rnr-mcp-server
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A Model Context Protocol (MCP) server for React Native Reusables components, providing AI assistants with access to component source code, demos, and metadata for React Native development.
113 lines (112 loc) • 3.08 kB
JavaScript
/**
* Circuit Breaker states
*/
export var CircuitBreakerState;
(function (CircuitBreakerState) {
CircuitBreakerState["CLOSED"] = "CLOSED";
CircuitBreakerState["OPEN"] = "OPEN";
CircuitBreakerState["HALF_OPEN"] = "HALF_OPEN";
})(CircuitBreakerState || (CircuitBreakerState = {}));
/**
* Circuit Breaker implementation for external API calls
*/
export class CircuitBreaker {
state = CircuitBreakerState.CLOSED;
failures = 0;
successes = 0;
lastFailureTime = 0;
config;
constructor(config = {}) {
this.config = {
failureThreshold: config.failureThreshold || 5,
timeout: config.timeout || 60000, // 1 minute
successThreshold: config.successThreshold || 2
};
}
/**
* Execute a function with circuit breaker protection
*/
async execute(fn) {
if (this.isOpen()) {
throw new Error('Service temporarily unavailable due to previous failures');
}
try {
const result = await fn();
this.onSuccess();
return result;
}
catch (error) {
this.onFailure();
throw error;
}
}
/**
* Check if circuit breaker is open
*/
isOpen() {
if (this.state === CircuitBreakerState.OPEN) {
if (Date.now() - this.lastFailureTime >= this.config.timeout) {
this.state = CircuitBreakerState.HALF_OPEN;
this.successes = 0;
return false;
}
return true;
}
return false;
}
/**
* Handle successful execution
*/
onSuccess() {
this.failures = 0;
if (this.state === CircuitBreakerState.HALF_OPEN) {
this.successes++;
if (this.successes >= this.config.successThreshold) {
this.state = CircuitBreakerState.CLOSED;
this.successes = 0;
}
}
}
/**
* Handle failed execution
*/
onFailure() {
this.failures++;
this.lastFailureTime = Date.now();
if (this.state === CircuitBreakerState.CLOSED && this.failures >= this.config.failureThreshold) {
this.state = CircuitBreakerState.OPEN;
}
else if (this.state === CircuitBreakerState.HALF_OPEN) {
this.state = CircuitBreakerState.OPEN;
this.successes = 0;
}
}
/**
* Get current state
*/
getState() {
return this.state;
}
/**
* Get failure count
*/
getFailureCount() {
return this.failures;
}
/**
* Reset circuit breaker
*/
reset() {
this.state = CircuitBreakerState.CLOSED;
this.failures = 0;
this.successes = 0;
this.lastFailureTime = 0;
}
}
/**
* Circuit breaker instances for different services
*/
export const circuitBreakers = {
github: new CircuitBreaker({ failureThreshold: 3, timeout: 30000 }),
external: new CircuitBreaker({ failureThreshold: 5, timeout: 60000 })
};