golang_datastore

type Store interface {
  Get(interface{}) interface{}
  Set(interface{})
}

type DatabaseStore struct {
  // wrap sql connection
  // or any other driver that your database needs
}

func (s *DatabaseStore) GetFollowers(userID string) ([]models.User, error) {
  // get users from db
  // can be any db, e.g. PostgreSQL, CouchDB, MongoDB
  return users, nil
}

type CacheStore struct {
   // embed any other store
   // this also makes unimplemented store methods just pass through
  Store
  // cache internals
}

func (s *CacheStore) GetFollowers(userID string) ([]models.User, error) {
  // return user from cache if it's there
  // if not, get from underlying store
  user, err = s.Store.GetFollowers(userID)
  // error check
  // add user to cache
  return users, nil
}

// easily instantiate any configuration you need
store := CacheStore{DatabaseStore{DB: db}}

// In package main, the store implementation should just return an object that can be passed around and queried