simplify power of 2 test

buger · Mar 19, 2015 · 2b497e6 · 2b497e6
1 parent 09f9cac
commit 2b497e6
Show file tree

Hide file tree

Showing 2 changed files with 7 additions and 4 deletions.
diff --git a/settings_header_hash_filters.go b/settings_header_hash_filters.go
@@ -39,10 +39,8 @@ func (h *HTTPHeaderHashFilters) Set(value string) error {
 		panic("need positive numerators and denominators, with the former less than the latter.")
 	}
 
-	for test := den; test != 1; test /= 2 {
-		if test%2 == 1 {
-			return errors.New("must have a denominator which is a power of two.")
-		}
+	if den & (den - 1) != 0 {
+		return errors.New("must have a denominator which is a power of two.")
 	}
 
 	var f headerHashFilter

diff --git a/settings_header_hash_filters_test.go b/settings_header_hash_filters_test.go
@@ -23,6 +23,11 @@ func TestHTTPHeaderHashFilters(t *testing.T) {
 		t.Error("Should error on HeaderIrrelevant:1/3")
 	}
 
+	err = filters.Set("Pow2Denom:1/31")
+	if err == nil {
+		t.Error("Should error on Pow2Denom:1/31")
+	}
+
 	req := http.Request{}
 	req.Header = make(map[string][]string)
 	req.Header.Add("Header1", "test3414")