metrics: counter: return error for -ve inc

performancecopilot · 7643da8a5134111e460e1bc875a9900c04c659c7 · suyash committed Aug 9, 2016 · Aug 9, 2016 · 7643da8
1 parent 7261a7b
commit 7643da8a5134111e460e1bc875a9900c04c659c7
Unified Split

Showing with 4 additions and 0 deletions.

+4 −0 metrics.go
diff --git a/metrics.go b/metrics.go
@@ -617,6 +617,10 @@ func (c *PCPCounter) Set(val int64) error {
 
 // Inc increases the stored counter's value by the passed increment
 func (c *PCPCounter) Inc(val int64) error {
+	if val < 0 {
+		return errors.New("cannot decrement a counter")
+	}
+
 	v := c.Val()
 	v += val
 	return c.Set(v)