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shezmu/stats/server.go

92 lines
1.9 KiB
Go

package stats
import (
"encoding/json"
"fmt"
"net/http"
"time"
)
type Server struct {
base
history map[string][]*serverStatsSnapshot
}
const (
serverSnapshotIntervl = 3 * time.Second
serverHistorySize = 30
)
func NewServer() *Server {
s := &Server{}
s.init()
s.history = make(map[string][]*serverStatsSnapshot)
go s.takeSnapshots()
return s
}
func (s *Server) History(rw http.ResponseWriter, _ *http.Request) {
encoded, err := json.Marshal(s.history)
if err != nil {
http.Error(rw, fmt.Sprintf("%v", err), http.StatusInternalServerError)
return
}
rw.Header().Add("Access-Control-Allow-Origin", "*")
rw.Write(encoded)
}
func (s *Server) takeSnapshots() {
for range time.NewTicker(serverSnapshotIntervl).C {
s.Lock()
for name, stat := range s.stats {
if len(s.history[name]) >= serverHistorySize {
s.history[name] = s.history[name][1:]
}
s.history[name] = append(s.history[name], makeServerStatsSnapshot(stat))
}
s.Reset()
s.Unlock()
}
}
//
// Stats
//
func makeServerStatsSnapshot(s *baseStats) *serverStatsSnapshot {
ps := s.time.Percentiles([]float64{0.25, 0.5, 0.75})
return &serverStatsSnapshot{
timestamp: time.Now().UTC().Unix(),
processed: s.time.Count(),
errors: s.errors.Count(),
min: round(float64(s.time.Min())/1000000, 6),
p25: round(ps[0]/1000000, 6),
mean: round(s.time.Mean()/1000000, 6),
median: round(ps[1]/1000000, 6),
p75: round(ps[2]/1000000, 6),
max: round(float64(s.time.Max())/1000000, 6),
}
}
type serverStatsSnapshot struct {
timestamp int64
processed int64
errors int64
min float64
p25 float64
mean float64
median float64
p75 float64
max float64
}
// Implements json.Marshaler
func (s *serverStatsSnapshot) MarshalJSON() ([]byte, error) {
return []byte(fmt.Sprintf("[%d,%d,%d,%.6f,%.6f,%.6f,%.6f,%.6f,%.6f]",
s.timestamp, s.processed, s.errors, s.min, s.p25,
s.mean, s.median, s.p75, s.max)), nil
}