1 // Package ratemap implements a goroutine-safe map of string to float64. It can 2 // be embedded in implementations whose metrics support fixed sample rates, so 3 // that an additional parameter doesn't have to be tracked through the e.g. 4 // lv.Space object. 5 package ratemap 6 7 import "sync" 8 9 // RateMap is a simple goroutine-safe map of string to float64. 10 type RateMap struct { 11 mtx sync.RWMutex 12 m map[string]float64 13 } 14 15 // New returns a new RateMap. 16 func New() *RateMap { 17 return &RateMap{ 18 m: map[string]float64{}, 19 } 20 } 21 22 // Set writes the given name/rate pair to the map. 23 // Set is safe for concurrent access by multiple goroutines. 24 func (m *RateMap) Set(name string, rate float64) { 25 m.mtx.Lock() 26 defer m.mtx.Unlock() 27 m.m[name] = rate 28 } 29 30 // Get retrieves the rate for the given name, or 1.0 if none is set. 31 // Get is safe for concurrent access by multiple goroutines. 32 func (m *RateMap) Get(name string) float64 { 33 m.mtx.RLock() 34 defer m.mtx.RUnlock() 35 f, ok := m.m[name] 36 if !ok { 37 f = 1.0 38 } 39 return f 40 } 41