src/squirrel/sqstdlib/sqstdblobimpl.h

   1 /*      see copyright notice in squirrel.h */\r
   2 #ifndef _SQSTD_BLOBIMPL_H_\r
   3 #define _SQSTD_BLOBIMPL_H_\r
   4 \r
   5 struct SQBlob : public SQStream\r
   6 {\r
   7         SQBlob(SQInteger size) {\r
   8                 _size = size;\r
   9                 _allocated = size;\r
  10                 _buf = (unsigned char *)sq_malloc(size);\r
  11                 memset(_buf, 0, _size);\r
  12                 _ptr = 0;\r
  13                 _owns = true;\r
  14         }\r
  15         virtual ~SQBlob() {\r
  16                 sq_free(_buf, _allocated);\r
  17         }\r
  18         SQInteger Write(void *buffer, SQInteger size) {\r
  19                 if(!CanAdvance(size)) {\r
  20                         GrowBufOf(_ptr + size - _size);\r
  21                 }\r
  22                 memcpy(&_buf[_ptr], buffer, size);\r
  23                 _ptr += size;\r
  24                 return size;\r
  25         }\r
  26         SQInteger Read(void *buffer,SQInteger size) {\r
  27                 SQInteger n = size;\r
  28                 if(!CanAdvance(size)) {\r
  29                         if((_size - _ptr) > 0)\r
  30                                 n = _size - _ptr;\r
  31                         else return 0;\r
  32                 }\r
  33                 memcpy(buffer, &_buf[_ptr], n);\r
  34                 _ptr += n;\r
  35                 return n;\r
  36         }\r
  37         bool Resize(SQInteger n) {\r
  38                 if(!_owns) return false;\r
  39                 if(n != _allocated) {\r
  40                         unsigned char *newbuf = (unsigned char *)sq_malloc(n);\r
  41                         memset(newbuf,0,n);\r
  42                         if(_size > n)\r
  43                                 memcpy(newbuf,_buf,n);\r
  44                         else\r
  45                                 memcpy(newbuf,_buf,_size);\r
  46                         sq_free(_buf,_allocated);\r
  47                         _buf=newbuf;\r
  48                         _allocated = n;\r
  49                         if(_size > _allocated)\r
  50                                 _size = _allocated;\r
  51                         if(_ptr > _allocated)\r
  52                                 _ptr = _allocated;\r
  53                 }\r
  54                 return true;\r
  55         }\r
  56         bool GrowBufOf(SQInteger n)\r
  57         {\r
  58                 bool ret = true;\r
  59                 if(_size + n > _allocated) {\r
  60                         if(_size + n > _size * 2)\r
  61                                 ret = Resize(_size + n);\r
  62                         else\r
  63                                 ret = Resize(_size * 2);\r
  64                 }\r
  65                 _size = _size + n;\r
  66                 return ret;\r
  67         }\r
  68         bool CanAdvance(SQInteger n) {\r
  69                 if(_ptr+n>_size)return false;\r
  70                 return true;\r
  71         }\r
  72         SQInteger Seek(SQInteger offset, SQInteger origin) {\r
  73                 switch(origin) {\r
  74                         case SQ_SEEK_SET:\r
  75                                 if(offset > _size || offset < 0) return -1;\r
  76                                 _ptr = offset;\r
  77                                 break;\r
  78                         case SQ_SEEK_CUR:\r
  79                                 if(_ptr + offset > _size || _ptr + offset < 0) return -1;\r
  80                                 _ptr += offset;\r
  81                                 break;\r
  82                         case SQ_SEEK_END:\r
  83                                 if(_size + offset > _size || _size + offset < 0) return -1;\r
  84                                 _ptr = _size + offset;\r
  85                                 break;\r
  86                         default: return -1;\r
  87                 }\r
  88                 return 0;\r
  89         }\r
  90         bool IsValid() {\r
  91                 return _buf?true:false;\r
  92         }\r
  93         bool EOS() {\r
  94                 return _ptr == _size;\r
  95         }\r
  96         SQInteger Flush() { return 0; }\r
  97         SQInteger Tell() { return _ptr; }\r
  98         SQInteger Len() { return _size; }\r
  99         SQUserPointer GetBuf(){ return _buf; }\r
 100 private:\r
 101         SQInteger _size;\r
 102         SQInteger _allocated;\r
 103         SQInteger _ptr;\r
 104         unsigned char *_buf;\r
 105         bool _owns;\r
 106 };\r
 107 \r
 108 #endif //_SQSTD_BLOBIMPL_H_\r