toolkit/components/maintenanceservice/servicebase.cpp

   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.h"
   6 #include "nsWindowsHelpers.h"
   7
   8 // Shared code between applications and updater.exe
   9 #include "nsWindowsRestart.cpp"
  10
  11 /**
  12  * Verifies if 2 files are byte for byte equivalent.
  13  *
  14  * @param  file1Path   The first file to verify.
  15  * @param  file2Path   The second file to verify.
  16  * @param  sameContent Out parameter, TRUE if the files are equal
  17  * @return TRUE If there was no error checking the files.
  18  */
  19 BOOL VerifySameFiles(LPCWSTR file1Path, LPCWSTR file2Path, BOOL& sameContent) {
  20   sameContent = FALSE;
  21   nsAutoHandle file1(CreateFileW(file1Path, GENERIC_READ, FILE_SHARE_READ,
  22                                  nullptr, OPEN_EXISTING, 0, nullptr));
  23   if (INVALID_HANDLE_VALUE == file1) {
  24     return FALSE;
  25   }
  26   nsAutoHandle file2(CreateFileW(file2Path, GENERIC_READ, FILE_SHARE_READ,
  27                                  nullptr, OPEN_EXISTING, 0, nullptr));
  28   if (INVALID_HANDLE_VALUE == file2) {
  29     return FALSE;
  30   }
  31
  32   DWORD fileSize1 = GetFileSize(file1, nullptr);
  33   DWORD fileSize2 = GetFileSize(file2, nullptr);
  34   if (INVALID_FILE_SIZE == fileSize1 || INVALID_FILE_SIZE == fileSize2) {
  35     return FALSE;
  36   }
  37
  38   if (fileSize1 != fileSize2) {
  39     // sameContent is already set to FALSE
  40     return TRUE;
  41   }
  42
  43   char buf1[COMPARE_BLOCKSIZE];
  44   char buf2[COMPARE_BLOCKSIZE];
  45   DWORD numBlocks = fileSize1 / COMPARE_BLOCKSIZE;
  46   DWORD leftOver = fileSize1 % COMPARE_BLOCKSIZE;
  47   DWORD readAmount;
  48   for (DWORD i = 0; i < numBlocks; i++) {
  49     if (!ReadFile(file1, buf1, COMPARE_BLOCKSIZE, &readAmount, nullptr) ||
  50         readAmount != COMPARE_BLOCKSIZE) {
  51       return FALSE;
  52     }
  53
  54     if (!ReadFile(file2, buf2, COMPARE_BLOCKSIZE, &readAmount, nullptr) ||
  55         readAmount != COMPARE_BLOCKSIZE) {
  56       return FALSE;
  57     }
  58
  59     if (memcmp(buf1, buf2, COMPARE_BLOCKSIZE)) {
  60       // sameContent is already set to FALSE
  61       return TRUE;
  62     }
  63   }
  64
  65   if (leftOver) {
  66     if (!ReadFile(file1, buf1, leftOver, &readAmount, nullptr) ||
  67         readAmount != leftOver) {
  68       return FALSE;
  69     }
  70
  71     if (!ReadFile(file2, buf2, leftOver, &readAmount, nullptr) ||
  72         readAmount != leftOver) {
  73       return FALSE;
  74     }
  75
  76     if (memcmp(buf1, buf2, leftOver)) {
  77       // sameContent is already set to FALSE
  78       return TRUE;
  79     }
  80   }
  81
  82   sameContent = TRUE;
  83   return TRUE;
  84 }