add custom metric types

client_test.go

@@ -1026,10 +1026,10 @@ func TestCounterVector(t *testing.T) {
 		t.Errorf("cannot set an instance, error: %v", err)
 	}
 
-	if val, err := cv.Val("m1"); val != 10 {
+	if val, verr := cv.Val("m1"); val != 10 {
 		t.Errorf("expected m.1[m1] to be 10, got %v", val)
-	} else if err != nil {
-		t.Errorf("cannot retrieve  m.1[m1] value")
+	} else if verr != nil {
+		t.Errorf("cannot retrieve  m.1[m1] value, error: %v", err)
 	}
 
 	// Inc
@@ -1039,9 +1039,9 @@ func TestCounterVector(t *testing.T) {
 		t.Errorf("cannot inc an instance, error: %v", err)
 	}
 
-	if val, err := cv.Val("m2"); val != 12 {
+	if val, verr := cv.Val("m2"); val != 12 {
 		t.Errorf("expected m.1[m2] to be 12, got %v", val)
-	} else if err != nil {
-		t.Errorf("cannot retrieve  m.1[m2] value")
+	} else if verr != nil {
+		t.Errorf("cannot retrieve  m.1[m2] value, error: %v", err)
 	}
 }

metrics.go

@@ -802,8 +802,10 @@ type CounterVector interface {
 	Val(string) int64
 
 	Set(int64, string) error
+	MustSet(int64, string)
 
 	Inc(int64, string) error
+	MustInc(int64, string)
 
 	Up(string)
 }
@@ -862,6 +864,13 @@ func (c *PCPCounterVector) Set(val int64, instance string) error {
 	return c.PCPInstanceMetric.SetInstance(instance, val)
 }
 
+// MustSet panics if Set fails
+func (c *PCPCounterVector) MustSet(val int64, instance string) {
+	if err := c.Set(val, instance); err != nil {
+		panic(err)
+	}
+}
+
 // Inc increments the value of a particular instance of PCPCounterVector
 func (c *PCPCounterVector) Inc(inc int64, instance string) error {
 	if inc < 0 {
@@ -880,14 +889,14 @@ func (c *PCPCounterVector) Inc(inc int64, instance string) error {
 	return c.Set(v+inc, instance)
 }
 
-// Up increments the value of a particular instance ny 1
-func (c *PCPCounterVector) Up(instance string) error {
-	v, err := c.Val(instance)
-	if err != nil {
-		return err
+// MustInc panics if Inc fails
+func (c *PCPCounterVector) MustInc(inc int64, instance string) {
+	if err := c.Inc(inc, instance); err != nil {
+		panic(err)
 	}
-
-	return c.Set(v+1, instance)
 }
 
+// Up increments the value of a particular instance ny 1
+func (c *PCPCounterVector) Up(instance string) { c.MustInc(1, instance) }
+
 ///////////////////////////////////////////////////////////////////////////////