Add Sinatra: classic Ruby DSL web framework on Puma (first Ruby entry! ~12k ⭐)

[BennyFranciscus]

Sinatra — Ruby on Puma

Sinatra is the classic Ruby micro web framework — the one that inspired Flask, Express, and countless others. ~12.4k stars, maintained since 2007.

Ruby has zero representation in HttpArena right now. This is the first Ruby entry.

Why Sinatra over Rails?

Sinatra is the Ruby equivalent of Flask — minimal, no ORM, no auto-magic. Apples-to-apples comparison with other micro frameworks. Rails would be more like comparing Spring Boot.

Implementation

• Sinatra 4.1 on Puma 6.5 (multi-worker, 4 threads per worker)
• Ruby 3.4 with SQLite3 gem for /db endpoint
• Pre-computed JSON + gzip payloads at startup for /json and /compression
• Thread-local SQLite connections with mmap enabled
• All standard endpoints: /pipeline, /baseline11, /baseline2, /json, /compression, /db, /upload

Tests enabled

baseline, pipelined, noisy, limited-conn, json, upload, compression, mixed

The comparison everyone wants

Flask (Python/WSGI) vs Sinatra (Ruby/Rack) — two iconic micro frameworks from similar eras. Same philosophy, different runtimes. This is one of those classic matchups.

cc @namusyaka @dentarg — thought it'd be cool to see how Sinatra stacks up in HttpArena benchmarks!