Tile38 is an in-memory geolocation data store, spatial index, and realtime geofencing server written in Go. It provides a Redis-compatible interface (RESP, HTTP, WebSocket, Telnet) for storing and querying geospatial objects (points, GeoJSON, bounding boxes, geohashes, tiles) with commands like SET, GET, NEARBY, WITHIN, INTERSECTS, and SCAN. The server supports leader/follower replication, AOF persistence, Lua scripting, and realtime geofencing via webhooks, pub/sub channels, and live connections. Its architecture is a single-binary server with a modular internal structure: a collection layer combining B-tree and R-tree indexing, a binary-encoded object and field storage for memory efficiency, a pluggable endpoint system for webhook delivery (HTTP, Kafka, MQTT, NATS, AMQP, SQS, etc.), and a custom protocol multiplexer. The codebase demonstrates high craftsmanship with reusable components like the collection data structure, glob matching, binary field lists, and endpoint manager, though some areas show signs of organic growth (e.g., large server.go, deprecated flags).
proxpi is a caching reverse-proxy server for PyPI and any PEP 503-compatible package index. It fronts one or more upstream indices, serves the Python simple repository API to pip clients in both HTML (PEP 691 v1.0) and JSON (PEP 691 v1.1) forms, and performs correct HTTP content negotiation including Accept, Accept-Encoding, and Vary headers. Index responses (project list and per-project file lists) are cached in memory with per-index TTLs; package files are cached on disk with a configurable size cap and least-frequently-used eviction. When a requested file is still downloading in the background, the server emits a 302 redirect to the upstream URL rather than blocking the client. The system is a single-process Starlette ASGI application (proxpi.server:app) designed for multi-threaded serving under Gunicorn/Hypercorn, configured entirely through environment variables (index URLs, TTLs, cache size/dir, connect/read/download timeouts, SSL verification toggle, log level). Its main target is reducing pip install latency and upstream load in CI pipelines. The implementation is a compact three-layer design: server.py handles routing, templating, and compression; _cache.py holds the caching engine (a File abstraction with FileFromHTML/FileFromJSON parsers for the dual-format simple repository API, an _IndexCache with per-package locks and a fast-path that fetches project pages without refreshing the full index, and a _FileCache with background downloads, atomic os.replace writes, and LFU eviction); _server_utils.py provides RFC-correct content-negotiation helpers built on the stdlib email header parser. The code is thread-safe by design (per-key locks, exception-storing worker threads) and memory-efficient, streaming HTML index parsing through lxml.iterparse via a custom file-like response adapter. The test suite is notably strong: parametrized integration tests against mock HTML/JSON indices covering yanked files, core-metadata hashes, gpg-sig attributes, content negotiation edge cases, cache invalidation, and 404 paths, plus end-to-end tests that run real pip downloads against live PyPI. CI runs the matrix across Python 3.8-3.14, lints with black/isort, and publishes multi-arch Docker images with fully hash-pinned dependencies. One caveat: the README is stale, documenting the pre-1.3 Flask implementation, while the code has already migrated to Starlette (listed in CHANGELOG as unreleased), and the Docker image now runs Gunicorn with an ASGI worker.