| "use strict"; |
| function arrayMove(src, srcIndex, dst, dstIndex, len) { |
| for (var j = 0; j < len; ++j) { |
| dst[j + dstIndex] = src[j + srcIndex]; |
| src[j + srcIndex] = void 0; |
| } |
| } |
| |
| function Queue(capacity) { |
| this._capacity = capacity; |
| this._length = 0; |
| this._front = 0; |
| } |
| |
| Queue.prototype._willBeOverCapacity = function (size) { |
| return this._capacity < size; |
| }; |
| |
| Queue.prototype._pushOne = function (arg) { |
| var length = this.length(); |
| this._checkCapacity(length + 1); |
| var i = (this._front + length) & (this._capacity - 1); |
| this[i] = arg; |
| this._length = length + 1; |
| }; |
| |
| Queue.prototype.push = function (fn, receiver, arg) { |
| var length = this.length() + 3; |
| if (this._willBeOverCapacity(length)) { |
| this._pushOne(fn); |
| this._pushOne(receiver); |
| this._pushOne(arg); |
| return; |
| } |
| var j = this._front + length - 3; |
| this._checkCapacity(length); |
| var wrapMask = this._capacity - 1; |
| this[(j + 0) & wrapMask] = fn; |
| this[(j + 1) & wrapMask] = receiver; |
| this[(j + 2) & wrapMask] = arg; |
| this._length = length; |
| }; |
| |
| Queue.prototype.shift = function () { |
| var front = this._front, |
| ret = this[front]; |
| |
| this[front] = undefined; |
| this._front = (front + 1) & (this._capacity - 1); |
| this._length--; |
| return ret; |
| }; |
| |
| Queue.prototype.length = function () { |
| return this._length; |
| }; |
| |
| Queue.prototype._checkCapacity = function (size) { |
| if (this._capacity < size) { |
| this._resizeTo(this._capacity << 1); |
| } |
| }; |
| |
| Queue.prototype._resizeTo = function (capacity) { |
| var oldCapacity = this._capacity; |
| this._capacity = capacity; |
| var front = this._front; |
| var length = this._length; |
| var moveItemsCount = (front + length) & (oldCapacity - 1); |
| arrayMove(this, 0, this, oldCapacity, moveItemsCount); |
| }; |
| |
| module.exports = Queue; |