ducky/devices

Paddy 2015-11-12 Parent:b6494e1a499e

4:7bc6a84ac906 Go to Latest

ducky/devices/vendor/code.google.com/p/go-uuid/uuid/uuid.go

Minimal Memstore implementation. Create an in-memory version of the Storer that meets the minimal requirements set by our Storer tests so far.

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paddy@0 1 // Copyright 2011 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 "bytes"
paddy@0 9 "crypto/rand"
paddy@0 10 "fmt"
paddy@0 11 "io"
paddy@0 12 "strings"
paddy@0 13 )
paddy@0 14
paddy@0 15 // A UUID is a 128 bit (16 byte) Universal Unique IDentifier as defined in RFC
paddy@0 16 // 4122.
paddy@0 17 type UUID []byte
paddy@0 18
paddy@0 19 // A Version represents a UUIDs version.
paddy@0 20 type Version byte
paddy@0 21
paddy@0 22 // A Variant represents a UUIDs variant.
paddy@0 23 type Variant byte
paddy@0 24
paddy@0 25 // Constants returned by Variant.
paddy@0 26 const (
paddy@0 27 Invalid = Variant(iota) // Invalid UUID
paddy@0 28 RFC4122 // The variant specified in RFC4122
paddy@0 29 Reserved // Reserved, NCS backward compatibility.
paddy@0 30 Microsoft // Reserved, Microsoft Corporation backward compatibility.
paddy@0 31 Future // Reserved for future definition.
paddy@0 32 )
paddy@0 33
paddy@0 34 var rander = rand.Reader // random function
paddy@0 35
paddy@0 36 // New returns a new random (version 4) UUID as a string. It is a convenience
paddy@0 37 // function for NewRandom().String().
paddy@0 38 func New() string {
paddy@0 39 return NewRandom().String()
paddy@0 40 }
paddy@0 41
paddy@0 42 // Parse decodes s into a UUID or returns nil. Both the UUID form of
paddy@0 43 // xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx and
paddy@0 44 // urn:uuid:xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx are decoded.
paddy@0 45 func Parse(s string) UUID {
paddy@0 46 if len(s) == 36+9 {
paddy@0 47 if strings.ToLower(s[:9]) != "urn:uuid:" {
paddy@0 48 return nil
paddy@0 49 }
paddy@0 50 s = s[9:]
paddy@0 51 } else if len(s) != 36 {
paddy@0 52 return nil
paddy@0 53 }
paddy@0 54 if s[8] != '-' || s[13] != '-' || s[18] != '-' || s[23] != '-' {
paddy@0 55 return nil
paddy@0 56 }
paddy@0 57 uuid := make([]byte, 16)
paddy@0 58 for i, x := range []int{
paddy@0 59 0, 2, 4, 6,
paddy@0 60 9, 11,
paddy@0 61 14, 16,
paddy@0 62 19, 21,
paddy@0 63 24, 26, 28, 30, 32, 34} {
paddy@0 64 if v, ok := xtob(s[x:]); !ok {
paddy@0 65 return nil
paddy@0 66 } else {
paddy@0 67 uuid[i] = v
paddy@0 68 }
paddy@0 69 }
paddy@0 70 return uuid
paddy@0 71 }
paddy@0 72
paddy@0 73 // Equal returns true if uuid1 and uuid2 are equal.
paddy@0 74 func Equal(uuid1, uuid2 UUID) bool {
paddy@0 75 return bytes.Equal(uuid1, uuid2)
paddy@0 76 }
paddy@0 77
paddy@0 78 // String returns the string form of uuid, xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx
paddy@0 79 // , or "" if uuid is invalid.
paddy@0 80 func (uuid UUID) String() string {
paddy@0 81 if uuid == nil || len(uuid) != 16 {
paddy@0 82 return ""
paddy@0 83 }
paddy@0 84 b := []byte(uuid)
paddy@0 85 return fmt.Sprintf("%08x-%04x-%04x-%04x-%012x",
paddy@0 86 b[:4], b[4:6], b[6:8], b[8:10], b[10:])
paddy@0 87 }
paddy@0 88
paddy@0 89 // URN returns the RFC 2141 URN form of uuid,
paddy@0 90 // urn:uuid:xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx, or "" if uuid is invalid.
paddy@0 91 func (uuid UUID) URN() string {
paddy@0 92 if uuid == nil || len(uuid) != 16 {
paddy@0 93 return ""
paddy@0 94 }
paddy@0 95 b := []byte(uuid)
paddy@0 96 return fmt.Sprintf("urn:uuid:%08x-%04x-%04x-%04x-%012x",
paddy@0 97 b[:4], b[4:6], b[6:8], b[8:10], b[10:])
paddy@0 98 }
paddy@0 99
paddy@0 100 // Variant returns the variant encoded in uuid. It returns Invalid if
paddy@0 101 // uuid is invalid.
paddy@0 102 func (uuid UUID) Variant() Variant {
paddy@0 103 if len(uuid) != 16 {
paddy@0 104 return Invalid
paddy@0 105 }
paddy@0 106 switch {
paddy@0 107 case (uuid[8] & 0xc0) == 0x80:
paddy@0 108 return RFC4122
paddy@0 109 case (uuid[8] & 0xe0) == 0xc0:
paddy@0 110 return Microsoft
paddy@0 111 case (uuid[8] & 0xe0) == 0xe0:
paddy@0 112 return Future
paddy@0 113 default:
paddy@0 114 return Reserved
paddy@0 115 }
paddy@0 116 panic("unreachable")
paddy@0 117 }
paddy@0 118
paddy@0 119 // Version returns the verison of uuid. It returns false if uuid is not
paddy@0 120 // valid.
paddy@0 121 func (uuid UUID) Version() (Version, bool) {
paddy@0 122 if len(uuid) != 16 {
paddy@0 123 return 0, false
paddy@0 124 }
paddy@0 125 return Version(uuid[6] >> 4), true
paddy@0 126 }
paddy@0 127
paddy@0 128 func (v Version) String() string {
paddy@0 129 if v > 15 {
paddy@0 130 return fmt.Sprintf("BAD_VERSION_%d", v)
paddy@0 131 }
paddy@0 132 return fmt.Sprintf("VERSION_%d", v)
paddy@0 133 }
paddy@0 134
paddy@0 135 func (v Variant) String() string {
paddy@0 136 switch v {
paddy@0 137 case RFC4122:
paddy@0 138 return "RFC4122"
paddy@0 139 case Reserved:
paddy@0 140 return "Reserved"
paddy@0 141 case Microsoft:
paddy@0 142 return "Microsoft"
paddy@0 143 case Future:
paddy@0 144 return "Future"
paddy@0 145 case Invalid:
paddy@0 146 return "Invalid"
paddy@0 147 }
paddy@0 148 return fmt.Sprintf("BadVariant%d", int(v))
paddy@0 149 }
paddy@0 150
paddy@0 151 // SetRand sets the random number generator to r, which implents io.Reader.
paddy@0 152 // If r.Read returns an error when the package requests random data then
paddy@0 153 // a panic will be issued.
paddy@0 154 //
paddy@0 155 // Calling SetRand with nil sets the random number generator to the default
paddy@0 156 // generator.
paddy@0 157 func SetRand(r io.Reader) {
paddy@0 158 if r == nil {
paddy@0 159 rander = rand.Reader
paddy@0 160 return
paddy@0 161 }
paddy@0 162 rander = r
paddy@0 163 }