By using `0` as the clock value for an empty state (without operations),
we simplify transaction code. Previously, there was no clock value for
empty states, which meant that we had to sometimes use an `Option`.
Sometimes it is more efficient to perform multiple operations at once
and store those in the collaborative object graph together.
Change the contents to be a non-empty sequence of byte sequences,
i.e. NonEmpty<Vec<u8>>. These are stored as blobs in a git tree in
order by their index in the non-empty sequence. They are, in turn,
retrieved in order of their original index.
Change the conversion of an `EntryWithClock` to return a non-empty
sequence of `Op`s, which are in turn used to apply many changes in
each `from_history` implementation.
Signed-off-by: Fintan Halpenny <fintan.halpenny@gmail.com>
X-Clacks-Overhead: GNU Terry Pratchett
This is a minimal port of the collaborative objects code from
radicle-link[0].
A `CollaborativeObject` is made up of a `History` of `Change`s that
are expected to be stored in a `git` backend.
The library exposes a CRU series of functions `create`, `get`, `list`,
and `update`.
This implementation differs, to previous one, in that it does not
assume any kind of identity system -- its only assumption is that
identities have an identifier and can be addressed in the `git`
database. This means that it does not require an `author` to be passed
in and it only uses the `resource` (previously `authorizing_identity`)
to store its content-address in the `Change`.
It also foregoes any caching to simplify the port and not make any
early optimisation assumptions.
[0]: https://github.com/radicle-dev/radicle-link/tree/master/cob
Signed-off-by: Fintan Halpenny <fintan.halpenny@gmail.com>