timeout.js 2.71 KB
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'use strict';

Object.defineProperty(exports, "__esModule", {
    value: true
});
exports.default = timeout;

var _initialParams = require('./internal/initialParams');

var _initialParams2 = _interopRequireDefault(_initialParams);

var _wrapAsync = require('./internal/wrapAsync');

var _wrapAsync2 = _interopRequireDefault(_wrapAsync);

function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }

/**
 * Sets a time limit on an asynchronous function. If the function does not call
 * its callback within the specified milliseconds, it will be called with a
 * timeout error. The code property for the error object will be `'ETIMEDOUT'`.
 *
 * @name timeout
 * @static
 * @memberOf module:Utils
 * @method
 * @category Util
 * @param {AsyncFunction} asyncFn - The async function to limit in time.
 * @param {number} milliseconds - The specified time limit.
 * @param {*} [info] - Any variable you want attached (`string`, `object`, etc)
 * to timeout Error for more information..
 * @returns {AsyncFunction} Returns a wrapped function that can be used with any
 * of the control flow functions.
 * Invoke this function with the same parameters as you would `asyncFunc`.
 * @example
 *
 * function myFunction(foo, callback) {
 *     doAsyncTask(foo, function(err, data) {
 *         // handle errors
 *         if (err) return callback(err);
 *
 *         // do some stuff ...
 *
 *         // return processed data
 *         return callback(null, data);
 *     });
 * }
 *
 * var wrapped = async.timeout(myFunction, 1000);
 *
 * // call `wrapped` as you would `myFunction`
 * wrapped({ bar: 'bar' }, function(err, data) {
 *     // if `myFunction` takes < 1000 ms to execute, `err`
 *     // and `data` will have their expected values
 *
 *     // else `err` will be an Error with the code 'ETIMEDOUT'
 * });
 */
function timeout(asyncFn, milliseconds, info) {
    var fn = (0, _wrapAsync2.default)(asyncFn);

    return (0, _initialParams2.default)(function (args, callback) {
        var timedOut = false;
        var timer;

        function timeoutCallback() {
            var name = asyncFn.name || 'anonymous';
            var error = new Error('Callback function "' + name + '" timed out.');
            error.code = 'ETIMEDOUT';
            if (info) {
                error.info = info;
            }
            timedOut = true;
            callback(error);
        }

        args.push(function () {
            if (!timedOut) {
                callback.apply(null, arguments);
                clearTimeout(timer);
            }
        });

        // setup timer and call original function
        timer = setTimeout(timeoutCallback, milliseconds);
        fn.apply(null, args);
    });
}
module.exports = exports['default'];