Files
pangolin/server/private/lib/rateLimit.ts
2025-10-11 19:02:15 -07:00

454 lines
16 KiB
TypeScript

/*
* This file is part of a proprietary work.
*
* Copyright (c) 2025 Fossorial, Inc.
* All rights reserved.
*
* This file is licensed under the Fossorial Commercial License.
* You may not use this file except in compliance with the License.
* Unauthorized use, copying, modification, or distribution is strictly prohibited.
*
* This file is not licensed under the AGPLv3.
*/
import logger from "@server/logger";
import redisManager from "#private/lib/redis";
import { build } from "@server/build";
// Rate limiting configuration
export const RATE_LIMIT_WINDOW = 60; // 1 minute in seconds
export const RATE_LIMIT_MAX_REQUESTS = 100;
export const RATE_LIMIT_PER_MESSAGE_TYPE = 20; // Per message type limit within the window
// Configuration for batched Redis sync
export const REDIS_SYNC_THRESHOLD = 15; // Sync to Redis every N messages
export const REDIS_SYNC_FORCE_INTERVAL = 30000; // Force sync every 30 seconds as backup
interface RateLimitTracker {
count: number;
windowStart: number;
pendingCount: number;
lastSyncedCount: number;
}
interface RateLimitResult {
isLimited: boolean;
reason?: string;
totalHits?: number;
resetTime?: Date;
}
export class RateLimitService {
private localRateLimitTracker: Map<string, RateLimitTracker> = new Map();
private localMessageTypeRateLimitTracker: Map<string, RateLimitTracker> = new Map();
private cleanupInterval: NodeJS.Timeout | null = null;
private forceSyncInterval: NodeJS.Timeout | null = null;
constructor() {
if (build == "oss") {
return;
}
// Start cleanup and sync intervals
this.cleanupInterval = setInterval(() => {
this.cleanupLocalRateLimit().catch((error) => {
logger.error("Error during rate limit cleanup:", error);
});
}, 60000); // Run cleanup every minute
this.forceSyncInterval = setInterval(() => {
this.forceSyncAllPendingData().catch((error) => {
logger.error("Error during force sync:", error);
});
}, REDIS_SYNC_FORCE_INTERVAL);
}
// Redis keys
private getRateLimitKey(clientId: string): string {
return `ratelimit:${clientId}`;
}
private getMessageTypeRateLimitKey(clientId: string, messageType: string): string {
return `ratelimit:${clientId}:${messageType}`;
}
// Helper function to sync local rate limit data to Redis
private async syncRateLimitToRedis(
clientId: string,
tracker: RateLimitTracker
): Promise<void> {
if (!redisManager.isRedisEnabled() || tracker.pendingCount === 0) return;
try {
const currentTime = Math.floor(Date.now() / 1000);
const globalKey = this.getRateLimitKey(clientId);
// Get current value and add pending count
const currentValue = await redisManager.hget(
globalKey,
currentTime.toString()
);
const newValue = (
parseInt(currentValue || "0") + tracker.pendingCount
).toString();
await redisManager.hset(globalKey, currentTime.toString(), newValue);
// Set TTL using the client directly
if (redisManager.getClient()) {
await redisManager
.getClient()
.expire(globalKey, RATE_LIMIT_WINDOW + 10);
}
// Update tracking
tracker.lastSyncedCount = tracker.count;
tracker.pendingCount = 0;
logger.debug(`Synced global rate limit to Redis for client ${clientId}`);
} catch (error) {
logger.error("Failed to sync global rate limit to Redis:", error);
}
}
private async syncMessageTypeRateLimitToRedis(
clientId: string,
messageType: string,
tracker: RateLimitTracker
): Promise<void> {
if (!redisManager.isRedisEnabled() || tracker.pendingCount === 0) return;
try {
const currentTime = Math.floor(Date.now() / 1000);
const messageTypeKey = this.getMessageTypeRateLimitKey(clientId, messageType);
// Get current value and add pending count
const currentValue = await redisManager.hget(
messageTypeKey,
currentTime.toString()
);
const newValue = (
parseInt(currentValue || "0") + tracker.pendingCount
).toString();
await redisManager.hset(
messageTypeKey,
currentTime.toString(),
newValue
);
// Set TTL using the client directly
if (redisManager.getClient()) {
await redisManager
.getClient()
.expire(messageTypeKey, RATE_LIMIT_WINDOW + 10);
}
// Update tracking
tracker.lastSyncedCount = tracker.count;
tracker.pendingCount = 0;
logger.debug(
`Synced message type rate limit to Redis for client ${clientId}, type ${messageType}`
);
} catch (error) {
logger.error("Failed to sync message type rate limit to Redis:", error);
}
}
// Initialize local tracker from Redis data
private async initializeLocalTracker(clientId: string): Promise<RateLimitTracker> {
const currentTime = Math.floor(Date.now() / 1000);
const windowStart = currentTime - RATE_LIMIT_WINDOW;
if (!redisManager.isRedisEnabled()) {
return {
count: 0,
windowStart: currentTime,
pendingCount: 0,
lastSyncedCount: 0
};
}
try {
const globalKey = this.getRateLimitKey(clientId);
const globalRateLimitData = await redisManager.hgetall(globalKey);
let count = 0;
for (const [timestamp, countStr] of Object.entries(globalRateLimitData)) {
const time = parseInt(timestamp);
if (time >= windowStart) {
count += parseInt(countStr);
}
}
return {
count,
windowStart: currentTime,
pendingCount: 0,
lastSyncedCount: count
};
} catch (error) {
logger.error("Failed to initialize global tracker from Redis:", error);
return {
count: 0,
windowStart: currentTime,
pendingCount: 0,
lastSyncedCount: 0
};
}
}
private async initializeMessageTypeTracker(
clientId: string,
messageType: string
): Promise<RateLimitTracker> {
const currentTime = Math.floor(Date.now() / 1000);
const windowStart = currentTime - RATE_LIMIT_WINDOW;
if (!redisManager.isRedisEnabled()) {
return {
count: 0,
windowStart: currentTime,
pendingCount: 0,
lastSyncedCount: 0
};
}
try {
const messageTypeKey = this.getMessageTypeRateLimitKey(clientId, messageType);
const messageTypeRateLimitData = await redisManager.hgetall(messageTypeKey);
let count = 0;
for (const [timestamp, countStr] of Object.entries(messageTypeRateLimitData)) {
const time = parseInt(timestamp);
if (time >= windowStart) {
count += parseInt(countStr);
}
}
return {
count,
windowStart: currentTime,
pendingCount: 0,
lastSyncedCount: count
};
} catch (error) {
logger.error("Failed to initialize message type tracker from Redis:", error);
return {
count: 0,
windowStart: currentTime,
pendingCount: 0,
lastSyncedCount: 0
};
}
}
// Main rate limiting function
async checkRateLimit(
clientId: string,
messageType?: string,
maxRequests: number = RATE_LIMIT_MAX_REQUESTS,
messageTypeLimit: number = RATE_LIMIT_PER_MESSAGE_TYPE,
windowMs: number = RATE_LIMIT_WINDOW * 1000
): Promise<RateLimitResult> {
const currentTime = Math.floor(Date.now() / 1000);
const windowStart = currentTime - Math.floor(windowMs / 1000);
// Check global rate limit
let globalTracker = this.localRateLimitTracker.get(clientId);
if (!globalTracker || globalTracker.windowStart < windowStart) {
// New window or first request - initialize from Redis if available
globalTracker = await this.initializeLocalTracker(clientId);
globalTracker.windowStart = currentTime;
this.localRateLimitTracker.set(clientId, globalTracker);
}
// Increment global counters
globalTracker.count++;
globalTracker.pendingCount++;
this.localRateLimitTracker.set(clientId, globalTracker);
// Check if global limit would be exceeded
if (globalTracker.count >= maxRequests) {
return {
isLimited: true,
reason: "global",
totalHits: globalTracker.count,
resetTime: new Date((globalTracker.windowStart + Math.floor(windowMs / 1000)) * 1000)
};
}
// Sync to Redis if threshold reached
if (globalTracker.pendingCount >= REDIS_SYNC_THRESHOLD) {
this.syncRateLimitToRedis(clientId, globalTracker);
}
// Check message type specific rate limit if messageType is provided
if (messageType) {
const messageTypeKey = `${clientId}:${messageType}`;
let messageTypeTracker = this.localMessageTypeRateLimitTracker.get(messageTypeKey);
if (!messageTypeTracker || messageTypeTracker.windowStart < windowStart) {
// New window or first request for this message type - initialize from Redis if available
messageTypeTracker = await this.initializeMessageTypeTracker(clientId, messageType);
messageTypeTracker.windowStart = currentTime;
this.localMessageTypeRateLimitTracker.set(messageTypeKey, messageTypeTracker);
}
// Increment message type counters
messageTypeTracker.count++;
messageTypeTracker.pendingCount++;
this.localMessageTypeRateLimitTracker.set(messageTypeKey, messageTypeTracker);
// Check if message type limit would be exceeded
if (messageTypeTracker.count >= messageTypeLimit) {
return {
isLimited: true,
reason: `message_type:${messageType}`,
totalHits: messageTypeTracker.count,
resetTime: new Date((messageTypeTracker.windowStart + Math.floor(windowMs / 1000)) * 1000)
};
}
// Sync to Redis if threshold reached
if (messageTypeTracker.pendingCount >= REDIS_SYNC_THRESHOLD) {
this.syncMessageTypeRateLimitToRedis(clientId, messageType, messageTypeTracker);
}
}
return {
isLimited: false,
totalHits: globalTracker.count,
resetTime: new Date((globalTracker.windowStart + Math.floor(windowMs / 1000)) * 1000)
};
}
// Decrement function for skipSuccessfulRequests/skipFailedRequests functionality
async decrementRateLimit(clientId: string, messageType?: string): Promise<void> {
// Decrement global counter
const globalTracker = this.localRateLimitTracker.get(clientId);
if (globalTracker && globalTracker.count > 0) {
globalTracker.count--;
// We need to account for this in pending count to sync correctly
globalTracker.pendingCount--;
}
// Decrement message type counter if provided
if (messageType) {
const messageTypeKey = `${clientId}:${messageType}`;
const messageTypeTracker = this.localMessageTypeRateLimitTracker.get(messageTypeKey);
if (messageTypeTracker && messageTypeTracker.count > 0) {
messageTypeTracker.count--;
messageTypeTracker.pendingCount--;
}
}
}
// Reset key function
async resetKey(clientId: string): Promise<void> {
// Remove from local tracking
this.localRateLimitTracker.delete(clientId);
// Remove all message type entries for this client
for (const [key] of this.localMessageTypeRateLimitTracker) {
if (key.startsWith(`${clientId}:`)) {
this.localMessageTypeRateLimitTracker.delete(key);
}
}
// Remove from Redis if enabled
if (redisManager.isRedisEnabled()) {
const globalKey = this.getRateLimitKey(clientId);
await redisManager.del(globalKey);
// Get all message type keys for this client and delete them
const client = redisManager.getClient();
if (client) {
const messageTypeKeys = await client.keys(`ratelimit:${clientId}:*`);
if (messageTypeKeys.length > 0) {
await Promise.all(messageTypeKeys.map(key => redisManager.del(key)));
}
}
}
}
// Cleanup old local rate limit entries and force sync pending data
private async cleanupLocalRateLimit(): Promise<void> {
const currentTime = Math.floor(Date.now() / 1000);
const windowStart = currentTime - RATE_LIMIT_WINDOW;
// Clean up global rate limit tracking and sync pending data
for (const [clientId, tracker] of this.localRateLimitTracker.entries()) {
if (tracker.windowStart < windowStart) {
// Sync any pending data before cleanup
if (tracker.pendingCount > 0) {
await this.syncRateLimitToRedis(clientId, tracker);
}
this.localRateLimitTracker.delete(clientId);
}
}
// Clean up message type rate limit tracking and sync pending data
for (const [key, tracker] of this.localMessageTypeRateLimitTracker.entries()) {
if (tracker.windowStart < windowStart) {
// Sync any pending data before cleanup
if (tracker.pendingCount > 0) {
const [clientId, messageType] = key.split(":", 2);
await this.syncMessageTypeRateLimitToRedis(clientId, messageType, tracker);
}
this.localMessageTypeRateLimitTracker.delete(key);
}
}
}
// Force sync all pending rate limit data to Redis
async forceSyncAllPendingData(): Promise<void> {
if (!redisManager.isRedisEnabled()) return;
logger.debug("Force syncing all pending rate limit data to Redis...");
// Sync all pending global rate limits
for (const [clientId, tracker] of this.localRateLimitTracker.entries()) {
if (tracker.pendingCount > 0) {
await this.syncRateLimitToRedis(clientId, tracker);
}
}
// Sync all pending message type rate limits
for (const [key, tracker] of this.localMessageTypeRateLimitTracker.entries()) {
if (tracker.pendingCount > 0) {
const [clientId, messageType] = key.split(":", 2);
await this.syncMessageTypeRateLimitToRedis(clientId, messageType, tracker);
}
}
logger.debug("Completed force sync of pending rate limit data");
}
// Cleanup function for graceful shutdown
async cleanup(): Promise<void> {
if (build == "oss") {
return;
}
// Clear intervals
if (this.cleanupInterval) {
clearInterval(this.cleanupInterval);
}
if (this.forceSyncInterval) {
clearInterval(this.forceSyncInterval);
}
// Force sync all pending data
await this.forceSyncAllPendingData();
// Clear local data
this.localRateLimitTracker.clear();
this.localMessageTypeRateLimitTracker.clear();
logger.info("Rate limit service cleanup completed");
}
}
// Export singleton instance
export const rateLimitService = new RateLimitService();