str): Any

  • context: IContext - (optional) a context to trace execution through a call chain.
  • key: str - unique value key.
  • returns: Any - removed value.

retrieve

Retrieves a cached value from the cache using its key. If the value is missing in the cache or expired, it returns None.

retrieve(context: Optional[IContext], key: str): Any

  • context: IContext - (optional) a context to trace execution through a call chain.
  • key: str - unique value key.
  • returns: Any - retrieved cached value or None if nothing was found.

set_references

Sets references to dependent components.

set_references(references: IReferences)

  • references: IReferences - references to locate the component dependencies.

store

Stores a value in the cache with an expiration time.

store(context: Optional[IContext], key: str, value: Any, timeout: int): Promise<any>

  • context: IContext - (optional) a context to trace execution through a call chain.
  • key: str - unique value key.
  • value: Any - value to store.
  • timeout: int - expiration timeout in milliseconds.
  • returns: Any - stored value.

Examples

cache = RedisCache()
cache.configure(ConfigParams.from_tuples(
    "host", "localhost",
    "port", 6379
))

cache.open("123")
cache.store("123", "key1", "ABC", None)
value = cache.retrieve("123", "key1") # Result: "ABC"