frame-state 0.2.0

Content-addressed state layer — haematite integration, entities, branching, cross-component references
Documentation
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use std::error::Error;
use std::sync::atomic::{AtomicBool, AtomicUsize, Ordering};
use std::sync::{Arc, Barrier, Mutex};

use frame_core::capability::{
    Capability, CapabilityDenied, CapabilityKind, CapabilityScope, CheckVerdict,
};
use frame_core::component::ComponentId;
use haematite::{CheckoutError, checkout};

use super::{TestDirectory, TestResult, component, install};
use crate::handle::ResolutionChecker;
use crate::types::{MetaState, ReferenceTargetState};
use crate::{ComponentStateStore, CrossComponentRef, EntityId, StateError};

struct RecordingChecker {
    component: ComponentId,
    allowed: AtomicBool,
    declared: bool,
    checks: AtomicUsize,
    denials: Mutex<Vec<CapabilityDenied>>,
}

impl RecordingChecker {
    fn new(component: ComponentId, allowed: bool, declared: bool) -> Self {
        Self {
            component,
            allowed: AtomicBool::new(allowed),
            declared,
            checks: AtomicUsize::new(0),
            denials: Mutex::new(Vec::new()),
        }
    }

    fn revoke(&self) {
        self.allowed.store(false, Ordering::Release);
    }

    fn check_count(&self) -> usize {
        self.checks.load(Ordering::Acquire)
    }

    fn events(&self) -> Vec<CapabilityDenied> {
        self.denials.lock().expect("denial recorder lock").clone()
    }
}

impl ResolutionChecker for RecordingChecker {
    fn component_id(&self) -> ComponentId {
        self.component
    }

    fn check(
        &self,
        capability: &Capability,
    ) -> Result<CheckVerdict, frame_core::capability::CapabilityCheckError> {
        self.checks.fetch_add(1, Ordering::AcqRel);
        if self.allowed.load(Ordering::Acquire) {
            return Ok(CheckVerdict::Allowed);
        }
        let denial = CapabilityDenied {
            component_id: self.component,
            kind: capability.kind(),
            scope: capability.scope(),
            declared: self.declared,
        };
        self.denials
            .lock()
            .expect("denial recorder lock")
            .push(denial.clone());
        Ok(CheckVerdict::Denied(denial))
    }
}

fn denial(error: StateError) -> Result<CapabilityDenied, Box<dyn Error>> {
    match error {
        StateError::CapabilityDenied(denial) => Ok(denial),
        other => Err(format!("expected capability denial, got {other}").into()),
    }
}

fn dangling_state(error: StateError) -> Result<ReferenceTargetState, Box<dyn Error>> {
    match error {
        StateError::DanglingReference { state, .. } => Ok(state),
        other => Err(format!("expected dangling reference, got {other}").into()),
    }
}

#[test]
fn cross_component_ref_v1_round_trips_as_entity_content_and_rejects_corruption() -> TestResult {
    let directory = TestDirectory::new("cross-ref-codec")?;
    let store = ComponentStateStore::open(directory.path())?;
    let reader = component("codec-reader");
    let target = component("codec-target");
    let reader_handle = install(&store, reader)?;
    let target_handle = install(&store, target)?;
    let entity = target_handle.put(b"linked bytes")?;
    target_handle.commit()?;
    let reference = CrossComponentRef::new(target, entity);
    let encoded = reference.to_bytes();
    let stored_link = reader_handle.put(&encoded)?;
    reader_handle.commit()?;
    let decoded = CrossComponentRef::from_bytes(
        &reader_handle
            .get(stored_link)?
            .expect("stored link entity exists"),
    )?;
    assert_eq!(decoded, reference);

    let mut wrong_version = encoded;
    wrong_version[0] = wrong_version[0].wrapping_add(1);
    assert!(matches!(
        CrossComponentRef::from_bytes(&wrong_version),
        Err(StateError::CorruptRecord { detail })
            if detail.contains("cross-component reference") && detail.contains("version")
    ));
    assert!(matches!(
        CrossComponentRef::from_bytes(&encoded[..encoded.len() - 1]),
        Err(StateError::CorruptRecord { detail })
            if detail.contains("cross-component reference") && detail.contains("bytes")
    ));
    Ok(())
}

#[test]
fn ungranted_flavors_are_verbatim_and_evented_once_per_resolution() -> TestResult {
    let directory = TestDirectory::new("cross-ref-denials")?;
    let store = ComponentStateStore::open(directory.path())?;
    let reader = component("denied-reader");
    let target = component("denied-target");
    let handle = install(&store, reader)?;
    let reference = CrossComponentRef::new(target, EntityId::of(b"absent"));

    for declared in [true, false] {
        let checker = RecordingChecker::new(reader, false, declared);
        let observed = denial(
            handle
                .resolve_cross_component_with(&checker, reference)
                .expect_err("ungranted resolution must fail"),
        )?;
        assert_eq!(observed.component_id, reader);
        assert_eq!(observed.kind, CapabilityKind::CrossComponentRead);
        assert_eq!(observed.scope, CapabilityScope::Component(target));
        assert_eq!(observed.declared, declared);
        assert_eq!(checker.check_count(), 1);
        assert_eq!(checker.events(), vec![observed]);
    }
    Ok(())
}

#[test]
fn denial_is_identical_before_target_inspection_for_every_target_state() -> TestResult {
    let reader = component("no-probe-reader");
    let target = component("no-probe-target");
    let entity = EntityId::of(b"no-probe");
    let mut observed = Vec::new();

    for state in ["active", "archived", "never-installed"] {
        let directory = TestDirectory::new(&format!("no-probe-{state}"))?;
        let store = ComponentStateStore::open(directory.path())?;
        let handle = install(&store, reader)?;
        if state != "never-installed" {
            let target_handle = install(&store, target)?;
            target_handle.put(b"no-probe")?;
            target_handle.commit()?;
            if state == "archived" {
                store.archive_storage(target)?;
            }
        }
        let checker = RecordingChecker::new(reader, false, true);
        observed.push(denial(
            handle
                .resolve_cross_component_with(&checker, CrossComponentRef::new(target, entity))
                .expect_err("denial precedes every target state"),
        )?);
        assert_eq!(checker.check_count(), 1);
        assert_eq!(checker.events().len(), 1);
    }
    assert!(observed.windows(2).all(|pair| pair[0] == pair[1]));
    Ok(())
}

#[test]
fn granted_link_content_round_trip_and_committed_root_visibility() -> TestResult {
    let directory = TestDirectory::new("cross-ref-content")?;
    let store = ComponentStateStore::open(directory.path())?;
    let reader = component("content-reader");
    let target = component("content-target");
    let reader_handle = install(&store, reader)?;
    let target_handle = install(&store, target)?;
    let entity = target_handle.put(b"committed target")?;
    let reference = CrossComponentRef::new(target, entity);
    let link_entity = reader_handle.put(&reference.to_bytes())?;
    reader_handle.commit()?;
    let stored = reader_handle
        .get(link_entity)?
        .expect("link persisted as entity content");
    let stored = CrossComponentRef::from_bytes(&stored)?;
    let checker = RecordingChecker::new(reader, true, true);

    assert_eq!(
        reader_handle.resolve_cross_component_with(&checker, stored)?,
        None,
        "uncommitted target content is invisible"
    );
    target_handle.commit()?;
    assert_eq!(
        reader_handle.resolve_cross_component_with(&checker, stored)?,
        Some(b"committed target".to_vec())
    );
    assert_eq!(checker.check_count(), 2, "one check per fresh resolution");
    Ok(())
}

#[test]
fn retained_handle_and_checker_refuse_the_next_act_after_revoke() -> TestResult {
    let directory = TestDirectory::new("cross-ref-revoke")?;
    let store = ComponentStateStore::open(directory.path())?;
    let reader = component("revoke-reader");
    let target = component("revoke-target");
    let handle = install(&store, reader)?;
    let target_handle = install(&store, target)?;
    let entity = target_handle.put(b"before revoke")?;
    target_handle.commit()?;
    let reference = CrossComponentRef::new(target, entity);
    let checker = RecordingChecker::new(reader, true, true);
    assert_eq!(
        handle.resolve_cross_component_with(&checker, reference)?,
        Some(b"before revoke".to_vec())
    );
    checker.revoke();
    let refused = denial(
        handle
            .resolve_cross_component_with(&checker, reference)
            .expect_err("next consuming act must observe revoke"),
    )?;
    assert!(refused.declared);
    assert_eq!(checker.check_count(), 2);
    assert_eq!(checker.events(), vec![refused]);
    Ok(())
}

#[test]
fn confused_deputy_and_self_target_have_no_shortcuts() -> TestResult {
    let directory = TestDirectory::new("cross-ref-uniformity")?;
    let store = ComponentStateStore::open(directory.path())?;
    let reader = component("uniform-reader");
    let deputy = component("uniform-deputy");
    let handle = install(&store, reader)?;
    let reference = CrossComponentRef::new(reader, EntityId::of(b"self"));

    let wrong_checker = RecordingChecker::new(deputy, true, true);
    assert!(matches!(
        handle.resolve_cross_component_with(&wrong_checker, reference),
        Err(StateError::CapabilityBinding {
            handle_component,
            checker_component
        }) if handle_component == reader && checker_component == deputy
    ));
    assert_eq!(wrong_checker.check_count(), 0);
    assert!(wrong_checker.events().is_empty());

    let own_checker = RecordingChecker::new(reader, false, true);
    let self_denial = denial(
        handle
            .resolve_cross_component_with(&own_checker, reference)
            .expect_err("self-target requires the same grant"),
    )?;
    assert_eq!(self_denial.scope, CapabilityScope::Component(reader));
    assert_eq!(own_checker.check_count(), 1);
    assert_eq!(own_checker.events(), vec![self_denial]);
    Ok(())
}

#[test]
fn dangling_states_are_typed_and_archived_content_remains_recoverable() -> TestResult {
    let directory = TestDirectory::new("cross-ref-dangling")?;
    let store = ComponentStateStore::open(directory.path())?;
    let reader = component("dangling-reader");
    let target = component("dangling-target");
    let handle = install(&store, reader)?;
    let checker = RecordingChecker::new(reader, true, true);
    let entity = EntityId::of(b"recoverable");
    let reference = CrossComponentRef::new(target, entity);
    assert_eq!(
        dangling_state(
            handle
                .resolve_cross_component_with(&checker, reference)
                .expect_err("never-installed target dangles")
        )?,
        ReferenceTargetState::NeverInstalled
    );

    let target_handle = install(&store, target)?;
    target_handle.put(b"recoverable")?;
    target_handle.commit()?;
    assert_eq!(
        handle.resolve_cross_component_with(&checker, reference)?,
        Some(b"recoverable".to_vec())
    );
    let archive = store.archive_storage(target)?;
    assert_eq!(
        dangling_state(
            handle
                .resolve_cross_component_with(&checker, reference)
                .expect_err("archived target dangles")
        )?,
        ReferenceTargetState::Archived {
            generation: archive.generation
        }
    );
    assert_eq!(
        store.get_archived(target, archive.generation, entity)?,
        Some(b"recoverable".to_vec())
    );
    Ok(())
}

#[test]
fn transitional_dangling_states_name_the_durable_meta_state() -> TestResult {
    let directory = TestDirectory::new("cross-ref-transitional")?;
    let store = ComponentStateStore::open(directory.path())?;
    let reader = component("transition-reader");
    let installing = component("transition-installing");
    let archiving = component("transition-archiving");
    let handle = install(&store, reader)?;
    let checker = RecordingChecker::new(reader, true, true);
    {
        let mut storage = store.lock_storage()?;
        let reader_record = storage
            .meta_record(reader)?
            .expect("reader meta record exists");
        let mut installing_record = reader_record.clone();
        installing_record.component = installing;
        installing_record.state = MetaState::Installing;
        storage.write_meta(&installing_record)?;
    }
    assert_eq!(
        dangling_state(
            handle
                .resolve_cross_component_with(
                    &checker,
                    CrossComponentRef::new(installing, EntityId::of(b"missing")),
                )
                .expect_err("installing target dangles"),
        )?,
        ReferenceTargetState::Installing
    );

    install(&store, archiving)?;
    {
        let mut storage = store.lock_storage()?;
        let mut record = storage
            .meta_record(archiving)?
            .expect("archiving meta record exists");
        record.state = MetaState::Archiving {
            generation: record.incarnation,
            abandoned_work: Vec::new(),
        };
        storage.write_meta(&record)?;
    }
    assert_eq!(
        dangling_state(
            handle
                .resolve_cross_component_with(
                    &checker,
                    CrossComponentRef::new(archiving, EntityId::of(b"missing")),
                )
                .expect_err("archiving target dangles"),
        )?,
        ReferenceTargetState::Archiving { generation: 0 }
    );
    Ok(())
}

#[test]
fn stale_reader_fence_precedes_target_checkout() -> TestResult {
    let directory = TestDirectory::new("cross-ref-stale-reader")?;
    let store = ComponentStateStore::open(directory.path())?;
    let reader = component("stale-reader");
    let target = component("stale-target");
    let stale = install(&store, reader)?;
    let target_handle = install(&store, target)?;
    let entity = target_handle.put(b"target")?;
    target_handle.commit()?;
    store.archive_storage(reader)?;
    let fresh = install(&store, reader)?;
    let checker = RecordingChecker::new(reader, true, true);
    assert!(matches!(
        stale.resolve_cross_component_with(&checker, CrossComponentRef::new(target, entity)),
        Err(StateError::StaleHandle {
            component: stale_component,
            held: 0,
            current: 1
        }) if stale_component == reader
    ));
    assert_eq!(fresh.get(entity)?, None);
    assert_eq!(checker.check_count(), 1);
    Ok(())
}

#[test]
fn archive_racing_resolution_has_exactly_bytes_or_typed_miss() -> TestResult {
    let directory = TestDirectory::new("cross-ref-archive-race")?;
    let store = Arc::new(ComponentStateStore::open(directory.path())?);
    let reader = component("race-reader");
    let target = component("race-target");
    let handle = install(&store, reader)?;
    let target_handle = install(&store, target)?;
    let entity = target_handle.put(b"valid root")?;
    target_handle.commit()?;
    let reference = CrossComponentRef::new(target, entity);
    let checker = RecordingChecker::new(reader, true, true);
    assert_eq!(
        handle.resolve_cross_component_with(&checker, reference)?,
        Some(b"valid root".to_vec()),
        "bytes-at-valid-root is reachable before the race"
    );

    let barrier = Arc::new(Barrier::new(2));
    let archive_store = Arc::clone(&store);
    let archive_barrier = Arc::clone(&barrier);
    let archive = std::thread::spawn(move || {
        archive_barrier.wait();
        archive_store.archive_storage(target)
    });
    barrier.wait();
    while !archive.is_finished() {
        match handle.resolve_cross_component_with(&checker, reference) {
            Ok(Some(bytes)) if bytes == b"valid root" => {}
            Err(StateError::DanglingReference { target: missed, .. }) if missed == target => {}
            other => {
                return Err(format!("outcome outside exhaustive race set: {other:?}").into());
            }
        }
    }
    archive.join().expect("archive thread did not panic")?;
    assert!(
        matches!(
            handle.resolve_cross_component_with(&checker, reference),
            Err(StateError::DanglingReference { target: missed, .. }) if missed == target
        ),
        "typed-miss is reachable after the race"
    );
    Ok(())
}

#[test]
fn checkout_write_surface_refuses_and_public_resolution_returns_only_owned_bytes() -> TestResult {
    let directory = TestDirectory::new("cross-ref-read-only")?;
    let store = ComponentStateStore::open(directory.path())?;
    let target = component("read-only-target");
    let target_handle = install(&store, target)?;
    target_handle.put(b"immutable view")?;
    let root = target_handle.commit()?;
    let storage = store.lock_storage()?;
    let view = checkout(&storage.nodes, root);
    assert!(matches!(
        view.put(b"key", b"value"),
        Err(CheckoutError::ReadOnly)
    ));
    assert!(matches!(view.delete(b"key"), Err(CheckoutError::ReadOnly)));
    assert!(matches!(view.commit(), Err(CheckoutError::ReadOnly)));

    for source in [
        include_str!("../lib.rs"),
        include_str!("../handle.rs"),
        include_str!("../store.rs"),
        include_str!("../types.rs"),
        include_str!("../archive.rs"),
        include_str!("../codec.rs"),
        include_str!("../engine.rs"),
        include_str!("../error.rs"),
        include_str!("../schema.rs"),
    ] {
        for pattern in [
            "-> ReadOnlyView",
            "-> haematite::ReadOnlyView",
            "Result<ReadOnlyView",
            "Result<haematite::ReadOnlyView",
            "Box<ReadOnlyView",
            "= ReadOnlyView",
            "= haematite::ReadOnlyView",
            "pub use haematite::ReadOnlyView",
        ] {
            assert!(
                !source.contains(pattern),
                "frame-state source must not return, alias, or re-export a checkout view (matched {pattern:?})"
            );
        }
    }
    Ok(())
}