Hier

provide hierarchical read from different data resources, e.g, db, cache, file system...

// hierarchical read from memoryStore, fileStore
hier.chain([ memoryStore, fileStore ]).read('key').then(function(value){
    // ...
})

api

Store interface

every get/set value operations in this module, rely on this Store interface

so if you want to create your own Store class, be sure to inherit fron Store

example

var hier= require('../');
var Store= hier.interface;
var util= require('util');
var Q= require('q');
 
var VirtualStore= function () {
    var self= this;
    self.stores= {};
    Store.call(self);
}
 
util.inherits(VirtualStore, Store);
 
VirtualStore.prototype.get = function(key) {
    var self= this;
    return Q.delay(100).then(function () {
        return self.stores[key] || null;
    })
};
 
VirtualStore.prototype.set = function(key, value, opts) {
    var self= this;
    return Q.delay(100).then(function () {
        self.stores[key]= value;
    })	
};
 
VirtualStore.prototype.destroy = function(key) {
    delete self.stores[key];
};

chain

hierarchical read from memoryStore, fileStore

read key in order from memoryStore, fileStore

hier.chain([ memoryStore, fileStore ]).read('key')
    .then(function (value) {
        //...
    })

License

MIT