build, cmd/stdiscosrv, cmd/strelaysrv: Rename binaries to add "st" prefix

GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/3371

cmd/stdiscosrv/stats.go

@@ -0,0 +1,141 @@
+// Copyright (C) 2014-2015 Jakob Borg and Contributors (see the CONTRIBUTORS file).
+
+package main
+
+import (
+	"bytes"
+	"database/sql"
+	"fmt"
+	"io/ioutil"
+	"log"
+	"os"
+	"sync/atomic"
+	"time"
+)
+
+type stats struct {
+	// Incremented atomically
+	announces int64
+	queries   int64
+	answers   int64
+	errors    int64
+}
+
+func (s *stats) Announce() {
+	atomic.AddInt64(&s.announces, 1)
+}
+
+func (s *stats) Query() {
+	atomic.AddInt64(&s.queries, 1)
+}
+
+func (s *stats) Answer() {
+	atomic.AddInt64(&s.answers, 1)
+}
+
+func (s *stats) Error() {
+	atomic.AddInt64(&s.errors, 1)
+}
+
+// Reset returns a copy of the current stats and resets the counters to
+// zero.
+func (s *stats) Reset() stats {
+	// Create a copy of the stats using atomic reads
+	copy := stats{
+		announces: atomic.LoadInt64(&s.announces),
+		queries:   atomic.LoadInt64(&s.queries),
+		answers:   atomic.LoadInt64(&s.answers),
+		errors:    atomic.LoadInt64(&s.errors),
+	}
+
+	// Reset the stats by subtracting the values that we copied
+	atomic.AddInt64(&s.announces, -copy.announces)
+	atomic.AddInt64(&s.queries, -copy.queries)
+	atomic.AddInt64(&s.answers, -copy.answers)
+	atomic.AddInt64(&s.errors, -copy.errors)
+
+	return copy
+}
+
+type statssrv struct {
+	intv time.Duration
+	file string
+	db   *sql.DB
+}
+
+func (s *statssrv) Serve() {
+	lastReset := time.Now()
+	for {
+		time.Sleep(next(s.intv))
+
+		stats := globalStats.Reset()
+		d := time.Since(lastReset).Seconds()
+		lastReset = time.Now()
+
+		log.Printf("Stats: %.02f announces/s, %.02f queries/s, %.02f answers/s, %.02f 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
+	}
+	defer func() {
+		err = fd.Close()
+		if err != nil {
+			log.Println("stats file:", err)
+		}
+	}()
+
+	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
+	}
+}