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var LinkedList = require('./LinkedList');
var PseudoMap = require('./PseudoMap');
var Class = require('./Class');
exports = Class({
initialize: function Lru(max) {
this._max = max;
this._list = new LinkedList();
this._map = new PseudoMap();
},
has: function(key) {
return this._map.has(key);
},
remove: function(key) {
var map = this._map;
if (this.has(key)) {
var node = map.get(key);
this._list.rmNode(node);
map.delete(key);
}
},
get: function(key) {
var list = this._list;
var map = this._map;
var ret;
if (this.has(key)) {
var node = map.get(key);
ret = node.value.val;
list.rmNode(node);
list.unshift(node.value);
map.set(key, list.head);
}
return ret;
},
set: function(key, val) {
var list = this._list;
var map = this._map;
if (this.has(key)) {
var node = map.get(key);
list.rmNode(node);
list.unshift({
key: key,
val: val
});
map.set(key, list.head);
} else {
list.unshift({
key: key,
val: val
});
map.set(key, list.head);
if (list.size > this._max) {
var item = list.pop();
map.delete(item.key);
}
}
},
clear: function() {
this._map = new PseudoMap();
this._list = new LinkedList();
}
});
module.exports = exports;