xpcom/glue/nsID.h

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  37
  38 #ifndef nsID_h__
  39 #define nsID_h__
  40
  41 #include <string.h>
  42
  43 #ifndef nscore_h___
  44 #include "nscore.h"
  45 #endif
  46
  47 #define NSID_LENGTH 39
  48
  49 /**
  50  * A "unique identifier". This is modeled after OSF DCE UUIDs.
  51  * @status FROZEN
  52  */
  53
  54 struct nsID {
  55   /**
  56    * @name Identifier values
  57    */
  58
  59   //@{
  60   PRUint32 m0;
  61   PRUint16 m1;
  62   PRUint16 m2;
  63   PRUint8 m3[8];
  64   //@}
  65
  66   /**
  67    * @name Methods
  68    */
  69
  70   //@{
  71   /**
  72    * Equivalency method. Compares this nsID with another.
  73    * @return <b>PR_TRUE</b> if they are the same, <b>PR_FALSE</b> if not.
  74    */
  75
  76   inline PRBool Equals(const nsID& other) const {
  77     // One would think that this could be done faster with a really
  78     // efficient implementation of memcmp(), but evidently no
  79     // memcmp()'s out there are better than this code.
  80     //
  81     // See bug http://bugzilla.mozilla.org/show_bug.cgi?id=164580 for
  82     // details.
  83
  84     return
  85       ((((PRUint32*) &m0)[0] == ((PRUint32*) &other.m0)[0]) &&
  86        (((PRUint32*) &m0)[1] == ((PRUint32*) &other.m0)[1]) &&
  87        (((PRUint32*) &m0)[2] == ((PRUint32*) &other.m0)[2]) &&
  88        (((PRUint32*) &m0)[3] == ((PRUint32*) &other.m0)[3]));
  89   }
  90
  91   /**
  92    * nsID Parsing method. Turns a {xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx}
  93    * string into an nsID
  94    */
  95   NS_COM_GLUE PRBool Parse(const char *aIDStr);
  96
  97 #ifndef XPCOM_GLUE_AVOID_NSPR
  98   /**
  99    * nsID string encoder. Returns an allocated string in
 100    * {xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx} format. Caller should free string.
 101    * YOU SHOULD ONLY USE THIS IF YOU CANNOT USE ToProvidedString() BELOW.
 102    */
 103   NS_COM_GLUE char* ToString() const;
 104
 105   /**
 106    * nsID string encoder. Builds a string in
 107    * {xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx} format, into a char[NSID_LENGTH]
 108    * buffer provided by the caller (for instance, on the stack).
 109    */
 110   NS_COM_GLUE void ToProvidedString(char (&dest)[NSID_LENGTH]) const;
 111
 112 #endif // XPCOM_GLUE_AVOID_NSPR
 113
 114   //@}
 115 };
 116
 117 /*
 118  * Class IDs
 119  */
 120
 121 typedef nsID nsCID;
 122
 123 // Define an CID
 124 #define NS_DEFINE_CID(_name, _cidspec) \
 125   const nsCID _name = _cidspec
 126
 127 #define REFNSCID const nsCID&
 128
 129 /**
 130  * An "interface id" which can be used to uniquely identify a given
 131  * interface.
 132  */
 133
 134 typedef nsID nsIID;
 135
 136 /**
 137  * A macro shorthand for <tt>const nsIID&<tt>
 138  */
 139
 140 #define REFNSIID const nsIID&
 141
 142 /**
 143  * Define an IID
 144  * obsolete - do not use this macro
 145  */
 146
 147 #define NS_DEFINE_IID(_name, _iidspec) \
 148   const nsIID _name = _iidspec
 149
 150 /**
 151  * A macro to build the static const IID accessor method. The Dummy
 152  * template parameter only exists so that the kIID symbol will be linked
 153  * properly (weak symbol on linux, gnu_linkonce on mac, multiple-definitions
 154  * merged on windows). Dummy should always be instantiated as "int".
 155  */
 156
 157 #define NS_DECLARE_STATIC_IID_ACCESSOR(the_iid)                         \
 158   template <class Dummy>                                                \
 159   struct COMTypeInfo                                                    \
 160   {                                                                     \
 161     static const nsIID kIID NS_HIDDEN;                                  \
 162   };                                                                    \
 163   static const nsIID& GetIID() {return COMTypeInfo<int>::kIID;}
 164
 165 #define NS_DEFINE_STATIC_IID_ACCESSOR(the_interface, the_iid)           \
 166   template <class Dummy>                                                \
 167   const nsIID the_interface::COMTypeInfo<Dummy>::kIID NS_HIDDEN = the_iid;
 168
 169 /**
 170  * A macro to build the static const CID accessor method
 171  */
 172
 173 #define NS_DEFINE_STATIC_CID_ACCESSOR(the_cid) \
 174   static const nsID& GetCID() {static const nsID cid = the_cid; return cid;}
 175
 176 #define NS_GET_IID(T) (::T::COMTypeInfo<int>::kIID)
 177 #define NS_GET_TEMPLATE_IID(T) (T::template COMTypeInfo<int>::kIID)
 178
 179 #endif