second set of patches

2 files changed, 82 insertions, 0 deletions

diff --git a/util/fasttime.go b/util/fasttime.go
index a18924cb..f1a81333 100644
--- a/util/fasttime.go
+++ b/util/fasttime.go
@@ -1,5 +1,41 @@
 package util
 
+import (
+	"sync/atomic"
+	"time"
+)
+
 // FastTime provides current unix time using specified resolution with reduced number of syscalls.
 type FastTime struct {
+	last   int64
+	ticker *time.Ticker
+}
+
+// NewFastTime returns new time provider with given resolution.
+func NewFastTime(resolution time.Duration) *FastTime {
+	ft := &FastTime{
+		last:   time.Now().UnixNano(),
+		ticker: time.NewTicker(resolution),
+	}
+
+	go ft.run()
+
+	return ft
+}
+
+// Stop ticking.
+func (ft *FastTime) Stop() {
+	ft.ticker.Stop()
+}
+
+// UnixNano returns current timestamps. Value might be delayed after current time by specified resolution.
+func (ft *FastTime) UnixNano() int64 {
+	return atomic.LoadInt64(&ft.last)
+}
+
+// consume time values over given resolution.
+func (ft *FastTime) run() {
+	for range ft.ticker.C {
+		atomic.StoreInt64(&ft.last, time.Now().UnixNano())
+	}
 }
diff --git a/util/fasttime_test.go b/util/fasttime_test.go
index c7d86821..c8ff0e13 100644
--- a/util/fasttime_test.go
+++ b/util/fasttime_test.go
@@ -1 +1,47 @@
 package util
+
+import (
+	"github.com/stretchr/testify/assert"
+	"testing"
+	"time"
+)
+
+func TestFTime_UnixNano(t *testing.T) {
+	ft := NewFastTime(time.Millisecond)
+	defer ft.Stop()
+
+	var d int64
+
+	d = time.Now().UnixNano() - ft.UnixNano()
+
+	assert.True(t, d >= 0)
+	assert.True(t, d <= int64(time.Millisecond*2))
+
+	time.Sleep(time.Millisecond * 100)
+	d = time.Now().UnixNano() - ft.UnixNano()
+
+	assert.True(t, d >= 0)
+	assert.True(t, d <= int64(time.Millisecond*2))
+}
+
+func Benchmark_FastTime(b *testing.B) {
+	ft := NewFastTime(time.Microsecond)
+	defer ft.Stop()
+
+	b.ReportAllocs()
+
+	for n := 0; n < b.N; n++ {
+		_ = ft.UnixNano()
+	}
+}
+
+func Benchmark_Time(b *testing.B) {
+	ft := NewFastTime(time.Microsecond)
+	defer ft.Stop()
+
+	b.ReportAllocs()
+
+	for n := 0; n < b.N; n++ {
+		_ = time.Now().UnixNano()
+	}
+}