Cache

Caching abstraction that stores data on disk and supports LRU (least recently used) access. Since extensions can only consume up to a max. heap memory size, the cache only maintains a lightweight index in memory and stores the actual data in separate files on disk in the extension's support directory.
API Reference
Cache
The Cache class provides CRUD-style methods (get, set, remove) to update and retrieve data synchronously based on a key. The data must be a string and it is up to the client to decide which serialization format to use. A typical use case would be to use JSON.stringify and JSON.parse.
By default, the cache is shared between the commands of an extension. Use Cache.Options to configure a namespace per command if needed (for example, set it to environment.commandName).
Signature
constructor(options: Cache.Options): Cache
Example
import { List, Cache } from "@raycast/api";
​
type Item = { id: string; title: string };
const cache = new Cache();
cache.set("items", JSON.stringify([{ id: "1", title: "Item 1" }]));
​
export default function Command() {
  const cached = cache.get("items");
  const items: Item[] = cached ? JSON.parse(cached) : [];
​
  return (
    <List>
      {items.map((item) => (
        <List.Item key={item.id} title={item.title} />
      ))}
    </List>
  );
}
Properties
Property
Description
Type
isEmpty*
Returns true if the cache is empty, false otherwise.
boolean
Methods
Method
​get(key: string): string | undefined​
​has(key: string): boolean​
​set(key: string, data: string): void​
​remove(key: string): boolean​
​clear(options = { notifySubscribers: true }): void​
​subscribe(subscriber: Cache.Subscriber): Cache.Subscription​
Cache#get
Returns the data for the given key. If there is no data for the key, undefined is returned. If you want to just check for the existence of a key, use has.
Signature
get(key: string): string | undefined
Parameters
Name
Description
Type
key*
The key of the Cache entry.
string
Cache#has
Returns true if data for the key exists, false otherwise. You can use this method to check for entries without affecting the LRU access.
Signature
has(key: string): boolean
Parameters
Name
Description
Type
key*
The key of the Cache entry.
string
Cache#set
Sets the data for the given key. If the data exceeds the configured capacity, the least recently used entries are removed. This also notifies registered subscribers (see subscribe).
Signature
set(key: string, data: string)
Parameters
Name
Description
Type
key*
The key of the Cache entry.
string
data*
The stringified data of the Cache entry.
string
Cache#remove
Removes the data for the given key. This also notifies registered subscribers (see subscribe). Returns true if data for the key was removed, false otherwise.
Signature
remove(key: string): boolean
Cache#clear
Clears all stored data. This also notifies registered subscribers (see subscribe) unless the notifySubscribers option is set to false.
Signature
clear((options = { notifySubscribers: true }));
Parameters
Name
Description
Type
options
Options with a notifySubscribers property. The default is true; set to false to disable notification of subscribers.
object
Cache#subscribe
Registers a new subscriber that gets notified when cache data is set or removed. Returns a function that can be called to remove the subscriber.
Signature
subscribe(subscriber: Cache.Subscriber): Cache.Subscription
Parameters
Name
Description
Type
subscriber
A function that is called when the Cache is updated. The function receives two values: the key of the Cache entry that was updated or undefined when the Cache is cleared, and the associated data.
​Cache.Subscriber​
Types
Cache.Options
The options for creating a new Cache.
Properties
Property
Description
Type
capacity
The capacity in bytes. If the stored data exceeds the capacity, the least recently used data is removed. The default capacity is 10 MB.
number
namespace
If set, the Cache will be namespaced via a subdirectory. This can be useful to separate the caches for individual commands of an extension. By default, the cache is shared between the commands of an extension.
string
Cache.Subscriber
Function type used as parameter for subscribe.
type Subscriber = (key: string | undefined, data: string | undefined) => void;
Cache.Subscription
Function type returned from subscribe.
type Subscription = () => void;

Property	Description	Type
isEmpty*	Returns `true` if the cache is empty, `false` otherwise.	`boolean`

Method
`get(key: string): string \| undefined`
`has(key: string): boolean`
`set(key: string, data: string): void`
`remove(key: string): boolean`
`clear(options = { notifySubscribers: true }): void`
`subscribe(subscriber: Cache.Subscriber): Cache.Subscription`

Name	Description	Type
key*	The key of the Cache entry.	`string`

Name	Description	Type
key*	The key of the Cache entry.	`string`

Name	Description	Type
key*	The key of the Cache entry.	`string`
data*	The stringified data of the Cache entry.	`string`

Name	Description	Type
options	Options with a `notifySubscribers` property. The default is `true`; set to `false` to disable notification of subscribers.	`object`

Name	Description	Type
subscriber	A function that is called when the Cache is updated. The function receives two values: the `key` of the Cache entry that was updated or `undefined` when the Cache is cleared, and the associated `data`.	`Cache.Subscriber`

Property	Description	Type
capacity	The capacity in bytes. If the stored data exceeds the capacity, the least recently used data is removed. The default capacity is 10 MB.	`number`
namespace	If set, the Cache will be namespaced via a subdirectory. This can be useful to separate the caches for individual commands of an extension. By default, the cache is shared between the commands of an extension.	`string`

Last modified 6mo ago