reactos/tools/rbuild/filesupportcode.cpp

   1 /*
   2  * Copyright (C) 2005 Casper S. Hornstrup
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (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 along
  15  * with this program; if not, write to the Free Software Foundation, Inc.,
  16  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  17  */
  18 #include "pch.h"
  19 #include <assert.h>
  20
  21 #include "rbuild.h"
  22
  23 using std::string;
  24
  25 /* static */ void
  26 FileSupportCode::WriteIfChanged ( char* outbuf,
  27                                   const string& filename,
  28                                   bool ignoreError )
  29 {
  30         FILE* out;
  31         unsigned int end;
  32         char* cmpbuf;
  33         unsigned int stat;
  34
  35         out = fopen ( filename.c_str (), "rb" );
  36         if ( out == NULL )
  37         {
  38                 out = fopen ( filename.c_str (), "wb" );
  39                 if ( out == NULL )
  40                 {
  41                         if ( ignoreError )
  42                                 return;
  43                         throw AccessDeniedException ( filename );
  44                 }
  45                 fputs ( outbuf, out );
  46                 fclose ( out );
  47                 return;
  48         }
  49
  50         fseek ( out, 0, SEEK_END );
  51         end = ftell ( out );
  52         cmpbuf = (char*) malloc ( end );
  53         if ( cmpbuf == NULL )
  54         {
  55                 fclose ( out );
  56                 throw OutOfMemoryException ();
  57         }
  58
  59         fseek ( out, 0, SEEK_SET );
  60         stat = fread ( cmpbuf, 1, end, out );
  61         if ( stat != end )
  62         {
  63                 free ( cmpbuf );
  64                 fclose ( out );
  65                 throw AccessDeniedException ( filename );
  66         }
  67         if ( end == strlen ( outbuf ) && memcmp ( cmpbuf, outbuf, end ) == 0 )
  68         {
  69                 free ( cmpbuf );
  70                 fclose ( out );
  71                 return;
  72         }
  73
  74         free ( cmpbuf );
  75         fclose ( out );
  76         out = fopen ( filename.c_str (), "wb" );
  77         if ( out == NULL )
  78         {
  79                 throw AccessDeniedException ( filename );
  80         }
  81
  82         stat = fwrite ( outbuf, 1, strlen ( outbuf ), out);
  83         if ( strlen ( outbuf ) != stat )
  84         {
  85                 fclose ( out );
  86                 throw AccessDeniedException ( filename );
  87         }
  88
  89         fclose ( out );
  90 }