generic_cache

A generic cached object which provide user two possible usage options.

1. Use Object::get() until it return TimeoutError then manually call Object::refresh() function.
2. Use Object::get_or_refresh() which will automatically refresh the value when it is expired.

Rationale

For performance critical application, most of the time, major cost came from IO. To reduce cost, the easiest way is to cache the value. In some case, it is possible to delegate this work to network layer, e.g. Proxy. In some other case, it is not possible due to security reason. An example of such case is the bearer token which is used to communicate between API server. It is normally obtained via HTTP POST which proxy won't cache. In such case, some vendor provide a library which handle token caching but it is not always the case. This is where this library fit in.

Breaking change

Version 0.3.0

• Change ttl argument type from u128 to std::time::Duration type.