update tool generet

pkg/utils/etag.go

@@ -0,0 +1,54 @@
+package utils
+
+import (
+	"fmt"
+	"strings"
+)
+
+// ParseETag extracts the ETag value from HTTP ETag header
+// Handles both strong ETags ("123") and weak ETags (W/"123")
+func ParseETag(etag string) string {
+	if etag == "" {
+		return ""
+	}
+
+	// Remove W/ prefix for weak ETags
+	if strings.HasPrefix(etag, "W/") {
+		etag = etag[2:]
+	}
+
+	// Remove surrounding quotes
+	if len(etag) >= 2 && strings.HasPrefix(etag, "\"") && strings.HasSuffix(etag, "\"") {
+		etag = etag[1 : len(etag)-1]
+	}
+
+	return etag
+}
+
+// FormatETag formats a version ID into a proper HTTP ETag header value
+func FormatETag(versionId string, weak bool) string {
+	if versionId == "" {
+		return ""
+	}
+
+	if weak {
+		return fmt.Sprintf(`W/"%s"`, versionId)
+	}
+
+	return fmt.Sprintf(`"%s"`, versionId)
+}
+
+// IsValidETag validates if the given string is a valid ETag format
+func IsValidETag(etag string) bool {
+	if etag == "" {
+		return false
+	}
+
+	// Check for weak ETag format
+	if strings.HasPrefix(etag, "W/") {
+		etag = etag[2:]
+	}
+
+	// Must be quoted
+	return len(etag) >= 2 && strings.HasPrefix(etag, "\"") && strings.HasSuffix(etag, "\"")
+}