version1/src/js/iotjs/src/slotbuffer.js

   1 "use strict";
   2
   3 var _createClass = function () { function defineProperties(target, props) { for (var i = 0; i < props.length; i++) { var descriptor = props[i]; descriptor.enumerable = descriptor.enumerable || false; descriptor.configurable = true; if ("value" in descriptor) descriptor.writable = true; Object.defineProperty(target, descriptor.key, descriptor); } } return function (Constructor, protoProps, staticProps) { if (protoProps) defineProperties(Constructor.prototype, protoProps); if (staticProps) defineProperties(Constructor, staticProps); return Constructor; }; }();
   4
   5 function _classCallCheck(instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } }
   6
   7 var SlotBuffer = function () {
   8         function SlotBuffer() {
   9                 _classCallCheck(this, SlotBuffer);
  10
  11                 this.DEFAULT_SIZE = 128;
  12                 this.array = [];
  13                 this.head = 0;
  14                 this.tail = 0;
  15                 this.oldestseqn = 0;
  16         }
  17
  18         _createClass(SlotBuffer, [{
  19                 key: "size",
  20                 value: function size() {
  21                         if (this.head >= this.tail) {
  22                                 return this.head - this.tail;
  23                         }
  24                         return this.array.length + this.head - this.tail;
  25                 }
  26         }, {
  27                 key: "capacity",
  28                 value: function capacity() {
  29                         return this.array.length - 1;
  30                 }
  31         }, {
  32                 key: "resize",
  33                 value: function resize(newsize) {
  34                         if (newsize === this.array.length - 1) {
  35                                 return;
  36                         }
  37                         var newarray = [];
  38                         var currsize = this.size();
  39                         var index = this.tail;
  40                         for (var i = 0; i < currsize; i++) {
  41                                 newarray[i] = this.array[index];
  42                                 if (++index === this.array.length) {
  43                                         index = 0;
  44                                 }
  45                                 this.array = newarray;
  46                                 this.tail = 0;
  47                                 this.head = currsize;
  48                         }
  49                 }
  50         }, {
  51                 key: "incrementHead",
  52                 value: function incrementHead() {
  53                         this.head++;
  54                         if (this.head >= this.array.length) {
  55                                 this.head = 0;
  56                         }
  57                 }
  58         }, {
  59                 key: "incrementTail",
  60                 value: function incrementTail() {
  61                         this.tail++;
  62                         if (this.tail >= this.array.length) {
  63                                 this.tail = 0;
  64                         }
  65                 }
  66         }, {
  67                 key: "putSlot",
  68                 value: function putSlot(s) {
  69                         if (!(s instanceof Slot)) {
  70                                 throw new Error("Error with arguments. Argument should be a slot object");
  71                         }
  72                         this.array[this.head] = s;
  73                         this.incrementHead();
  74
  75                         if (this.oldestseqn === 0) {
  76                                 this.oldestseqn = s.getSequenceNumber();
  77                         }
  78
  79                         if (this.head === this.tail) {
  80                                 this.incrementTail();
  81                                 this.oldestseqn++;
  82                         }
  83                 }
  84         }, {
  85                 key: "getSlot",
  86                 value: function getSlot(seqnum) {
  87                         var diff = seqnum - this.oldestseqn;
  88                         var index = diff + this.tail;
  89                         if (index >= this.array.length) {
  90                                 if (this.head >= this.tail) {
  91                                         return null;
  92                                 }
  93                                 index = index - this.array.length;
  94                         }
  95                         if (index >= this.array.length) {
  96                                 return null;
  97                         }
  98
  99                         if (this.head >= this.tail && index >= this.head) {
 100                                 return null;
 101                         }
 102
 103                         return this.array[index];
 104                 }
 105         }, {
 106                 key: "getOldestSeqNum",
 107                 value: function getOldestSeqNum() {
 108                         return this.oldestseqn;
 109                 }
 110         }, {
 111                 key: "getNewestSeqNum",
 112                 value: function getNewestSeqNum() {
 113                         return this.oldestseqn + this.size() - 1;
 114                 }
 115         }]);
 116
 117         return SlotBuffer;
 118 }();