httpraw looking good

http/httpraw/cookie.go

@@ -0,0 +1,165 @@
+package httpraw
+
+import (
+	"bytes"
+	"errors"
+)
+
+// Cookie implements cookie key-value parsing. Methods function similarly to eponymous [Header] methods.
+type Cookie struct {
+	buf []byte
+	kvs []argsKV // first key-value pair is the data Key/Value pair.
+}
+
+// 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) Key() []byte {
+	if len(c.kvs) == 0 || c.kvs[0].key.len == 0 {
+		return nil
+	}
+	return tok2bytes(c.buf, c.kvs[0].key)
+}
+
+func (c *Cookie) Value() []byte {
+	if len(c.kvs) == 0 || c.kvs[0].value.len == 0 {
+		return nil
+	}
+	return tok2bytes(c.buf, c.kvs[0].value)
+}
+
+func (c *Cookie) ParseBytes(cookie []byte) error {
+	c.Reset(nil)
+	c.buf = append(c.buf[:0], cookie...)
+	return c.Parse()
+}
+
+func (c *Cookie) CopyTo(dst *Cookie) {
+	dst.buf = append(dst.buf[:0], c.buf...)
+	dst.kvs = append(dst.kvs[:0], c.kvs...)
+}
+
+func (c *Cookie) Parse() error {
+	if len(c.kvs) > 0 {
+		return errors.New("cookies already parsed, reset before parsing again")
+	}
+	off := 0
+	for {
+		k, v, n := parseCookie(c.buf[off:])
+		if n == 0 {
+			break
+		}
+		c.kvs = append(c.kvs, argsKV{
+			key:   bytes2tok(c.buf, k),
+			value: bytes2tok(c.buf, v),
+		})
+		off += n
+	}
+	return nil
+}
+
+func (c *Cookie) ForEach(cb func(key, value []byte) error) error {
+	nc := len(c.kvs)
+	for i := 0; i < nc; i++ {
+		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
+}
+
+func (c *Cookie) Get(key string) []byte {
+	nc := len(c.kvs)
+	for i := 0; i < nc; i++ {
+		kv := c.kvs[i]
+		if b2s(tok2bytes(c.buf, kv.key)) == key {
+			return tok2bytes(c.buf, kv.value)
+		}
+	}
+	return nil
+}
+
+func (c *Cookie) HasValueOrKey(keyOrSingleValue string) bool {
+	nc := len(c.kvs)
+	for i := 0; i < nc; i++ {
+		kv := c.kvs[i]
+		if kv.key.len == 0 && b2s(tok2bytes(c.buf, kv.value)) == keyOrSingleValue ||
+			b2s(tok2bytes(c.buf, kv.key)) == keyOrSingleValue {
+			return true
+		}
+	}
+	return false
+}
+
+// parseCookie parses a cookie inside cookie buffer and adds it to cookie buffer..
+//
+//	Cookie: <cookie>\r\n
+func parseCookie(cookie []byte) (key, value []byte, cookieEnd int) {
+	if len(cookie) == 0 {
+		return nil, nil, 0
+	}
+	valueEnd := bytes.IndexByte(cookie, ';')
+	if valueEnd < 0 { // Ouch this `if` looks like it kills CPU pipepline.
+		valueEnd = len(cookie)
+		cookieEnd = len(cookie)
+	} else {
+		cookieEnd = valueEnd + 1
+	}
+	eqIdx := bytes.IndexByte(cookie[:valueEnd], '=')
+	key = cookie[:0]
+	if eqIdx > 0 {
+		key = trimCookie(cookie[:eqIdx], false)
+	}
+	value = trimCookie(cookie[eqIdx+1:valueEnd], true)
+	return key, value, cookieEnd
+}
+
+func trimCookie(src []byte, trimQuotes bool) []byte {
+	for len(src) > 0 && src[0] == ' ' {
+		src = src[1:] // skip leading whitespace.
+	}
+	for len(src) > 0 && src[len(src)-1] == ' ' {
+		src = src[:len(src)-1] // skip trailing whitespace
+	}
+	if trimQuotes {
+		if len(src) > 1 && src[0] == '"' && src[len(src)-1] == '"' {
+			src = src[1 : len(src)-1] // Trim leading+trailing quotes.
+		}
+	}
+	return src
+}
+
+func (c *Cookie) String() string {
+	buf := c.AppendKeyValues(nil)
+	return b2s(buf)
+}
+
+func (c *Cookie) AppendKeyValues(dst []byte) []byte {
+	nc := len(c.kvs)
+	for i := 0; i < nc; i++ {
+		kv := c.kvs[i]
+		key := tok2bytes(c.buf, kv.key)
+		value := tok2bytes(c.buf, kv.value)
+		if len(key) != 0 {
+			dst = append(dst, key...)
+			dst = append(dst, '=')
+		}
+		dst = append(dst, value...)
+		if i+1 < nc {
+			dst = append(dst, ';', ' ')
+		}
+	}
+	return dst
+}