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Diffstat (limited to 'node_modules/async/retry.js')
| -rw-r--r-- | node_modules/async/retry.js | 159 |
1 files changed, 159 insertions, 0 deletions
diff --git a/node_modules/async/retry.js b/node_modules/async/retry.js new file mode 100644 index 0000000..dba3030 --- /dev/null +++ b/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'];
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