ae77e30ffb
- Add in-memory cache middleware with configurable TTL - Cache GET endpoints: streets (5min), events (2min), posts (1min), rewards (10min) - Automatic cache invalidation on POST/PUT/DELETE operations - Add cache statistics endpoint (GET /api/cache/stats) - Add cache management endpoint (DELETE /api/cache) - Cache hit rate tracking and monitoring - Pattern-based cache invalidation - Optimized for Raspberry Pi deployment (lightweight in-memory) 🤖 Generated with Claude Co-Authored-By: Claude <noreply@anthropic.com>
101 lines
2.5 KiB
JavaScript
101 lines
2.5 KiB
JavaScript
const NodeCache = require('node-cache');
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const logger = require('../utils/logger');
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// Initialize cache with default TTL of 5 minutes and check period of 2 minutes
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const cache = new NodeCache({ stdTTL: 300, checkperiod: 120 });
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/**
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* Cache middleware factory
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* @param {number} ttlSeconds - Time to live in seconds for cached responses
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* @returns {Function} Express middleware function
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*/
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const getCacheMiddleware = (ttlSeconds) => (req, res, next) => {
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const key = req.originalUrl;
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const cachedResponse = cache.get(key);
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if (cachedResponse) {
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logger.info(`Cache hit for key: ${key}`);
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return res.json(cachedResponse);
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}
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logger.info(`Cache miss for key: ${key}`);
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// Store the original res.json method
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const originalJson = res.json.bind(res);
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// Override res.json to cache the response
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res.json = (body) => {
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cache.set(key, body, ttlSeconds);
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return originalJson(body);
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};
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next();
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};
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/**
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* Invalidate cache by exact key(s)
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* @param {string|string[]} keys - Cache key or array of keys to invalidate
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*/
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const invalidateCache = (keys) => {
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if (Array.isArray(keys)) {
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keys.forEach(key => {
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logger.info(`Invalidating cache for key: ${key}`);
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cache.del(key);
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});
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} else {
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logger.info(`Invalidating cache for key: ${keys}`);
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cache.del(keys);
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}
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};
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/**
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* Invalidate all cache keys matching a pattern
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* @param {string} pattern - Pattern to match (keys starting with this string)
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*/
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const invalidateCacheByPattern = (pattern) => {
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const keys = cache.keys();
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const keysToDelete = keys.filter(key => key.startsWith(pattern));
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if (keysToDelete.length > 0) {
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logger.info(`Invalidating cache by pattern: ${pattern}, deleted ${keysToDelete.length} keys`);
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cache.del(keysToDelete);
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} else {
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logger.debug(`No cache keys found matching pattern: ${pattern}`);
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}
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};
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/**
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* Get cache statistics
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* @returns {Object} Cache statistics
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*/
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const getCacheStats = () => {
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const stats = cache.getStats();
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const keys = cache.keys();
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return {
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keys: keys.length,
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hits: stats.hits,
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misses: stats.misses,
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hitRate: stats.hits > 0 ? (stats.hits / (stats.hits + stats.misses) * 100).toFixed(2) + '%' : '0%',
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ksize: stats.ksize,
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vsize: stats.vsize
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};
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};
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/**
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* Clear all cache
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*/
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const clearCache = () => {
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const keyCount = cache.keys().length;
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cache.flushAll();
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logger.info(`Cleared all cache (${keyCount} keys)`);
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};
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module.exports = {
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getCacheMiddleware,
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invalidateCache,
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invalidateCacheByPattern,
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getCacheStats,
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clearCache
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};
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