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

http/httpraw/cookie.go

@@ -7,105 +7,89 @@ import (
 // Cookie implements cookie key-value parsing. Methods function similarly to eponymous [Header] methods.
 // Cookie represents a single-line Cookie header value in a HTTP header, much like the standard library Cookie.
 type Cookie struct {
-	buf []byte
-	kvs []argsKV // first key-value pair is the data Key/Value pair.
+	kv kvBuffer
+}
+
+// EnableBufferGrowth allows the cookie's buffer to grow past what [Cookie.Reset] was
+// handed. See [kvBuffer.EnableBufferGrowth].
+func (c *Cookie) EnableBufferGrowth(enableBufferGrowth bool) {
+	c.kv.EnableBufferGrowth(enableBufferGrowth)
 }
 
 // Reset functions very similarly to [Header.Reset]. Can be used for in-place cookie parsing.
-func (c *Cookie) Reset(buf []byte) {
-	if buf == nil {
-		buf = c.buf[:0]
-	}
-	*c = Cookie{
-		buf: buf,
-		kvs: c.kvs[:0],
-	}
+func (c *Cookie) Reset(buf []byte, capKV int) { c.kv.Reset(buf, capKV) }
+
+func (c *Cookie) valid() bool {
+	return len(c.kv.kvs) > 0 && c.kv.kvs[0].key.len > 0
 }
 
 // Name returns the first cookie key which is commonly referred to as the cookie's name. Returns nil if not found.
 func (c *Cookie) Name() []byte {
-	if len(c.kvs) == 0 || c.kvs[0].key.len == 0 {
+	if !c.valid() {
 		return nil
 	}
-	return tok2bytes(c.buf, c.kvs[0].key)
+	return c.kv.AtKey(0)
 }
 
 // Value returns the first cookie value associated with the name. Returns nil if not found.
 func (c *Cookie) Value() []byte {
-	if len(c.kvs) == 0 || c.kvs[0].value.len == 0 {
+	if !c.valid() {
 		return nil
 	}
-	return tok2bytes(c.buf, c.kvs[0].value)
+	return c.kv.AtValue(0)
 }
 
 // ParseBytes copies the argument bytes to the Cookie's underlying buffer and parses the cookie.
 func (c *Cookie) ParseBytes(cookie []byte) error {
-	c.Reset(nil)
-	c.buf = append(c.buf[:0], cookie...)
+	c.Reset(nil, 0)
+	c.kv.buf = append(c.kv.buf[:0], cookie...)
 	return c.Parse()
 }
 
 // CopyFrom makes a copy of the argument cookie to the receiver dst argument. No memory is shared between cookies.
-func (dst *Cookie) CopyFrom(c Cookie) {
-	dst.buf = append(dst.buf[:0], c.buf...)
-	dst.kvs = append(dst.kvs[:0], c.kvs...)
-}
+func (dst *Cookie) CopyFrom(c Cookie) { dst.kv.CopyFrom(&c.kv) }
 
 // Parse parses the cookie's buffer in place.
 func (c *Cookie) Parse() error {
-	if len(c.kvs) > 0 {
+	if c.kv.Len() > 0 {
 		return errCookiesParsed
 	}
 	off := 0
 	for {
-		k, v, n := parseCookie(c.buf[off:])
+		k, v, n := parseCookie(c.kv.buf[off:])
 		if n == 0 {
 			break
 		}
-		c.kvs = append(c.kvs, argsKV{
-			key:   bytes2tok(c.buf, k),
-			value: bytes2tok(c.buf, v),
-		})
+		if !c.kv.setInternal(k, v) {
+			return ErrBufferExhausted
+		}
+
 		off += n
 	}
-	if len(c.kvs) == 0 {
+	if c.kv.Len() == 0 {
 		return errNoCookies
 	}
 	return nil
 }
 
-func (c *Cookie) ForEach(cb func(key, value []byte) error) error {
-	nc := len(c.kvs)
-	for i := range nc {
-		kv := c.kvs[i]
-		key := tok2bytes(c.buf, kv.key)
-		value := tok2bytes(c.buf, kv.value)
-		err := cb(key, value)
-		if err != nil {
-			return err
-		}
-	}
-	return nil
+// ForEach iterates over the cookie's key-value pairs, stopping on the first
+// error returned by cb and returning it.
+func (c *Cookie) ForEach(cb func(key, value []byte) bool) {
+	c.kv.ForEach(cb)
 }
 
 // Get gets a cookie's value from its key. Use HasValueOrKey to check if a key or single-valued cookie is present in the cookie.
-func (c *Cookie) Get(key string) []byte {
-	nc := len(c.kvs)
-	for i := range nc {
-		kv := c.kvs[i]
-		if b2s(tok2bytes(c.buf, kv.key)) == key {
-			return tok2bytes(c.buf, kv.value)
-		}
-	}
-	return nil
-}
+func (c *Cookie) Get(key string) []byte { return c.kv.Get(key) }
 
+// HasKeyOrSingleValue returns true if the cookie contains a pair with the given
+// key or a valueless attribute with the given text, i.e: "Secure" or "HttpOnly".
+// It cannot defer to [KVBuffer.Present]: parseCookie stores a valueless
+// attribute with an empty key and the text as the value, so a key-only lookup
+// would never match one.
 func (c *Cookie) HasKeyOrSingleValue(keyOrSingleValue string) bool {
-	nc := len(c.kvs)
-	for i := range nc {
-		kv := c.kvs[i]
-		if kv.key.len == 0 && b2s(tok2bytes(c.buf, kv.value)) == keyOrSingleValue ||
-			b2s(tok2bytes(c.buf, kv.key)) == keyOrSingleValue {
+	for i, nc := 0, c.kv.Len(); i < nc; i++ {
+		k, v := c.kv.At(i)
+		if (len(k) == 0 && b2s(v) == keyOrSingleValue) || b2s(k) == keyOrSingleValue {
 			return true
 		}
 	}
@@ -158,16 +142,14 @@ func (c *Cookie) String() string {
 
 // AppendKeyValues appends the HTTP header value of the cookie expected after the "Cookie:" string. Does not include trailing \r\n's.
 func (c *Cookie) AppendKeyValues(dst []byte) []byte {
-	nc := len(c.kvs)
+	nc := c.kv.Len()
 	for i := range nc {
-		kv := c.kvs[i]
-		key := tok2bytes(c.buf, kv.key)
-		value := tok2bytes(c.buf, kv.value)
-		if len(key) != 0 {
-			dst = append(dst, key...)
+		k, v := c.kv.At(i)
+		if len(k) != 0 {
+			dst = append(dst, k...)
 			dst = append(dst, '=')
 		}
-		dst = append(dst, value...)
+		dst = append(dst, v...)
 		if i+1 < nc {
 			dst = append(dst, ';', ' ')
 		}