1 files changed, 97 insertions, 0 deletions
diff --git a/onlineupdate/source/service/servicebase.cxx b/onlineupdate/source/service/servicebase.cxx
new file mode 100644
index 000000000..4fb632878
--- /dev/null
+++ b/onlineupdate/source/service/servicebase.cxx
@@ -0,0 +1,97 @@
+/* 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.hxx"
+#include "windowsHelper.hxx"
+
+// Shared code between applications and updater.exe
+
+/**
+ * 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;
+    AutoHandle file1(CreateFileW(file1Path, GENERIC_READ, FILE_SHARE_READ,
+                                 nullptr, OPEN_EXISTING, 0, nullptr));
+    if (file1 == INVALID_HANDLE_VALUE)
+    {
+        return FALSE;
+    }
+    AutoHandle file2(CreateFileW(file2Path, GENERIC_READ, FILE_SHARE_READ,
+                                 nullptr, OPEN_EXISTING, 0, nullptr));
+    if (file2 == INVALID_HANDLE_VALUE)
+    {
+        return FALSE;
+    }
+
+    DWORD fileSize1 = GetFileSize(file1.get(), nullptr);
+    DWORD fileSize2 = GetFileSize(file2.get(), 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.get(), buf1, COMPARE_BLOCKSIZE, &readAmount, nullptr) ||
+                readAmount != COMPARE_BLOCKSIZE)
+        {
+            return FALSE;
+        }
+
+        if (!ReadFile(file2.get(), 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.get(), buf1, leftOver, &readAmount, nullptr) ||
+                readAmount != leftOver)
+        {
+            return FALSE;
+        }
+
+        if (!ReadFile(file2.get(), 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;
+}