You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
124 lines
3.7 KiB
124 lines
3.7 KiB
/**
|
|
* A queue
|
|
* @param {Object} options
|
|
* Available options:
|
|
* - delay: number When a number, the queue will be flushed
|
|
* automatically after an inactivity of this delay
|
|
* in milliseconds.
|
|
* Default value is null.
|
|
* - max: number When the queue exceeds the given maximum number
|
|
* of entries, the queue is flushed automatically.
|
|
* Default value of max is Infinity.
|
|
* @constructor
|
|
*/
|
|
function Queue(options) {
|
|
// options
|
|
this.delay = options && typeof options.delay === 'number' ? options.delay : null;
|
|
this.max = options && typeof options.max === 'number' ? options.max : Infinity;
|
|
|
|
// properties
|
|
this._queue = [];
|
|
this._timeout = null;
|
|
}
|
|
|
|
/**
|
|
* Extend an object with queuing functionality.
|
|
* The object will be extended with a function flush, and the methods provided
|
|
* in options.replace will be replaced with queued ones.
|
|
* @param {Object} object
|
|
* @param {Object} options
|
|
* Available options:
|
|
* - replace: Array.<string>
|
|
* A list with method names of the methods
|
|
* on the object to be replaced with queued ones.
|
|
* - delay: number When a number, the queue will be flushed
|
|
* automatically after an inactivity of this delay
|
|
* in milliseconds.
|
|
* When false (default), the queue is not flushed
|
|
* - max: number When the queue exceeds the given maximum number
|
|
* of entries, the queue is flushed automatically.
|
|
* Default value of max is Infinity.
|
|
*/
|
|
Queue.extend = function (object, options) {
|
|
var queue = new Queue(options);
|
|
|
|
if (object.flush !== undefined) {
|
|
throw new Error('Target object already has a property flush');
|
|
}
|
|
object.flush = function () {
|
|
queue.flush();
|
|
};
|
|
|
|
if (options && options.replace) {
|
|
for (var i = 0; i < options.replace.length; i++) {
|
|
queue.replace(object, options.replace[i]);
|
|
}
|
|
}
|
|
};
|
|
|
|
/**
|
|
* Replace a method on an object with a queued version
|
|
* @param {Object} object Object having the method
|
|
* @param {string} method The method name
|
|
*/
|
|
Queue.prototype.replace = function(object, method) {
|
|
var me = this;
|
|
var original = object[method];
|
|
if (!original) {
|
|
throw new Error('Method ' + method + ' undefined');
|
|
}
|
|
|
|
object[method] = function () {
|
|
// create an Array with the arguments
|
|
var args = [];
|
|
for (var i = 0; i < arguments.length; i++) {
|
|
args[i] = arguments[i];
|
|
}
|
|
|
|
// add this call to the queue
|
|
me.queue({
|
|
args: args,
|
|
fn: original,
|
|
context: this
|
|
});
|
|
};
|
|
};
|
|
|
|
/**
|
|
* Queue a call
|
|
* @param {function | {fn: function, args: Array} | {fn: function, args: Array, context: Object}} entry
|
|
*/
|
|
Queue.prototype.queue = function(entry) {
|
|
if (typeof entry === 'function') {
|
|
this._queue.push({fn: entry});
|
|
}
|
|
else {
|
|
this._queue.push(entry);
|
|
}
|
|
|
|
// flush when the maximum is exceeded.
|
|
if (this._queue.length > this.max) {
|
|
this.flush();
|
|
}
|
|
|
|
// flush after a period of inactivity when a delay is configured
|
|
if (typeof this.delay === 'number') {
|
|
var me = this;
|
|
clearTimeout(this._timeout);
|
|
this._timeout = setTimeout(function () {
|
|
me.flush();
|
|
}, this.delay);
|
|
}
|
|
};
|
|
|
|
/**
|
|
* Flush all queued calls
|
|
*/
|
|
Queue.prototype.flush = function () {
|
|
while (this._queue.length > 0) {
|
|
var entry = this._queue.shift();
|
|
entry.fn.apply(entry.context || entry.fn, entry.args || []);
|
|
}
|
|
};
|
|
|
|
module.exports = Queue;
|