Httpz – Zero-Allocation HTTP/1.1 Parser for OxCaml

Summary

httpz - Zero-Allocation HTTP/1.1 Parser for OxCaml A high-performance HTTP/1.1 parser and serializer that aims for zero heap allocations using OxCaml's unboxed types and local allocations. Will soon have io_uring on Linux. Features Zero heap allocations : Parser results are stack-allocated using OxCaml unboxed records and local lists : Parser results are stack-allocated using OxCaml unboxed records and local lists Direct bigstring I/O : Read and write directly to/from bigarray buffers : Read and write directly to/from bigarray buffers HTTP/1.1 support : Methods, headers, chunked transfer encoding, keep-alive : Methods, headers, chunked transfer encoding, keep-alive Async file server included: Production-ready static file server. Soon to be parallel. Architecture httpz achieves zero-allocation parsing through: Unboxed records ( #{...} ): Request and span types are stack-allocated Local lists ( @ local ): Header list grows on the stack, not heap Span-based parsing: Strings are referenced by offset+length into the input buffer Pre-allocated buffers: 32KB read buffer reused across requests Performance Benchmarks comparing httpz (OxCaml) vs httpe (Eio-based parser): Request Size httpz (ns/op) httpe (ns/op) Speedup Allocation Reduction Small (35B) 69 218 3.14x 94x fewer words Medium (439B) 792 1,690 2.13x 399x fewer words Large (1155B) 1,771 4,017 2.27x 829x fewer words Throughput: 14.6M requests/sec (vs 4.6M for httpe) Detailed Timings Operation Time Heap Allocations Parse minimal request 209ns 3 words Parse browser request (10 headers) 2.8μs 3 words Parse 50 headers 7.7μs 3 words Write status line 21ns 3 words Write full response headers 62ns 3 words Installation Requires OxCaml compiler from https://oxcaml.org/ Static File Server An Async-based static file server is included: # Serve current directory on port 8080 dune exec bin/httpz_server.exe # Serve specific directory on custom port dune exec bin/httpz_server.exe -- -d /var/www -p 3000 # Get help dune exec bin/httpz...