diff options
Diffstat (limited to 'src/pkg/expvar/expvar.go')
| -rw-r--r-- | src/pkg/expvar/expvar.go | 62 |
1 files changed, 46 insertions, 16 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]}) } } |