github.com/FUSIONFoundation/efsn@v3.6.2-0.20200916075423-dbb5dd5d2cc7+incompatible/swarm/storage/mru/timestampprovider.go (about) 1 // Copyright 2018 The go-ethereum Authors 2 // This file is part of the go-ethereum library. 3 // 4 // The go-ethereum library is free software: you can redistribute it and/or modify 5 // it under the terms of the GNU Lesser General Public License as published by 6 // the Free Software Foundation, either version 3 of the License, or 7 // (at your option) any later version. 8 // 9 // The go-ethereum library is distributed in the hope that it will be useful, 10 // but WITHOUT ANY WARRANTY; without even the implied warranty of 11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 // GNU Lesser General Public License for more details. 13 // 14 // You should have received a copy of the GNU Lesser General Public License 15 // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>. 16 17 package mru 18 19 import ( 20 "encoding/binary" 21 "time" 22 ) 23 24 // TimestampProvider sets the time source of the mru package 25 var TimestampProvider timestampProvider = NewDefaultTimestampProvider() 26 27 // Encodes a point in time as a Unix epoch 28 type Timestamp struct { 29 Time uint64 // Unix epoch timestamp, in seconds 30 } 31 32 // 8 bytes uint64 Time 33 const timestampLength = 8 34 35 // timestampProvider interface describes a source of timestamp information 36 type timestampProvider interface { 37 Now() Timestamp // returns the current timestamp information 38 } 39 40 // binaryGet populates the timestamp structure from the given byte slice 41 func (t *Timestamp) binaryGet(data []byte) error { 42 if len(data) != timestampLength { 43 return NewError(ErrCorruptData, "timestamp data has the wrong size") 44 } 45 t.Time = binary.LittleEndian.Uint64(data[:8]) 46 return nil 47 } 48 49 // binaryPut Serializes a Timestamp to a byte slice 50 func (t *Timestamp) binaryPut(data []byte) error { 51 if len(data) != timestampLength { 52 return NewError(ErrCorruptData, "timestamp data has the wrong size") 53 } 54 binary.LittleEndian.PutUint64(data, t.Time) 55 return nil 56 } 57 58 type DefaultTimestampProvider struct { 59 } 60 61 // NewDefaultTimestampProvider creates a system clock based timestamp provider 62 func NewDefaultTimestampProvider() *DefaultTimestampProvider { 63 return &DefaultTimestampProvider{} 64 } 65 66 // Now returns the current time according to this provider 67 func (dtp *DefaultTimestampProvider) Now() Timestamp { 68 return Timestamp{ 69 Time: uint64(time.Now().Unix()), 70 } 71 }