xref: /freebsd/lib/libdevdctl/guid.h (revision 86c9d9918f1db7cdd968b60f8902466887bcd9e9)
1 /*-
2  * Copyright (c) 2012, 2013 Spectra Logic Corporation
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions, and the following disclaimer,
10  *    without modification.
11  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
12  *    substantially similar to the "NO WARRANTY" disclaimer below
13  *    ("Disclaimer") and any redistribution must be conditioned upon
14  *    including a substantially similar Disclaimer requirement for further
15  *    binary redistribution.
16  *
17  * NO WARRANTY
18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
21  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
22  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
26  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
27  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
28  * POSSIBILITY OF SUCH DAMAGES.
29  *
30  * Authors: Alan Somers         (Spectra Logic Corporation)
31  *
32  * $FreeBSD$
33  */
34 
35 /**
36  * \file devdctl_guid.h
37  *
38  * Definition of the Guid class.
39  */
40 #ifndef	_DEVDCTL_GUID_H_
41 #define	_DEVDCTL_GUID_H_
42 
43 /*============================ Namespace Control =============================*/
44 namespace DevdCtl
45 {
46 
47 /*============================= Class Definitions ============================*/
48 /*----------------------------------- Guid -----------------------------------*/
49 /**
50  * \brief Object that represents guids.
51  *
52  * It can generally be manipulated as a uint64_t, but with a special
53  * value INVALID_GUID that does not equal any valid guid.
54  *
55  * As of this writing, this class is only used to represent ZFS
56  * guids in events and spa_generate_guid() in spa_misc.c explicitly
57  * refuses to return a guid of 0.  So this class uses 0 as the value
58  * for INVALID_GUID.  In the future, if 0 is allowed to be a valid
59  * guid, the implementation of this class must change.
60  */
61 class Guid
62 {
63 public:
64 	/* Constructors */
65 	Guid();
66 	Guid(uint64_t guid);
67 	Guid(const std::string &guid);
68 
69 	/* Assignment */
70 	Guid& operator=(const Guid& rhs);
71 
72 	/* Test the validity of this guid. */
73 	bool IsValid()			 const;
74 
75 	/* Comparison to other Guid operators */
76 	bool operator==(const Guid& rhs) const;
77 	bool operator!=(const Guid& rhs) const;
78 
79 	/* Integer conversion operators */
80 	operator uint64_t()		 const;
81 	operator bool()			 const;
82 
83 	static const uint64_t INVALID_GUID = 0;
84 protected:
85 	/* The integer value of the GUID. */
86 	uint64_t  m_GUID;
87 };
88 
89 //- Guid Inline Public Methods ------------------------------------------------
90 inline
91 Guid::Guid()
92   : m_GUID(INVALID_GUID)
93 {
94 }
95 
96 inline
97 Guid::Guid(uint64_t guid)
98   : m_GUID(guid)
99 {
100 }
101 
102 inline Guid&
103 Guid::operator=(const Guid &rhs)
104 {
105 	m_GUID = rhs.m_GUID;
106 	return (*this);
107 }
108 
109 inline bool
110 Guid::IsValid() const
111 {
112 	return (m_GUID != INVALID_GUID);
113 }
114 
115 inline bool
116 Guid::operator==(const Guid& rhs) const
117 {
118 	return (m_GUID == rhs.m_GUID);
119 }
120 
121 inline bool
122 Guid::operator!=(const Guid& rhs) const
123 {
124 	return (m_GUID != rhs.m_GUID);
125 }
126 
127 inline
128 Guid::operator uint64_t() const
129 {
130 	return (m_GUID);
131 }
132 
133 inline
134 Guid::operator bool() const
135 {
136 	return (m_GUID != INVALID_GUID);
137 }
138 
139 /** Convert the GUID into its string representation */
140 std::ostream& operator<< (std::ostream& out, Guid g);
141 
142 } // namespace DevdCtl
143 #endif /* _DEVDCTL_GUID_H_ */
144