feat(bus): 进程内事件总线（通配订阅/非阻塞扇出/Close 幂等）

internal/bus/match.go

@@ -0,0 +1,63 @@
+package bus
+
+import (
+	"fmt"
+	"strings"
+)
+
+// match reports whether subject matches pattern using the wildcard rules
+// described in the package comment: "*" matches exactly one non-empty token,
+// ">" matches one or more trailing tokens and must be the last token, and any
+// other token matches an identical subject token. Callers must have validated
+// both inputs, so an empty token or a misplaced ">" never reaches here.
+func match(pattern, subject string) bool {
+	p := strings.Split(pattern, ".")
+	s := strings.Split(subject, ".")
+	i, j := 0, 0
+	for i < len(p) {
+		if p[i] == ">" {
+			// ">" is guaranteed to be the last token; it needs at least one
+			// remaining subject token.
+			return j < len(s)
+		}
+		if j >= len(s) {
+			return false
+		}
+		if p[i] != "*" && p[i] != s[j] {
+			return false
+		}
+		i++
+		j++
+	}
+	return j == len(s)
+}
+
+// validateSubject rejects an empty subject or one containing an empty token
+// (leading/trailing/repeated dots).
+func validateSubject(subject string) error {
+	if subject == "" {
+		return fmt.Errorf("bus: subject must not be empty: %w", ErrInvalidArgument)
+	}
+	if strings.HasPrefix(subject, ".") || strings.HasSuffix(subject, ".") || strings.Contains(subject, "..") {
+		return fmt.Errorf("bus: subject %q contains an empty token: %w", subject, ErrInvalidArgument)
+	}
+	return nil
+}
+
+// validatePattern rejects an empty pattern, one with an empty token, or one
+// where the ">" wildcard is not the final token.
+func validatePattern(pattern string) error {
+	if pattern == "" {
+		return fmt.Errorf("bus: pattern must not be empty: %w", ErrInvalidArgument)
+	}
+	if strings.HasPrefix(pattern, ".") || strings.HasSuffix(pattern, ".") || strings.Contains(pattern, "..") {
+		return fmt.Errorf("bus: pattern %q contains an empty token: %w", pattern, ErrInvalidArgument)
+	}
+	tokens := strings.Split(pattern, ".")
+	for i, tok := range tokens {
+		if tok == ">" && i != len(tokens)-1 {
+			return fmt.Errorf("bus: pattern %q: '>' wildcard must be the last token: %w", pattern, ErrInvalidArgument)
+		}
+	}
+	return nil
+}