headers/private/support/StringPrivate.h

   1 /*
   2  * Copyright 2011, Ingo Weinhold, ingo_weinhold@gmx.de.
   3  * Distributed under the terms of the MIT License.
   4  */
   5 #ifndef _SUPPORT_BSTRING_PRIVATE_H_
   6 #define _SUPPORT_BSTRING_PRIVATE_H_
   7
   8
   9 #include <stdlib.h>
  10
  11 #include <String.h>
  12
  13
  14 class BString::Private {
  15 public:
  16         static const uint32 kPrivateDataOffset = 2 * sizeof(int32);
  17
  18 public:
  19         Private(const BString& string)
  20                 :
  21                 fString(string)
  22         {
  23         }
  24
  25         char* Data()
  26         {
  27                 return fString.fPrivateData;
  28         }
  29
  30         bool IsShareable() const
  31         {
  32                 return fString._IsShareable();
  33         }
  34
  35         static int32& DataRefCount(char* data)
  36         {
  37                 return *(((int32 *)data) - 2);
  38         }
  39
  40         int32& DataRefCount()
  41         {
  42                 return DataRefCount(Data());
  43         }
  44
  45         static int32& DataLength(char* data)
  46         {
  47                 return *(((int32*)data) - 1);
  48         }
  49
  50         int32& DataLength()
  51         {
  52                 return DataLength(Data());
  53         }
  54
  55         static void IncrementDataRefCount(char* data)
  56         {
  57                 if (data != NULL)
  58                         atomic_add(&DataRefCount(data), 1);
  59         }
  60
  61         static void DecrementDataRefCount(char* data)
  62         {
  63                 if (data != NULL) {
  64                         if (atomic_add(&DataRefCount(data), -1) == 1)
  65                                 free(data - kPrivateDataOffset);
  66                 }
  67         }
  68
  69         static BString StringFromData(char* data)
  70         {
  71                 return BString(data, BString::PRIVATE_DATA);
  72         }
  73
  74 private:
  75         const BString&  fString;
  76 };
  77
  78
  79 #endif  // _SUPPORT_BSTRING_PRIVATE_H_
  80