add README.md

http/httphi/README.md

@@ -0,0 +1,51 @@
+# httφ
+
+Heapless HTTP/1.1 router with `net/http`-shaped handlers. Benchmarked against `net/http` and friends at [**soypat/httpbench**](https://github.com/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`](https://github.com/soypat/lneto) TCP stack or a test pipe. No listener, no OS, no clock.
+
+Parsing is [`httpraw`](../httpraw).
+
+## Example
+
+```go
+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`](./example_test.go).

http/httphi/bench_test.go

@@ -125,7 +125,7 @@ func BenchmarkRequestParseForm(b *testing.B) {
 	b.ReportAllocs()
 	b.SetBytes(int64(len(request)))
 	b.ResetTimer()
-	for i := 0; i < b.N; i++ {
+	for b.Loop() {
 		conn.rewind()
 		exch.Release()
 		exch.Acquire(conn)