durable-utils/retries.d.ts

Utilities for Cloudflare Durable Objects and Workers, including SQL migrations, sharding and retry utilities, and more.

/**
 * Returns the number of milliseconds to wait before retrying a request.
 * See the "Full Jitter" approach in https://aws.amazon.com/blogs/architecture/exponential-backoff-and-jitter/.
 * @param attempt The number of attempts so far.
 * @param baseDelayMs Number of milliseconds to use as multiplier for the exponential backoff.
 * @param maxDelayMs Maximum number of milliseconds to wait.
 * @returns Milliseconds to wait before retrying.
 */
export declare function jitterBackoff(attempt: number, baseDelayMs: number, maxDelayMs: number): number;
export type TryNOptions = {
    /**
     * @param err Error thrown by the function.
     * @param nextAttempt Number of next attempt to make.
     * @returns Returns true if the error and nextAttempt number is retryable.
     */
    isRetryable?: (err: unknown, nextAttempt: number) => boolean;
    /**
     * Number of milliseconds to use as multiplier for the exponential backoff.
     */
    baseDelayMs?: number;
    /**
     * Maximum number of milliseconds to wait.
     */
    maxDelayMs?: number;
    /**
     * If true, logs the error and attempt number to the console.
     */
    verbose?: boolean;
};
/**
 * @param n Number of total attempts to make.
 * @param fn The function to call for each attempt. Receives the attempt number.
 * @param options The options for the retry strategy.
 * @param options.isRetryable The function to call to determine if the error is retryable. Receives the error and the next attempt number.
 * @param options.baseDelayMs Number of milliseconds to use as multiplier for the exponential backoff.
 * @param options.maxDelayMs Maximum number of milliseconds to wait.
 * @param options.verbose If true, logs the error and attempt number to the console.
 * @returns The result of the `fn` function or propagates the last error thrown once `isRetryable` returns false or all retries failed.
 */
export declare function tryN<T>(n: number, fn: (attempt: number) => Promise<T>, options?: TryNOptions): Promise<T>;
/**
 * @deprecated Use the overload with 3rd argument being `options`. This function overload will be removed in the next version.
 * @param n Number of total attempts to make.
 * @param fn The function to call for each attempt. Receives the attempt number.
 * @param isRetryable The function to call to determine if the error is retryable. Receives the error and the next attempt number.
 * @param options The options for the retry strategy.
 * @param options.baseDelayMs Number of milliseconds to use as multiplier for the exponential backoff.
 * @param options.maxDelayMs Maximum number of milliseconds to wait.
 * @param options.verbose If true, logs the error and attempt number to the console.
 * @returns The result of the `fn` function or propagates the last error thrown once `isRetryable` returns false or all retries failed.
 */
export declare function tryN<T>(n: number, fn: (attempt: number) => Promise<T>, isRetryable: (err: unknown, nextAttempt: number) => boolean, 
/**
 * @deprecated Use the `options` 3rd argument instead.
 */
options?: TryNOptions): Promise<T>;
/**
 * @param fn The function to call for each attempt. Receives the attempt number.
 * @param isRetryable The function to call to determine if the error is retryable. Receives the error and the next attempt number.
 * @param options The options for the retry strategy.
 * @param options.baseDelayMs Number of milliseconds to use as multiplier for the exponential backoff.
 * @param options.maxDelayMs Maximum number of milliseconds to wait.
 * @param options.verbose If true, logs the error and attempt number to the console.
 * @returns The result of the `fn` function or propagates the last error thrown once `isRetryable` returns false or all retries failed.
 */
export declare function tryWhile<T>(fn: (attempt: number) => Promise<T>, isRetryable: (err: unknown, nextAttempt: number) => boolean, options?: {
    baseDelayMs?: number;
    maxDelayMs?: number;
    verbose?: boolean;
}): Promise<T>;