ducky/devices

Paddy 2016-01-02 Parent:a700ede02f91

20:ed1b5ba69551 Go to Latest

ducky/devices/vendor/github.com/pborman/uuid/time.go

Add updating devices to apiv1. We needed a way to be able to update devices after they were created. This is supported in the devices package, we just needed to expose it using apiv1 endpoints. In doing so, it became apparent that allowing users to change the Owner of their Devices wasn't properly thought through, and pending a reason to use it, I'm just removing it. The biggest issue came when trying to return usable error messages; we couldn't distinguish between "you don't own the device you're trying to update" and "you're not allowed to change the owner of the device". I also couldn't figure out _who should be able to_ change the owner of the device, which is generally an indication that I'm building a feature before I have a use case for it. To support this change, the apiv1.DeviceChange type needed its Owner property removed. I also needed to add deviceFromAPI and devicesFromAPI helpers to return devices.Device types from apiv1.Device types. There's now a new validateDeviceUpdate helper that checks to ensure that a device update request is valid and the user has the appropriate permissions. The createRequest type now accepts a slice of Devices, not a slice of DeviceChanges, because we want to pass the Owner in. A new updateRequest type is created, which accepts a DeviceChange to apply. A new handleUpdateDevice handler is created, which is assigned to the endpoint for PATCH requests against a device ID. It checks that the user is logged in, the Device they're trying to update exists, and that it's a valid update. If all of that is true, the device is updated and the updated device is returned. Finally, we had to add two new scopes to support new functionality: ScopeUpdateOtherUserDevices allows a user to update other user's devices, and ScopeUpdateLastSeen allows a user to update the LastSeen property of a device. Pending some better error messages, this should be a full implementation of updating a device, which leaves only the deletion endpoint to deal with.

History
paddy@0 1 // Copyright 2014 Google Inc. All rights reserved.
paddy@0 2 // Use of this source code is governed by a BSD-style
paddy@0 3 // license that can be found in the LICENSE file.
paddy@0 4
paddy@0 5 package uuid
paddy@0 6
paddy@0 7 import (
paddy@0 8 "encoding/binary"
paddy@0 9 "sync"
paddy@0 10 "time"
paddy@0 11 )
paddy@0 12
paddy@0 13 // A Time represents a time as the number of 100's of nanoseconds since 15 Oct
paddy@0 14 // 1582.
paddy@0 15 type Time int64
paddy@0 16
paddy@0 17 const (
paddy@0 18 lillian = 2299160 // Julian day of 15 Oct 1582
paddy@0 19 unix = 2440587 // Julian day of 1 Jan 1970
paddy@0 20 epoch = unix - lillian // Days between epochs
paddy@0 21 g1582 = epoch * 86400 // seconds between epochs
paddy@0 22 g1582ns100 = g1582 * 10000000 // 100s of a nanoseconds between epochs
paddy@0 23 )
paddy@0 24
paddy@0 25 var (
paddy@0 26 mu sync.Mutex
paddy@0 27 lasttime uint64 // last time we returned
paddy@0 28 clock_seq uint16 // clock sequence for this run
paddy@0 29
paddy@0 30 timeNow = time.Now // for testing
paddy@0 31 )
paddy@0 32
paddy@0 33 // UnixTime converts t the number of seconds and nanoseconds using the Unix
paddy@0 34 // epoch of 1 Jan 1970.
paddy@0 35 func (t Time) UnixTime() (sec, nsec int64) {
paddy@0 36 sec = int64(t - g1582ns100)
paddy@0 37 nsec = (sec % 10000000) * 100
paddy@0 38 sec /= 10000000
paddy@0 39 return sec, nsec
paddy@0 40 }
paddy@0 41
paddy@0 42 // GetTime returns the current Time (100s of nanoseconds since 15 Oct 1582) and
paddy@0 43 // clock sequence as well as adjusting the clock sequence as needed. An error
paddy@0 44 // is returned if the current time cannot be determined.
paddy@0 45 func GetTime() (Time, uint16, error) {
paddy@0 46 defer mu.Unlock()
paddy@0 47 mu.Lock()
paddy@0 48 return getTime()
paddy@0 49 }
paddy@0 50
paddy@0 51 func getTime() (Time, uint16, error) {
paddy@0 52 t := timeNow()
paddy@0 53
paddy@0 54 // If we don't have a clock sequence already, set one.
paddy@0 55 if clock_seq == 0 {
paddy@0 56 setClockSequence(-1)
paddy@0 57 }
paddy@0 58 now := uint64(t.UnixNano()/100) + g1582ns100
paddy@0 59
paddy@0 60 // If time has gone backwards with this clock sequence then we
paddy@0 61 // increment the clock sequence
paddy@0 62 if now <= lasttime {
paddy@0 63 clock_seq = ((clock_seq + 1) & 0x3fff) | 0x8000
paddy@0 64 }
paddy@0 65 lasttime = now
paddy@0 66 return Time(now), clock_seq, nil
paddy@0 67 }
paddy@0 68
paddy@0 69 // ClockSequence returns the current clock sequence, generating one if not
paddy@0 70 // already set. The clock sequence is only used for Version 1 UUIDs.
paddy@0 71 //
paddy@0 72 // The uuid package does not use global static storage for the clock sequence or
paddy@0 73 // the last time a UUID was generated. Unless SetClockSequence a new random
paddy@0 74 // clock sequence is generated the first time a clock sequence is requested by
paddy@0 75 // ClockSequence, GetTime, or NewUUID. (section 4.2.1.1) sequence is generated
paddy@0 76 // for
paddy@0 77 func ClockSequence() int {
paddy@0 78 defer mu.Unlock()
paddy@0 79 mu.Lock()
paddy@0 80 return clockSequence()
paddy@0 81 }
paddy@0 82
paddy@0 83 func clockSequence() int {
paddy@0 84 if clock_seq == 0 {
paddy@0 85 setClockSequence(-1)
paddy@0 86 }
paddy@0 87 return int(clock_seq & 0x3fff)
paddy@0 88 }
paddy@0 89
paddy@0 90 // SetClockSeq sets the clock sequence to the lower 14 bits of seq. Setting to
paddy@0 91 // -1 causes a new sequence to be generated.
paddy@0 92 func SetClockSequence(seq int) {
paddy@0 93 defer mu.Unlock()
paddy@0 94 mu.Lock()
paddy@0 95 setClockSequence(seq)
paddy@0 96 }
paddy@0 97
paddy@0 98 func setClockSequence(seq int) {
paddy@0 99 if seq == -1 {
paddy@0 100 var b [2]byte
paddy@0 101 randomBits(b[:]) // clock sequence
paddy@0 102 seq = int(b[0])<<8 | int(b[1])
paddy@0 103 }
paddy@0 104 old_seq := clock_seq
paddy@0 105 clock_seq = uint16(seq&0x3fff) | 0x8000 // Set our variant
paddy@0 106 if old_seq != clock_seq {
paddy@0 107 lasttime = 0
paddy@0 108 }
paddy@0 109 }
paddy@0 110
paddy@0 111 // Time returns the time in 100s of nanoseconds since 15 Oct 1582 encoded in
paddy@0 112 // uuid. It returns false if uuid is not valid. The time is only well defined
paddy@0 113 // for version 1 and 2 UUIDs.
paddy@0 114 func (uuid UUID) Time() (Time, bool) {
paddy@0 115 if len(uuid) != 16 {
paddy@0 116 return 0, false
paddy@0 117 }
paddy@0 118 time := int64(binary.BigEndian.Uint32(uuid[0:4]))
paddy@0 119 time |= int64(binary.BigEndian.Uint16(uuid[4:6])) << 32
paddy@0 120 time |= int64(binary.BigEndian.Uint16(uuid[6:8])&0xfff) << 48
paddy@0 121 return Time(time), true
paddy@0 122 }
paddy@0 123
paddy@0 124 // ClockSequence returns the clock sequence encoded in uuid. It returns false
paddy@0 125 // if uuid is not valid. The clock sequence is only well defined for version 1
paddy@0 126 // and 2 UUIDs.
paddy@0 127 func (uuid UUID) ClockSequence() (int, bool) {
paddy@0 128 if len(uuid) != 16 {
paddy@0 129 return 0, false
paddy@0 130 }
paddy@0 131 return int(binary.BigEndian.Uint16(uuid[8:10])) & 0x3fff, true
paddy@0 132 }