feat: trie implementation

internal/utils/trie/key.go

@@ -0,0 +1,80 @@
+package trie
+
+import (
+	"slices"
+	"strings"
+
+	"github.com/yusing/go-proxy/internal/utils/strutils"
+)
+
+type Key struct {
+	segments    []string // escaped segments
+	full        string   // unescaped original key
+	hasWildcard bool
+}
+
+func Namespace(ns string) *Key {
+	return &Key{
+		segments:    []string{ns},
+		full:        ns,
+		hasWildcard: false,
+	}
+}
+
+func NewKey(keyStr string) *Key {
+	key := &Key{
+		segments: strutils.SplitRune(keyStr, '.'),
+		full:     keyStr,
+	}
+	for _, seg := range key.segments {
+		if seg == "*" || seg == "**" {
+			key.hasWildcard = true
+		}
+	}
+	return key
+}
+
+func EscapeSegment(seg string) string {
+	var sb strings.Builder
+	for _, r := range seg {
+		switch r {
+		case '.', '*':
+			sb.WriteString("__")
+		default:
+			sb.WriteRune(r)
+		}
+	}
+	return sb.String()
+}
+
+func (ns Key) With(segment string) *Key {
+	ns.segments = append(ns.segments, segment)
+	ns.full = ns.full + "." + segment
+	ns.hasWildcard = ns.hasWildcard || segment == "*" || segment == "**"
+	return &ns
+}
+
+func (ns Key) WithEscaped(segment string) *Key {
+	ns.segments = append(ns.segments, EscapeSegment(segment))
+	ns.full = ns.full + "." + segment
+	return &ns
+}
+
+func (ns *Key) NumSegments() int {
+	return len(ns.segments)
+}
+
+func (ns *Key) HasWildcard() bool {
+	return ns.hasWildcard
+}
+
+func (ns *Key) String() string {
+	return ns.full
+}
+
+func (ns *Key) Clone() *Key {
+	clone := *ns
+	clone.segments = slices.Clone(ns.segments)
+	clone.full = strings.Clone(ns.full)
+	return &clone
+}