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.
This change updates to the latest radicle-git-ext, which required a
few changes within the radicle family of crates.
One set of changes is that the radicle-git-ext crate subsumes
git-commit, git-trailers, and git-ref-format -- so all those imports
go through radicle-git-ext.
The commit code requires that parent `Oid`s point to commits, which
made some tests fail. One of the reasons for these failures is that
the patch tests used fabricated `Oid`s and so the verification would
fail. This is fixed by allowing the test context code to create
`PatchRequest`s that create valid commits.
The other reason for failure was that the identity `Action` passed an
`Oid` that pointed to a blob. This is fixed by removing that code and
making a note of it in documentation.
The final major change was moving the Refspec type into git-ref-format
and removing the AsRefspecs trait. The trait was not required and
could its usage could be replaced by simpler code.
Signed-off-by: Fintan Halpenny <fintan.halpenny@gmail.com>
X-Clacks-Overhead: GNU Terry Pratchett
By introducing a small limitation: only allowing entries in the change
graph to be addressable, instead of individual operations; we
drastically simplify the CRDT implementation.
There are four advantages:
1. Op ids are just regular SHA-1s
2. There's no need for relative IDs, ops never refer to other ops within the
same commit
3. There's no need for a nonce, since commits can't collide, and neither can op IDs
4. `OpId` can just be an alias of `EntryId`
The disadvantage of course, is that we have to be mindful of how we
create op transactions, since each transaction creates an addressable
unit. For example, we must not include multiple patch revisions in the
same transaction.
Added the `parse_refname` function for parsing a reference into its
`TypeName` and `ObjectId`, if possible.
This replaces the `cob_suffix` function in `radicle`.
This change also fixes the `FromStr` instance of `ObjectId` to use
`from_str` instead of `TryFrom` for bytes.
Signed-off-by: Fintan Halpenny <fintan.halpenny@gmail.com>
X-Clacks-Overhead: GNU Terry Pratchett
`TypeName` and `ObjectId` are expected to be used in reference
names.
Add `From` conversions to `Component` for both of these types to make
it easier for using them with `git-ref-format`.
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>
cloudhead
Fintan Halpenny
Alexis Sellier
Alexis Sellier