Files
marathon/crates/libmarathon/src/networking/apply_ops.rs
2026-02-07 18:19:21 +00:00

552 lines
19 KiB
Rust

//! Apply remote operations to local ECS state
//!
//! This module handles incoming EntityDelta messages and applies them to the
//! local Bevy world using CRDT merge semantics.
use std::collections::HashMap;
use bevy::prelude::*;
use uuid::Uuid;
use crate::networking::{
VectorClock,
blob_support::{
BlobStore,
get_component_data,
},
delta_generation::NodeVectorClock,
entity_map::NetworkEntityMap,
merge::compare_operations_lww,
messages::{
ComponentData,
EntityDelta,
SyncMessage,
},
operations::ComponentOp,
};
/// Resource to track the last vector clock and originating node for each
/// component on each entity
///
/// This enables Last-Write-Wins conflict resolution by comparing incoming
/// operations' vector clocks with the current component's vector clock.
/// The node_id is used as a deterministic tiebreaker for concurrent operations.
#[derive(Resource, Default)]
pub struct ComponentVectorClocks {
/// Maps (entity_network_id, component_type) -> (vector_clock,
/// originating_node_id)
clocks: HashMap<(Uuid, String), (VectorClock, Uuid)>,
}
impl ComponentVectorClocks {
pub fn new() -> Self {
Self {
clocks: HashMap::new(),
}
}
/// Get the current vector clock and node_id for a component
pub fn get(&self, entity_id: Uuid, component_type: &str) -> Option<&(VectorClock, Uuid)> {
self.clocks.get(&(entity_id, component_type.to_string()))
}
/// Update the vector clock and node_id for a component
pub fn set(
&mut self,
entity_id: Uuid,
component_type: String,
clock: VectorClock,
node_id: Uuid,
) {
self.clocks
.insert((entity_id, component_type), (clock, node_id));
}
/// Remove all clocks for an entity (when entity is deleted)
pub fn remove_entity(&mut self, entity_id: Uuid) {
self.clocks.retain(|(eid, _), _| *eid != entity_id);
}
}
/// Apply an EntityDelta message to the local world
///
/// This function:
/// 1. Checks tombstone registry to prevent resurrection
/// 2. Looks up the entity by network_id
/// 3. Spawns a new entity if it doesn't exist
/// 4. Applies each ComponentOp using CRDT merge semantics
///
/// # Parameters
///
/// - `delta`: The EntityDelta to apply
/// - `world`: The Bevy world to apply changes to
pub fn apply_entity_delta(delta: &EntityDelta, world: &mut World) {
// Validate and merge the remote vector clock
{
let mut node_clock = world.resource_mut::<NodeVectorClock>();
// Check for clock regression (shouldn't happen in correct implementations)
if delta.vector_clock.happened_before(&node_clock.clock) {
warn!(
"Received operation with clock from the past for entity {:?}. \
Remote clock happened before our clock. This may indicate clock issues.",
delta.entity_id
);
}
// Merge the remote vector clock into ours
node_clock.clock.merge(&delta.vector_clock);
}
// Check if any operations are Delete operations
for op in &delta.operations {
if let crate::networking::ComponentOp::Delete { vector_clock } = op {
// Record tombstone
if let Some(mut registry) =
world.get_resource_mut::<crate::networking::TombstoneRegistry>()
{
registry.record_deletion(delta.entity_id, delta.node_id, vector_clock.clone());
// Despawn the entity if it exists locally
let entity_to_despawn = {
let entity_map = world.resource::<NetworkEntityMap>();
entity_map.get_entity(delta.entity_id)
};
if let Some(entity) = entity_to_despawn {
world.despawn(entity);
let mut entity_map = world.resource_mut::<NetworkEntityMap>();
entity_map.remove_by_network_id(delta.entity_id);
info!(
"Despawned entity {:?} due to Delete operation",
delta.entity_id
);
}
// Don't process other operations - entity is deleted
return;
}
}
}
// Check if we should ignore this delta due to deletion
if let Some(registry) = world.get_resource::<crate::networking::TombstoneRegistry>() {
if registry.should_ignore_operation(delta.entity_id, &delta.vector_clock) {
debug!("Ignoring delta for deleted entity {:?}", delta.entity_id);
return;
}
}
let entity = {
let entity_map = world.resource::<NetworkEntityMap>();
if let Some(entity) = entity_map.get_entity(delta.entity_id) {
entity
} else {
// Use shared helper to spawn networked entity with persistence
crate::networking::spawn_networked_entity(world, delta.entity_id, delta.node_id)
}
};
// Apply each operation (skip Delete operations - handled above)
for op in &delta.operations {
if !op.is_delete() {
apply_component_op(entity, op, delta.node_id, world);
}
}
// Trigger persistence by marking Persisted as changed
// This ensures remote entities are persisted after sync
if let Ok(mut entity_mut) = world.get_entity_mut(entity) {
if let Some(mut persisted) = entity_mut.get_mut::<crate::persistence::Persisted>() {
// Accessing &mut triggers Bevy's change detection
let _ = &mut *persisted;
debug!(
"Triggered persistence for synced entity {:?}",
delta.entity_id
);
}
}
}
/// Apply a single ComponentOp to an entity
///
/// This dispatches to the appropriate CRDT merge logic based on the operation
/// type.
fn apply_component_op(entity: Entity, op: &ComponentOp, incoming_node_id: Uuid, world: &mut World) {
match op {
| ComponentOp::Set {
discriminant,
data,
vector_clock,
} => {
apply_set_operation_with_lww(
entity,
*discriminant,
data,
vector_clock,
incoming_node_id,
world,
);
},
| ComponentOp::SetAdd { discriminant, .. } => {
// OR-Set add - Phase 10 provides OrSet<T> type
// Application code should use OrSet in components and handle SetAdd/SetRemove
// Full integration will be in Phase 12 plugin
debug!(
"SetAdd operation for discriminant {} (use OrSet<T> in components)",
discriminant
);
},
| ComponentOp::SetRemove { discriminant, .. } => {
// OR-Set remove - Phase 10 provides OrSet<T> type
// Application code should use OrSet in components and handle SetAdd/SetRemove
// Full integration will be in Phase 12 plugin
debug!(
"SetRemove operation for discriminant {} (use OrSet<T> in components)",
discriminant
);
},
| ComponentOp::SequenceInsert { .. } => {
// RGA insert - will be implemented in Phase 11
debug!("SequenceInsert operation not yet implemented");
},
| ComponentOp::SequenceDelete { .. } => {
// RGA delete - will be implemented in Phase 11
debug!("SequenceDelete operation not yet implemented");
},
| ComponentOp::Delete { .. } => {
// Entity deletion - will be implemented in Phase 9
debug!("Delete operation not yet implemented");
},
}
}
/// Apply a Set operation with Last-Write-Wins conflict resolution
///
/// Compares the incoming vector clock with the stored clock for this component.
/// Only applies the operation if the incoming clock wins the LWW comparison.
/// Uses node_id as a deterministic tiebreaker for concurrent operations.
fn apply_set_operation_with_lww(
entity: Entity,
discriminant: u16,
data: &ComponentData,
incoming_clock: &VectorClock,
incoming_node_id: Uuid,
world: &mut World,
) {
// Get component type name for logging and clock tracking
let type_registry = {
let registry_resource = world.resource::<crate::persistence::ComponentTypeRegistryResource>();
registry_resource.0
};
let component_type_name = match type_registry.get_type_name(discriminant) {
| Some(name) => name,
| None => {
error!("Unknown discriminant {} - component not registered", discriminant);
return;
},
};
// Get the network ID for this entity
let entity_network_id = {
if let Ok(entity_ref) = world.get_entity(entity) {
if let Some(networked) = entity_ref.get::<crate::networking::NetworkedEntity>() {
networked.network_id
} else {
warn!("Entity {:?} has no NetworkedEntity component", entity);
return;
}
} else {
warn!("Entity {:?} not found", entity);
return;
}
};
// Check if we should apply this operation based on LWW
let should_apply = {
if let Some(component_clocks) = world.get_resource::<ComponentVectorClocks>() {
if let Some((current_clock, current_node_id)) =
component_clocks.get(entity_network_id, component_type_name)
{
// We have a current clock - do LWW comparison with real node IDs
let decision = compare_operations_lww(
current_clock,
*current_node_id,
incoming_clock,
incoming_node_id,
);
match decision {
| crate::networking::merge::MergeDecision::ApplyRemote => {
debug!(
"Applying remote Set for {} (remote is newer)",
component_type_name
);
true
},
| crate::networking::merge::MergeDecision::KeepLocal => {
debug!(
"Ignoring remote Set for {} (local is newer)",
component_type_name
);
false
},
| crate::networking::merge::MergeDecision::Concurrent => {
// For concurrent operations, use node_id comparison as deterministic
// tiebreaker This ensures all nodes make the same
// decision for concurrent updates
if incoming_node_id > *current_node_id {
debug!(
"Applying remote Set for {} (concurrent, remote node_id {:?} > local {:?})",
component_type_name, incoming_node_id, current_node_id
);
true
} else {
debug!(
"Ignoring remote Set for {} (concurrent, local node_id {:?} >= remote {:?})",
component_type_name, current_node_id, incoming_node_id
);
false
}
},
| crate::networking::merge::MergeDecision::Equal => {
debug!("Ignoring remote Set for {} (clocks equal)", component_type_name);
false
},
}
} else {
// No current clock - this is the first time we're setting this component
debug!(
"Applying remote Set for {} (no current clock)",
component_type_name
);
true
}
} else {
// No ComponentVectorClocks resource - apply unconditionally
warn!("ComponentVectorClocks resource not found - applying Set without LWW check");
true
}
};
if !should_apply {
return;
}
// Apply the operation
apply_set_operation(entity, discriminant, data, world);
// Update the stored vector clock with node_id
if let Some(mut component_clocks) = world.get_resource_mut::<ComponentVectorClocks>() {
component_clocks.set(
entity_network_id,
component_type_name.to_string(),
incoming_clock.clone(),
incoming_node_id,
);
debug!(
"Updated vector clock for {} on entity {:?} (node_id: {:?})",
component_type_name, entity_network_id, incoming_node_id
);
}
}
/// Apply a Set operation (Last-Write-Wins)
///
/// Deserializes the component and inserts/updates it on the entity.
/// Handles both inline data and blob references.
fn apply_set_operation(
entity: Entity,
discriminant: u16,
data: &ComponentData,
world: &mut World,
) {
let blob_store = world.get_resource::<BlobStore>();
// Get the actual data (resolve blob if needed)
let data_bytes = match data {
| ComponentData::Inline(bytes) => bytes.clone(),
| ComponentData::BlobRef { hash: _, size: _ } => {
if let Some(store) = blob_store {
match get_component_data(data, store) {
| Ok(bytes) => bytes,
| Err(e) => {
error!(
"Failed to retrieve blob for discriminant {}: {}",
discriminant, e
);
return;
},
}
} else {
error!(
"Blob reference for discriminant {} but no blob store available",
discriminant
);
return;
}
},
};
// Get component type registry
let type_registry = {
let registry_resource = world.resource::<crate::persistence::ComponentTypeRegistryResource>();
registry_resource.0
};
// Look up deserialize and insert functions by discriminant
let deserialize_fn = type_registry.get_deserialize_fn(discriminant);
let insert_fn = type_registry.get_insert_fn(discriminant);
let (deserialize_fn, insert_fn) = match (deserialize_fn, insert_fn) {
| (Some(d), Some(i)) => (d, i),
| _ => {
error!("Discriminant {} not registered in ComponentTypeRegistry", discriminant);
return;
},
};
// Deserialize the component
let boxed_component = match deserialize_fn(&data_bytes) {
| Ok(component) => component,
| Err(e) => {
error!("Failed to deserialize discriminant {}: {}", discriminant, e);
return;
},
};
// Insert the component into the entity
if let Ok(mut entity_mut) = world.get_entity_mut(entity) {
insert_fn(&mut entity_mut, boxed_component);
debug!("Applied Set operation for discriminant {}", discriminant);
// If we just inserted a Transform component, also add NetworkedTransform
// This ensures remote entities can have their Transform changes detected
let type_path = type_registry.get_type_path(discriminant);
if type_path == Some("bevy_transform::components::transform::Transform") {
if let Ok(mut entity_mut) = world.get_entity_mut(entity) {
if entity_mut
.get::<crate::networking::NetworkedTransform>()
.is_none()
{
entity_mut.insert(crate::networking::NetworkedTransform::default());
debug!("Added NetworkedTransform to entity with Transform");
}
}
}
} else {
error!(
"Entity {:?} not found when applying discriminant {}",
entity, discriminant
);
}
}
/// System to receive and apply incoming EntityDelta messages
///
/// This system polls the GossipBridge for incoming messages and applies them
/// to the local world.
///
/// Add this to your app:
///
/// ```no_run
/// use bevy::prelude::*;
/// use libmarathon::networking::receive_and_apply_deltas_system;
///
/// App::new().add_systems(Update, receive_and_apply_deltas_system);
/// ```
pub fn receive_and_apply_deltas_system(world: &mut World) {
// Check if bridge exists
if world
.get_resource::<crate::networking::GossipBridge>()
.is_none()
{
return;
}
// Clone the bridge to avoid borrowing issues
let bridge = world.resource::<crate::networking::GossipBridge>().clone();
// Poll for incoming messages
while let Some(message) = bridge.try_recv() {
match message.message {
| SyncMessage::EntityDelta {
entity_id,
node_id,
vector_clock,
operations,
} => {
let delta = EntityDelta {
entity_id,
node_id,
vector_clock,
operations,
};
debug!(
"Received EntityDelta for entity {:?} with {} operations",
delta.entity_id,
delta.operations.len()
);
apply_entity_delta(&delta, world);
},
| SyncMessage::JoinRequest { .. } => {
// Handled by handle_join_requests_system
debug!("JoinRequest handled by dedicated system");
},
| SyncMessage::FullState { .. } => {
// Handled by handle_full_state_system
debug!("FullState handled by dedicated system");
},
| SyncMessage::SyncRequest { .. } => {
// Handled by handle_sync_requests_system
debug!("SyncRequest handled by dedicated system");
},
| SyncMessage::MissingDeltas { .. } => {
// Handled by handle_missing_deltas_system
debug!("MissingDeltas handled by dedicated system");
},
| SyncMessage::Lock { .. } => {
// Handled by lock message dispatcher
debug!("Lock message handled by dedicated system");
},
}
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_node_clock_merge() {
let node_id = uuid::Uuid::new_v4();
let mut node_clock = NodeVectorClock::new(node_id);
let remote_node = uuid::Uuid::new_v4();
let mut remote_clock = crate::networking::VectorClock::new();
remote_clock.increment(remote_node);
remote_clock.increment(remote_node);
// Merge remote clock
node_clock.clock.merge(&remote_clock);
// Our clock should have the remote node's sequence
assert_eq!(node_clock.clock.get(remote_node), 2);
}
#[test]
fn test_entity_delta_structure() {
let entity_id = uuid::Uuid::new_v4();
let node_id = uuid::Uuid::new_v4();
let clock = crate::networking::VectorClock::new();
let delta = EntityDelta::new(entity_id, node_id, clock, vec![]);
assert_eq!(delta.entity_id, entity_id);
assert_eq!(delta.node_id, node_id);
assert_eq!(delta.operations.len(), 0);
}
}