reactbits-mcp-server/utils/circuit-breaker.js

MCP Server for React Bits - Access 99+ React components with animations, backgrounds, and UI elements

import { logWarning, logInfo } from './logger.js';
/**
 * Circuit breaker states
 */
var CircuitBreakerState;
(function (CircuitBreakerState) {
    CircuitBreakerState["CLOSED"] = "CLOSED";
    CircuitBreakerState["OPEN"] = "OPEN";
    CircuitBreakerState["HALF_OPEN"] = "HALF_OPEN";
})(CircuitBreakerState || (CircuitBreakerState = {}));
/**
 * Circuit breaker implementation for protecting external calls
 */
class CircuitBreaker {
    state = CircuitBreakerState.CLOSED;
    failureCount = 0;
    lastFailureTime = 0;
    config;
    constructor(config) {
        this.config = config;
    }
    /**
     * Execute a function with circuit breaker protection
     * @param fn - Function to execute
     * @returns Promise with the result
     */
    async execute(fn) {
        if (this.state === CircuitBreakerState.OPEN) {
            if (this.shouldAttemptReset()) {
                this.state = CircuitBreakerState.HALF_OPEN;
                logInfo('Circuit breaker transitioning to HALF_OPEN state');
            }
            else {
                throw new Error('Circuit breaker is OPEN - request rejected');
            }
        }
        try {
            const result = await fn();
            this.onSuccess();
            return result;
        }
        catch (error) {
            this.onFailure();
            throw error;
        }
    }
    /**
     * Handle successful execution
     */
    onSuccess() {
        this.failureCount = 0;
        if (this.state === CircuitBreakerState.HALF_OPEN) {
            this.state = CircuitBreakerState.CLOSED;
            logInfo('Circuit breaker reset to CLOSED state');
        }
    }
    /**
     * Handle failed execution
     */
    onFailure() {
        this.failureCount++;
        this.lastFailureTime = Date.now();
        if (this.failureCount >= this.config.failureThreshold) {
            this.state = CircuitBreakerState.OPEN;
            logWarning(`Circuit breaker opened after ${this.failureCount} failures`);
        }
    }
    /**
     * Check if we should attempt to reset the circuit breaker
     * @returns True if we should attempt reset
     */
    shouldAttemptReset() {
        return Date.now() - this.lastFailureTime >= this.config.recoveryTimeout;
    }
    /**
     * Get current circuit breaker state
     * @returns Current state
     */
    getState() {
        return this.state;
    }
    /**
     * Get failure count
     * @returns Current failure count
     */
    getFailureCount() {
        return this.failureCount;
    }
    /**
     * Reset the circuit breaker manually
     */
    reset() {
        this.state = CircuitBreakerState.CLOSED;
        this.failureCount = 0;
        this.lastFailureTime = 0;
        logInfo('Circuit breaker manually reset');
    }
}
/**
 * Circuit breaker instances for different types of operations
 */
export const circuitBreakers = {
    // For external API calls (GitHub, etc.)
    external: new CircuitBreaker({
        failureThreshold: 5,
        recoveryTimeout: 60000, // 1 minute
        monitoringPeriod: 10000 // 10 seconds
    }),
    // For file system operations
    filesystem: new CircuitBreaker({
        failureThreshold: 3,
        recoveryTimeout: 30000, // 30 seconds
        monitoringPeriod: 5000 // 5 seconds
    })
};
export { CircuitBreaker, CircuitBreakerState };