diff options
Diffstat (limited to 'src/pkg/expvar')
| -rw-r--r-- | src/pkg/expvar/expvar.go | 62 | ||||
| -rw-r--r-- | src/pkg/expvar/expvar_test.go | 32 |
2 files changed, 75 insertions, 19 deletions
diff --git a/src/pkg/expvar/expvar.go b/src/pkg/expvar/expvar.go index b06599505..9b6dab487 100644 --- a/src/pkg/expvar/expvar.go +++ b/src/pkg/expvar/expvar.go @@ -29,6 +29,7 @@ import ( "net/http" "os" "runtime" + "sort" "strconv" "sync" ) @@ -40,8 +41,8 @@ type Var interface { // Int is a 64-bit integer variable that satisfies the Var interface. type Int struct { - i int64 mu sync.RWMutex + i int64 } func (v *Int) String() string { @@ -64,8 +65,8 @@ func (v *Int) Set(value int64) { // Float is a 64-bit float variable that satisfies the Var interface. type Float struct { - f float64 mu sync.RWMutex + f float64 } func (v *Float) String() string { @@ -90,8 +91,9 @@ func (v *Float) Set(value float64) { // Map is a string-to-Var map variable that satisfies the Var interface. type Map struct { - m map[string]Var - mu sync.RWMutex + mu sync.RWMutex + m map[string]Var + keys []string // sorted } // KeyValue represents a single entry in a Map. @@ -106,13 +108,13 @@ func (v *Map) String() string { var b bytes.Buffer fmt.Fprintf(&b, "{") first := true - for key, val := range v.m { + v.doLocked(func(kv KeyValue) { if !first { fmt.Fprintf(&b, ", ") } - fmt.Fprintf(&b, "\"%s\": %v", key, val) + fmt.Fprintf(&b, "%q: %v", kv.Key, kv.Value) first = false - } + }) fmt.Fprintf(&b, "}") return b.String() } @@ -122,6 +124,20 @@ func (v *Map) Init() *Map { return v } +// updateKeys updates the sorted list of keys in v.keys. +// must be called with v.mu held. +func (v *Map) updateKeys() { + if len(v.m) == len(v.keys) { + // No new key. + return + } + v.keys = v.keys[:0] + for k := range v.m { + v.keys = append(v.keys, k) + } + sort.Strings(v.keys) +} + func (v *Map) Get(key string) Var { v.mu.RLock() defer v.mu.RUnlock() @@ -132,6 +148,7 @@ func (v *Map) Set(key string, av Var) { v.mu.Lock() defer v.mu.Unlock() v.m[key] = av + v.updateKeys() } func (v *Map) Add(key string, delta int64) { @@ -141,9 +158,11 @@ func (v *Map) Add(key string, delta int64) { if !ok { // check again under the write lock v.mu.Lock() - if _, ok = v.m[key]; !ok { + av, ok = v.m[key] + if !ok { av = new(Int) v.m[key] = av + v.updateKeys() } v.mu.Unlock() } @@ -162,9 +181,11 @@ func (v *Map) AddFloat(key string, delta float64) { if !ok { // check again under the write lock v.mu.Lock() - if _, ok = v.m[key]; !ok { + av, ok = v.m[key] + if !ok { av = new(Float) v.m[key] = av + v.updateKeys() } v.mu.Unlock() } @@ -181,15 +202,21 @@ func (v *Map) AddFloat(key string, delta float64) { func (v *Map) Do(f func(KeyValue)) { v.mu.RLock() defer v.mu.RUnlock() - for k, v := range v.m { - f(KeyValue{k, v}) + v.doLocked(f) +} + +// doLocked calls f for each entry in the map. +// v.mu must be held for reads. +func (v *Map) doLocked(f func(KeyValue)) { + for _, k := range v.keys { + f(KeyValue{k, v.m[k]}) } } // String is a string variable, and satisfies the Var interface. type String struct { - s string mu sync.RWMutex + s string } func (v *String) String() string { @@ -215,8 +242,9 @@ func (f Func) String() string { // All published variables. var ( - mutex sync.RWMutex - vars map[string]Var = make(map[string]Var) + mutex sync.RWMutex + vars = make(map[string]Var) + varKeys []string // sorted ) // Publish declares a named exported variable. This should be called from a @@ -229,6 +257,8 @@ func Publish(name string, v Var) { log.Panicln("Reuse of exported var name:", name) } vars[name] = v + varKeys = append(varKeys, name) + sort.Strings(varKeys) } // Get retrieves a named exported variable. @@ -270,8 +300,8 @@ func NewString(name string) *String { func Do(f func(KeyValue)) { mutex.RLock() defer mutex.RUnlock() - for k, v := range vars { - f(KeyValue{k, v}) + for _, k := range varKeys { + f(KeyValue{k, vars[k]}) } } diff --git a/src/pkg/expvar/expvar_test.go b/src/pkg/expvar/expvar_test.go index 572c62bee..765e3b757 100644 --- a/src/pkg/expvar/expvar_test.go +++ b/src/pkg/expvar/expvar_test.go @@ -5,7 +5,10 @@ package expvar import ( + "bytes" "encoding/json" + "net/http/httptest" + "strconv" "testing" ) @@ -15,6 +18,7 @@ func RemoveAll() { mutex.Lock() defer mutex.Unlock() vars = make(map[string]Var) + varKeys = nil } func TestInt(t *testing.T) { @@ -93,15 +97,15 @@ func TestMapCounter(t *testing.T) { colors.Add("red", 1) colors.Add("red", 2) colors.Add("blue", 4) - colors.AddFloat("green", 4.125) + colors.AddFloat(`green "midori"`, 4.125) if x := colors.m["red"].(*Int).i; x != 3 { t.Errorf("colors.m[\"red\"] = %v, want 3", x) } if x := colors.m["blue"].(*Int).i; x != 4 { t.Errorf("colors.m[\"blue\"] = %v, want 4", x) } - if x := colors.m["green"].(*Float).f; x != 4.125 { - t.Errorf("colors.m[\"green\"] = %v, want 3.14", x) + if x := colors.m[`green "midori"`].(*Float).f; x != 4.125 { + t.Errorf("colors.m[`green \"midori\"] = %v, want 3.14", x) } // colors.String() should be '{"red":3, "blue":4}', @@ -139,3 +143,25 @@ func TestFunc(t *testing.T) { t.Errorf(`f.String() = %q, want %q`, s, exp) } } + +func TestHandler(t *testing.T) { + RemoveAll() + m := NewMap("map1") + m.Add("a", 1) + m.Add("z", 2) + m2 := NewMap("map2") + for i := 0; i < 9; i++ { + m2.Add(strconv.Itoa(i), int64(i)) + } + rr := httptest.NewRecorder() + rr.Body = new(bytes.Buffer) + expvarHandler(rr, nil) + want := `{ +"map1": {"a": 1, "z": 2}, +"map2": {"0": 0, "1": 1, "2": 2, "3": 3, "4": 4, "5": 5, "6": 6, "7": 7, "8": 8} +} +` + if got := rr.Body.String(); got != want { + t.Errorf("HTTP handler wrote:\n%s\nWant:\n%s", got, want) + } +} |