PROTOCOL

`StorageDriver`

public protocol StorageDriver: AnyObject

Abstract Storage Driver API

Describes both permanent (database, filesystem) and temporary (cache, memory) storage methods. SDK actively uses both storage strategies distinguished by name: * storage - permanent storage * cache - temporary storage

Example

 await write(driver: storage, meta: StorageMeta(room: "323", topic: "dinner"), data: try serialize([ "foo": "boo" ]))

 let supperTry1 = await read(driver: storage, meta: StorageMeta(room: "323", topic: "supper"))

 XCTAssertEqual(supperTry1.flatMap({ try? deserialize([String : String].self, $0) }), [ "boo": "woo" ])

 let supperTry2 = await read(driver: storage, meta: StorageMeta(room: "323", topic: "supper"))

 XCTAssertEqual(supperTry2.flatMap({ try? deserialize([String : String].self, $0) }), [ "boo": "woo" ])

 let dinnerTry1 = await take(driver: storage, meta: StorageMeta(room: "323", topic: "dinner"))

 XCTAssertEqual(dinnerTry1.flatMap({ try? deserialize([String : String].self, $0) }), [ "foo": "boo" ])

 let dinnerTry2 = await take(driver: storage, meta: StorageMeta(room: "323", topic: "dinner"))

 XCTAssertEqual(dinnerTry2.flatMap({ try? deserialize([String : String].self, $0) }), nil)

Methods

`write(meta:data:)`

func write(meta: StorageMeta, data: StorageData) async

Write a unit of data into storage, uniquely identified by meta

If such unit of data already exists it is silently overwritten

Parameters

Name	Description
meta	`StorageMeta` composite identifier
data	`StorageData` unit of data to insert

Returns

void

`read(meta:)`

func read(meta: StorageMeta) async -> StorageData?

Read data stored under provided meta

This method is typically used in permanent storage strategy

Parameters

Name	Description
meta	`StorageMeta` composite identifier

Returns

StorageData

stored data (StorageData), or null if not found

`take(meta:)`

func take(meta: StorageMeta) async -> StorageData?

Take data stored under provided meta and remove original

This method is typically used in temporary storage strategy and as a mean to delete stored entry

Parameters

Name	Description
meta	`StorageMeta` composite identifier

Returns

StorageData

stored data (StorageData), or null if not found