onlineupdate/source/service/servicebase.cxx

   1 /* This Source Code Form is subject to the terms of the Mozilla Public
   2  * License, v. 2.0. If a copy of the MPL was not distributed with this
   3  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   4
   5 #include "servicebase.hxx"
   6 #include "windowsHelper.hxx"
   7
   8 // Shared code between applications and updater.exe
   9
  10 /**
  11  * Verifies if 2 files are byte for byte equivalent.
  12  *
  13  * @param  file1Path   The first file to verify.
  14  * @param  file2Path   The second file to verify.
  15  * @param  sameContent Out parameter, TRUE if the files are equal
  16  * @return TRUE If there was no error checking the files.
  17  */
  18 BOOL
  19 VerifySameFiles(LPCWSTR file1Path, LPCWSTR file2Path, BOOL &sameContent)
  20 {
  21     sameContent = FALSE;
  22     AutoHandle file1(CreateFileW(file1Path, GENERIC_READ, FILE_SHARE_READ,
  23                                  nullptr, OPEN_EXISTING, 0, nullptr));
  24     if (file1 == INVALID_HANDLE_VALUE)
  25     {
  26         return FALSE;
  27     }
  28     AutoHandle file2(CreateFileW(file2Path, GENERIC_READ, FILE_SHARE_READ,
  29                                  nullptr, OPEN_EXISTING, 0, nullptr));
  30     if (file2 == INVALID_HANDLE_VALUE)
  31     {
  32         return FALSE;
  33     }
  34
  35     DWORD fileSize1 = GetFileSize(file1.get(), nullptr);
  36     DWORD fileSize2 = GetFileSize(file2.get(), nullptr);
  37     if (INVALID_FILE_SIZE == fileSize1 || INVALID_FILE_SIZE == fileSize2)
  38     {
  39         return FALSE;
  40     }
  41
  42     if (fileSize1 != fileSize2)
  43     {
  44         // sameContent is already set to FALSE
  45         return TRUE;
  46     }
  47
  48     char buf1[COMPARE_BLOCKSIZE];
  49     char buf2[COMPARE_BLOCKSIZE];
  50     DWORD numBlocks = fileSize1 / COMPARE_BLOCKSIZE;
  51     DWORD leftOver = fileSize1 % COMPARE_BLOCKSIZE;
  52     DWORD readAmount;
  53     for (DWORD i = 0; i < numBlocks; i++)
  54     {
  55         if (!ReadFile(file1.get(), buf1, COMPARE_BLOCKSIZE, &readAmount, nullptr) ||
  56                 readAmount != COMPARE_BLOCKSIZE)
  57         {
  58             return FALSE;
  59         }
  60
  61         if (!ReadFile(file2.get(), buf2, COMPARE_BLOCKSIZE, &readAmount, nullptr) ||
  62                 readAmount != COMPARE_BLOCKSIZE)
  63         {
  64             return FALSE;
  65         }
  66
  67         if (memcmp(buf1, buf2, COMPARE_BLOCKSIZE))
  68         {
  69             // sameContent is already set to FALSE
  70             return TRUE;
  71         }
  72     }
  73
  74     if (leftOver)
  75     {
  76         if (!ReadFile(file1.get(), buf1, leftOver, &readAmount, nullptr) ||
  77                 readAmount != leftOver)
  78         {
  79             return FALSE;
  80         }
  81
  82         if (!ReadFile(file2.get(), buf2, leftOver, &readAmount, nullptr) ||
  83                 readAmount != leftOver)
  84         {
  85             return FALSE;
  86         }
  87
  88         if (memcmp(buf1, buf2, leftOver))
  89         {
  90             // sameContent is already set to FALSE
  91             return TRUE;
  92         }
  93     }
  94
  95     sameContent = TRUE;
  96     return TRUE;
  97 }