import { ClientError, ClientMiddleware, Status } from 'nice-grpc-common';
/**
 * These options are added to `CallOptions` by
 * `nice-grpc-client-middleware-retry`.
 */
export type RetryOptions = {
    /**
     * Boolean indicating whether retries are enabled.
     *
     * If the method is marked as idempotent in Protobuf, i.e. has
     *
     *     option idempotency_level = IDEMPOTENT;
     *
     * then the default is `true`. Otherwise the default is `false`.
     *
     * Method options currently work only when compiling with `ts-proto`.
     */
    retry?: boolean;
    /**
     * Base delay between retry attempts in milliseconds.
     *
     * Defaults to 1000.
     *
     * Example: if `retryBaseDelayMs` is 100, then retries will be attempted in
     * 100ms, 200ms, 400ms etc (not counting jitter).
     */
    retryBaseDelayMs?: number;
    /**
     * Maximum delay between attempts in milliseconds.
     *
     * Defaults to 30 seconds.
     *
     * Example: if `retryBaseDelayMs` is 1000 and `retryMaxDelayMs` is 3000, then
     * retries will be attempted in 1000ms, 2000ms, 3000ms, 3000ms etc (not
     * counting jitter).
     */
    retryMaxDelayMs?: number;
    /**
     * Maximum for the total number of attempts. `Infinity` is supported.
     *
     * Defaults to 1, i.e. a single retry will be attempted.
     */
    retryMaxAttempts?: number;
    /**
     * Array of retryable status codes.
     *
     * Default is `[UNKNOWN, INTERNAL, UNAVAILABLE, CANCELLED]`.
     */
    retryableStatuses?: Status[];
    /**
     * Called after receiving error with retryable status code before setting
     * backoff delay timer.
     *
     * If the error code is not retryable, or the maximum attempts exceeded, this
     * function will not be called and the error will be thrown from the client
     * method.
     */
    onRetryableError?(error: ClientError, attempt: number, delayMs: number): void;
};
/**
 * Client middleware that adds automatic retries to unary calls.
 */
export declare const retryMiddleware: ClientMiddleware<RetryOptions>;