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