time_to_unixnano.patch

diff --git a/tsdb/engine/tsm1/cache_test.go b/tsdb/engine/tsm1/cache_test.go
index 2151270..d74b7a9 100644
--- a/tsdb/engine/tsm1/cache_test.go
+++ b/tsdb/engine/tsm1/cache_test.go
@@ -359,3 +359,13 @@ func mustMarshalEntry(entry WALEntry) (WalEntryType, []byte) {
 
 	return entry.Type(), snappy.Encode(b, b)
 }
+
+func BenchmarkCacheFloatEntries(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		cache := NewCache(10000)
+		for j := 0; j < 10000; j++ {
+			v := NewValue(time.Unix(1, 0), float64(j))
+			cache.Write("test", []Value{v})
+		}
+	}
+}
diff --git a/tsdb/engine/tsm1/encoding.go b/tsdb/engine/tsm1/encoding.go
index e5bb295..9abbf00 100644
--- a/tsdb/engine/tsm1/encoding.go
+++ b/tsdb/engine/tsm1/encoding.go
@@ -41,7 +41,7 @@ func NewValue(t time.Time, value interface{}) Value {
 	case int64:
 		return &Int64Value{time: t, value: v}
 	case float64:
-		return &FloatValue{time: t, value: v}
+		return &FloatValue{unixnano: t.UnixNano(), value: v}
 	case bool:
 		return &BoolValue{time: t, value: v}
 	case string:
@@ -222,16 +222,16 @@ func (a Values) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }
 func (a Values) Less(i, j int) bool { return a[i].Time().UnixNano() < a[j].Time().UnixNano() }
 
 type FloatValue struct {
-	time  time.Time
-	value float64
+	unixnano int64
+	value    float64
 }
 
 func (f *FloatValue) Time() time.Time {
-	return f.time
+	return time.Unix(0, f.unixnano)
 }
 
 func (f *FloatValue) UnixNano() int64 {
-	return f.time.UnixNano()
+	return f.unixnano
 }
 
 func (f *FloatValue) Value() interface{} {
@@ -308,10 +308,10 @@ func DecodeFloatBlock(block []byte, a []FloatValue) ([]FloatValue, error) {
 		ts := dec.Read()
 		v := iter.Values()
 		if i < len(a) {
-			a[i].time = ts
+			a[i].unixnano = ts.UnixNano()
 			a[i].value = v
 		} else {
-			a = append(a, FloatValue{ts, v})
+			a = append(a, FloatValue{ts.UnixNano(), v})
 		}
 		i++
 	}
diff --git a/tsdb/engine/tsm1/wal.go b/tsdb/engine/tsm1/wal.go
index ff09351..4566453 100644
--- a/tsdb/engine/tsm1/wal.go
+++ b/tsdb/engine/tsm1/wal.go
@@ -462,7 +462,8 @@ func (w *WriteWALEntry) UnmarshalBinary(b []byte) error {
 		}
 
 		for j := 0; j < nvals; j++ {
-			t := time.Unix(0, int64(btou64(b[i:i+8])))
+			un := int64(btou64(b[i : i+8]))
+			t := time.Unix(0, un)
 			i += 8
 
 			switch typ {
@@ -470,7 +471,7 @@ func (w *WriteWALEntry) UnmarshalBinary(b []byte) error {
 				v := math.Float64frombits((btou64(b[i : i+8])))
 				i += 8
 				if fv, ok := values[j].(*FloatValue); ok {
-					fv.time = t
+					fv.unixnano = un
 					fv.value = v
 				}
 			case int64EntryType: