src/ptclib/memfile.cxx

   1 /*
   2  * memfile.cxx
   3  *
   4  * memory file I/O channel class.
   5  *
   6  * Portable Windows Library
   7  *
   8  * Copyright (c) 2002 Equivalence Pty. Ltd.
   9  *
  10  * The contents of this file are subject to the Mozilla Public License
  11  * Version 1.0 (the "License"); you may not use this file except in
  12  * compliance with the License. You may obtain a copy of the License at
  13  * http://www.mozilla.org/MPL/
  14  *
  15  * Software distributed under the License is distributed on an "AS IS"
  16  * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
  17  * the License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * The Original Code is Portable Windows Library.
  21  *
  22  * The Initial Developer of the Original Code is Equivalence Pty. Ltd.
  23  *
  24  * Contributor(s): ______________________________________.
  25  *
  26  * $Log$
  27  * Revision 1.5  2004/04/03 08:22:21  csoutheren
  28  * Remove pseudo-RTTI and replaced with real RTTI
  29  *
  30  * Revision 1.4  2002/12/19 03:35:43  robertj
  31  * Fixed missing set of lastWriteCount in Write() function.
  32  *
  33  * Revision 1.3  2002/11/06 22:47:25  robertj
  34  * Fixed header comment (copyright etc)
  35  *
  36  * Revision 1.2  2002/06/27 03:53:35  robertj
  37  * Cleaned up documentation and added Compare() function.
  38  *
  39  * Revision 1.1  2002/06/26 09:03:16  craigs
  40  * Initial version
  41  *
  42  */
  43
  44 #include <ptlib.h>
  45
  46 #ifdef __GNUC__
  47 #pragma implementation "memfile.h"
  48 #endif
  49
  50 #include <ptclib/memfile.h>
  51
  52
  53
  54 //////////////////////////////////////////////////////////////////////////////
  55
  56 PMemoryFile::PMemoryFile()
  57 {
  58   position = 0;
  59 }
  60
  61
  62 PMemoryFile::PMemoryFile(const PBYTEArray & ndata)
  63 {
  64   data = ndata;
  65   position = 0;
  66 }
  67
  68
  69 PObject::Comparison PMemoryFile::Compare(const PObject & obj) const
  70 {
  71   PAssert(PIsDescendant(&obj, PMemoryFile), PInvalidCast);
  72   return data.Compare(((const PMemoryFile &)obj).data);
  73 }
  74
  75
  76 BOOL PMemoryFile::Read(void * buf, PINDEX len)
  77 {
  78   if ((position + len) > data.GetSize())
  79     len = data.GetSize() - position;
  80
  81   lastReadCount = len;
  82
  83   if (len != 0) {
  84     ::memcpy(buf, position + (const BYTE * )data, len);
  85     position += len;
  86     lastReadCount = len;
  87   }
  88
  89   return lastReadCount != 0;
  90 }
  91
  92
  93 BOOL PMemoryFile::Write(const void * buf, PINDEX len)
  94 {
  95   memcpy(data.GetPointer(position+len) + position, buf, len);
  96   position += len;
  97   lastWriteCount = len;
  98   return TRUE;
  99 }
 100
 101
 102 off_t PMemoryFile::GetLength() const
 103 {
 104   return data.GetSize();
 105 }
 106
 107
 108 BOOL PMemoryFile::SetLength(off_t len)
 109 {
 110   return data.SetSize(len);
 111 }
 112
 113
 114 BOOL PMemoryFile::SetPosition(off_t pos, FilePositionOrigin origin)
 115 {
 116   switch (origin) {
 117     case Start:
 118       if (pos > data.GetSize())
 119         return FALSE;
 120       position = pos;
 121       break;
 122
 123     case Current:
 124       if (pos < -position || pos > (data.GetSize() - position))
 125         return FALSE;
 126       position += pos;
 127       break;
 128
 129     case End:
 130       if (pos < -data.GetSize())
 131         return FALSE;
 132       position = data.GetSize() - pos;
 133       break;
 134   }
 135   return TRUE;
 136 }
 137
 138
 139 off_t PMemoryFile::GetPosition() const
 140 {
 141   return position;
 142 }
 143
 144
 145 // End of File ///////////////////////////////////////////////////////////////
 146