expvar: add Func for functions that return values that are JSON marshalable.
Remove {Float,Int,String}Func, which are now redundant.
Fixes #1684.
R=rsc, r, r2
CC=golang-dev
https://golang.org/cl/4410041
diff --git a/src/pkg/expvar/expvar.go b/src/pkg/expvar/expvar.go
index ed6cff7..7736aea 100644
--- a/src/pkg/expvar/expvar.go
+++ b/src/pkg/expvar/expvar.go
@@ -180,23 +180,14 @@
func (v *String) Set(value string) { v.s = value }
-// IntFunc wraps a func() int64 to create a value that satisfies the Var interface.
-// The function will be called each time the Var is evaluated.
-type IntFunc func() int64
+// Func implements Var by calling the function
+// and formatting the returned value using JSON.
+type Func func() interface{}
-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
-
-func (f StringFunc) String() string { return strconv.Quote(f()) }
+func (f Func) String() string {
+ v, _ := json.Marshal(f())
+ return string(v)
+}
// All published variables.
@@ -282,18 +273,16 @@
fmt.Fprintf(w, "\n}\n")
}
-func memstats() string {
- b, _ := json.MarshalIndent(&runtime.MemStats, "", "\t")
- return string(b)
+func cmdline() interface{} {
+ return os.Args
}
-func cmdline() string {
- b, _ := json.Marshal(os.Args)
- return string(b)
+func memstats() interface{} {
+ return runtime.MemStats
}
func init() {
http.Handle("/debug/vars", http.HandlerFunc(expvarHandler))
- Publish("cmdline", StringFunc(cmdline))
- Publish("memstats", StringFunc(memstats))
+ Publish("cmdline", Func(cmdline))
+ Publish("memstats", Func(memstats))
}
diff --git a/src/pkg/expvar/expvar_test.go b/src/pkg/expvar/expvar_test.go
index a8b1a96..94926d9 100644
--- a/src/pkg/expvar/expvar_test.go
+++ b/src/pkg/expvar/expvar_test.go
@@ -114,41 +114,15 @@
}
}
-func TestIntFunc(t *testing.T) {
- x := int64(4)
- ix := IntFunc(func() int64 { return x })
- if s := ix.String(); s != "4" {
- t.Errorf("ix.String() = %v, want 4", s)
+func TestFunc(t *testing.T) {
+ var x interface{} = []string{"a", "b"}
+ f := Func(func() interface{} { return x })
+ if s, exp := f.String(), `["a","b"]`; s != exp {
+ t.Errorf(`f.String() = %q, want %q`, s, exp)
}
- x++
- if s := ix.String(); s != "5" {
- t.Errorf("ix.String() = %v, want 5", s)
- }
-}
-
-func TestFloatFunc(t *testing.T) {
- x := 8.5
- ix := FloatFunc(func() float64 { return x })
- if s := ix.String(); s != "8.5" {
- t.Errorf("ix.String() = %v, want 3.14", s)
- }
-
- x -= 1.25
- if s := ix.String(); s != "7.25" {
- t.Errorf("ix.String() = %v, want 4.34", s)
- }
-}
-
-func TestStringFunc(t *testing.T) {
- x := "hello"
- sx := StringFunc(func() string { return x })
- if s, exp := sx.String(), `"hello"`; s != exp {
- t.Errorf(`sx.String() = %q, want %q`, s, exp)
- }
-
- x = "goodbye"
- if s, exp := sx.String(), `"goodbye"`; s != exp {
- t.Errorf(`sx.String() = %q, want %q`, s, exp)
+ x = 17
+ if s, exp := f.String(), `17`; s != exp {
+ t.Errorf(`f.String() = %q, want %q`, s, exp)
}
}
