Paper Search MCP

/** * 请求速率限制器 * 用于控制API请求频率，遵守各平台的使用限制 */ import { logDebug } from './Logger.js'; export interface RateLimiterOptions { /** 每秒最大请求数 */ requestsPerSecond: number; /** 突发请求容量 */ burstCapacity?: number; /** 是否启用调试日志 */ debug?: boolean; } export class RateLimiter { private readonly requestsPerSecond: number; private readonly intervalMs: number; private readonly burstCapacity: number; private readonly debug: boolean; private tokens: number; private lastRefill: number; private intervalHandle: NodeJS.Timeout; private readonly pendingRequests: Array<{ resolve: () => void; timestamp: number; }> = []; constructor(options: RateLimiterOptions) { this.requestsPerSecond = options.requestsPerSecond; this.intervalMs = 1000 / this.requestsPerSecond; this.burstCapacity = options.burstCapacity || this.requestsPerSecond; this.debug = options.debug || false; this.tokens = this.burstCapacity; this.lastRefill = Date.now(); // 定期处理等待中的请求 this.intervalHandle = setInterval(() => this.processPendingRequests(), Math.min(this.intervalMs, 100)); // Don't keep the process alive just because of the limiter interval (important for tests/MCP) this.intervalHandle.unref?.(); } /** * 等待直到可以发送请求 */ async waitForPermission(): Promise<void> { this.refillTokens(); if (this.tokens > 0) { this.tokens--; if (this.debug) { logDebug(`RateLimiter: Request allowed, ${this.tokens} tokens remaining`); } return Promise.resolve(); } // 没有可用令牌，加入等待队列 return new Promise<void>((resolve) => { this.pendingRequests.push({ resolve, timestamp: Date.now() }); if (this.debug) { logDebug(`RateLimiter: Request queued, ${this.pendingRequests.length} waiting`); } }); } /** * 补充令牌（令牌桶算法） */ private refillTokens(): void { const now = Date.now(); const timePassed = now - this.lastRefill; if (timePassed >= this.intervalMs) { const tokensToAdd = Math.floor(timePassed / this.intervalMs); this.tokens = Math.min(this.burstCapacity, this.tokens + tokensToAdd); this.lastRefill = now; if (this.debug && tokensToAdd > 0) { logDebug(`RateLimiter: Added ${tokensToAdd} tokens, total: ${this.tokens}`); } } } /** * 处理等待中的请求 */ private processPendingRequests(): void { this.refillTokens(); while (this.tokens > 0 && this.pendingRequests.length > 0) { const request = this.pendingRequests.shift(); if (request) { this.tokens--; request.resolve(); if (this.debug) { const waitTime = Date.now() - request.timestamp; logDebug(`RateLimiter: Released waiting request (waited ${waitTime}ms), ${this.tokens} tokens remaining`); } } } } /** * 获取当前状态 */ getStatus(): { availableTokens: number; maxTokens: number; requestsPerSecond: number; pendingRequests: number; } { this.refillTokens(); return { availableTokens: this.tokens, maxTokens: this.burstCapacity, requestsPerSecond: this.requestsPerSecond, pendingRequests: this.pendingRequests.length }; } /** * 清理过期的等待请求（超过30秒） */ cleanup(): void { const now = Date.now(); const timeoutMs = 30000; // 30秒超时 let removedCount = 0; while (this.pendingRequests.length > 0) { const first = this.pendingRequests[0]; if (now - first.timestamp > timeoutMs) { this.pendingRequests.shift(); // 拒绝过期的请求 first.resolve(); // 或者可以reject，但这里选择允许继续 removedCount++; } else { break; } } if (this.debug && removedCount > 0) { logDebug(`RateLimiter: Cleaned up ${removedCount} expired requests`); } } dispose(): void { clearInterval(this.intervalHandle); } }