timestamp: add means to convert Timestamp to & from time.Time

ptypes/timestamp/timestamp.go

@@ -0,0 +1,20 @@
+package timestamp
+
+import "time"
+
+//NewTimestamp returns a Timestamp given a time.Time
+//
+//There will be data loss
+func NewTimestamp(t time.Time) *Timestamp {
+	return &Timestamp{
+		Seconds: t.Unix(),
+		Nanos:   int32(t.Nanosecond()),
+	}
+}
+
+//Time Transforms timestamp to time.Time
+//
+//There will be data loss
+func (m *Timestamp) Time() time.Time {
+	return time.Unix(m.Seconds, int64(m.Nanos))
+}

ptypes/timestamp/timestamp_test.go

@@ -0,0 +1,34 @@
+package timestamp
+
+import (
+	"testing"
+	"time"
+)
+
+func TestTimestampsConversions(t *testing.T) {
+
+	times := []time.Time{
+		time.Time{},
+		time.Date(2014, time.January, 1, 1, 1, 1, 1, time.UTC),
+		time.Date(2015, time.February, 2, 1, 1, 1, 1, time.UTC),
+		time.Date(2016, time.March, 1, 2, 1, 1, 1, time.UTC),
+		time.Date(2017, time.April, 1, 1, 2, 1, 1, time.UTC),
+		time.Date(2018, time.May, 1, 1, 1, 2, 1, time.UTC),
+		time.Date(2019, time.June, 1, 1, 1, 1, 2, time.UTC),
+		time.Date(2020, time.July, 2, 2, 2, 2, 2, time.UTC),
+		time.Date(2021, time.August, 2, 2, 2, 2, 2, time.UTC),
+		time.Date(2021, time.August, 2, 2, 2, 2, 9999999999, time.UTC),
+	}
+
+	for _, tc := range times {
+		ts := NewTimestamp(tc)
+		tsTime := ts.Time()
+
+		// equality can't be true but difference
+		// gives us approximate correctness
+		if tsTime.Sub(tc) != 0 {
+			t.Errorf("NewDuration(%s).Duration() != %[1]s. Duration: %[2]v. Diff: %s", tc, ts, tsTime.Sub(tc))
+		}
+	}
+
+}