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 32 package ptypes 33 34 // This file implements operations on google.protobuf.Timestamp. 35 36 import ( 37 "errors" 38 "fmt" 39 "time" 40 41 tspb "github.com/golang/protobuf/ptypes/timestamp" 42 ) 43 44 const ( 45 // Seconds field of the earliest valid Timestamp. 46 // This is time.Date(1, 1, 1, 0, 0, 0, 0, time.UTC).Unix(). 47 minValidSeconds = -62135596800 48 // Seconds field just after the latest valid Timestamp. 49 // This is time.Date(10000, 1, 1, 0, 0, 0, 0, time.UTC).Unix(). 50 maxValidSeconds = 253402300800 51 ) 52 53 // validateTimestamp determines whether a Timestamp is valid. 54 // A valid timestamp represents a time in the range 55 // [0001-01-01, 10000-01-01) and has a Nanos field 56 // in the range [0, 1e9). 57 // 58 // If the Timestamp is valid, validateTimestamp returns nil. 59 // Otherwise, it returns an error that describes 60 // the problem. 61 // 62 // Every valid Timestamp can be represented by a time.Time, but the converse is not true. 63 func validateTimestamp(ts *tspb.Timestamp) error { 64 if ts == nil { 65 return errors.New("timestamp: nil Timestamp") 66 } 67 if ts.Seconds < minValidSeconds { 68 return fmt.Errorf("timestamp: %v before 0001-01-01", ts) 69 } 70 if ts.Seconds >= maxValidSeconds { 71 return fmt.Errorf("timestamp: %v after 10000-01-01", ts) 72 } 73 if ts.Nanos < 0 || ts.Nanos >= 1e9 { 74 return fmt.Errorf("timestamp: %v: nanos not in range [0, 1e9)", ts) 75 } 76 return nil 77 } 78 79 // Timestamp converts a google.protobuf.Timestamp proto to a time.Time. 80 // It returns an error if the argument is invalid. 81 // 82 // Unlike most Go functions, if Timestamp returns an error, the first return value 83 // is not the zero time.Time. Instead, it is the value obtained from the 84 // time.Unix function when passed the contents of the Timestamp, in the UTC 85 // locale. This may or may not be a meaningful time; many invalid Timestamps 86 // do map to valid time.Times. 87 // 88 // A nil Timestamp returns an error. The first return value in that case is 89 // undefined. 90 func Timestamp(ts *tspb.Timestamp) (time.Time, error) { 91 // Don't return the zero value on error, because corresponds to a valid 92 // timestamp. Instead return whatever time.Unix gives us. 93 var t time.Time 94 if ts == nil { 95 t = time.Unix(0, 0).UTC() // treat nil like the empty Timestamp 96 } else { 97 t = time.Unix(ts.Seconds, int64(ts.Nanos)).UTC() 98 } 99 return t, validateTimestamp(ts) 100 } 101 102 // TimestampNow returns a google.protobuf.Timestamp for the current time. 103 func TimestampNow() *tspb.Timestamp { 104 ts, err := TimestampProto(time.Now()) 105 if err != nil { 106 panic("ptypes: time.Now() out of Timestamp range") 107 } 108 return ts 109 } 110 111 // TimestampProto converts the time.Time to a google.protobuf.Timestamp proto. 112 // It returns an error if the resulting Timestamp is invalid. 113 func TimestampProto(t time.Time) (*tspb.Timestamp, error) { 114 seconds := t.Unix() 115 nanos := int32(t.Sub(time.Unix(seconds, 0))) 116 ts := &tspb.Timestamp{ 117 Seconds: seconds, 118 Nanos: nanos, 119 } 120 if err := validateTimestamp(ts); err != nil { 121 return nil, err 122 } 123 return ts, nil 124 } 125 126 // TimestampString returns the RFC 3339 string for valid Timestamps. For invalid 127 // Timestamps, it returns an error message in parentheses. 128 func TimestampString(ts *tspb.Timestamp) string { 129 t, err := Timestamp(ts) 130 if err != nil { 131 return fmt.Sprintf("(%v)", err) 132 } 133 return t.Format(time.RFC3339Nano) 134 } 135
