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.
74 lines
1.8 KiB
74 lines
1.8 KiB
"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;
|