Struct CircuitBreakerMiddleware 

pub struct CircuitBreakerMiddleware { /* private fields */ }

Circuit breaker middleware for fault tolerance.

Examples

use pmcp::shared::{CircuitBreakerMiddleware, AdvancedMiddleware, MiddlewareContext};
use pmcp::types::{JSONRPCRequest, RequestId};
use std::time::Duration;

// Circuit breaker: 5 failures in 60s window trips for 30s
let circuit_breaker = CircuitBreakerMiddleware::new(
    5,                          // failure_threshold
    Duration::from_secs(60),    // time_window
    Duration::from_secs(30),    // timeout_duration
);
let context = MiddlewareContext::default();

let mut request = JSONRPCRequest {
    jsonrpc: "2.0".to_string(),
    method: "external_service.call".to_string(),
    params: Some(serde_json::json!({"data": "test"})),
    id: RequestId::from(456i64),
};

// This will fail fast if circuit is open
circuit_breaker.on_request_with_context(&mut request, &context).await?;

Implementations

impl CircuitBreakerMiddleware

pub fn new( failure_threshold: u32, time_window: Duration, timeout_duration: Duration, ) -> Self

Create a new circuit breaker middleware.

Trait Implementations

impl AdvancedMiddleware for CircuitBreakerMiddleware

fn name(&self) -> &'static str

Get middleware name for identification

fn priority(&self) -> MiddlewarePriority

Get middleware priority for execution ordering

fn on_request_with_context<'life0, 'life1, 'life2, 'async_trait>( &'life0 self, request: &'life1 mut JSONRPCRequest, context: &'life2 MiddlewareContext, ) -> Pin<Box<dyn Future<Output = Result<()>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait, 'life2: 'async_trait,

Called before a request is sent with context.

fn on_error<'life0, 'life1, 'life2, 'async_trait>( &'life0 self, _error: &'life1 Error, _context: &'life2 MiddlewareContext, ) -> Pin<Box<dyn Future<Output = Result<()>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait, 'life2: 'async_trait,

Called when an error occurs in the chain

fn should_execute<'life0, 'life1, 'async_trait>( &'life0 self, _context: &'life1 MiddlewareContext, ) -> Pin<Box<dyn Future<Output = bool> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait,

Check if middleware should be executed for this context

fn on_response_with_context<'life0, 'life1, 'life2, 'async_trait>( &'life0 self, response: &'life1 mut JSONRPCResponse, context: &'life2 MiddlewareContext, ) -> Pin<Box<dyn Future<Output = Result<()>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait, 'life2: 'async_trait,

Called after a response is received with context.

fn on_send_with_context<'life0, 'life1, 'life2, 'async_trait>( &'life0 self, message: &'life1 TransportMessage, context: &'life2 MiddlewareContext, ) -> Pin<Box<dyn Future<Output = Result<()>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait, 'life2: 'async_trait,

Called when a message is sent with context.

fn on_receive_with_context<'life0, 'life1, 'life2, 'async_trait>( &'life0 self, message: &'life1 TransportMessage, context: &'life2 MiddlewareContext, ) -> Pin<Box<dyn Future<Output = Result<()>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait, 'life2: 'async_trait,

Called when a message is received with context.

fn on_chain_start<'life0, 'life1, 'async_trait>( &'life0 self, _context: &'life1 MiddlewareContext, ) -> Pin<Box<dyn Future<Output = Result<()>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait,

Called when middleware chain starts

fn on_chain_complete<'life0, 'life1, 'async_trait>( &'life0 self, _context: &'life1 MiddlewareContext, ) -> Pin<Box<dyn Future<Output = Result<()>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait,

Called when middleware chain completes

impl Debug for CircuitBreakerMiddleware

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.