KurrentDB

This is unofficial Kurrent (formerly: EventStore) Database gRPC Client SDK, developing in Swift language

Getting the library

Swift Package Manager

The Swift Package Manager is the preferred way to get EventStoreDB. Simply add the package dependency to your Package.swift:

dependencies: [
  .package(url: "https://github.com/gradyzhuo/KurrentDB-Swift.git", from: "1.0.0")
]

...and depend on "KurrentDB" in the necessary targets:

.target(
  name: ...,
  dependencies: [.product(name: "KurrentDB", package: "KurrentDB-Swift")]
]

Examples

The library name to import.

import KurrentDB

ClientSettings

// Using a client settings for a single node configuration by parsing a connection string.
let settings: ClientSettings = .parse(connectionString: "kurrent://localhost:2113")

// convenience 
let settings: ClientSettings = "kurrent://localhost:2113".parse()

// using string literal 
let settings: ClientSettings = "kurrent://localhost:2113"

//using constructor
let settings: ClientSettings = .localhost()

ClientSettings with credentials authentication.

// Using a client settings for a single node configuration by parsing a connection string.
let settings: ClientSettings = .parse(connectionString: "kurrent://admin:changeit@localhost:2113")

// convenience 
let settings: ClientSettings = "kurrent://admin:changeit@localhost:2113".parse()

// using string literal 
let settings: ClientSettings = "kurrent://admin:changeit@localhost:2113"

//using constructor
let settings: ClientSettings = .localhost()
                               .authenticated(.credentials(username: "admin", password: "changeit"))

ClientSettings with CA file.

// parse from connection string
let caPath = "the path of ca file..."
let settings: ClientSettings = "kurrent://admin:changeit@localhost:2113?tls=true&tlsCaFile=\(caPath)".parse()

//or construct in coding.
//settings with credentials with adding ssl file by path
let settings: ClientSettings = .localhost()
                               .secure(true) //required
                               .cerificate(path: caPath!)
                               .authenticated(.credentials(username: "admin", password: "changeit"))

//or add ssl file with bundle
let settings: ClientSettings = .localhost()
                               .secure(true) //required
                               .cerificate(source: .crtInBundle("ca")!)
                               .authenticated(.credentials(username: "admin", password: "changeit"))

Appending Event

// Import packages of KurrentDB.
import KurrentDB

// Using a client settings for a single node configuration by parsing a connection string.
let settings: ClientSettings = .localhost()

// Create the data array of events.
let events:[EventData] = [
    .init(id: .init(uuidString: "b989fe21-9469-4017-8d71-9820b8dd1164")!, eventType: "ItemAdded", model: ["Description": "Xbox One S 1TB (Console)"]),
    .init(id: .init(uuidString: "b989fe21-9469-4017-8d71-9820b8dd1174")!, eventType: "ItemAdded", model: "Gears of War 4")]

// Append two events with one response
let client = KurrentDBClient(settings: .localhost())
try await client.appendStream(on: "stream_for_testing", events: events){
    $0.revision(expected: .any)
}

Read Event

// Import packages of EventStoreDB.
import KurrentDB

// Using a client settings for a single node configuration by parsing a connection string.
let settings: ClientSettings = .localhost()

// Read responses of event from specified stream.
let responses = try await client.readStream(on: "stream_for_testing", startFrom: .start){
    $0.backward()
}

// loop it.
for try await response in responses {
    //handle response
    if let readEvent = try response.event {
        //handle event
    }
}

PersistentSubscriptions

Create

// Import packages of EventStoreDB.
import KurrentDB

// Using a client settings for a single node configuration by parsing a connection string.
let settings: ClientSettings = .localhost()

// Build a persistentSubscriptions client.
let client = KurrentDBClient(settings: settings)

// the stream identifier to subscribe.
let streamIdentifier = StreamIdentifier(name: UUID().uuidString)

// the group of subscription
let groupName = "myGroupTest"

// Create it to specified identifier of stream
try await client.createPersistentSubscription(to: streamIdentifier, groupName: groupName)

Subscribe

// Import packages of EventStoreDB.
import KurrentDB

// Using a client settings for a single node configuration by parsing a connection string.
let settings: ClientSettings = .localhost()

// Build a persistentSubscriptions client.
let client = KurrentDBClient(settings: settings)

// the stream identifier to subscribe.
let streamIdentifier = StreamIdentifier(name: UUID().uuidString)

// the group of subscription
let groupName = "myGroupTest"

// Subscribe to stream or all, and get a subscription.
let subscription = try await client.subscribePersistentSubscription(to: streamIdentifier, groupName: groupName)

// Loop all results by subscription.events
for try await result in subscription.events {
    //handle result
    // ...
    
    // ack the readEvent if succeed
    try await subscription.ack(readEvents: result.event)
    // else nack thr readEvent if not succeed.
    // try await subscription.nack(readEvents: result.event, action: .park, reason: "It's failed.")
}