add http/httphi (#171)

* add http/httphi

* begin adding httphi tests

* claude found neat bugs

* add low level Handle function and more tests

* more tests, run go generate

* add Hijacker-like functionality

* improve locking and acquisition of Exchanges in reconfiguring

* several bugfixes, add internal.IntLen, round up http-linux example with new router API

* small nit

* add benchmarks

* add query handling

* remove ForEach pattern, allocates in TinyGo

* massive documentation push and code reordering in files

* Router.Handle returns error after being torn down

* run go fix

* rework Mux interface to receive a string request path

* add MethodFrom

* minor doc nit

* fail on incomplete staging

* add raw buffer access

* add streaming API distinct from Exchange

* begin adding multipart form logic

* finish rounding up multipart form parsing

* remove status type

* first Multipart approach

* begin adding readMultiPart

* add Exchange.ReadMultiparts reimagining of clanker slop

* ai insists with backoffs

* simplify clanker slop

* apply go fix

* add a pattern argument to Mux

* explicit header key/value alloc and add ExchangeConfig

* fix tests after excplicit header alloc change

* fix examples

* run go fix

* expose rawsock as experimental package (will use for external benchmarks)

* remove backoff from form parsing

* @MDr164 suggestions get potential fixes

* apply go fix

* add examples

* add README.md

* fix rawsock tinygo implementation

* apply @MDr164 various fixes

* update documentation on ContentLength methods and fix bug in Form reset on empty body

* fix tests

* add fuzz tests

* run go fix

* io.ErrNoProgress on parsing form spin

* run go fix

* remove backoff assumption from Router

* httphi.Handle rejects unsupported protocols

* go format router.go

* add kvbuffer

* rewrite Cookie with KVBuffer

* mid refactor of KVBuffer into Header

* work on KVBuffer exhausted semantics

* add Go's ServeMux Request.PathValue access semantics to Exchange, Mux and MuxSlice

* add PathValue example

* document all the things; improve req Query semantics; add Form.EnableBufferGrowth

* unexport kvBuffer

* add Exchange.PathValueAppend

* use stdlib in example instead of rawsock

* remove rawsock from http example

* add darwin arch rawsock

* fix example

* rename Router.TeardownGoroutines to Shutdown matching http.Server.Shutdown

* rename types and identifiers

* @MDr164 Content-Type and Transfer-Encoding bug catches

internet/pcap/capture.go

@@ -768,6 +768,11 @@ func httpBodyClass(contentType, body []byte) FieldClass {
 	return FieldClassText
 }
 
+// maxCapturedHeaderFields bounds the field table a captured HTTP header is
+// parsed into. Captures are read once and discarded, so the table is sized for
+// a realistic request rather than for whatever the capture happens to hold.
+const maxCapturedHeaderFields = 64
+
 func (pc *PacketBreakdown) CaptureHTTP(dst []Frame, pkt []byte, bitOffset int) ([]Frame, error) {
 	debuglog("pcap:http:start")
 	const httpProtocol = "HTTP"
@@ -777,10 +782,10 @@ func (pc *PacketBreakdown) CaptureHTTP(dst []Frame, pkt []byte, bitOffset int) (
 	const asResponse = true
 	const asRequest = false
 	httpData := pkt[bitOffset/8:]
-	pc.hdr.Reset(httpData)
+	pc.hdr.Reset(httpData, maxCapturedHeaderFields)
 	err := pc.hdr.Parse(asResponse)
 	if err != nil {
-		pc.hdr.Reset(httpData)
+		pc.hdr.Reset(httpData, 0)     // Field table already sized, reuse it.
 		err = pc.hdr.Parse(asRequest) // try as request.
 	}
 	if err != nil {

internet/pcap/stringers.go

@@ -33,8 +33,9 @@ const _FieldClass_name = "undefinedsourcedestinationprotocolversiontypesizeflags
 var _FieldClass_index = [...]uint8{0, 9, 15, 26, 34, 41, 45, 49, 54, 68, 76, 83, 90, 94, 101, 112, 114, 123, 131}
 
 func (i FieldClass) String() string {
-	if i >= FieldClass(len(_FieldClass_index)-1) {
+	idx := int(i) - 0
+	if i < 0 || idx >= len(_FieldClass_index)-1 {
 		return "FieldClass(" + strconv.FormatInt(int64(i), 10) + ")"
 	}
-	return _FieldClass_name[_FieldClass_index[i]:_FieldClass_index[i+1]]
+	return _FieldClass_name[_FieldClass_index[idx]:_FieldClass_index[idx+1]]
 }