When evaluating a COB, expose to the `apply` function the operations
concurrent to the current one being applied. These are essentially
"related" nodes in the graph, that are neither ancestors or descendants.
This will let us for example have different failure modes depending on
whether there were conflicting operations, as well as expose conflicts
to the user.
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".
Introduces a new COB type to store repository identity documents.
The reason for this change is to:
1. Simplify the code, as the identity document logic resembled a COB,
yet it had custom logic. This allows existing COB code to be used for
identities.
2. Make identity document update logic more flexible, since COB actions
can be added in the future.
3. Re-purpose existing tools around COBs to work on identities, eg. `rad
cob`.
4. Unify the concept of an identity change proposal, with regular identity
changes. This means we can remove the `id.proposal` COB in favor of
using the `id` COB itself.
Notes
-----
* Each repository has one Identity COB.
* The `Proposal` COB has been repurposed into the `Identity` COB.
* Identity documents are stored as *embeds* inside the Identity COB
actions.
* The action that contains new document versions is called `revision`,
just like the Patches COB.
* The namespaced `rad/id` ref is a symbolic reference to that Identity
COB.
* The canonical `rad/id` ref is a direct reference to the commit in the
Identity COB that contains the latest *accepted* revision of the
document.
* All commands for managing identities have been folded into `rad id`.
Hence `rad delegate` and `rad edit` are removed.
* The concept of "rebasing" an identity document is gone.
* The `rad id` output has been updated to match the style of other
commands.
* When a revision has enough signatures, it is automatically adopted as
the current identity, there is no longer the need for a "commit"
action.
* When an identity revision is proposed, and the current identity has a
threshold of `1`, that identity is automatically accepted due to the
above point.
* The idea of "verifying a peer's identity branch" no longer applies, as
COBs cannot be verified one history at a time.
* Since the root commit of the Identity COB does not have a "Resource"
to point to (it would have to point to itself, which is impossible),
we've made the resource id optional for COBs.
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.
Clippy warns that EntryId::from and RevisionId::from are not
required.
Remove the unecessary calls in radicle-cob and radicle.
Signed-off-by: Fintan Halpenny <fintan.halpenny@gmail.com>
X-Clacks-Overhead: GNU Terry Pratchett
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.
This change allows for files (blobs) to be embedded into COB entries.
This allows for things like image attachments in issue comments for example.
For now, we only enable this in the `issue` COB.
The way it works is that relevant COB actions carry metadata about which
files are attached to them; and we store those files as blobs inside the
COB entry's *tree* object, under an `embeds/` folder.
The `Embed<T>` type is used for the above, and either carries actual
content, or carries a content-id. Retrieving the actual content is as
simple as asking the repository for a blob with that content-id.
As a possible future extension, MIME types could be stored alongside the
files in a "metadata" file. This could help clients display the content
appropriately.
> I'm going to be making a set of breaking changes to COBs in order to
stabilize the data formats. This is hopefully a one-time change that
bundles various breaking changes.
All COBs have been reworked: issue, patch, id.
The changes included are:
* Revise the assign and tag actions to take a single list of
assignees/tags to set, instead of an "add" and a "remove" list. This
makes API usage simpler when editing issues, and simplifies the apply
function
* Rename "tags" to "labels", and the tag action to label. This is
because tag is confusing in the context of git, as it could mean a git
tag. Using label removes that confusion.
* Use DIDs instead of PublicKeys for assignees -- this is more
future-proof
* Modify the manifest file format in the COB tree. Mainly, remove the
`history_type` key which is redundant, and use camelCase for keys
* Flatten the `Thread` actions into the parent action type
* Ensure that operations on redacted objects do not fail, since
redactions could have happened concurrently
* Use a consistent naming scheme for actions, using `.` as separator
* Consolidate comment types and remove `CodeComment`, by adding an
optional `location` field to `Comment`
* Add many placeholder actions that are not yet implemented
To preserve backwards compatibility, a `legacy` module is created with
the old `apply` function. When loading the manifest, we check whether it
is a legacy COB or a "stable" COB, and in the legacy case, use the
legacy code to materialize the state and then convert the object into
the stable type. Eventually, we'll delete the legacy code.
It turns out that the CRDT formed by the union of Git DAGs
is enough to guarantee everything we need for COBs.
This changes the following things:
* COB operations no longer need to be commutative
* COB histories are traversed in the same deterministic order on all
replicas
* It's now possible to implement RSMs on top of COBs, eg. scripting
* Lamport clocks have been removed
* `radicle-crdt` is no longer a dependency of `radicle`
* COBs are no longer instances of `Semilattice`
* The `Ops` type was removed in favor of having `Op` contain multiple
actions
Simplify graph traversal and evaluation by building in some of the
functionality into `radicle-dag`, namely the pruning fold.
We avoid building vectors of graph nodes this way, and simply iterate
over the graph in one go.
This commit addresses the issue of recursion in the TryFrom
call of Reference by resolving the parent in a lazy way.
Due to constraints posed by the need to access `git2::Repository`
or `git2::Commit` to resolve the parent, this commit decides to
pull out the parent resolution logic from the `cob::object::Commit`
module and move it inside the `cob::store::Store` implementation by adding
a new method `parents_of`.
Suggested-by: Fintan Halpenny <fintan.halpenny@gmail.com>
Tested-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
Signed-off-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
This allows change commits to have more than one parent that isn't
part of the DAG.
We can use this to create dependencies towards git objects such as
commits, in the case of patch actions.
We're using petgraph to encode an operation based CRDT (each graph node
is an operation) as a DAG, and one of the important things to ensure
is that the final state is not influenced by the order of concurrent
operations. In this case a concurrent operation would mean two potential
graph traversal orders, as there's no direct edge between the two
concurrent ops. This is essential a "partial order" of operations.
To be able to test this, we'd want some kind of control over how
neighbors are iterated over I guess, when there's more than one possible
sort order. Say we have a graph like this:
┌────────b◄─────┐
▼ │
a d
▲ │
└────────c◄─────┘
There are two possible topological traverse orders: [a, b, c, d] and [a,
c, b, d]. Having a way to go through these different orders would
be super handy.
One option would be to allow random order traversal. This would allow us
to test all orders by running the test enough times to likely test all
permutations.
Since petgraph doesn't support this, we implement our own simple DAG in
`radicle-dag`, which implements random-order topological orders.
For now, we don't make explicit use of these improvements, we simply
replace the underlying graph with our own.
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
Vincenzo Palazzo
Alexis Sellier