var util = require("util");

var extend = util._extend;

var instances = {};

var defaultCacheInitConfig = {

name: '_default',

type: 'memory'

};

module.exports = {

init: function(config){

config = config || {};

config = extend(defaultCacheInitConfig, config);

var instance = initNewCacheInstance(config);

instances[config.name] = instance;

return instance;

},

retrieve: function(name){

if(!name){

name = '_default';

}

if(instances[name]){

return instances[name];

}

return null;

},

destroy: function(name){

if(!instances[name]){

return true;

}

instances[name].clear();

delete instances[name];

return true;

}

};

function initNewCacheInstance(config){

try{

var Instance = require('./storage/' + config.type);

return new Instance(config);

} catch(e){

console.log('initNewCacheInstance()', e, e.stack);

throw new Error(util.format('unknown cache storage %s', config.type));

}

}