1// Go support for Protocol Buffers - Google's data interchange format 2// 3// Copyright 2016 The Go Authors. All rights reserved. 4// https://github.com/golang/protobuf 5// 6// Redistribution and use in source and binary forms, with or without 7// modification, are permitted provided that the following conditions are 8// met: 9// 10// * Redistributions of source code must retain the above copyright 11// notice, this list of conditions and the following disclaimer. 12// * Redistributions in binary form must reproduce the above 13// copyright notice, this list of conditions and the following disclaimer 14// in the documentation and/or other materials provided with the 15// distribution. 16// * Neither the name of Google Inc. nor the names of its 17// contributors may be used to endorse or promote products derived from 18// this software without specific prior written permission. 19// 20// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 21// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 22// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 23// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 24// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 25// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 26// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 27// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 28// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 29// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 30// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 31 32package proto 33 34// This file implements operations on google.protobuf.Timestamp. 35 36import ( 37 "errors" 38 "fmt" 39 "time" 40) 41 42const ( 43 // Seconds field of the earliest valid Timestamp. 44 // This is time.Date(1, 1, 1, 0, 0, 0, 0, time.UTC).Unix(). 45 minValidSeconds = -62135596800 46 // Seconds field just after the latest valid Timestamp. 47 // This is time.Date(10000, 1, 1, 0, 0, 0, 0, time.UTC).Unix(). 48 maxValidSeconds = 253402300800 49) 50 51// validateTimestamp determines whether a Timestamp is valid. 52// A valid timestamp represents a time in the range 53// [0001-01-01, 10000-01-01) and has a Nanos field 54// in the range [0, 1e9). 55// 56// If the Timestamp is valid, validateTimestamp returns nil. 57// Otherwise, it returns an error that describes 58// the problem. 59// 60// Every valid Timestamp can be represented by a time.Time, but the converse is not true. 61func validateTimestamp(ts *timestamp) error { 62 if ts == nil { 63 return errors.New("timestamp: nil Timestamp") 64 } 65 if ts.Seconds < minValidSeconds { 66 return fmt.Errorf("timestamp: %#v before 0001-01-01", ts) 67 } 68 if ts.Seconds >= maxValidSeconds { 69 return fmt.Errorf("timestamp: %#v after 10000-01-01", ts) 70 } 71 if ts.Nanos < 0 || ts.Nanos >= 1e9 { 72 return fmt.Errorf("timestamp: %#v: nanos not in range [0, 1e9)", ts) 73 } 74 return nil 75} 76 77// TimestampFromProto converts a google.protobuf.Timestamp proto to a time.Time. 78// It returns an error if the argument is invalid. 79// 80// Unlike most Go functions, if Timestamp returns an error, the first return value 81// is not the zero time.Time. Instead, it is the value obtained from the 82// time.Unix function when passed the contents of the Timestamp, in the UTC 83// locale. This may or may not be a meaningful time; many invalid Timestamps 84// do map to valid time.Times. 85// 86// A nil Timestamp returns an error. The first return value in that case is 87// undefined. 88func timestampFromProto(ts *timestamp) (time.Time, error) { 89 // Don't return the zero value on error, because corresponds to a valid 90 // timestamp. Instead return whatever time.Unix gives us. 91 var t time.Time 92 if ts == nil { 93 t = time.Unix(0, 0).UTC() // treat nil like the empty Timestamp 94 } else { 95 t = time.Unix(ts.Seconds, int64(ts.Nanos)).UTC() 96 } 97 return t, validateTimestamp(ts) 98} 99 100// TimestampProto converts the time.Time to a google.protobuf.Timestamp proto. 101// It returns an error if the resulting Timestamp is invalid. 102func timestampProto(t time.Time) (*timestamp, error) { 103 seconds := t.Unix() 104 nanos := int32(t.Sub(time.Unix(seconds, 0))) 105 ts := ×tamp{ 106 Seconds: seconds, 107 Nanos: nanos, 108 } 109 if err := validateTimestamp(ts); err != nil { 110 return nil, err 111 } 112 return ts, nil 113} 114