lneto/http/httphi/README.md

httφ

Heapless HTTP/1.1 router with net/http-shaped handlers. Benchmarked against net/http and friends at soypat/httpbench.

Why

net/http allocates per request: Request, header map, response buffer, goroutine. Fine on a server, fatal on a microcontroller. httφ pays that cost once, at Router.Configure:

• Exchanges and goroutines are fixed there. Serving allocates nothing; memory does not grow with load.
• No free exchange means Handle refuses the connection unclosed, rather than allocating one more of everything.
• Handle takes an io.ReadWriteCloser, so the router runs over a raw socket, an lneto TCP stack or a test pipe. No listener, no OS, no clock.

Parsing is httpraw.

Example

var mux httphi.MuxSlice
mux.Handle("GET /", func(ex *httphi.Exchange) {
	ex.WriteBody([]byte("hello world"))
})

var router httphi.Router
err := router.Configure(httphi.RouterConfig{
	FixedNumGoroutines:          4, // 4 workers, 4 exchanges, allocated here and never again.
	MaxAwaitingConns:            8, // Queue depth. Full queue drops connections.
	RequestHeaderBufferSize:     1024,
	ResponseHeaderMinBufferSize: 32, // Shares the request buffer.
	RequestNumHeaderKVCap:       32,
	Backoff:                     func(uint) time.Duration { return time.Millisecond },
	Mux:                         &mux,
})
if err != nil {
	log.Fatal(err)
}
for {
	conn, err := listener.Accept() // Accepting is the caller's job.
	if err != nil {
		log.Fatal(err)
	}
	if err = router.Handle(conn); err != nil {
		conn.Close() // Refused: never blocks, never queues unboundedly.
	}
}

FixedNumGoroutines: -1 gives the unbounded flavor, a goroutine and an exchange per connection.

Runnable server over raw Linux sockets, plus query, form and multipart handlers: example_test.go.