Port XEX patcher from Unleashed Recompiled. (#4)

* Port XEX patcher from Unleashed Recompiled.

* Fix compilation error on Linux.

XenonUtils/memory_mapped_file.cpp

@@ -0,0 +1,169 @@
+#include "memory_mapped_file.h"
+
+#if !defined(_WIN32)
+#   include <cstring>
+#   include <cstdio>
+#   include <fcntl.h>
+#   include <unistd.h>
+#endif
+
+MemoryMappedFile::MemoryMappedFile()
+{
+    // Default constructor.
+}
+
+MemoryMappedFile::MemoryMappedFile(const std::filesystem::path &path)
+{
+    open(path);
+}
+
+MemoryMappedFile::~MemoryMappedFile()
+{
+    close();
+}
+
+MemoryMappedFile::MemoryMappedFile(MemoryMappedFile &&other)
+{
+#if defined(_WIN32)
+    fileHandle = other.fileHandle;
+    fileMappingHandle = other.fileMappingHandle;
+    fileView = other.fileView;
+    fileSize = other.fileSize;
+
+    other.fileHandle = nullptr;
+    other.fileMappingHandle = nullptr;
+    other.fileView = nullptr;
+    other.fileSize.QuadPart = 0;
+#else
+    fileHandle = other.fileHandle;
+    fileView = other.fileView;
+    fileSize = other.fileSize;
+
+    other.fileHandle = -1;
+    other.fileView = MAP_FAILED;
+    other.fileSize = 0;
+#endif
+}
+
+bool MemoryMappedFile::open(const std::filesystem::path &path)
+{
+#if defined(_WIN32)
+    fileHandle = CreateFileW(path.c_str(), GENERIC_READ, FILE_SHARE_READ, nullptr, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, nullptr);
+    if (fileHandle == INVALID_HANDLE_VALUE)
+    {
+        fprintf(stderr, "CreateFileW failed with error %lu.\n", GetLastError());
+        fileHandle = nullptr;
+        return false;
+    }
+
+    if (!GetFileSizeEx(fileHandle, &fileSize))
+    {
+        fprintf(stderr, "GetFileSizeEx failed with error %lu.\n", GetLastError());
+        CloseHandle(fileHandle);
+        fileHandle = nullptr;
+        return false;
+    }
+
+    fileMappingHandle = CreateFileMappingW(fileHandle, nullptr, PAGE_READONLY, 0, 0, nullptr);
+    if (fileMappingHandle == nullptr)
+    {
+        fprintf(stderr, "CreateFileMappingW failed with error %lu.\n", GetLastError());
+        CloseHandle(fileHandle);
+        fileHandle = nullptr;
+        return false;
+    }
+
+    fileView = MapViewOfFile(fileMappingHandle, FILE_MAP_READ, 0, 0, 0);
+    if (fileView == nullptr)
+    {
+        fprintf(stderr, "MapViewOfFile failed with error %lu.\n", GetLastError());
+        CloseHandle(fileMappingHandle);
+        CloseHandle(fileHandle);
+        fileMappingHandle = nullptr;
+        fileHandle = nullptr;
+        return false;
+    }
+
+    return true;
+#else
+    fileHandle = ::open(path.c_str(), O_RDONLY);
+    if (fileHandle == -1)
+    {
+        fprintf(stderr, "open for %s failed with error %s.\n", path.c_str(), strerror(errno));
+        return false;
+    }
+
+    fileSize = lseek(fileHandle, 0, SEEK_END);
+    if (fileSize == (off_t)(-1))
+    {
+        fprintf(stderr, "lseek failed with error %s.\n", strerror(errno));
+        ::close(fileHandle);
+        fileHandle = -1;
+        return false;
+    }
+
+    fileView = mmap(nullptr, fileSize, PROT_READ, MAP_PRIVATE, fileHandle, 0);
+    if (fileView == MAP_FAILED)
+    {
+        fprintf(stderr, "mmap failed with error %s.\n", strerror(errno));
+        ::close(fileHandle);
+        fileHandle = -1;
+        return false;
+    }
+
+    return true;
+#endif
+}
+
+void MemoryMappedFile::close()
+{
+#if defined(_WIN32)
+    if (fileView != nullptr)
+    {
+        UnmapViewOfFile(fileView);
+    }
+
+    if (fileMappingHandle != nullptr)
+    {
+        CloseHandle(fileMappingHandle);
+    }
+
+    if (fileHandle != nullptr)
+    {
+        CloseHandle(fileHandle);
+    }
+#else
+    if (fileView != MAP_FAILED)
+    {
+        munmap(fileView, fileSize);
+    }
+
+    if (fileHandle != -1)
+    {
+        ::close(fileHandle);
+    }
+#endif
+}
+
+bool MemoryMappedFile::isOpen() const
+{
+#if defined(_WIN32)
+    return (fileView != nullptr);
+#else
+    return (fileView != MAP_FAILED);
+#endif
+}
+
+uint8_t *MemoryMappedFile::data() const
+{
+    return reinterpret_cast<uint8_t *>(fileView);
+}
+
+size_t MemoryMappedFile::size() const
+{
+#if defined(_WIN32)
+    return fileSize.QuadPart;
+#else
+    return static_cast<size_t>(fileSize);
+#endif
+}