dcache

* DCache
a redis cache:
#+begin_src go
// Cache defines interface to cache
type Cache interface {
	// Get returns value of f while caching in redis and inmemcache
	// Inputs:
	// queryKey	 - key used in cache
	// target	 	 - an instance of the same type as the return interface{}
	// expire 	 - expiration of cache key
	// f				 - actual call that hits underlying data source
	// noCache 	 - whether force read from data source
	Get(ctx context.Context, queryKey QueryKey, target interface{}, expire time.Duration, f PassThroughFunc, noCache bool) (interface{}, error)

	// Set explicitly set a cache key to a val
	// Inputs:
	// key		- key to set
	// val	  - val to set
	// ttl    - ttl of key
	Set(ctx context.Context, key QueryKey, val interface{}, ttl time.Duration) error

	// Invalidate explicitly invalidates a cache key
	// Inputs:
	// key    - key to invalidate
	Invalidate(ctx context.Context, key QueryKey) error

	// Close closes resources used by cache
	Close()
}
#+end_src