1 | ;
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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 _wrapAsync = require('./internal/wrapAsync');
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9 |
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10 | var _wrapAsync2 = _interopRequireDefault(_wrapAsync);
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11 |
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12 | var _promiseCallback = require('./internal/promiseCallback');
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13 |
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14 | function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
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15 |
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16 | function constant(value) {
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17 | return function () {
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18 | return value;
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19 | };
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20 | }
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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 | * @returns {Promise} a promise if no callback provided
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55 | *
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56 | * @example
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57 | *
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58 | * // The `retry` function can be used as a stand-alone control flow by passing
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59 | * // a callback, as shown below:
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60 | *
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61 | * // try calling apiMethod 3 times
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62 | * async.retry(3, apiMethod, function(err, result) {
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63 | * // do something with the result
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64 | * });
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65 | *
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66 | * // try calling apiMethod 3 times, waiting 200 ms between each retry
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67 | * async.retry({times: 3, interval: 200}, apiMethod, function(err, result) {
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68 | * // do something with the result
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69 | * });
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70 | *
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71 | * // try calling apiMethod 10 times with exponential backoff
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72 | * // (i.e. intervals of 100, 200, 400, 800, 1600, ... milliseconds)
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73 | * async.retry({
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74 | * times: 10,
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75 | * interval: function(retryCount) {
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76 | * return 50 * Math.pow(2, retryCount);
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77 | * }
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78 | * }, apiMethod, function(err, result) {
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79 | * // do something with the result
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80 | * });
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81 | *
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82 | * // try calling apiMethod the default 5 times no delay between each retry
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83 | * async.retry(apiMethod, function(err, result) {
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84 | * // do something with the result
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85 | * });
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86 | *
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87 | * // try calling apiMethod only when error condition satisfies, all other
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88 | * // errors will abort the retry control flow and return to final callback
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89 | * async.retry({
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90 | * errorFilter: function(err) {
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91 | * return err.message === 'Temporary error'; // only retry on a specific error
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92 | * }
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93 | * }, apiMethod, function(err, result) {
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94 | * // do something with the result
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95 | * });
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96 | *
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97 | * // to retry individual methods that are not as reliable within other
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98 | * // control flow functions, use the `retryable` wrapper:
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99 | * async.auto({
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100 | * users: api.getUsers.bind(api),
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101 | * payments: async.retryable(3, api.getPayments.bind(api))
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102 | * }, function(err, results) {
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103 | * // do something with the results
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104 | * });
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105 | *
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106 | */
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107 | const DEFAULT_TIMES = 5;
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108 | const DEFAULT_INTERVAL = 0;
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109 |
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110 | function retry(opts, task, callback) {
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111 | var options = {
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112 | times: DEFAULT_TIMES,
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113 | intervalFunc: constant(DEFAULT_INTERVAL)
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114 | };
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115 |
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116 | if (arguments.length < 3 && typeof opts === 'function') {
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117 | callback = task || (0, _promiseCallback.promiseCallback)();
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118 | task = opts;
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119 | } else {
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120 | parseTimes(options, opts);
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121 | callback = callback || (0, _promiseCallback.promiseCallback)();
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122 | }
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123 |
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124 | if (typeof task !== 'function') {
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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 | var _task = (0, _wrapAsync2.default)(task);
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129 |
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130 | var attempt = 1;
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131 | function retryAttempt() {
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132 | _task((err, ...args) => {
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133 | if (err === false) return;
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134 | if (err && attempt++ < options.times && (typeof options.errorFilter != 'function' || options.errorFilter(err))) {
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135 | setTimeout(retryAttempt, options.intervalFunc(attempt - 1));
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136 | } else {
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137 | callback(err, ...args);
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138 | }
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139 | });
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140 | }
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141 |
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142 | retryAttempt();
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143 | return callback[_promiseCallback.PROMISE_SYMBOL];
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144 | }
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145 |
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146 | function parseTimes(acc, t) {
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147 | if (typeof t === 'object') {
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148 | acc.times = +t.times || DEFAULT_TIMES;
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149 |
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150 | acc.intervalFunc = typeof t.interval === 'function' ? t.interval : constant(+t.interval || DEFAULT_INTERVAL);
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151 |
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152 | acc.errorFilter = t.errorFilter;
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153 | } else if (typeof t === 'number' || typeof t === 'string') {
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154 | acc.times = +t || DEFAULT_TIMES;
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155 | } else {
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156 | throw new Error("Invalid arguments for async.retry");
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157 | }
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158 | }
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159 | module.exports = exports['default']; |
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