{"slug": "s3fifo-1-0-zero-allocation-s3-fifo-cache-for-node-js-is-ready-for-production", "title": "s3fifo 1.0: Zero-Allocation S3-FIFO Cache for Node.js is Ready for Production", "summary": "Developer Jeongseop Byeon released s3fifo v1.0.0, a zero-allocation S3-FIFO cache for Node.js that eliminates garbage collection pressure by using pre-allocated TypedArrays. The production-ready release adds features like serialization, dispose callbacks, and re-entrancy protection, achieving up to 43% higher throughput than lru-cache in benchmarks.", "body_md": "*Disclaimer: As a non-native English speaker, I used AI to help structure and polish this article.*\n\nA few dayss ago, I shared [Implementing a Zero-Allocation S3-FIFO Cache in Node.js](https://dev.to/jeongseop_byeon_9d8f61627/implementing-a-zero-allocation-s3-fifo-cache-in-nodejs-520d)—an exploratory v0.1 release demonstrating how the **S3-FIFO (Simple and Scalable Scan-Resistant FIFO)** caching algorithm can be implemented using pre-allocated `TypedArray`\n\ns to eliminate Garbage Collection (GC) pressure in Node.js.\n\nToday, after extensive stress testing, architectural hardening, and 100% unit test coverage, I'm excited to announce the release of ** s3fifo v1.0.0**! 🚀\n\nTraditional **LRU (Least Recently Used)** caches suffer from two major production drawbacks:\n\n`set()`\n\n, triggering frequent GC pauses under high-throughput workloads.\n`s3fifo`\n\nachieves `get`\n\n/`set`\n\ncycles by backing these queues with contiguous TypedArrays (`Uint32Array`\n\n, `Float64Array`\n\n) and reusable index pools.\n---\n## What's New in v1.0.0? (Production Readiness)\nWhile v0.1 focused on core algorithm speed, `dump`\n\n& `load`\n\n)\nPrevent `s3fifo`\n\n1.0 supports serializing active resident entries alongside their original creation timestamps and remaining TTL:\n\n``` python\nimport fs from \"node:fs\";\nimport { S3Fifo } from \"s3fifo\";\nconst cache = new S3Fifo<string>({ max: 10000 });\n// 1. Export active cache items (optionally filter out temporary keys)\nconst dumpData = cache.dump((key, value) => !key.startsWith(\"temp:\"));\nfs.writeFileSync(\"cache-snapshot.json\", JSON.stringify(dumpData));\n// 2. On server startup / pre-warming: restore cache state instantly\nconst snapshot = JSON.parse(fs.readFileSync(\"cache-snapshot.json\", \"utf-8\"));\ncache.load(snapshot);\n```\n\n`dispose`\n\nCallback)\nWhen cache items are evicted, overwritten, or cleared, you often need to release external resources (e.g., closing file descriptors, destroying DB handles, or tracking eviction metrics).\n\n``` js\nconst cache = new S3Fifo<Buffer>({\n  max: 500,\n  dispose: (key, buffer, reason) => {\n    console.log(`Key ${key} removed due to: ${reason}`); // 'evict' | 'set' | 'delete' | 'clear'\n    // Safely free native memory or resources\n  },\n});\n```\n\n🛡️\n\nRe-Entrancy Protection:`dispose`\n\ncallbacks are safely deferred until the cache operation completes, preventing internal state corruption if a callback invokes`cache.set()`\n\nor`cache.delete()`\n\nrecursively.## 3. 🔍 Side-Effect-Free Inspection (\n\n`peek`\n\n)Need to check a cached value for logging, health checks, or monitoring without bumping frequency counters or altering eviction status?\n\n`peek()`\n\nallows pure, side-effect-free reading:\n\n``` js\n// Does not modify S3-FIFO frequency bit fields or TTL timestamps\nconst val = cache.peek(\"user:1001\");\n```\n\n`s3fifo`\n\n1.0 integrates seamlessly with JavaScript's native iteration protocols:\n\n```\n// Standard JS Map style iterators\nfor (const [key, value] of cache) {\n  console.log(key, value);\n}\nconst keys = Array.from(cache.keys());\nconst values = Array.from(cache.values());\nconst entries = Array.from(cache.entries());\ncache.forEach((val, key) => {\n  /* ... */\n});\n```\n\n`close`\n\n)\nIn serverless, hot-reloading (HMR), or test environments, background timers can prevent process termination. The `close()`\n\nmethod clears active background TTL tickers, releases memory buffers, and prevents memory leaks:\n\n```\n// Clean teardown on shutdown\ncache.close();\nconsole.log(cache.isClosed); // true\n```\n\nTested on a Zipfian distribution (skew `0.99`\n\n, working set of `100,000`\n\nkeys) comparing `s3fifo`\n\nv1.0 to Node's popular `lru-cache`\n\n:\n\n| Cache Size (% of Pool) | lru-cache | s3fifo |\n|---|---|---|\n| 1% | 48.90% | 58.30% |\n| 5% | 65.00% | 71.10% |\n| 10% | 72.30% | 76.40% |\n| 25% | 82.10% | 82.70% |\n| 50% | 89.00% |\n86.30% |\n\n| Cache Size (% of Pool) | lru-cache | s3fifo |\n|---|---|---|\n| 1% | 10.8M | 15.5M |\n| 5% | 10.8M | 14.4M |\n| 10% | 10.2M | 14.3M |\n| 25% | 10.3M | 13.5M |\n| 50% | 10.3M | 14.7M |\n\n`get`\n\n/`set`\n\noperations.\nInstall via npm:\n\n```\nnpm install s3fifo\n```\n\nBasic usage:\n\n``` js\nimport { S3Fifo } from \"s3fifo\";\nconst cache = new S3Fifo<string>({\n  max: 1000,\n  ttl: 60000, // 60s global TTL\n});\ncache.set(\"session:abc\", \"user_data\");\nconsole.log(cache.get(\"session:abc\")); // 'user_data'\nconsole.log(cache.size); // 1\n```\n\n`s3fifo`\n\na try! Bug reports, feedback, and GitHub stars are greatly appreciated! 🙏", "url": "https://wpnews.pro/news/s3fifo-1-0-zero-allocation-s3-fifo-cache-for-node-js-is-ready-for-production", "canonical_source": "https://dev.to/jeongseop_byeon_9d8f61627/s3fifo-10-zero-allocation-s3-fifo-cache-for-nodejs-is-ready-for-production-27oc", "published_at": "2026-07-23 16:24:28+00:00", "updated_at": "2026-07-23 16:33:58.318636+00:00", "lang": "en", "topics": ["developer-tools", "machine-learning"], "entities": ["Jeongseop Byeon", "s3fifo", "Node.js", "lru-cache"], "alternates": {"html": "https://wpnews.pro/news/s3fifo-1-0-zero-allocation-s3-fifo-cache-for-node-js-is-ready-for-production", "markdown": "https://wpnews.pro/news/s3fifo-1-0-zero-allocation-s3-fifo-cache-for-node-js-is-ready-for-production.md", "text": "https://wpnews.pro/news/s3fifo-1-0-zero-allocation-s3-fifo-cache-for-node-js-is-ready-for-production.txt", "jsonld": "https://wpnews.pro/news/s3fifo-1-0-zero-allocation-s3-fifo-cache-for-node-js-is-ready-for-production.jsonld"}}