MACHIN

32/node_modules/async/retry.js

@@ -0,0 +1,159 @@
+'use strict';
+
+Object.defineProperty(exports, "__esModule", {
+    value: true
+});
+exports.default = retry;
+
+var _wrapAsync = require('./internal/wrapAsync.js');
+
+var _wrapAsync2 = _interopRequireDefault(_wrapAsync);
+
+var _promiseCallback = require('./internal/promiseCallback.js');
+
+function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
+
+function constant(value) {
+    return function () {
+        return value;
+    };
+}
+
+/**
+ * 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).
+ * @returns {Promise} a promise if no callback provided
+ *
+ * @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
+ * });
+ *
+ * // to retry individual methods that are not as reliable within other
+ * // control flow functions, use the `retryable` wrapper:
+ * async.auto({
+ *     users: api.getUsers.bind(api),
+ *     payments: async.retryable(3, api.getPayments.bind(api))
+ * }, function(err, results) {
+ *     // do something with the results
+ * });
+ *
+ */
+const DEFAULT_TIMES = 5;
+const DEFAULT_INTERVAL = 0;
+
+function retry(opts, task, callback) {
+    var options = {
+        times: DEFAULT_TIMES,
+        intervalFunc: constant(DEFAULT_INTERVAL)
+    };
+
+    if (arguments.length < 3 && typeof opts === 'function') {
+        callback = task || (0, _promiseCallback.promiseCallback)();
+        task = opts;
+    } else {
+        parseTimes(options, opts);
+        callback = callback || (0, _promiseCallback.promiseCallback)();
+    }
+
+    if (typeof task !== 'function') {
+        throw new Error("Invalid arguments for async.retry");
+    }
+
+    var _task = (0, _wrapAsync2.default)(task);
+
+    var attempt = 1;
+    function retryAttempt() {
+        _task((err, ...args) => {
+            if (err === false) return;
+            if (err && attempt++ < options.times && (typeof options.errorFilter != 'function' || options.errorFilter(err))) {
+                setTimeout(retryAttempt, options.intervalFunc(attempt - 1));
+            } else {
+                callback(err, ...args);
+            }
+        });
+    }
+
+    retryAttempt();
+    return callback[_promiseCallback.PROMISE_SYMBOL];
+}
+
+function parseTimes(acc, t) {
+    if (typeof t === 'object') {
+        acc.times = +t.times || DEFAULT_TIMES;
+
+        acc.intervalFunc = typeof t.interval === 'function' ? t.interval : constant(+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");
+    }
+}
+module.exports = exports['default'];