Previously, COB change commits would not distinguish between their
parents. This means that they would try to load source code commits
(eg. for patch COBs) and then fail since those commits wouldn't have a
manifest or `Rad-Resource`.
We introduce a backwards compatible change here which is that parent
oids that are not COB commits are accompanied by a commit trailer called
`Rad-Related`. This is for all related content that should be pulled in
but is not part of the change graph proper.
When building the change graph, we simply ignore commits that are marked
as "related".
Instead of returning histories from `radicle-cob`, we return an
evaluated object which we build during initial graph traversal.
We do this so that branches can be correctly pruned when operations are
invalid at the application level. This way, new operations are not
building on top of invalid ones contained in the history.
To achieve this, we introduce a new `Evaluate` trait that is implemented
by all COBs, and we make change graph evaluation fallible.
Doing this means that we get `apply` errors returned for free when an
invalid transaction is applied, and no longer need to check for action
validity in multiple places.
We also implement a new `Dag::prune` method to avoid having to copy
graph nodes during traversal.
Instead of having two types, we simply have one, called `Entry`, which
we rename from `Change`.
There was no real benefit to having two almost identical types, but lots
of added complexity. This patch simplifies the crate by removing one of
the types.
The additional flexibility in choosing a backend for the COB store will
allow things like "draft" COBs that are stored in a different location,
without changing much of the logic.
Objects does not need to be separated by `local` and `remotes`, it
uses `iter` internally, so all references are used regardless.
Simplify Objects by having it be a simple vector of references.
This also means that the `identifier` is not needed. This was only
required to identify the local reference, so it can now be removed.
Signed-off-by: Fintan Halpenny <fintan.halpenny@gmail.com>
X-Clacks-Overhead: GNU Terry Pratchett
The `Store` trait had a paramter for a `Resource`. This is too
restrictive for implementations, particularly `heartwood`.
Instead, where a unique identifier is needed for the
`object::Storage`, i.e. in `create` and `update`, the identifier
becomes a parameter.
This allows the removal of passing the resource in `list`, `get` and
`changegraph`.
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>