// Copyright 2016 The Go Authors. All rights reserved. // Use of this source code is governed by a BSD-style // license that can be found in the LICENSE file. package ptypes // This file implements operations on google.protobuf.Timestamp. import ( "errors" "fmt" "time" tspb "github.com/golang/protobuf/ptypes/timestamp" ) 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 *tspb.Timestamp) error { if ts == nil { return errors.New("timestamp: nil Timestamp") } if ts.Seconds < minValidSeconds { return fmt.Errorf("timestamp: %v before 0001-01-01", ts) } if ts.Seconds >= maxValidSeconds { return fmt.Errorf("timestamp: %v after 10000-01-01", ts) } if ts.Nanos < 0 || ts.Nanos >= 1e9 { return fmt.Errorf("timestamp: %v: nanos not in range [0, 1e9)", ts) } return nil } // Timestamp converts a google.protobuf.Timestamp proto to a time.Time. // It returns an error if the argument is invalid. // // Unlike most Go functions, if Timestamp returns an error, the first return value // is not the zero time.Time. Instead, it is the value obtained from the // time.Unix function when passed the contents of the Timestamp, in the UTC // locale. This may or may not be a meaningful time; many invalid Timestamps // do map to valid time.Times. // // A nil Timestamp returns an error. The first return value in that case is // undefined. func Timestamp(ts *tspb.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) } // TimestampNow returns a google.protobuf.Timestamp for the current time. func TimestampNow() *tspb.Timestamp { ts, err := TimestampProto(time.Now()) if err != nil { panic("ptypes: time.Now() out of Timestamp range") } return ts } // TimestampProto converts the time.Time to a google.protobuf.Timestamp proto. // It returns an error if the resulting Timestamp is invalid. func TimestampProto(t time.Time) (*tspb.Timestamp, error) { ts := &tspb.Timestamp{ Seconds: t.Unix(), Nanos: int32(t.Nanosecond()), } if err := validateTimestamp(ts); err != nil { return nil, err } return ts, nil } // TimestampString returns the RFC 3339 string for valid Timestamps. For invalid // Timestamps, it returns an error message in parentheses. func TimestampString(ts *tspb.Timestamp) string { t, err := Timestamp(ts) if err != nil { return fmt.Sprintf("(%v)", err) } return t.Format(time.RFC3339Nano) }