path.cpp

   1 //uchime by Robert C. Edgar http://drive5.com/uchime This code is donated to the public domain.\r
   2 \r
   3 #include "myutils.h"\r
   4 #include "path.h"\r
   5 #include "timing.h"\r
   6 \r
   7 #define TRACE   0\r
   8 \r
   9 const unsigned PathMagic = 0x9A783A16;\r
  10 \r
  11 struct PathBuffer\r
  12         {\r
  13         unsigned Magic;\r
  14         char *Buffer;\r
  15         unsigned Size;\r
  16         bool InUse;\r
  17         };\r
  18 \r
  19 static PathBuffer **g_PathBuffers;\r
  20 static unsigned g_PathBufferSize;\r
  21 \r
  22 static char *AllocBuffer(unsigned Size)\r
  23         {\r
  24         if (Size == 0)\r
  25                 return 0;\r
  26 \r
  27 // Is a free buffer that is big enough?\r
  28         for (unsigned i = 0; i < g_PathBufferSize; ++i)\r
  29                 {\r
  30                 PathBuffer *PB = g_PathBuffers[i];\r
  31                 asserta(PB->Magic == PathMagic);\r
  32                 if (!PB->InUse)\r
  33                         {\r
  34                         if (PB->Size >= Size)\r
  35                                 {\r
  36                                 PB->InUse = true;\r
  37                                 return PB->Buffer;\r
  38                                 }\r
  39                         if (PB->Buffer == 0)\r
  40                                 {\r
  41                                 unsigned Size2 = Size + 1024;\r
  42                                 PB->Buffer = MYALLOC(char, Size2, Path);\r
  43                                 PB->Size = Size2;\r
  44                                 PB->InUse = true;\r
  45                                 return PB->Buffer;\r
  46                                 }\r
  47                         }\r
  48                 }\r
  49 \r
  50 // No available buffer, must expand g_PathBuffers[]\r
  51         unsigned NewPathBufferSize = g_PathBufferSize + 1024;\r
  52         PathBuffer **NewPathBuffers = MYALLOC(PathBuffer *, NewPathBufferSize, Path);\r
  53         \r
  54         for (unsigned i = 0; i < g_PathBufferSize; ++i)\r
  55                 NewPathBuffers[i] = g_PathBuffers[i];\r
  56 \r
  57         for (unsigned i = g_PathBufferSize; i < NewPathBufferSize; ++i)\r
  58                 {\r
  59                 PathBuffer *PB = MYALLOC(PathBuffer, 1, Path);\r
  60                 PB->Magic = PathMagic;\r
  61                 PB->Buffer = 0;\r
  62                 PB->Size = 0;\r
  63                 PB->InUse = false;\r
  64                 NewPathBuffers[i] = PB;\r
  65                 }\r
  66 \r
  67         PathBuffer *PB = NewPathBuffers[g_PathBufferSize];\r
  68 \r
  69         MYFREE(g_PathBuffers, g_PathBufferSize, Path);\r
  70         g_PathBuffers = NewPathBuffers;\r
  71         g_PathBufferSize = NewPathBufferSize;\r
  72 \r
  73         asserta(!PB->InUse && PB->Buffer == 0);\r
  74 \r
  75         unsigned Size2 = Size + 1024;\r
  76         PB->Buffer = MYALLOC(char, Size2, Path);\r
  77         PB->Size = Size2;\r
  78         PB->InUse = true;\r
  79         return PB->Buffer;\r
  80         }\r
  81 \r
  82 static void FreeBuffer(char *Buffer)\r
  83         {\r
  84         if (Buffer == 0)\r
  85                 return;\r
  86 \r
  87         for (unsigned i = 0; i < g_PathBufferSize; ++i)\r
  88                 {\r
  89                 PathBuffer *PB = g_PathBuffers[i];\r
  90                 if (PB->Buffer == Buffer)\r
  91                         {\r
  92                         asserta(PB->InUse);\r
  93                         PB->InUse = false;\r
  94                         return;\r
  95                         }\r
  96                 }\r
  97 \r
  98         Die("FreeBuffer, not found");\r
  99         }\r
 100 \r
 101 void PathData::Alloc(unsigned MaxLen)\r
 102         {\r
 103         if (MaxLen < Bytes)\r
 104                 return;\r
 105 \r
 106         StartTimer(PathAlloc);\r
 107         if (Bytes > 0)\r
 108                 {\r
 109                 FreeBuffer(Front);\r
 110                 }\r
 111 \r
 112         Bytes = MaxLen + 1;\r
 113         Front = AllocBuffer(Bytes);\r
 114         Back = Front + Bytes - 1;\r
 115         Start = 0;\r
 116         EndTimer(PathAlloc);\r
 117         }\r
 118 \r
 119 void PathData::Free()\r
 120         {\r
 121         FreeBuffer(Front);\r
 122         Front = 0;\r
 123         Start = 0;\r
 124         Back = 0;\r
 125         }\r
 126 \r
 127 void PathData::Copy(const PathData &rhs)\r
 128         {\r
 129         Alloc(rhs.Bytes);\r
 130         strcpy(Front, rhs.Front);\r
 131         Start = Front + (rhs.Start - rhs.Front);\r
 132         }\r
 133 \r
 134 void PathData::FromStr(const char *PathStr)\r
 135         {\r
 136         asserta(PathStr != 0);\r
 137         unsigned NeededBytes = (unsigned) strlen(PathStr) + 1;\r
 138         Alloc(NeededBytes);\r
 139         strcpy(Front, PathStr);\r
 140         Start = Front;\r
 141         }\r
 142 \r
 143 void LogPathStats()\r
 144         {\r
 145         Log("\n");\r
 146         unsigned Bytes = 0;\r
 147         for (unsigned i = 0; i < g_PathBufferSize; ++i)\r
 148                 {\r
 149                 const PathBuffer *PB = g_PathBuffers[i];\r
 150                 Bytes += PB->Size;\r
 151                 }\r
 152         Log("%u paths allocated, total memory %u bytes\n", g_PathBufferSize, Bytes);\r
 153         }\r