ducky/devices
2015-11-14
Parent:b6494e1a499e
ducky/devices/vendor/code.google.com/p/go-uuid/uuid/node.go
Add more interface tests. Add a test to ensure that, when retrieving Devices, no error is returned if a Device cannot be found. Add a test to ensure that, when adding Devices, adding a Device that shares an ID with a Device already in the Storer returns an ErrDeviceAlreadyExists error. This involved creating the ErrDeviceAlreadyExists error, and modifying the in-memory implementation to properly return it. Fix a go vet issue in our previous test, wherein we forgot to pass the storer to a log message, resulting in a mismatch between the number of variables expected and the number of variables provided. Rename our tests to be better reflective of what they actually test.
1 // Copyright 2011 Google Inc. All rights reserved.
2 // Use of this source code is governed by a BSD-style
3 // license that can be found in the LICENSE file.
5 package uuid
7 import "net"
9 var (
10 interfaces []net.Interface // cached list of interfaces
11 ifname string // name of interface being used
12 nodeID []byte // hardware for version 1 UUIDs
13 )
15 // NodeInterface returns the name of the interface from which the NodeID was
16 // derived. The interface "user" is returned if the NodeID was set by
17 // SetNodeID.
18 func NodeInterface() string {
19 return ifname
20 }
22 // SetNodeInterface selects the hardware address to be used for Version 1 UUIDs.
23 // If name is "" then the first usable interface found will be used or a random
24 // Node ID will be generated. If a named interface cannot be found then false
25 // is returned.
26 //
27 // SetNodeInterface never fails when name is "".
28 func SetNodeInterface(name string) bool {
29 if interfaces == nil {
30 var err error
31 interfaces, err = net.Interfaces()
32 if err != nil && name != "" {
33 return false
34 }
35 }
37 for _, ifs := range interfaces {
38 if len(ifs.HardwareAddr) >= 6 && (name == "" || name == ifs.Name) {
39 if setNodeID(ifs.HardwareAddr) {
40 ifname = ifs.Name
41 return true
42 }
43 }
44 }
46 // We found no interfaces with a valid hardware address. If name
47 // does not specify a specific interface generate a random Node ID
48 // (section 4.1.6)
49 if name == "" {
50 if nodeID == nil {
51 nodeID = make([]byte, 6)
52 }
53 randomBits(nodeID)
54 return true
55 }
56 return false
57 }
59 // NodeID returns a slice of a copy of the current Node ID, setting the Node ID
60 // if not already set.
61 func NodeID() []byte {
62 if nodeID == nil {
63 SetNodeInterface("")
64 }
65 nid := make([]byte, 6)
66 copy(nid, nodeID)
67 return nid
68 }
70 // SetNodeID sets the Node ID to be used for Version 1 UUIDs. The first 6 bytes
71 // of id are used. If id is less than 6 bytes then false is returned and the
72 // Node ID is not set.
73 func SetNodeID(id []byte) bool {
74 if setNodeID(id) {
75 ifname = "user"
76 return true
77 }
78 return false
79 }
81 func setNodeID(id []byte) bool {
82 if len(id) < 6 {
83 return false
84 }
85 if nodeID == nil {
86 nodeID = make([]byte, 6)
87 }
88 copy(nodeID, id)
89 return true
90 }
92 // NodeID returns the 6 byte node id encoded in uuid. It returns nil if uuid is
93 // not valid. The NodeID is only well defined for version 1 and 2 UUIDs.
94 func (uuid UUID) NodeID() []byte {
95 if len(uuid) != 16 {
96 return nil
97 }
98 node := make([]byte, 6)
99 copy(node, uuid[10:])
100 return node
101 }