fs/FileInfo: use GetFileAttributesEx() on WIN32

src/fs/FileInfo.hxx

@@ -25,7 +25,29 @@
 #include "util/Error.hxx"
 
 #include <stdint.h>
+
+#ifdef WIN32
+#include <fileapi.h>
+#else
 #include <sys/stat.h>
+#endif
+
+#ifdef WIN32
+
+static inline constexpr uint64_t
+ConstructUint64(DWORD lo, DWORD hi)
+{
+	return uint64_t(lo) | (uint64_t(hi) << 32);
+}
+
+static constexpr time_t
+FileTimeToTimeT(FILETIME ft)
+{
+	return (ConstructUint64(ft.dwLowDateTime, ft.dwHighDateTime)
+		- 116444736000000000) / 10000000;
+}
+
+#endif
 
 class FileInfo {
 	friend bool GetFileInfo(Path path, FileInfo &info,
@@ -33,23 +55,43 @@ class FileInfo {
 	friend bool GetFileInfo(Path path, FileInfo &info,
 				Error &error);
 
+#ifdef WIN32
+	WIN32_FILE_ATTRIBUTE_DATA data;
+#else
 	struct stat st;
+#endif
 
 public:
 	bool IsRegular() const {
+#ifdef WIN32
+		return data.dwFileAttributes & FILE_ATTRIBUTE_NORMAL;
+#else
 		return S_ISREG(st.st_mode);
+#endif
 	}
 
 	bool IsDirectory() const {
+#ifdef WIN32
+		return data.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY;
+#else
 		return S_ISDIR(st.st_mode);
+#endif
 	}
 
 	uint64_t GetSize() const {
+#ifdef WIN32
+		return ConstructUint64(data.nFileSizeLow, data.nFileSizeHigh);
+#else
 		return st.st_size;
+#endif
 	}
 
 	time_t GetModificationTime() const {
+#ifdef WIN32
+		return FileTimeToTimeT(data.ftLastWriteTime);
+#else
 		return st.st_mtime;
+#endif
 	}
 
 #ifndef WIN32
@@ -76,7 +118,8 @@ GetFileInfo(Path path, FileInfo &info, bool follow_symlinks=true)
 {
 #ifdef WIN32
 	(void)follow_symlinks;
-	return stat(path.c_str(), &info.st) == 0;
+	return GetFileAttributesEx(path.c_str(), GetFileExInfoStandard,
+				   &info.data);
 #else
 	int ret = follow_symlinks
 		? stat(path.c_str(), &info.st)
@@ -91,7 +134,12 @@ GetFileInfo(Path path, FileInfo &info, bool follow_symlinks, Error &error)
 	bool success = GetFileInfo(path, info, follow_symlinks);
 	if (!success) {
 		const auto path_utf8 = path.ToUTF8();
+#ifdef WIN32
+		error.FormatLastError("Failed to access %s",
+				      path_utf8.c_str());
+#else
 		error.FormatErrno("Failed to access %s", path_utf8.c_str());
+#endif
 	}
 
 	return success;