The Tor Browser: toolkit/components/maintenanceservice/servicebase.cpp@b8a032363ba2

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

     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/. */

     5 #include "servicebase.h"

     6 #include "nsWindowsHelpers.h"

     8 // Shared code between applications and updater.exe

     9 #include "nsWindowsRestart.cpp"

    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

    20 VerifySameFiles(LPCWSTR file1Path, LPCWSTR file2Path, BOOL &sameContent)

    21 {

    22   sameContent = FALSE;

    23   nsAutoHandle file1(CreateFileW(file1Path, GENERIC_READ, FILE_SHARE_READ,

    24                                  nullptr, OPEN_EXISTING, 0, nullptr));

    25   if (INVALID_HANDLE_VALUE == file1) {

    26     return FALSE;

    27   }

    28   nsAutoHandle file2(CreateFileW(file2Path, GENERIC_READ, FILE_SHARE_READ,

    29                                  nullptr, OPEN_EXISTING, 0, nullptr));

    30   if (INVALID_HANDLE_VALUE == file2) {

    31     return FALSE;

    32   }

    34   DWORD fileSize1 = GetFileSize(file1, nullptr);

    35   DWORD fileSize2 = GetFileSize(file2, nullptr);

    36   if (INVALID_FILE_SIZE == fileSize1 || INVALID_FILE_SIZE == fileSize2) {

    37     return FALSE;

    38   }

    40   if (fileSize1 != fileSize2) {

    41     // sameContent is already set to FALSE

    42     return TRUE;

    43   }

    45   char buf1[COMPARE_BLOCKSIZE];

    46   char buf2[COMPARE_BLOCKSIZE];

    47   DWORD numBlocks = fileSize1 / COMPARE_BLOCKSIZE;

    48   DWORD leftOver = fileSize1 % COMPARE_BLOCKSIZE;

    49   DWORD readAmount;

    50   for (DWORD i = 0; i < numBlocks; i++) {

    51     if (!ReadFile(file1, buf1, COMPARE_BLOCKSIZE, &readAmount, nullptr) ||

    52         readAmount != COMPARE_BLOCKSIZE) {

    53       return FALSE;

    54     }

    56     if (!ReadFile(file2, buf2, COMPARE_BLOCKSIZE, &readAmount, nullptr) ||

    57         readAmount != COMPARE_BLOCKSIZE) {

    58       return FALSE;

    59     }

    61     if (memcmp(buf1, buf2, COMPARE_BLOCKSIZE)) {

    62       // sameContent is already set to FALSE

    63       return TRUE;

    64     }

    65   }

    67   if (leftOver) {

    68     if (!ReadFile(file1, buf1, leftOver, &readAmount, nullptr) ||

    69         readAmount != leftOver) {

    70       return FALSE;

    71     }

    73     if (!ReadFile(file2, buf2, leftOver, &readAmount, nullptr) ||

    74         readAmount != leftOver) {

    75       return FALSE;

    76     }

    78     if (memcmp(buf1, buf2, leftOver)) {

    79       // sameContent is already set to FALSE

    80       return TRUE;

    81     }

    82   }

    84   sameContent = TRUE;

    85   return TRUE;

    86 }

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