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use frame_core::component::ComponentId;
use haematite::CustomMergeFn;
use crate::error::StateError;
use crate::store::ComponentStateStore;
use crate::types::{ComponentSchema, MergePolicy, MetaState};
impl ComponentStateStore {
/// Registers a named custom resolver available to schema declaration.
///
/// Re-registering a name is refused so a durable schema cannot silently
/// change behavior during one process lifetime. The embedding host installs
/// the same function under the same name on every process boot.
///
/// # Errors
///
/// Returns a typed duplicate-name or synchronization failure.
pub fn register_custom_resolver(
&self,
name: impl Into<String>,
resolver: CustomMergeFn,
) -> Result<(), StateError> {
let name = name.into();
let mut resolvers = self
.shared
.resolvers
.lock()
.map_err(|_| StateError::SynchronizationPoisoned)?;
if resolvers.contains_key(&name) {
return Err(StateError::ResolverAlreadyRegistered { name });
}
resolvers.insert(name, resolver);
Ok(())
}
/// Declares the policy that every Work merge for the next incarnation uses.
///
/// Declaration rejects policies the published engine cannot execute and
/// custom names not already registered. Haematite 0.5.0 exposes
/// `VectorClock` but its resolver returns `Unimplemented`, so it is refused
/// here at declaration time.
///
/// # Errors
///
/// Returns typed active, duplicate, unsupported-policy, resolver, or
/// synchronization failures.
pub fn declare_schema(
&self,
component: ComponentId,
schema: ComponentSchema,
) -> Result<(), StateError> {
if self
.lock_storage()?
.meta_record(component)?
.is_some_and(|record| !matches!(record.state, MetaState::Archived { .. }))
{
return Err(StateError::AlreadyActive { component });
}
match &schema.merge_policy {
MergePolicy::Lww => {}
MergePolicy::VectorClock => {
return Err(StateError::UnsupportedPolicy {
policy: MergePolicy::VectorClock,
});
}
MergePolicy::Custom(name) => {
if !self
.shared
.resolvers
.lock()
.map_err(|_| StateError::SynchronizationPoisoned)?
.contains_key(name)
{
return Err(StateError::ResolverNotRegistered { name: name.clone() });
}
}
}
let mut declarations = self
.shared
.declarations
.lock()
.map_err(|_| StateError::SynchronizationPoisoned)?;
if declarations.contains_key(&component) {
return Err(StateError::SchemaAlreadyDeclared { component });
}
declarations.insert(component, schema);
Ok(())
}
}