OrcLib: Utils: add MapFile

Author: fabienfl-orc

src/OrcLib/CMakeLists.txt

@@ -831,6 +831,8 @@ set(SRC_UTILITIES
     "Utils/Guard/Winsock.cpp"
     "Utils/Locker.h"
     "Utils/MakeArray.h"
+    "Utils/MapFile.h"
+    "Utils/MapFile.cpp"
     "Utils/MetaPtr.h"
     "Utils/Result.h"
     "Utils/Round.h"

src/OrcLib/Utils/MapFile.cpp

@@ -0,0 +1,86 @@
+//
+// SPDX-License-Identifier: LGPL-2.1-or-later
+//
+// Copyright © 2024 ANSSI. All Rights Reserved.
+//
+// Author(s): fabienfl (ANSSI)
+//
+
+#include "Utils/MapFile.h"
+
+#include "Utils/Result.h"
+#include "Utils/Guard.h"
+
+using namespace Orc;
+
+namespace {
+
+Result<uint64_t> GetFileSize(HANDLE hFile)
+{
+    LARGE_INTEGER fileSize;
+    if (!GetFileSizeEx(hFile, &fileSize))
+    {
+        return LastWin32Error();
+    }
+
+    return fileSize.QuadPart;
+}
+
+}  // namespace
+
+namespace Orc {
+
+Result<std::vector<uint8_t>> MapFile(const std::filesystem::path& path)
+{
+    Guard::FileHandle file = CreateFileW(
+        path.c_str(),
+        GENERIC_READ,
+        FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE,
+        NULL,
+        OPEN_EXISTING,
+        FILE_ATTRIBUTE_NORMAL,
+        NULL);
+    if (!file.IsValid())
+    {
+        auto ec = LastWin32Error();
+        Log::Debug("Failed CreateFile [{}]", ec);
+        return ec;
+    }
+
+    auto bytesToRead = GetFileSize(file.value());
+    if (bytesToRead.has_error())
+    {
+        Log::Debug("Failed GetFileSizeEx [{}]", bytesToRead.error());
+        return bytesToRead.error();
+    }
+
+    if (*bytesToRead > UINT32_MAX)
+    {
+        Log::Debug("File is too big");
+        return std::make_error_code(std::errc::no_buffer_space);
+    }
+
+    std::vector<uint8_t> buffer;
+
+    try
+    {
+        buffer.resize(*bytesToRead);
+    }
+    catch (const std::exception& e)
+    {
+        Log::Debug("Failed to resize buffer [{}]", e.what());
+        return std::make_error_code(std::errc::no_buffer_space);
+    }
+
+    DWORD bytesRead = 0;
+    if (!ReadFile(file.value(), buffer.data(), static_cast<DWORD>(buffer.size()), &bytesRead, NULL))
+    {
+        auto ec = LastWin32Error();
+        Log::Debug("Failed ReadFile [{}]", ec);
+        return ec;
+    }
+
+    return buffer;
+}
+
+}  // namespace Orc

src/OrcLib/Utils/MapFile.h

@@ -0,0 +1,20 @@
+//
+// SPDX-License-Identifier: LGPL-2.1-or-later
+//
+// Copyright © 2024 ANSSI. All Rights Reserved.
+//
+// Author(s): fabienfl (ANSSI)
+//
+
+#pragma once
+
+#include <filesystem>
+#include <vector>
+
+#include "Utils/Result.h"
+
+namespace Orc {
+
+Result<std::vector<uint8_t>> MapFile(const std::filesystem::path& path);
+
+}  // namespace Orc