Disclaimer: These are planning documents. The functionalities described here may be unimplemented, partially implemented, or implemented differently than the original design.

Artifact and ArtifactStore

Artifact

Artifact is a marker trait that signals a set of requirements on an artifact produced by the Publisher or validated by ArtifactValidator. These values do need to be passed across thread boundaries.

trait Artifact: Clone + Send {
    type Identifier: ?Sized;

    fn artifact_id(&self) -> &Self::Identifier;
}

ArtifactStore

The ArtifactStore should provide a way to save and load the artifact based on an identifier. This identifier is recommended to be a hash or signature of the artifact.

The ArtifactStore should support being used both on its own, or within a StoreCommand (i.e. within an existing database transaction).

trait ArtifactStore {
       type Artifact: Artifact;

    /// Save an artifact to the store, with a given artifact identifier
    fn create_artifact(&self, artifact: Self::Artifact)
        -> Result<(), StoreError>;

    /// Return an artifact for the given identifier, if it exists
    fn get_artifact(&self, identifier: &<Self as Artifact>::Identifier)
        -> Result<Option<Self::Artifact>, StoreError>;

    // Delete the artifact, if it is unreferenced.
    fn delete_if_unref_artifact(
        &self,
        identifier: &<Self as Artifact>::Identifier
    ) -> Result<(), StoreError>;
}

Commands are generated via a StoreCommand generator

trait ArtifactStoreCommandGenerator {
    type Artifact: Artifact;
    type Context;

    fn create_artifact_command(&self, artifact: Self::Artifact)
        -> Box<dyn StoreCommand<Context = Self::Context>>;
}

StoreError

This design also references a general store error, made up of the following variants:

pub enum StoreError {
    Internal(InternalError),
    ConstraintViolation(ConstraintViolationError),
    ResourceTemporarilyUnavailable(ResourceTemporarilyUnavailableError),
}

The intent of this error is to be used by all future stores as a replacement for identical, store-specific errors.