1 | "use strict";
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2 | function arrayMove(src, srcIndex, dst, dstIndex, len) {
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3 | for (var j = 0; j < len; ++j) {
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4 | dst[j + dstIndex] = src[j + srcIndex];
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5 | src[j + srcIndex] = void 0;
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6 | }
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7 | }
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8 |
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9 | function Queue(capacity) {
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10 | this._capacity = capacity;
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11 | this._length = 0;
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12 | this._front = 0;
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13 | }
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14 |
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15 | Queue.prototype._willBeOverCapacity = function (size) {
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16 | return this._capacity < size;
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17 | };
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18 |
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19 | Queue.prototype._pushOne = function (arg) {
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20 | var length = this.length();
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21 | this._checkCapacity(length + 1);
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22 | var i = (this._front + length) & (this._capacity - 1);
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23 | this[i] = arg;
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24 | this._length = length + 1;
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25 | };
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26 |
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27 | Queue.prototype.push = function (fn, receiver, arg) {
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28 | var length = this.length() + 3;
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29 | if (this._willBeOverCapacity(length)) {
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30 | this._pushOne(fn);
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31 | this._pushOne(receiver);
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32 | this._pushOne(arg);
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33 | return;
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34 | }
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35 | var j = this._front + length - 3;
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36 | this._checkCapacity(length);
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37 | var wrapMask = this._capacity - 1;
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38 | this[(j + 0) & wrapMask] = fn;
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39 | this[(j + 1) & wrapMask] = receiver;
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40 | this[(j + 2) & wrapMask] = arg;
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41 | this._length = length;
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42 | };
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43 |
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44 | Queue.prototype.shift = function () {
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45 | var front = this._front,
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46 | ret = this[front];
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47 |
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48 | this[front] = undefined;
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49 | this._front = (front + 1) & (this._capacity - 1);
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50 | this._length--;
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51 | return ret;
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52 | };
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53 |
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54 | Queue.prototype.length = function () {
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55 | return this._length;
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56 | };
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57 |
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58 | Queue.prototype._checkCapacity = function (size) {
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59 | if (this._capacity < size) {
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60 | this._resizeTo(this._capacity << 1);
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61 | }
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62 | };
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63 |
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64 | Queue.prototype._resizeTo = function (capacity) {
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65 | var oldCapacity = this._capacity;
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66 | this._capacity = capacity;
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67 | var front = this._front;
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68 | var length = this._length;
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69 | var moveItemsCount = (front + length) & (oldCapacity - 1);
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70 | arrayMove(this, 0, this, oldCapacity, moveItemsCount);
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71 | };
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72 |
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73 | module.exports = Queue;
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