| 1 |
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| 2 | /*!
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| 3 | * Connect - Cache
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| 4 | * Copyright(c) 2011 Sencha Inc.
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| 5 | * MIT Licensed
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| 6 | */
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| 7 |
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| 8 | /**
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| 9 | * Expose `Cache`.
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| 10 | */
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| 11 |
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| 12 | module.exports = Cache;
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| 13 |
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| 14 | /**
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| 15 | * LRU cache store.
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| 16 | *
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| 17 | * @param {Number} limit
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| 18 | * @api private
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| 19 | */
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| 20 |
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| 21 | function Cache(limit) {
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| 22 | this.store = {};
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| 23 | this.keys = [];
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| 24 | this.limit = limit;
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| 25 | }
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| 26 |
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| 27 | /**
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| 28 | * Touch `key`, promoting the object.
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| 29 | *
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| 30 | * @param {String} key
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| 31 | * @param {Number} i
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| 32 | * @api private
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| 33 | */
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| 34 |
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| 35 | Cache.prototype.touch = function(key, i){
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| 36 | this.keys.splice(i,1);
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| 37 | this.keys.push(key);
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| 38 | };
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| 39 |
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| 40 | /**
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| 41 | * Remove `key`.
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| 42 | *
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| 43 | * @param {String} key
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| 44 | * @api private
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| 45 | */
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| 46 |
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| 47 | Cache.prototype.remove = function(key){
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| 48 | delete this.store[key];
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| 49 | };
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| 50 |
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| 51 | /**
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| 52 | * Get the object stored for `key`.
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| 53 | *
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| 54 | * @param {String} key
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| 55 | * @return {Array}
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| 56 | * @api private
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| 57 | */
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| 58 |
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| 59 | Cache.prototype.get = function(key){
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| 60 | return this.store[key];
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| 61 | };
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| 62 |
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| 63 | /**
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| 64 | * Add a cache `key`.
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| 65 | *
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| 66 | * @param {String} key
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| 67 | * @return {Array}
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| 68 | * @api private
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| 69 | */
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| 70 |
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| 71 | Cache.prototype.add = function(key){
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| 72 | // initialize store
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| 73 | var len = this.keys.push(key);
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| 74 |
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| 75 | // limit reached, invalid LRU
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| 76 | if (len > this.limit) this.remove(this.keys.shift());
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| 77 |
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| 78 | var arr = this.store[key] = [];
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| 79 | arr.createdAt = new Date;
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| 80 | return arr;
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| 81 | };
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