1// Copyright 2016 The Go Authors. All rights reserved. 2// Use of this source code is governed by a BSD-style 3// license that can be found in the LICENSE file. 4 5package ptypes 6 7import ( 8 "errors" 9 "fmt" 10 "time" 11 12 timestamppb "github.com/golang/protobuf/ptypes/timestamp" 13) 14 15// Range of google.protobuf.Duration as specified in timestamp.proto. 16const ( 17 // Seconds field of the earliest valid Timestamp. 18 // This is time.Date(1, 1, 1, 0, 0, 0, 0, time.UTC).Unix(). 19 minValidSeconds = -62135596800 20 // Seconds field just after the latest valid Timestamp. 21 // This is time.Date(10000, 1, 1, 0, 0, 0, 0, time.UTC).Unix(). 22 maxValidSeconds = 253402300800 23) 24 25// Timestamp converts a timestamppb.Timestamp to a time.Time. 26// It returns an error if the argument is invalid. 27// 28// Unlike most Go functions, if Timestamp returns an error, the first return 29// value is not the zero time.Time. Instead, it is the value obtained from the 30// time.Unix function when passed the contents of the Timestamp, in the UTC 31// locale. This may or may not be a meaningful time; many invalid Timestamps 32// do map to valid time.Times. 33// 34// A nil Timestamp returns an error. The first return value in that case is 35// undefined. 36func Timestamp(ts *timestamppb.Timestamp) (time.Time, error) { 37 // Don't return the zero value on error, because corresponds to a valid 38 // timestamp. Instead return whatever time.Unix gives us. 39 var t time.Time 40 if ts == nil { 41 t = time.Unix(0, 0).UTC() // treat nil like the empty Timestamp 42 } else { 43 t = time.Unix(ts.Seconds, int64(ts.Nanos)).UTC() 44 } 45 return t, validateTimestamp(ts) 46} 47 48// TimestampNow returns a google.protobuf.Timestamp for the current time. 49func TimestampNow() *timestamppb.Timestamp { 50 ts, err := TimestampProto(time.Now()) 51 if err != nil { 52 panic("ptypes: time.Now() out of Timestamp range") 53 } 54 return ts 55} 56 57// TimestampProto converts the time.Time to a google.protobuf.Timestamp proto. 58// It returns an error if the resulting Timestamp is invalid. 59func TimestampProto(t time.Time) (*timestamppb.Timestamp, error) { 60 ts := ×tamppb.Timestamp{ 61 Seconds: t.Unix(), 62 Nanos: int32(t.Nanosecond()), 63 } 64 if err := validateTimestamp(ts); err != nil { 65 return nil, err 66 } 67 return ts, nil 68} 69 70// TimestampString returns the RFC 3339 string for valid Timestamps. 71// For invalid Timestamps, it returns an error message in parentheses. 72func TimestampString(ts *timestamppb.Timestamp) string { 73 t, err := Timestamp(ts) 74 if err != nil { 75 return fmt.Sprintf("(%v)", err) 76 } 77 return t.Format(time.RFC3339Nano) 78} 79 80// validateTimestamp determines whether a Timestamp is valid. 81// A valid timestamp represents a time in the range [0001-01-01, 10000-01-01) 82// and has a Nanos field in the range [0, 1e9). 83// 84// If the Timestamp is valid, validateTimestamp returns nil. 85// Otherwise, it returns an error that describes the problem. 86// 87// Every valid Timestamp can be represented by a time.Time, 88// but the converse is not true. 89func validateTimestamp(ts *timestamppb.Timestamp) error { 90 if ts == nil { 91 return errors.New("timestamp: nil Timestamp") 92 } 93 if ts.Seconds < minValidSeconds { 94 return fmt.Errorf("timestamp: %v before 0001-01-01", ts) 95 } 96 if ts.Seconds >= maxValidSeconds { 97 return fmt.Errorf("timestamp: %v after 10000-01-01", ts) 98 } 99 if ts.Nanos < 0 || ts.Nanos >= 1e9 { 100 return fmt.Errorf("timestamp: %v: nanos not in range [0, 1e9)", ts) 101 } 102 return nil 103} 104