xref: /freebsd/lib/libdevdctl/guid.h (revision 12a88a3d637e7e7a3726e8dedbcf82cb96cea529)
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(uint64_t guid);
66 	Guid(const std::string &guid);
67 	static Guid InvalidGuid();
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 protected:
84 	static const uint64_t INVALID_GUID = 0;
85 
86 	/* The integer value of the GUID. */
87 	uint64_t  m_GUID;
88 };
89 
90 //- Guid Inline Public Methods ------------------------------------------------
91 inline
92 Guid::Guid(uint64_t guid)
93   : m_GUID(guid)
94 {
95 }
96 
97 inline Guid
98 Guid::InvalidGuid()
99 {
100 	return (Guid(INVALID_GUID));
101 }
102 
103 inline Guid&
104 Guid::operator=(const Guid &rhs)
105 {
106 	m_GUID = rhs.m_GUID;
107 	return (*this);
108 }
109 
110 inline bool
111 Guid::IsValid() const
112 {
113 	return (m_GUID != INVALID_GUID);
114 }
115 
116 inline bool
117 Guid::operator==(const Guid& rhs) const
118 {
119 	return (m_GUID == rhs.m_GUID);
120 }
121 
122 inline bool
123 Guid::operator!=(const Guid& rhs) const
124 {
125 	return (m_GUID != rhs.m_GUID);
126 }
127 
128 inline
129 Guid::operator uint64_t() const
130 {
131 	return (m_GUID);
132 }
133 
134 inline
135 Guid::operator bool() const
136 {
137 	return (m_GUID != INVALID_GUID);
138 }
139 
140 /** Convert the GUID into its string representation */
141 std::ostream& operator<< (std::ostream& out, Guid g);
142 
143 } // namespace DevdCtl
144 #endif /* _DEVDCTL_GUID_H_ */
145