gemrb/core/System/MemoryStream.cpp

   1 /* GemRB - Infinity Engine Emulator
   2  * Copyright (C) 2003 The GemRB Project
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public License
   6  * as published by the Free Software Foundation; either version 2
   7  * of the License, or (at your option) any later version.
   8
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  17  *
  18  *
  19  */
  20
  21 #include "System/MemoryStream.h"
  22
  23 #include "win32def.h"
  24
  25 #include <cstring>
  26
  27 MemoryStream::MemoryStream(void* buffer, int length, bool autoFree)
  28 {
  29         ptr = buffer;
  30         size = length;
  31         Pos = 0;
  32         strcpy( filename, "" );
  33         this->autoFree = autoFree;
  34 }
  35
  36 MemoryStream::~MemoryStream(void)
  37 {
  38         if (autoFree) {
  39                 free( ptr );
  40         }
  41 }
  42
  43 int MemoryStream::Read(void* dest, unsigned int length)
  44 {
  45         if (length + Pos > size) {
  46                 return GEM_ERROR;
  47         }
  48         ieByte* p = ( ieByte* ) ptr + Pos;
  49         memcpy( dest, p, length );
  50         if (Encrypted) {
  51                 ReadDecrypted( dest, length );
  52         }
  53         Pos += length;
  54         return GEM_OK;
  55 }
  56
  57 int MemoryStream::Seek(int newpos, int type)
  58 {
  59         switch (type) {
  60                 case GEM_CURRENT_POS:
  61                         if (( Pos + newpos ) > size) {
  62                                 printf("[Streams]: Invalid seek\n");
  63                                 return GEM_ERROR;
  64                         }
  65                         Pos += newpos;
  66                         break;
  67
  68                 case GEM_STREAM_START:
  69                         if ((unsigned long) newpos > size) {
  70                                 printf("[Streams]: Invalid seek\n");
  71                                 return GEM_ERROR;
  72                         }
  73                         Pos = newpos;
  74                         break;
  75
  76                 default:
  77                         return GEM_ERROR;
  78         }
  79         return GEM_OK;
  80 }
  81
  82 /** No descriptions */
  83 int MemoryStream::ReadLine(void* buf, unsigned int maxlen)
  84 {
  85         if(!maxlen) {
  86                 return 0;
  87         }
  88         unsigned char * p = ( unsigned char * ) buf;
  89         if (Pos >= size) {
  90                 p[0]=0;
  91                 return -1;
  92         }
  93         unsigned int i = 0;
  94         while (i < ( maxlen - 1 )) {
  95                 ieByte ch = *( ( ieByte* ) ptr + Pos );
  96                 if (Pos == size)
  97                         break;
  98                 if (Encrypted)
  99                         p[i] ^= GEM_ENCRYPTION_KEY[Pos & 63];
 100                 Pos++;
 101                 if (( ( char ) ch ) == '\n')
 102                         break;
 103                 if (( ( char ) ch ) == '\t')
 104                         ch = ' ';
 105                 if (( ( char ) ch ) != '\r')
 106                         p[i++] = ch;
 107         }
 108         p[i] = 0;
 109         return i;
 110 }