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'use strict';
Object.defineProperty(exports, "__esModule", {
value: true
});
exports.default = retry;
var _noop = require('lodash/noop');
var _noop2 = _interopRequireDefault(_noop);
var _constant = require('lodash/constant');
var _constant2 = _interopRequireDefault(_constant);
var _wrapAsync = require('./internal/wrapAsync');
var _wrapAsync2 = _interopRequireDefault(_wrapAsync);
function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
/**
* Attempts to get a successful response from `task` no more than `times` times
* before returning an error. If the task is successful, the `callback` will be
* passed the result of the successful task. If all attempts fail, the callback
* will be passed the error and result (if any) of the final attempt.
*
* @name retry
* @static
* @memberOf module:ControlFlow
* @method
* @category Control Flow
* @see [async.retryable]{@link module:ControlFlow.retryable}
* @param {Object|number} [opts = {times: 5, interval: 0}| 5] - Can be either an
* object with `times` and `interval` or a number.
* * `times` - The number of attempts to make before giving up. The default
* is `5`.
* * `interval` - The time to wait between retries, in milliseconds. The
* default is `0`. The interval may also be specified as a function of the
* retry count (see example).
* * `errorFilter` - An optional synchronous function that is invoked on
* erroneous result. If it returns `true` the retry attempts will continue;
* if the function returns `false` the retry flow is aborted with the current
* attempt's error and result being returned to the final callback.
* Invoked with (err).
* * If `opts` is a number, the number specifies the number of times to retry,
* with the default interval of `0`.
* @param {AsyncFunction} task - An async function to retry.
* Invoked with (callback).
* @param {Function} [callback] - An optional callback which is called when the
* task has succeeded, or after the final failed attempt. It receives the `err`
* and `result` arguments of the last attempt at completing the `task`. Invoked
* with (err, results).
*
* @example
*
* // The `retry` function can be used as a stand-alone control flow by passing
* // a callback, as shown below:
*
* // try calling apiMethod 3 times
* async.retry(3, apiMethod, function(err, result) {
* // do something with the result
* });
*
* // try calling apiMethod 3 times, waiting 200 ms between each retry
* async.retry({times: 3, interval: 200}, apiMethod, function(err, result) {
* // do something with the result
* });
*
* // try calling apiMethod 10 times with exponential backoff
* // (i.e. intervals of 100, 200, 400, 800, 1600, ... milliseconds)
* async.retry({
* times: 10,
* interval: function(retryCount) {
* return 50 * Math.pow(2, retryCount);
* }
* }, apiMethod, function(err, result) {
* // do something with the result
* });
*
* // try calling apiMethod the default 5 times no delay between each retry
* async.retry(apiMethod, function(err, result) {
* // do something with the result
* });
*
* // try calling apiMethod only when error condition satisfies, all other
* // errors will abort the retry control flow and return to final callback
* async.retry({
* errorFilter: function(err) {
* return err.message === 'Temporary error'; // only retry on a specific error
* }
* }, apiMethod, function(err, result) {
* // do something with the result
* });
*
* // It can also be embedded within other control flow functions to retry
* // individual methods that are not as reliable, like this:
* async.auto({
* users: api.getUsers.bind(api),
* payments: async.retryable(3, api.getPayments.bind(api))
* }, function(err, results) {
* // do something with the results
* });
*
*/
function retry(opts, task, callback) {
var DEFAULT_TIMES = 5;
var DEFAULT_INTERVAL = 0;
var options = {
times: DEFAULT_TIMES,
intervalFunc: (0, _constant2.default)(DEFAULT_INTERVAL)
};
function parseTimes(acc, t) {
if (typeof t === 'object') {
acc.times = +t.times || DEFAULT_TIMES;
acc.intervalFunc = typeof t.interval === 'function' ? t.interval : (0, _constant2.default)(+t.interval || DEFAULT_INTERVAL);
acc.errorFilter = t.errorFilter;
} else if (typeof t === 'number' || typeof t === 'string') {
acc.times = +t || DEFAULT_TIMES;
} else {
throw new Error("Invalid arguments for async.retry");
}
}
if (arguments.length < 3 && typeof opts === 'function') {
callback = task || _noop2.default;
task = opts;
} else {
parseTimes(options, opts);
callback = callback || _noop2.default;
}
if (typeof task !== 'function') {
throw new Error("Invalid arguments for async.retry");
}
var _task = (0, _wrapAsync2.default)(task);
var attempt = 1;
function retryAttempt() {
_task(function (err) {
if (err && attempt++ < options.times && (typeof options.errorFilter != 'function' || options.errorFilter(err))) {
setTimeout(retryAttempt, options.intervalFunc(attempt));
} else {
callback.apply(null, arguments);
}
});
}
retryAttempt();
}
module.exports = exports['default'];
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