sap_http

C++20 HTTP/HTTPS library built on sap_network. Provides a templated client and server parameterised over the socket type — swap TCPSocket for TLSSocket to get TLS for free.

Part of the Sapfire library ecosystem.

What's inside

Client

Client<S> is templated on any type satisfying the sap::network::Socket concept:

using HttpClient  = Client<sap::network::TCPSocket>;
using HttpsClient = Client<sap::network::TLSSocket>;

Features:

• Connection pooling — idle connections are reused per host:port. Connections idle longer than idle_timeout (default 90s, matching nginx's keepalive default) are evicted on next checkout.
• Async requests — async_send_req() returns std::future<stl::result<Response>>.
• Configurable limits — max_response_size (default 10MB), per-request timeout.
• Static convenience API — HttpClient::get(url), HttpClient::post(url, body) backed by a shared default instance.

HTTPS client config exposes peer verification, hostname verification, CA file/dir, client certificates, and ALPN protocol list.

Server

Server<S> is also templated, giving HttpServer and HttpsServer from the same implementation.

Features:

• Route matching — path segments are pre-split at registration time. Parameterised routes (:id) are detected and extracted into Request::params at match time — no regex at runtime for typical routes.
• Middleware chain — use(fn) registers middleware applied before route handlers. public_route() bypasses the middleware chain for routes that must run ungated (e.g. /auth/login).
• Multithreaded dispatch — backed by sap_core's job_system; set is_multithreaded = true in config.
• Graceful shutdown — stop() closes idle keep-alive sockets parked in header reads; in-flight handlers are allowed to finish.
• Size guards — max_header_size (8KB) and max_body_size (1MB) are enforced before any handler runs.
• Chunked transfer encoding — read_chunked_body<S>() decodes HTTP/1.1 chunked bodies with a configurable size cap.

Build

Requires CMake 3.20+, C++20, sap_core, and sap_network.

cmake -B build -DCMAKE_BUILD_TYPE=Release
cmake --build build
ctest --test-dir build

Usage examples

#include <sap_http/net/http.h>

// HTTP GET
auto future = sap::http::HttpClient::get("http://example.com/api/data");
auto response = future.get();
if (response && response->is_success())
    std::println("{}", response->body);

// HTTPS POST
sap::http::HttpsClient client{sap::http::HttpsClientConfig{.verify_peer = true}};
sap::http::Request req{sap::http::EMethod::POST, *sap::http::URL::parse("https://api.example.com/users")};
req.set_body(R"({"name":"dominik"})");
req.set_header("Content-Type", "application/json");
auto res = client.send_req(req);

// HTTP server with middleware
sap::http::HttpServer server{sap::http::HttpServerConfig{.host = "0.0.0.0", .port = 8080}};

server.use([](sap::http::Request& req) -> std::optional<sap::http::Response> {
    if (!req.headers.has("Authorization"))
        return sap::http::Response{sap::http::EStatusCode::Unauthorized};
    return std::nullopt; // continue
});

server.route("/users/:id", sap::http::EMethod::GET, [](const sap::http::Request& req) {
    auto id = req.params.at("id");
    return sap::http::Response{sap::http::EStatusCode::OK, "user: " + id};
});

server.public_route("/auth/login", sap::http::EMethod::POST, [](const sap::http::Request& req) {
    return sap::http::Response{sap::http::EStatusCode::OK, "token"};
});

server.start();
server.run();