ducky/devices

Paddy 2015-11-15 Parent:b6494e1a499e

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

Ignore coverage output. Add a .hgignore file to ignore the output file that tracks our test coverage.

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 "net"
paddy@0	8
paddy@0	9 var (
paddy@0	10 interfaces []net.Interface // cached list of interfaces
paddy@0	11 ifname string // name of interface being used
paddy@0	12 nodeID []byte // hardware for version 1 UUIDs
paddy@0	13 )
paddy@0	14
paddy@0	15 // NodeInterface returns the name of the interface from which the NodeID was
paddy@0	16 // derived. The interface "user" is returned if the NodeID was set by
paddy@0	17 // SetNodeID.
paddy@0	18 func NodeInterface() string {
paddy@0	19 return ifname
paddy@0	20 }
paddy@0	21
paddy@0	22 // SetNodeInterface selects the hardware address to be used for Version 1 UUIDs.
paddy@0	23 // If name is "" then the first usable interface found will be used or a random
paddy@0	24 // Node ID will be generated. If a named interface cannot be found then false
paddy@0	25 // is returned.
paddy@0	26 //
paddy@0	27 // SetNodeInterface never fails when name is "".
paddy@0	28 func SetNodeInterface(name string) bool {
paddy@0	29 if interfaces == nil {
paddy@0	30 var err error
paddy@0	31 interfaces, err = net.Interfaces()
paddy@0	32 if err != nil && name != "" {
paddy@0	33 return false
paddy@0	34 }
paddy@0	35 }
paddy@0	36
paddy@0	37 for _, ifs := range interfaces {
paddy@0	38 if len(ifs.HardwareAddr) >= 6 && (name == "" \|\| name == ifs.Name) {
paddy@0	39 if setNodeID(ifs.HardwareAddr) {
paddy@0	40 ifname = ifs.Name
paddy@0	41 return true
paddy@0	42 }
paddy@0	43 }
paddy@0	44 }
paddy@0	45
paddy@0	46 // We found no interfaces with a valid hardware address. If name
paddy@0	47 // does not specify a specific interface generate a random Node ID
paddy@0	48 // (section 4.1.6)
paddy@0	49 if name == "" {
paddy@0	50 if nodeID == nil {
paddy@0	51 nodeID = make([]byte, 6)
paddy@0	52 }
paddy@0	53 randomBits(nodeID)
paddy@0	54 return true
paddy@0	55 }
paddy@0	56 return false
paddy@0	57 }
paddy@0	58
paddy@0	59 // NodeID returns a slice of a copy of the current Node ID, setting the Node ID
paddy@0	60 // if not already set.
paddy@0	61 func NodeID() []byte {
paddy@0	62 if nodeID == nil {
paddy@0	63 SetNodeInterface("")
paddy@0	64 }
paddy@0	65 nid := make([]byte, 6)
paddy@0	66 copy(nid, nodeID)
paddy@0	67 return nid
paddy@0	68 }
paddy@0	69
paddy@0	70 // SetNodeID sets the Node ID to be used for Version 1 UUIDs. The first 6 bytes
paddy@0	71 // of id are used. If id is less than 6 bytes then false is returned and the
paddy@0	72 // Node ID is not set.
paddy@0	73 func SetNodeID(id []byte) bool {
paddy@0	74 if setNodeID(id) {
paddy@0	75 ifname = "user"
paddy@0	76 return true
paddy@0	77 }
paddy@0	78 return false
paddy@0	79 }
paddy@0	80
paddy@0	81 func setNodeID(id []byte) bool {
paddy@0	82 if len(id) < 6 {
paddy@0	83 return false
paddy@0	84 }
paddy@0	85 if nodeID == nil {
paddy@0	86 nodeID = make([]byte, 6)
paddy@0	87 }
paddy@0	88 copy(nodeID, id)
paddy@0	89 return true
paddy@0	90 }
paddy@0	91
paddy@0	92 // NodeID returns the 6 byte node id encoded in uuid. It returns nil if uuid is
paddy@0	93 // not valid. The NodeID is only well defined for version 1 and 2 UUIDs.
paddy@0	94 func (uuid UUID) NodeID() []byte {
paddy@0	95 if len(uuid) != 16 {
paddy@0	96 return nil
paddy@0	97 }
paddy@0	98 node := make([]byte, 6)
paddy@0	99 copy(node, uuid[10:])
paddy@0	100 return node
paddy@0	101 }