[6a3a178] | 1 | 'use strict';
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| 2 |
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| 3 | Object.defineProperty(exports, "__esModule", {
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| 4 | value: true
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| 5 | });
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| 6 | exports.default = retry;
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| 7 |
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| 8 | var _noop = require('lodash/noop');
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| 9 |
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| 10 | var _noop2 = _interopRequireDefault(_noop);
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| 11 |
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| 12 | var _constant = require('lodash/constant');
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| 13 |
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| 14 | var _constant2 = _interopRequireDefault(_constant);
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| 15 |
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| 16 | var _wrapAsync = require('./internal/wrapAsync');
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| 17 |
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| 18 | var _wrapAsync2 = _interopRequireDefault(_wrapAsync);
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| 19 |
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| 20 | function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
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| 21 |
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| 22 | /**
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| 23 | * Attempts to get a successful response from `task` no more than `times` times
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| 24 | * before returning an error. If the task is successful, the `callback` will be
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| 25 | * passed the result of the successful task. If all attempts fail, the callback
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| 26 | * will be passed the error and result (if any) of the final attempt.
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| 27 | *
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| 28 | * @name retry
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| 29 | * @static
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| 30 | * @memberOf module:ControlFlow
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| 31 | * @method
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| 32 | * @category Control Flow
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| 33 | * @see [async.retryable]{@link module:ControlFlow.retryable}
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| 34 | * @param {Object|number} [opts = {times: 5, interval: 0}| 5] - Can be either an
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| 35 | * object with `times` and `interval` or a number.
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| 36 | * * `times` - The number of attempts to make before giving up. The default
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| 37 | * is `5`.
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| 38 | * * `interval` - The time to wait between retries, in milliseconds. The
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| 39 | * default is `0`. The interval may also be specified as a function of the
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| 40 | * retry count (see example).
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| 41 | * * `errorFilter` - An optional synchronous function that is invoked on
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| 42 | * erroneous result. If it returns `true` the retry attempts will continue;
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| 43 | * if the function returns `false` the retry flow is aborted with the current
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| 44 | * attempt's error and result being returned to the final callback.
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| 45 | * Invoked with (err).
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| 46 | * * If `opts` is a number, the number specifies the number of times to retry,
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| 47 | * with the default interval of `0`.
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| 48 | * @param {AsyncFunction} task - An async function to retry.
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| 49 | * Invoked with (callback).
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| 50 | * @param {Function} [callback] - An optional callback which is called when the
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| 51 | * task has succeeded, or after the final failed attempt. It receives the `err`
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| 52 | * and `result` arguments of the last attempt at completing the `task`. Invoked
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| 53 | * with (err, results).
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| 54 | *
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| 55 | * @example
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| 56 | *
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| 57 | * // The `retry` function can be used as a stand-alone control flow by passing
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| 58 | * // a callback, as shown below:
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| 59 | *
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| 60 | * // try calling apiMethod 3 times
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| 61 | * async.retry(3, apiMethod, function(err, result) {
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| 62 | * // do something with the result
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| 63 | * });
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| 64 | *
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| 65 | * // try calling apiMethod 3 times, waiting 200 ms between each retry
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| 66 | * async.retry({times: 3, interval: 200}, apiMethod, function(err, result) {
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| 67 | * // do something with the result
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| 68 | * });
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| 69 | *
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| 70 | * // try calling apiMethod 10 times with exponential backoff
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| 71 | * // (i.e. intervals of 100, 200, 400, 800, 1600, ... milliseconds)
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| 72 | * async.retry({
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| 73 | * times: 10,
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| 74 | * interval: function(retryCount) {
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| 75 | * return 50 * Math.pow(2, retryCount);
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| 76 | * }
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| 77 | * }, apiMethod, function(err, result) {
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| 78 | * // do something with the result
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| 79 | * });
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| 80 | *
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| 81 | * // try calling apiMethod the default 5 times no delay between each retry
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| 82 | * async.retry(apiMethod, function(err, result) {
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| 83 | * // do something with the result
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| 84 | * });
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| 85 | *
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| 86 | * // try calling apiMethod only when error condition satisfies, all other
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| 87 | * // errors will abort the retry control flow and return to final callback
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| 88 | * async.retry({
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| 89 | * errorFilter: function(err) {
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| 90 | * return err.message === 'Temporary error'; // only retry on a specific error
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| 91 | * }
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| 92 | * }, apiMethod, function(err, result) {
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| 93 | * // do something with the result
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| 94 | * });
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| 95 | *
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| 96 | * // to retry individual methods that are not as reliable within other
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| 97 | * // control flow functions, use the `retryable` wrapper:
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| 98 | * async.auto({
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| 99 | * users: api.getUsers.bind(api),
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| 100 | * payments: async.retryable(3, api.getPayments.bind(api))
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| 101 | * }, function(err, results) {
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| 102 | * // do something with the results
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| 103 | * });
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| 104 | *
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| 105 | */
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| 106 | function retry(opts, task, callback) {
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| 107 | var DEFAULT_TIMES = 5;
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| 108 | var DEFAULT_INTERVAL = 0;
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| 109 |
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| 110 | var options = {
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| 111 | times: DEFAULT_TIMES,
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| 112 | intervalFunc: (0, _constant2.default)(DEFAULT_INTERVAL)
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| 113 | };
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| 114 |
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| 115 | function parseTimes(acc, t) {
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| 116 | if (typeof t === 'object') {
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| 117 | acc.times = +t.times || DEFAULT_TIMES;
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| 118 |
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| 119 | acc.intervalFunc = typeof t.interval === 'function' ? t.interval : (0, _constant2.default)(+t.interval || DEFAULT_INTERVAL);
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| 120 |
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| 121 | acc.errorFilter = t.errorFilter;
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| 122 | } else if (typeof t === 'number' || typeof t === 'string') {
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| 123 | acc.times = +t || DEFAULT_TIMES;
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| 124 | } else {
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| 125 | throw new Error("Invalid arguments for async.retry");
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| 126 | }
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| 127 | }
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| 128 |
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| 129 | if (arguments.length < 3 && typeof opts === 'function') {
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| 130 | callback = task || _noop2.default;
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| 131 | task = opts;
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| 132 | } else {
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| 133 | parseTimes(options, opts);
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| 134 | callback = callback || _noop2.default;
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| 135 | }
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| 136 |
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| 137 | if (typeof task !== 'function') {
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| 138 | throw new Error("Invalid arguments for async.retry");
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| 139 | }
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| 140 |
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| 141 | var _task = (0, _wrapAsync2.default)(task);
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| 142 |
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| 143 | var attempt = 1;
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| 144 | function retryAttempt() {
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| 145 | _task(function (err) {
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| 146 | if (err && attempt++ < options.times && (typeof options.errorFilter != 'function' || options.errorFilter(err))) {
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| 147 | setTimeout(retryAttempt, options.intervalFunc(attempt));
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| 148 | } else {
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| 149 | callback.apply(null, arguments);
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| 150 | }
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| 151 | });
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| 152 | }
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| 153 |
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| 154 | retryAttempt();
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| 155 | }
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| 156 | module.exports = exports['default']; |
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