Reactive Node Implementation

This document describes the implementation details of reactive nodes in the Floxide framework.

Overview

Reactive nodes in Floxide provide stream-based processing capabilities with proper backpressure handling and error management.

Core Components

ReactiveNode Trait

The ReactiveNode trait defines the core interface for reactive processing:

#[async_trait]
pub trait ReactiveNode<Change, Context, Action>: Send + Sync
where
    Change: Send + Sync + 'static,
    Context: Send + Sync + 'static,
    Action: ActionType + Send + Sync + 'static + Debug,
{
    async fn watch(&self) -> Result<Box<dyn Stream<Item = Change> + Send + Unpin>, FloxideError>;
    async fn react_to_change(&self, change: Change, ctx: &mut Context) -> Result<Action, FloxideError>;
    fn id(&self) -> NodeId;
}

CustomReactiveNode

The CustomReactiveNode provides a flexible implementation that allows users to define their own watch and react functions:

pub struct CustomReactiveNode<Change, Context, Action, WatchFn, ReactFn> {
    watch_fn: WatchFn,
    react_fn: ReactFn,
    id: NodeId,
    _phantom: PhantomData<(Change, Context, Action)>,
}

Implementation Details

Stream Management

  1. Watch Function
  2. Creates and manages the underlying stream
  3. Handles backpressure through Tokio's async streams

  4. Provides proper cleanup on drop

  5. Change Detection

  6. Processes changes as they arrive
  7. Maintains order of changes

  8. Handles errors gracefully

  9. Context Updates

  10. Updates context based on changes
  11. Maintains thread safety
  12. Provides atomic updates when needed

Error Handling

  1. Stream Errors
  2. Proper error propagation
  3. Recovery mechanisms

  4. Error context preservation

  5. Processing Errors

  6. Custom error types
  7. Error recovery strategies
  8. Error reporting

Resource Management

  1. Memory Usage
  2. Efficient stream buffering
  3. Proper cleanup of resources

  4. Memory leak prevention

  5. Thread Safety

  6. Thread-safe context access
  7. Safe concurrent processing
  8. Proper synchronization

Usage Patterns

Basic Usage

let node = CustomReactiveNode::new(
    || { /* watch implementation */ },
    |change, ctx| { /* react implementation */ },
);

With Error Handling

let node = CustomReactiveNode::new(
    || {
        if let Err(e) = check_preconditions() {
            return Err(e.into());
        }
        Ok(create_stream())
    },
    |change, ctx| {
        match process_change(change) {
            Ok(result) => Ok(DefaultAction::change_detected()),
            Err(e) => Err(e.into()),
        }
    },
);

With Backpressure

let node = CustomReactiveNode::new(
    || {
        Ok(Box::new(
            stream::iter(0..100)
                .throttle(Duration::from_millis(100))
        ))
    },
    |change, ctx| { /* react implementation */ },
);

Testing

The implementation includes comprehensive tests:

  1. Unit Tests
  2. Stream creation
  3. Change processing
  4. Error handling

  5. Resource cleanup

  6. Integration Tests

  7. End-to-end workflows
  8. Complex scenarios
  9. Performance tests

Performance Considerations

  1. Stream Efficiency
  2. Minimal allocations
  3. Efficient buffering

  4. Proper backpressure

  5. Processing Overhead

  6. Optimized change detection
  7. Efficient context updates
  8. Minimal locking

Future Improvements

  1. Enhanced Features
  2. More stream combinators
  3. Additional error recovery strategies

  4. Extended composition patterns

  5. Performance Optimizations

  6. Improved buffering strategies
  7. Better resource utilization
  8. Enhanced concurrency