llhttp

HTTP request/response parser extracted from nodejs/llhttp.

This is the HTTP parser used by Node.js - battle-tested against billions of requests. It's a pure C library with no dependencies, designed for high-performance HTTP parsing with a callback-based, zero-copy API.

• Upstream Repository: https://github.com/nodejs/llhttp
• Upstream Version: v9.3.0
• Upstream Commit: release/v9.3.0
• Upstream Date: 2025年05月23日
• License: MIT - see LICENSE

• Pure C, zero dependencies
• Callback-based, zero-copy parsing (pointers into your buffer)
• Incremental parsing (feed bytes as they arrive)
• Handles all HTTP/1.x edge cases:
  • Chunked transfer encoding
  • Keep-alive detection
  • Header line folding
  • Request pipelining
  • Content-Length vs Transfer-Encoding
• ~20KB compiled
• Extensively tested (Node.js test suite)

1. Check for new releases at https://github.com/nodejs/llhttp/releases

2. Download the release tarball:

   gh release download release/vX.Y.Z --repo nodejs/llhttp --archive=tar.gz -D /tmp
   cd /tmp && tar -xzf nodejs-llhttp-*.tar.gz

3. Copy the files:

   cp /tmp/llhttp-release-vX.Y.Z/include/llhttp.h include/
   cp /tmp/llhttp-release-vX.Y.Z/src/*.c src/
   cp /tmp/llhttp-release-vX.Y.Z/LICENSE-MIT LICENSE

4. Update this README with the new version, commit hash, and date.

5. Test the build in IREE.

• llhttp.h - Public API header with types, callbacks, and function declarations

• llhttp.c - Core parser state machine (auto-generated)
• api.c - User-facing API functions (init, execute, settings)
• http.c - HTTP-specific helpers (keep-alive, upgrade detection)

#include "llhttp.h"
// Callbacks receive pointers into your buffer (zero-copy)
int on_url(llhttp_t* parser, const char* at, size_t length) {
 printf("URL: %.*s\n", (int)length, at);
 return 0;
}
int on_header_field(llhttp_t* parser, const char* at, size_t length) {
 printf("Header: %.*s\n", (int)length, at);
 return 0;
}
int main() {
 llhttp_t parser;
 llhttp_settings_t settings;
 llhttp_settings_init(&settings);
 settings.on_url = on_url;
 settings.on_header_field = on_header_field;
 llhttp_init(&parser, HTTP_REQUEST, &settings);
 const char* request = "GET /hello HTTP/1.1\r\nHost: example.com\r\n\r\n";
 enum llhttp_errno err = llhttp_execute(&parser, request, strlen(request));
 if (err != HPE_OK) {
 fprintf(stderr, "Parse error: %s\n", llhttp_errno_name(err));
 return 1;
 }
 return 0;
}

cc_library(
 name = "llhttp",
 srcs = glob(["src/*.c"]),
 hdrs = ["include/llhttp.h"],
 includes = ["include"],
 visibility = ["//visibility:public"],
)

add_library(llhttp
 src/llhttp.c
 src/api.c
 src/http.c
)
target_include_directories(llhttp PUBLIC include)

(none)