| # Token Cache |
| |
| ## Overview |
| |
| Token Cache provides an ephemeral cache for short-lived authentication tokens |
| such as OAuth access and ID tokens and Firebase tokens. The cache contents are |
| only stored in memory so are not preserved across executions. |
| |
| This crate is used by the Token Manager library. |
| |
| |
| ## Key Dependencies |
| |
| None |
| |
| |
| ## Design |
| |
| The `TokenCache` struct stores tokens as a mapping from `CacheKey` to |
| `CacheToken` implementors. `CacheKey` and `CacheToken` are traits that define |
| the requirements for keys and tokens stored in the cache. A `CacheToken` |
| implementation must provide an expiration time used for cache eviction. A |
| `CacheKey` must provide the Service Provider account (user_profile_id) and the |
| Auth Provider used to communicate with it (auth_provider_type), as well as some |
| unique identifier. A `CacheKey` is also statically tied to a specific |
| `CacheToken` type to enforce type safety. `CacheKey` and `CacheToken` |
| implementations are provided by the user. |
| |
| |
| ## Future Work |
| |
| The cache is a simple crate that is unlikely to ever be used outside of Token |
| Manager. Potentially it will be merged into Token Manager at some point. |
