Stats files

cmd/discosrv/stats.go

@@ -3,7 +3,12 @@
 package main
 
 import (
+	"bytes"
+	"database/sql"
+	"fmt"
+	"io/ioutil"
 	"log"
+	"os"
 	"sync"
 	"time"
 )
@@ -52,6 +57,8 @@ func (s *stats) Reset() stats {
 
 type statssrv struct {
 	intv time.Duration
+	file string
+	db   *sql.DB
 }
 
 func (s *statssrv) Serve() {
@@ -59,12 +66,71 @@ func (s *statssrv) Serve() {
 		time.Sleep(next(s.intv))
 
 		stats := globalStats.Reset()
-		s := time.Since(stats.reset).Seconds()
+		d := time.Since(stats.reset).Seconds()
 		log.Printf("Stats: %.02f announces/s, %.02f queries/s, %.02f answers/s, %.02f errors/s",
-			float64(stats.announces)/s, float64(stats.queries)/s, float64(stats.answers)/s, float64(stats.errors)/s)
+			float64(stats.announces)/d, float64(stats.queries)/d, float64(stats.answers)/d, float64(stats.errors)/d)
+
+		if s.file != "" {
+			s.writeToFile(stats, d)
+		}
 	}
 }
 
 func (s *statssrv) Stop() {
 	panic("stop unimplemented")
 }
+
+func (s *statssrv) writeToFile(stats stats, secs float64) {
+	newLine := []byte("\n")
+
+	var addrs int
+	row := s.db.QueryRow("SELECT COUNT(*) FROM Addresses")
+	if err := row.Scan(&addrs); err != nil {
+		log.Println("stats query:", err)
+		return
+	}
+
+	fd, err := os.OpenFile(s.file, os.O_RDWR|os.O_CREATE, 0666)
+	if err != nil {
+		log.Println("stats file:", err)
+		return
+	}
+
+	bs, err := ioutil.ReadAll(fd)
+	if err != nil {
+		log.Println("stats file:", err)
+		return
+	}
+	lines := bytes.Split(bytes.TrimSpace(bs), newLine)
+	if len(lines) > 12 {
+		lines = lines[len(lines)-12:]
+	}
+
+	latest := fmt.Sprintf("%v: %6d addresses, %8.02f announces/s, %8.02f queries/s, %8.02f answers/s, %8.02f errors/s\n",
+		time.Now().UTC().Format(time.RFC3339), addrs,
+		float64(stats.announces)/secs, float64(stats.queries)/secs, float64(stats.answers)/secs, float64(stats.errors)/secs)
+	lines = append(lines, []byte(latest))
+
+	_, err = fd.Seek(0, 0)
+	if err != nil {
+		log.Println("stats file:", err)
+		return
+	}
+	err = fd.Truncate(0)
+	if err != nil {
+		log.Println("stats file:", err)
+		return
+	}
+
+	_, err = fd.Write(bytes.Join(lines, newLine))
+	if err != nil {
+		log.Println("stats file:", err)
+		return
+	}
+
+	err = fd.Close()
+	if err != nil {
+		log.Println("stats file:", err)
+		return
+	}
+}