expvar: add Float
R=r, rsc, dsymonds
CC=golang-dev
https://golang.org/cl/4044041
diff --git a/src/pkg/expvar/expvar.go b/src/pkg/expvar/expvar.go
index fb20b25..b1f0f6c 100644
--- a/src/pkg/expvar/expvar.go
+++ b/src/pkg/expvar/expvar.go
@@ -38,7 +38,7 @@
String() string
}
-// Int is a 64-bit integer variable, and satisfies the Var interface.
+// Int is a 64-bit integer variable that satisfies the Var interface.
type Int struct {
i int64
mu sync.Mutex
@@ -58,7 +58,29 @@
v.i = value
}
-// Map is a string-to-Var map variable, and satisfies the Var interface.
+// Float is a 64-bit float variable that satisfies the Var interface.
+type Float struct {
+ f float64
+ mu sync.Mutex
+}
+
+func (v *Float) String() string { return strconv.Ftoa64(v.f, 'g', -1) }
+
+// Add adds delta to v.
+func (v *Float) Add(delta float64) {
+ v.mu.Lock()
+ defer v.mu.Unlock()
+ v.f += delta
+}
+
+// Set sets v to value.
+func (v *Float) Set(value float64) {
+ v.mu.Lock()
+ defer v.mu.Unlock()
+ v.f = value
+}
+
+// Map is a string-to-Var map variable that satisfies the Var interface.
type Map struct {
m map[string]Var
mu sync.Mutex
@@ -119,6 +141,22 @@
}
}
+// AddFloat adds delta to the *Float value stored under the given map key.
+func (v *Map) AddFloat(key string, delta float64) {
+ v.mu.Lock()
+ defer v.mu.Unlock()
+ av, ok := v.m[key]
+ if !ok {
+ av = new(Float)
+ v.m[key] = av
+ }
+
+ // Add to Float; ignore otherwise.
+ if iv, ok := av.(*Float); ok {
+ iv.Add(delta)
+ }
+}
+
// TODO(rsc): Make sure map access in separate thread is safe.
func (v *Map) iterate(c chan<- KeyValue) {
for k, v := range v.m {
@@ -148,6 +186,12 @@
func (v IntFunc) String() string { return strconv.Itoa64(v()) }
+// FloatFunc wraps a func() float64 to create a value that satisfies the Var interface.
+// The function will be called each time the Var is evaluated.
+type FloatFunc func() float64
+
+func (v FloatFunc) String() string { return strconv.Ftoa64(v(), 'g', -1) }
+
// StringFunc wraps a func() string to create value that satisfies the Var interface.
// The function will be called each time the Var is evaluated.
type StringFunc func() string
@@ -192,6 +236,12 @@
return v
}
+func NewFloat(name string) *Float {
+ v := new(Float)
+ Publish(name, v)
+ return v
+}
+
func NewMap(name string) *Map {
v := new(Map).Init()
Publish(name, v)
