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 1.4  2002/12/19 03:35:43  robertj
  28  * Fixed missing set of lastWriteCount in Write() function.
  29  *
  30  * Revision 1.3  2002/11/06 22:47:25  robertj
  31  * Fixed header comment (copyright etc)
  32  *
  33  * Revision 1.2  2002/06/27 03:53:35  robertj
  34  * Cleaned up documentation and added Compare() function.
  35  *
  36  * Revision 1.1  2002/06/26 09:03:16  craigs
  37  * Initial version
  38  *
  39  */
  40
  41 #include <ptlib.h>
  42
  43 #ifdef __GNUC__
  44 #pragma implementation "memfile.h"
  45 #endif
  46
  47 #include <ptclib/memfile.h>
  48
  49
  50
  51 //////////////////////////////////////////////////////////////////////////////
  52
  53 PMemoryFile::PMemoryFile()
  54 {
  55   position = 0;
  56 }
  57
  58
  59 PMemoryFile::PMemoryFile(const PBYTEArray & ndata)
  60 {
  61   data = ndata;
  62   position = 0;
  63 }
  64
  65
  66 PObject::Comparison PMemoryFile::Compare(const PObject & obj) const
  67 {
  68   PAssert(obj.IsDescendant(Class()), PInvalidCast);
  69   return data.Compare(((const PMemoryFile &)obj).data);
  70 }
  71
  72
  73 BOOL PMemoryFile::Read(void * buf, PINDEX len)
  74 {
  75   if ((position + len) > data.GetSize())
  76     len = data.GetSize() - position;
  77
  78   lastReadCount = len;
  79
  80   if (len != 0) {
  81     ::memcpy(buf, position + (const BYTE * )data, len);
  82     position += len;
  83     lastReadCount = len;
  84   }
  85
  86   return lastReadCount != 0;
  87 }
  88
  89
  90 BOOL PMemoryFile::Write(const void * buf, PINDEX len)
  91 {
  92   memcpy(data.GetPointer(position+len) + position, buf, len);
  93   position += len;
  94   lastWriteCount = len;
  95   return TRUE;
  96 }
  97
  98
  99 off_t PMemoryFile::GetLength() const
 100 {
 101   return data.GetSize();
 102 }
 103
 104
 105 BOOL PMemoryFile::SetLength(off_t len)
 106 {
 107   return data.SetSize(len);
 108 }
 109
 110
 111 BOOL PMemoryFile::SetPosition(off_t pos, FilePositionOrigin origin)
 112 {
 113   switch (origin) {
 114     case Start:
 115       if (pos > data.GetSize())
 116         return FALSE;
 117       position = pos;
 118       break;
 119
 120     case Current:
 121       if (pos < -position || pos > (data.GetSize() - position))
 122         return FALSE;
 123       position += pos;
 124       break;
 125
 126     case End:
 127       if (pos < -data.GetSize())
 128         return FALSE;
 129       position = data.GetSize() - pos;
 130       break;
 131   }
 132   return TRUE;
 133 }
 134
 135
 136 off_t PMemoryFile::GetPosition() const
 137 {
 138   return position;
 139 }
 140
 141
 142 // End of File ///////////////////////////////////////////////////////////////
 143