import CacheBase from '@alexvv13/tpapi/lib/cache/cacheBase.js'

public class | source

CacheBase

Our base Cache implementation
Extend this class with new implementations to create different cache types (in-memory, database, file system etc.)

Constructor Summary

Public Constructor
public	constructor(options: Object)

Member Summary

Public Members
public	failedCacheWraps: {} Create a stack containing all failed cache sessions
public	memCache: {}
public	memoryLayerEnabled: * Setting the memory options
public	pendingCacheWraps: {} Create a stack and wait before every caching session is finished

Method Summary

Public Methods
public	async get(key: string, getFullObject: boolean): Object \| undefined Get a cached object
public	async getKeys(prefix: string): array<string> Get an array of all the cached keys matching the supplied prefix
public	async set(key: string, value: Object, ttl: Function \| number) Set a key in our cache
public	async wrap(key: string, fn: function, ttl: function \| number): * A helper "wrap" function that will return a cached value if present This will call the supplied function to fetch it if the value isn't present in the cache

Private Methods
private abstract	async _del(key: string) Internal operation to delete a key
private abstract	async _get(key: string): Object \| undefined Internal implementation of Get()
private abstract	async _getKeys(prefix: string) Internal implementation of getKeys()
private abstract	async _set(key: string, object: Object) Internal implementation of Set()

Public Constructors

public constructor(options: Object) source

Params:

Name	Type	Attribute	Description
options	Object
options.useMemoryCache	boolean	optional default: true	Use an in-memory layer on top of this cache Avoid hitting databases too often Not useful if using any distributed setup where memory will be out-of-sync between processes
options.memoryCacheTimeout	number \| null	optional default: null	Timeout for in-memory cache values Default is null, which will use the incoming ttl values for each key

Public Members

public failedCacheWraps: {} source

Create a stack containing all failed cache sessions

public memCache: {} source

public memoryLayerEnabled: * source

Setting the memory options

public pendingCacheWraps: {} source

Create a stack and wait before every caching session is finished

Public Methods

public async get(key: string, getFullObject: boolean): Object | undefined source

Get a cached object

Params:

Name	Type	Attribute	Description
key	string		Unique key name for this cache entry
getFullObject	boolean	optional	Get the full cache entry, including expiry time, even if expired

Return:

Object | undefined

Returns the object in the cache, or undefined if not present

public async getKeys(prefix: string): array<string> source

Get an array of all the cached keys matching the supplied prefix

Params:

Name	Type	Attribute	Description
prefix	string	optional default: ''

Return:

array<string>

public async set(key: string, value: Object, ttl: Function | number) source

Set a key in our cache

Params:

Name	Type	Attribute	Description
key	string		Unique key name for this cache entry
value	Object
ttl	Function \| number	optional default: 3600000	How long the cache entry should last in milliseconds Can be a number or a function that will return a number Default 1 hour

public async wrap(key: string, fn: function, ttl: function | number): * source

A helper "wrap" function that will return a cached value if present
This will call the supplied function to fetch it if the value isn't present in the cache

Params:

Name	Type	Attribute	Description
key	string		Unique key name for this cache entry
fn	function		Fetch function that will be called if the cache entry is not present
ttl	function \| number	optional	How long the cache entry should last in milliseconds Can be a number or a function that will return a number

Return:

Private Methods

private abstract async _del(key: string) source

Internal operation to delete a key

Params:

Name	Type	Attribute	Description
key	string		Key name to delete

private abstract async _get(key: string): Object | undefined source

Internal implementation of Get()

Params:

Name	Type	Attribute	Description
key	string		Unique key name for this cache entry

Return:

Object | undefined

Returns the object in the cache, or undefined if not present

private abstract async _getKeys(prefix: string) source

Internal implementation of getKeys()

Params:

Name	Type	Attribute	Description
prefix	string

private abstract async _set(key: string, object: Object) source

Internal implementation of Set()

Params:

Name	Type	Attribute	Description
key	string		Unique key name for this cache entry
object	Object		Data to be set