1 files changed, 86 insertions, 0 deletions
diff --git a/toolkit/components/maintenanceservice/servicebase.cpp b/toolkit/components/maintenanceservice/servicebase.cpp
new file mode 100644
index 000000000..a858c4537
--- /dev/null
+++ b/toolkit/components/maintenanceservice/servicebase.cpp
@@ -0,0 +1,86 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "servicebase.h"
+#include "nsWindowsHelpers.h"
+
+// Shared code between applications and updater.exe
+#include "nsWindowsRestart.cpp"
+
+/**
+ * Verifies if 2 files are byte for byte equivalent.
+ *
+ * @param  file1Path   The first file to verify.
+ * @param  file2Path   The second file to verify.
+ * @param  sameContent Out parameter, TRUE if the files are equal
+ * @return TRUE If there was no error checking the files.
+ */
+BOOL
+VerifySameFiles(LPCWSTR file1Path, LPCWSTR file2Path, BOOL &sameContent)
+{
+  sameContent = FALSE;
+  nsAutoHandle file1(CreateFileW(file1Path, GENERIC_READ, FILE_SHARE_READ, 
+                                 nullptr, OPEN_EXISTING, 0, nullptr));
+  if (INVALID_HANDLE_VALUE == file1) {
+    return FALSE;
+  }
+  nsAutoHandle file2(CreateFileW(file2Path, GENERIC_READ, FILE_SHARE_READ, 
+                                 nullptr, OPEN_EXISTING, 0, nullptr));
+  if (INVALID_HANDLE_VALUE == file2) {
+    return FALSE;
+  }
+
+  DWORD fileSize1 = GetFileSize(file1, nullptr);
+  DWORD fileSize2 = GetFileSize(file2, nullptr);
+  if (INVALID_FILE_SIZE == fileSize1 || INVALID_FILE_SIZE == fileSize2) {
+    return FALSE;
+  }
+
+  if (fileSize1 != fileSize2) {
+    // sameContent is already set to FALSE
+    return TRUE;
+  }
+
+  char buf1[COMPARE_BLOCKSIZE];
+  char buf2[COMPARE_BLOCKSIZE];
+  DWORD numBlocks = fileSize1 / COMPARE_BLOCKSIZE;
+  DWORD leftOver = fileSize1 % COMPARE_BLOCKSIZE;
+  DWORD readAmount;
+  for (DWORD i = 0; i < numBlocks; i++) {
+    if (!ReadFile(file1, buf1, COMPARE_BLOCKSIZE, &readAmount, nullptr) ||
+        readAmount != COMPARE_BLOCKSIZE) {
+      return FALSE;
+    }
+
+    if (!ReadFile(file2, buf2, COMPARE_BLOCKSIZE, &readAmount, nullptr) ||
+        readAmount != COMPARE_BLOCKSIZE) {
+      return FALSE;
+    }
+
+    if (memcmp(buf1, buf2, COMPARE_BLOCKSIZE)) {
+      // sameContent is already set to FALSE
+      return TRUE;
+    }
+  }
+
+  if (leftOver) {
+    if (!ReadFile(file1, buf1, leftOver, &readAmount, nullptr) ||
+        readAmount != leftOver) {
+      return FALSE;
+    }
+
+    if (!ReadFile(file2, buf2, leftOver, &readAmount, nullptr) ||
+        readAmount != leftOver) {
+      return FALSE;
+    }
+
+    if (memcmp(buf1, buf2, leftOver)) {
+      // sameContent is already set to FALSE
+      return TRUE;
+    }
+  }
+
+  sameContent = TRUE;
+  return TRUE;
+}