utils/dev.kindling.utils.method/KRetryRunner

KRetryRunner

class KRetryRunner<T>(scope: CoroutineScope, val retries: Int = 3, val delay: Duration = 250.milliseconds, val backoffFactor: Double = 2.0, val maxDelay: Duration = 10.seconds, val onSuccess: (T) -> Unit? = null, val onError: (Throwable) -> Unit? = null)(source)

A utility that retries a suspending operation with configurable exponential back-off and jitter.

This is a Kotlin implementation of the useRetry pattern. It manages the lifecycle of asynchronous attempts, providing reactive state for loading status, current attempt count, successful values, and the last encountered error.

Example usage:

val runner = KRetryRunner<User>(
    scope = viewModelScope,
    retries = 3,
    delay = 500.milliseconds,
    backoffFactor = 2.0,
    onSuccess = { user -> println("User fetched: ${user.name}") },
    onError = { err -> println("Attempt failed: ${err.message}") }
)

// Trigger manually:
runner.launch { api.getUser(id) }

// Observe in UI:
val isLoading by runner.isLoading.collectAsState()
val error by runner.error.collectAsState()
val user by runner.value.collectAsState()

if (isLoading) CircularProgressIndicator()
error?.let { Text("Error: ${it.message}") }
user?.let { UserProfile(it) }

Parameters

scope

The CoroutineScope that owns the retry jobs.

retries

The maximum number of additional attempts after the first failure. Default: 3.

delay

The initial wait duration between the first and second attempt. Default: 250ms.

backoffFactor

The multiplier applied to the wait duration after each failure. Default: 2.0.

maxDelay

The maximum allowed delay between attempts. Default: 10s.

onSuccess

Optional callback invoked when an attempt succeeds.

onError

Optional callback invoked after each failed attempt.

Type Parameters

The type of the result produced by the asynchronous operation.

Constructors

KRetryRunner

constructor(scope: CoroutineScope, retries: Int = 3, delay: Duration = 250.milliseconds, backoffFactor: Double = 2.0, maxDelay: Duration = 10.seconds, onSuccess: (T) -> Unit? = null, onError: (Throwable) -> Unit? = null)