os_win32/wmiquery.h

   1 /*
   2  * os_win32/wmiquery.h
   3  *
   4  * Home page of code is: http://www.smartmontools.org
   5  *
   6  * Copyright (C) 2011-18 Christian Franke
   7  *
   8  * SPDX-License-Identifier: GPL-2.0-or-later
   9  */
  10
  11 #ifndef WMIQUERY_H
  12 #define WMIQUERY_H
  13
  14 #define WMIQUERY_H_CVSID "$Id: wmiquery.h 4760 2018-08-19 18:45:53Z chrfranke $"
  15
  16 #include <wbemcli.h>
  17
  18 #include <string>
  19
  20 #ifndef __GNUC__
  21 #define __attribute_format_printf(x, y)  /**/
  22 #elif defined(__MINGW32__) && __USE_MINGW_ANSI_STDIO
  23 // Check format of __mingw_*printf() instead of MSVCRT.DLL:*printf()
  24 #define __attribute_format_printf(x, y)  __attribute__((format (gnu_printf, x, y)))
  25 #else
  26 #define __attribute_format_printf(x, y)  __attribute__((format (printf, x, y)))
  27 #endif
  28
  29 /////////////////////////////////////////////////////////////////////////////
  30 // com_bstr
  31
  32 /// Wrapper class for COM BSTR
  33 class com_bstr
  34 {
  35 public:
  36   /// Construct from string.
  37   explicit com_bstr(const char * str);
  38
  39   /// Destructor frees BSTR.
  40   ~com_bstr()
  41     { SysFreeString(m_bstr); }
  42
  43   /// Implicit conversion to BSTR.
  44   operator BSTR()
  45     { return m_bstr; }
  46
  47   /// Convert BSTR back to std::string.
  48   static bool to_str(const BSTR & bstr, std::string & str);
  49
  50 private:
  51   BSTR m_bstr;
  52
  53   com_bstr(const com_bstr &);
  54   void operator=(const com_bstr &);
  55 };
  56
  57
  58 /////////////////////////////////////////////////////////////////////////////
  59 // com_intf_ptr
  60
  61 /// Wrapper class for COM Interface pointer
  62 template <class T>
  63 class com_intf_ptr
  64 {
  65 public:
  66   /// Construct empty object
  67   com_intf_ptr()
  68     : m_ptr(0) { }
  69
  70   /// Destructor releases the interface.
  71   ~com_intf_ptr()
  72     { reset(); }
  73
  74   /// Release interface and clear the pointer.
  75   void reset()
  76     {
  77       if (m_ptr) {
  78         m_ptr->Release(); m_ptr = 0;
  79       }
  80     }
  81
  82   /// Return the pointer.
  83   T * get()
  84     { return m_ptr; }
  85
  86   /// Pointer dereferencing.
  87   T * operator->()
  88     { return m_ptr; }
  89
  90   /// Return address of pointer for replacement.
  91   T * * replace()
  92     { reset(); return &m_ptr; }
  93
  94   /// For (ptr != 0) check.
  95   operator bool() const
  96     { return !!m_ptr; }
  97
  98   /// For (ptr == 0) check.
  99   bool operator!() const
 100     { return !m_ptr; }
 101
 102 private:
 103   T * m_ptr;
 104
 105   com_intf_ptr(const com_intf_ptr &);
 106   void operator=(const com_intf_ptr &);
 107 };
 108
 109
 110 /////////////////////////////////////////////////////////////////////////////
 111 // wbem_object
 112
 113 class wbem_enumerator;
 114
 115 /// Wrapper class for IWbemClassObject
 116 class wbem_object
 117 {
 118 public:
 119   /// Get string representation.
 120   std::string get_str(const char * name) /*const*/;
 121
 122 private:
 123   /// Contents is set by wbem_enumerator.
 124   friend class wbem_enumerator;
 125   com_intf_ptr<IWbemClassObject> m_intf;
 126 };
 127
 128
 129 /////////////////////////////////////////////////////////////////////////////
 130 // wbem_enumerator
 131
 132 class wbem_services;
 133
 134 /// Wrapper class for IEnumWbemClassObject
 135 class wbem_enumerator
 136 {
 137 public:
 138   /// Get next object, return false if none or error.
 139   bool next(wbem_object & obj);
 140
 141 private:
 142   /// Contents is set by wbem_services.
 143   friend class wbem_services;
 144   com_intf_ptr<IEnumWbemClassObject> m_intf;
 145 };
 146
 147
 148 /////////////////////////////////////////////////////////////////////////////
 149 // wbem_services
 150
 151 /// Wrapper class for IWbemServices
 152 class wbem_services
 153 {
 154 public:
 155   /// Connect to service, return false on error.
 156   bool connect();
 157
 158   /// Execute query, get result list.
 159   /// Return false on error.
 160   bool vquery(wbem_enumerator & result, const char * qstr, va_list args) /*const*/
 161        __attribute_format_printf(3, 0);
 162
 163   /// Execute query, get single result object.
 164   /// Return false on error or result size != 1.
 165   bool vquery1(wbem_object & obj, const char * qstr, va_list args) /*const*/
 166        __attribute_format_printf(3, 0);
 167
 168   /// Version of vquery() with printf() formatting.
 169   bool query(wbem_enumerator & result, const char * qstr, ...) /*const*/
 170        __attribute_format_printf(3, 4);
 171
 172   /// Version of vquery1() with printf() formatting.
 173   bool query1(wbem_object & obj, const char * qstr, ...) /*const*/
 174        __attribute_format_printf(3, 4);
 175
 176 private:
 177   com_intf_ptr<IWbemServices> m_intf;
 178 };
 179
 180 #endif // WMIQUERY_H