Module Cache導致inherits共用錯誤 #3
Description
目的
最近初學node.js,
想要自己嘗試寫一個Map module讓其他module去繼承,
但是require module的cache機制導致inherits的module共用了同一個map,
請問應該如何修改才有辦法讓各module有自己的map?
使用的工具
ubuntu 12.04
node.js 4.4.3
操作流程
node server.js
遇到的問題
目的已詳述
嘗試過的解法
應該是架構問題, 完全不知道該從何處下手
(想過用不同的路徑載入Map Module, 但就捨棄了module cache的機制)
程式碼
-----server.js-----
//Load Library
var Player_list_lib = require(global.LIB_DIR + '/player_list_lib');
var Monster_list_lib = require(global.LIB_DIR + '/monster_list_lib');
//Create Monster
for (var monster_index = 1; monster_index <= 3; ++monster_index) {
Monster_list_lib.set(monster_index, 'a');
}
//Show Map
console.log(Monster_list_lib.keys());
console.log(Player_list_lib.keys());-----map.js-----
/**
* Map Library
*/
function Map_lib() {
/**
* Map
*/
_map = {};
/**
* Map Count
*/
this.size = 0;
}
/**
* Get
* @param key
* @param default_val
*/
Map_lib.prototype.get = function(key, default_val) {
//Initail Parameter
default_val = default_val || undefined;
//Check Key Exists
if ( ! _map.hasOwnProperty(key)) {
return default_val;
}
//Response Item
return _map[key];
};
/**
* Set
* @param key
* @param value
*/
Map_lib.prototype.set = function(key, value) {
//Set Item
_map[key] = value;
//Increase Map Count
++this.size;
};
/**
* Has
* @param key
* @returns {Boolean}
*/
Map_lib.prototype.has = function(key) {
return _map.hasOwnProperty(key);
};
/**
* Remove
* @returns mixed
*/
Map_lib.prototype.remove = function(key) {
//Check Map Count
if (this.size < 1) {
return;
}
//Check Key Exists
if ( ! _map.hasOwnProperty(key)) {
return;
}
//Remove
delete _map[key];
//Decrease Map Count
--this.size;
};
/**
* Get Map Size
* @returns {Number}
*/
Map_lib.prototype.size = function() {
return this.size;
};
/**
* Clear Map
*/
Map_lib.prototype.clear = function() {
//Re-initial Map
_map = {};
//Re-initial Map Count
this.size = 0;
};
/**
* Get Entries
* @returns {Array}
*/
Map_lib.prototype.entries = function() {
//Initial List
var list = [];
//Deal With Map
this.keys().forEach(function(key) {
list.push([key, _map[key]]);
}, this);
//Response List
return list;
};
/**
* Get Keys
* @returns {Array}
*/
Map_lib.prototype.keys = function() {
return Object.keys(_map);
};
/**
* Get Values
* @returns {Array}
*/
Map_lib.prototype.values = function() {
//Initial List
var list = [];
//Deal With Map
this.keys().forEach(function(key) {
list.push(_map[key]);
}, this);
//Response List
return list;
};
//Export
module.exports = Map_lib;-----Player_list_lib.js / Monster_list_lib.js-----
//Load Module
var util = require('util');
//Load Library
var Map_lib = require(global.LIB_DIR + '/map_lib');
/**
* Constructor
*/
function Player_list_lib() {
//Parent Constructor
Player_list_lib.super_.apply(this, arguments);
};
/**
* Instance
*/
Player_list_lib._instance = undefined;
/**
* Get Instance
*/
Player_list_lib.getInstance = function() {
if (this._instance === undefined) {
this._instance = new Player_list_lib();
}
return this._instance;
};
//Inherits 'List_lib'
util.inherits(Player_list_lib, Map_lib);
//Exports
module.exports = Player_list_lib.getInstance();輸出
[ '1', '2', '3' ]
[ '1', '2', '3' ]