s3 cache client-side support

Signed-off-by: CrazyMax <crazy-max@users.noreply.github.com>

vendor/github.com/aws/smithy-go/transport/http/url.go

@@ -0,0 +1,44 @@
+package http
+
+import "strings"
+
+// JoinPath returns an absolute URL path composed of the two paths provided.
+// Enforces that the returned path begins with '/'. If added path is empty the
+// returned path suffix will match the first parameter suffix.
+func JoinPath(a, b string) string {
+	if len(a) == 0 {
+		a = "/"
+	} else if a[0] != '/' {
+		a = "/" + a
+	}
+
+	if len(b) != 0 && b[0] == '/' {
+		b = b[1:]
+	}
+
+	if len(b) != 0 && len(a) > 1 && a[len(a)-1] != '/' {
+		a = a + "/"
+	}
+
+	return a + b
+}
+
+// JoinRawQuery returns an absolute raw query expression. Any duplicate '&'
+// will be collapsed to single separator between values.
+func JoinRawQuery(a, b string) string {
+	a = strings.TrimFunc(a, isAmpersand)
+	b = strings.TrimFunc(b, isAmpersand)
+
+	if len(a) == 0 {
+		return b
+	}
+	if len(b) == 0 {
+		return a
+	}
+
+	return a + "&" + b
+}
+
+func isAmpersand(v rune) bool {
+	return v == '&'
+}