Loki: Create component for sending logs to Loki (#51500)

pkg/components/loki/logproto/timestamp.go

@@ -0,0 +1,106 @@
+package logproto
+
+import (
+	"errors"
+	"strconv"
+	"time"
+
+	"github.com/gogo/protobuf/types"
+)
+
+const (
+	// Seconds field of the earliest valid Timestamp.
+	// This is time.Date(1, 1, 1, 0, 0, 0, 0, time.UTC).Unix().
+	minValidSeconds = -62135596800
+	// Seconds field just after the latest valid Timestamp.
+	// This is time.Date(10000, 1, 1, 0, 0, 0, 0, time.UTC).Unix().
+	maxValidSeconds = 253402300800
+)
+
+// validateTimestamp determines whether a Timestamp is valid.
+// A valid timestamp represents a time in the range
+// [0001-01-01, 10000-01-01) and has a Nanos field
+// in the range [0, 1e9).
+//
+// If the Timestamp is valid, validateTimestamp returns nil.
+// Otherwise, it returns an error that describes
+// the problem.
+//
+// Every valid Timestamp can be represented by a time.Time, but the converse is not true.
+func validateTimestamp(ts *types.Timestamp) error {
+	if ts == nil {
+		return errors.New("timestamp: nil Timestamp")
+	}
+	if ts.Seconds < minValidSeconds {
+		return errors.New("timestamp: " + formatTimestamp(ts) + " before 0001-01-01")
+	}
+	if ts.Seconds >= maxValidSeconds {
+		return errors.New("timestamp: " + formatTimestamp(ts) + " after 10000-01-01")
+	}
+	if ts.Nanos < 0 || ts.Nanos >= 1e9 {
+		return errors.New("timestamp: " + formatTimestamp(ts) + ": nanos not in range [0, 1e9)")
+	}
+	return nil
+}
+
+// formatTimestamp is equivalent to fmt.Sprintf("%#v", ts)
+// but avoids the escape incurred by using fmt.Sprintf, eliminating
+// unnecessary heap allocations.
+func formatTimestamp(ts *types.Timestamp) string {
+	if ts == nil {
+		return "nil"
+	}
+
+	seconds := strconv.FormatInt(ts.Seconds, 10)
+	nanos := strconv.FormatInt(int64(ts.Nanos), 10)
+	return "&types.Timestamp{Seconds: " + seconds + ",\nNanos: " + nanos + ",\n}"
+}
+
+func SizeOfStdTime(t time.Time) int {
+	ts, err := timestampProto(t)
+	if err != nil {
+		return 0
+	}
+	return ts.Size()
+}
+
+func StdTimeMarshalTo(t time.Time, data []byte) (int, error) {
+	ts, err := timestampProto(t)
+	if err != nil {
+		return 0, err
+	}
+	return ts.MarshalTo(data)
+}
+
+func StdTimeUnmarshal(t *time.Time, data []byte) error {
+	ts := &types.Timestamp{}
+	if err := ts.Unmarshal(data); err != nil {
+		return err
+	}
+	tt, err := timestampFromProto(ts)
+	if err != nil {
+		return err
+	}
+	*t = tt
+	return nil
+}
+
+func timestampFromProto(ts *types.Timestamp) (time.Time, error) {
+	// Don't return the zero value on error, because corresponds to a valid
+	// timestamp. Instead return whatever time.Unix gives us.
+	var t time.Time
+	if ts == nil {
+		t = time.Unix(0, 0).UTC() // treat nil like the empty Timestamp
+	} else {
+		t = time.Unix(ts.Seconds, int64(ts.Nanos)).UTC()
+	}
+	return t, validateTimestamp(ts)
+}
+
+func timestampProto(t time.Time) (types.Timestamp, error) {
+	ts := types.Timestamp{
+		Seconds: t.Unix(),
+		Nanos:   int32(t.Nanosecond()),
+	}
+	return ts, validateTimestamp(&ts)
+}