Glyph11

Glyph11 is a dependency free, low allocation HTTP/1.1 parser for C#. It does not rely on any specific network technology but can be used with any (such as Socket, NetworkStream, PipeReader or anything else).

Usage

Glyph11 works with any source that produces a ReadOnlySequence<byte> or ReadOnlyMemory<byte> — PipeReader, Socket, NetworkStream, or raw byte arrays.

using System.Buffers;
using Glyph11;
using Glyph11.Protocol;
using Glyph11.Parser.Hardened;
using Glyph11.Validation;

var request = new BinaryRequest();
var limits = ParserLimits.Default;

ReadOnlySequence<byte> buffer = ...; // from any network source

if (HardenedParser.TryExtractFullHeader(ref buffer, request, in limits, out int bytesRead))
{
    // All parsed fields are zero-copy slices into the original buffer:
    // request.Method.Span  → e.g. "GET"
    // request.Path.Span    → e.g. "/api/users"
    // request.Version.Span → e.g. "HTTP/1.1"
    // request.Headers      → KeyValueList of name/value pairs
    // request.QueryParameters → KeyValueList of query params

    // Run post-parse semantic checks on untrusted input:
    if (RequestSemantics.HasTransferEncodingWithContentLength(request))
        throw new HttpParseException("Request smuggling: TE + CL.");

    if (RequestSemantics.HasDotSegments(request))
        throw new HttpParseException("Path traversal detected.");

    // Process request, then advance your reader by bytesRead.

    // Reuse between requests — clear instead of reallocating:
    request.Headers.Clear();
    request.QueryParameters.Clear();
}

For a complete PipeReader integration loop, see the integration guide.

Parsers

Glyph11 ships two parsers:

• HardenedParser — RFC 9110/9112 compliant with full validation and configurable resource limits. Recommended for internet-facing applications.
• FlexibleParser — Minimal validation for maximum throughput. Suitable for trusted environments where input is pre-validated.

Performance

• ROM path is zero-allocation — no GC pressure regardless of request size
• SIMD-accelerated validation keeps the HardenedParser within ~1.4-1.6x of the unvalidated FlexibleParser
• Multi-segment linearization provides ROM-speed parsing with a single upfront allocation

See the live benchmarks for latest numbers and trend charts.

CI Workflows

Benchmarks

The Benchmark workflow (.github/workflows/benchmark.yml) measures parser throughput and allocation using BenchmarkDotNet.

Trigger	Job	What it does
pull_request	Parser Benchmarks	Runs FlexibleParserBenchmark and HardenedParserBenchmark, compares against the baseline on gh-pages, and posts a comment on the PR. Fails if any metric regresses by more than 15%.
workflow_dispatch	Full Benchmarks	Runs all benchmarks (parsers + AllSemanticChecksBenchmark), updates the baseline on gh-pages, and triggers a docs site rebuild.

Data flow: benchmark results are stored as benchmarks/data.js on the gh-pages branch. The docs site loads this file to render trend charts at /benchmarks/.

To publish updated benchmark data:

1. Merge your changes to main.
2. Go to Actions > Benchmark > Run workflow on main.

Compliance Probe

The Probe workflow (.github/workflows/probe.yml) tests HTTP/1.1 compliance across multiple server frameworks using Glyph11.Probe, a tool that sends malformed and ambiguous HTTP requests and checks the server's response against strict RFC 9110/9112 expectations.

Servers tested: Glyph11 (raw TCP + HardenedParser), Kestrel (ASP.NET Core), Flask (Python), Express (Node.js), Spring Boot (Java), Quarkus (Java), Nancy (.NET), Jetty (Java), Nginx (native), Apache (native), Caddy (native), Pingora (Rust).

Trigger	What it does
pull_request	Starts all three servers, probes each one, evaluates results with strict status-code matching (e.g. a parser error must return 400, not 404), and posts a comparison table as a PR comment. Never fails the build — this is informational.
workflow_dispatch	Same as above, plus pushes probe/data.js to gh-pages and triggers a docs site rebuild.

Data flow: probe results are stored as probe/data.js on the gh-pages branch. The docs site loads this file to render the comparison matrix at /probe-results/.

To publish updated probe data:

1. Merge your changes to main.
2. Go to Actions > Probe > Run workflow on main.