Implement caching for the `Issue` and `Patch` COB. This is achieved by
having the `Transaction::initial` and `Transaction::commit` methods
take a cache which can update the newly created/updated object. The
`Store::remove` method also takes the cache for removing the object
from the cache, as well as the repository.
This meant that the `*Mut` types for the respective COBs are required
to carry a cache alongside the repository store. Identities will not
be cached, and so this is always set to `NoCache` -- which performs no
caching, and always succeeds.
To perform cache reading for issues and patches, the `cache::Issues`
and `cache::Patches` traits are introduced. They capture the minimal
amount of methods that are needed for the `rad issue` and `rad patch`
CLI commands.
The implementor for each of these traits is there respective `Cache`
types, which combines their backing repository store and the SQLite
database. They both provide convenience methods:
- `create` (and `draft` for patches)
- `get_mut`
- `remove`
which can be used instead of their repository store counterparts.
All uses of the repository stores (where needed) are replaced with
`Cache` types.
Signed-off-by: Fintan Halpenny <fintan.halpenny@gmail.com>
X-Clacks-Overhead: GNU Terry Pratchett
985b0af3f6