--- /dev/null
+'use strict';
+
+Object.defineProperty(exports, "__esModule", {
+ value: true
+});
+
+exports.default = function (tasks, concurrency, callback) {
+ if (typeof concurrency === 'function') {
+ // concurrency is optional, shift the args.
+ callback = concurrency;
+ concurrency = null;
+ }
+ callback = (0, _once2.default)(callback || _noop2.default);
+ var keys = (0, _keys2.default)(tasks);
+ var numTasks = keys.length;
+ if (!numTasks) {
+ return callback(null);
+ }
+ if (!concurrency) {
+ concurrency = numTasks;
+ }
+
+ var results = {};
+ var runningTasks = 0;
+ var hasError = false;
+
+ var listeners = Object.create(null);
+
+ var readyTasks = [];
+
+ // for cycle detection:
+ var readyToCheck = []; // tasks that have been identified as reachable
+ // without the possibility of returning to an ancestor task
+ var uncheckedDependencies = {};
+
+ (0, _baseForOwn2.default)(tasks, function (task, key) {
+ if (!(0, _isArray2.default)(task)) {
+ // no dependencies
+ enqueueTask(key, [task]);
+ readyToCheck.push(key);
+ return;
+ }
+
+ var dependencies = task.slice(0, task.length - 1);
+ var remainingDependencies = dependencies.length;
+ if (remainingDependencies === 0) {
+ enqueueTask(key, task);
+ readyToCheck.push(key);
+ return;
+ }
+ uncheckedDependencies[key] = remainingDependencies;
+
+ (0, _arrayEach2.default)(dependencies, function (dependencyName) {
+ if (!tasks[dependencyName]) {
+ throw new Error('async.auto task `' + key + '` has a non-existent dependency `' + dependencyName + '` in ' + dependencies.join(', '));
+ }
+ addListener(dependencyName, function () {
+ remainingDependencies--;
+ if (remainingDependencies === 0) {
+ enqueueTask(key, task);
+ }
+ });
+ });
+ });
+
+ checkForDeadlocks();
+ processQueue();
+
+ function enqueueTask(key, task) {
+ readyTasks.push(function () {
+ runTask(key, task);
+ });
+ }
+
+ function processQueue() {
+ if (readyTasks.length === 0 && runningTasks === 0) {
+ return callback(null, results);
+ }
+ while (readyTasks.length && runningTasks < concurrency) {
+ var run = readyTasks.shift();
+ run();
+ }
+ }
+
+ function addListener(taskName, fn) {
+ var taskListeners = listeners[taskName];
+ if (!taskListeners) {
+ taskListeners = listeners[taskName] = [];
+ }
+
+ taskListeners.push(fn);
+ }
+
+ function taskComplete(taskName) {
+ var taskListeners = listeners[taskName] || [];
+ (0, _arrayEach2.default)(taskListeners, function (fn) {
+ fn();
+ });
+ processQueue();
+ }
+
+ function runTask(key, task) {
+ if (hasError) return;
+
+ var taskCallback = (0, _onlyOnce2.default)((0, _rest2.default)(function (err, args) {
+ runningTasks--;
+ if (args.length <= 1) {
+ args = args[0];
+ }
+ if (err) {
+ var safeResults = {};
+ (0, _baseForOwn2.default)(results, function (val, rkey) {
+ safeResults[rkey] = val;
+ });
+ safeResults[key] = args;
+ hasError = true;
+ listeners = Object.create(null);
+
+ callback(err, safeResults);
+ } else {
+ results[key] = args;
+ taskComplete(key);
+ }
+ }));
+
+ runningTasks++;
+ var taskFn = task[task.length - 1];
+ if (task.length > 1) {
+ taskFn(results, taskCallback);
+ } else {
+ taskFn(taskCallback);
+ }
+ }
+
+ function checkForDeadlocks() {
+ // Kahn's algorithm
+ // https://en.wikipedia.org/wiki/Topological_sorting#Kahn.27s_algorithm
+ // http://connalle.blogspot.com/2013/10/topological-sortingkahn-algorithm.html
+ var currentTask;
+ var counter = 0;
+ while (readyToCheck.length) {
+ currentTask = readyToCheck.pop();
+ counter++;
+ (0, _arrayEach2.default)(getDependents(currentTask), function (dependent) {
+ if (--uncheckedDependencies[dependent] === 0) {
+ readyToCheck.push(dependent);
+ }
+ });
+ }
+
+ if (counter !== numTasks) {
+ throw new Error('async.auto cannot execute tasks due to a recursive dependency');
+ }
+ }
+
+ function getDependents(taskName) {
+ var result = [];
+ (0, _baseForOwn2.default)(tasks, function (task, key) {
+ if ((0, _isArray2.default)(task) && (0, _baseIndexOf2.default)(task, taskName, 0) >= 0) {
+ result.push(key);
+ }
+ });
+ return result;
+ }
+};
+
+var _arrayEach = require('lodash/_arrayEach');
+
+var _arrayEach2 = _interopRequireDefault(_arrayEach);
+
+var _baseForOwn = require('lodash/_baseForOwn');
+
+var _baseForOwn2 = _interopRequireDefault(_baseForOwn);
+
+var _baseIndexOf = require('lodash/_baseIndexOf');
+
+var _baseIndexOf2 = _interopRequireDefault(_baseIndexOf);
+
+var _isArray = require('lodash/isArray');
+
+var _isArray2 = _interopRequireDefault(_isArray);
+
+var _keys = require('lodash/keys');
+
+var _keys2 = _interopRequireDefault(_keys);
+
+var _noop = require('lodash/noop');
+
+var _noop2 = _interopRequireDefault(_noop);
+
+var _rest = require('./internal/rest');
+
+var _rest2 = _interopRequireDefault(_rest);
+
+var _once = require('./internal/once');
+
+var _once2 = _interopRequireDefault(_once);
+
+var _onlyOnce = require('./internal/onlyOnce');
+
+var _onlyOnce2 = _interopRequireDefault(_onlyOnce);
+
+function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
+
+module.exports = exports['default'];
+
+/**
+ * Determines the best order for running the functions in `tasks`, based on
+ * their requirements. Each function can optionally depend on other functions
+ * being completed first, and each function is run as soon as its requirements
+ * are satisfied.
+ *
+ * If any of the functions pass an error to their callback, the `auto` sequence
+ * will stop. Further tasks will not execute (so any other functions depending
+ * on it will not run), and the main `callback` is immediately called with the
+ * error.
+ *
+ * Functions also receive an object containing the results of functions which
+ * have completed so far as the first argument, if they have dependencies. If a
+ * task function has no dependencies, it will only be passed a callback.
+ *
+ * @name auto
+ * @static
+ * @memberOf module:ControlFlow
+ * @method
+ * @category Control Flow
+ * @param {Object} tasks - An object. Each of its properties is either a
+ * function or an array of requirements, with the function itself the last item
+ * in the array. The object's key of a property serves as the name of the task
+ * defined by that property, i.e. can be used when specifying requirements for
+ * other tasks. The function receives one or two arguments:
+ * * a `results` object, containing the results of the previously executed
+ * functions, only passed if the task has any dependencies,
+ * * a `callback(err, result)` function, which must be called when finished,
+ * passing an `error` (which can be `null`) and the result of the function's
+ * execution.
+ * @param {number} [concurrency=Infinity] - An optional `integer` for
+ * determining the maximum number of tasks that can be run in parallel. By
+ * default, as many as possible.
+ * @param {Function} [callback] - An optional callback which is called when all
+ * the tasks have been completed. It receives the `err` argument if any `tasks`
+ * pass an error to their callback. Results are always returned; however, if an
+ * error occurs, no further `tasks` will be performed, and the results object
+ * will only contain partial results. Invoked with (err, results).
+ * @returns undefined
+ * @example
+ *
+ * async.auto({
+ * // this function will just be passed a callback
+ * readData: async.apply(fs.readFile, 'data.txt', 'utf-8'),
+ * showData: ['readData', function(results, cb) {
+ * // results.readData is the file's contents
+ * // ...
+ * }]
+ * }, callback);
+ *
+ * async.auto({
+ * get_data: function(callback) {
+ * console.log('in get_data');
+ * // async code to get some data
+ * callback(null, 'data', 'converted to array');
+ * },
+ * make_folder: function(callback) {
+ * console.log('in make_folder');
+ * // async code to create a directory to store a file in
+ * // this is run at the same time as getting the data
+ * callback(null, 'folder');
+ * },
+ * write_file: ['get_data', 'make_folder', function(results, callback) {
+ * console.log('in write_file', JSON.stringify(results));
+ * // once there is some data and the directory exists,
+ * // write the data to a file in the directory
+ * callback(null, 'filename');
+ * }],
+ * email_link: ['write_file', function(results, callback) {
+ * console.log('in email_link', JSON.stringify(results));
+ * // once the file is written let's email a link to it...
+ * // results.write_file contains the filename returned by write_file.
+ * callback(null, {'file':results.write_file, 'email':'user@example.com'});
+ * }]
+ * }, function(err, results) {
+ * console.log('err = ', err);
+ * console.log('results = ', results);
+ * });
+ */
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projects / yaffs-website / blobdiff