Core Types

This section documents the core trait abstractions and types in AirsSys OSL.

Current Status

Implementation Phase: ✅ Implemented
Module Location: src/core/
RustDoc: Run cargo doc --open in airssys-osl for complete API documentation

Overview

The core module provides the foundational abstractions for the OSL framework:

• Operation Trait: Core Operation trait defining operations that can be executed
• OSExecutor Trait: Generic-based executor interface for running operations
• Middleware Trait: Core middleware abstraction for operation interception
• Context Types: Execution contexts and security context for operation metadata
• Error Types: Structured error types following canonical error patterns

Generic-First Pattern

The core types follow a generic-first design pattern to enable zero-cost abstractions:

pub trait OSExecutor<O>: Debug + Send + Sync + 'static 
where O: Operation
{
    async fn execute(&self, operation: O, context: &ExecutionContext) -> OSResult<ExecutionResult>;
}

Key Traits

Operation Trait

Defines the interface for operations that can be executed:

pub trait Operation: Debug + Send + Sync + 'static {
    fn operation_type(&self) -> OperationType;
    fn requires_privilege(&self) -> bool;
}

OSExecutor Trait

Generic executor interface:

pub trait OSExecutor<O: Operation>: Debug + Send + Sync + 'static {
    async fn execute(&self, operation: O, context: &ExecutionContext) 
        -> OSResult<ExecutionResult>;
}

Middleware Trait

Operation interception interface:

#[async_trait]
pub trait Middleware<O: Operation>: Send + Sync {
    fn name(&self) -> &str;
    fn priority(&self) -> u32;

    async fn before_execution(&self, operation: O, context: &ExecutionContext) 
        -> MiddlewareResult<Option<O>>;

    async fn after_execution(&self, operation: &O, result: ExecutionResult, context: &ExecutionContext) 
        -> MiddlewareResult<ExecutionResult>;
}

Context Types

ExecutionContext

Contains metadata for operation execution:

pub struct ExecutionContext {
    security: SecurityContext,
    metadata: HashMap<String, String>,
    // ... additional fields
}

SecurityContext

Encapsulates security information:

pub struct SecurityContext {
    principal: String,
    roles: Vec<String>,
    permissions: Vec<String>,
}

Error Types

Structured error handling with OSError and OSResult<T>:

pub type OSResult<T> = Result<T, OSError>;

pub enum OSError {
    PermissionDenied { operation: String, principal: String },
    NotFound { resource: String },
    ExecutionFailed { details: String },
    // ... other variants
}

For complete API documentation with all methods and examples, see the generated RustDoc (cargo doc --open).