BeatSaberManager/Bsm.Core/IoUtil.cs

using System;
using System.ComponentModel;
using System.IO;
using System.Runtime.InteropServices;

namespace Bsm.Core
{
    public static class IoUtil
    {
        public static long GetFileSize(string filename)
        {
            FindClose(FindFirstFile(filename, out var findData));
            return (((long)findData.nFileSizeHigh) << 32) | findData.nFileSizeLow;
        }

        public static bool GetFileInfo(string path, out WIN32_FIND_DATA data)
        {
            var hFind = FindFirstFileEx(path, FINDEX_INFO_LEVELS.FindExInfoBasic, out var file, 0, IntPtr.Zero, 0);
            if (hFind == new IntPtr(INVALID_HANDLE_VALUE))
            {
                var ex = new Win32Exception();
                data = new WIN32_FIND_DATA();
                return false;
            }

            data = file;
            FindClose(hFind);
            return true;
        }

        public static void LookupEntries(string dir, Action<WIN32_FIND_DATA> callback, string pattern = "*")
        {
            var hFind = FindFirstFileEx(Path.Combine(dir, pattern), FINDEX_INFO_LEVELS.FindExInfoBasic, out var file, 0, IntPtr.Zero, 0);
            if (hFind == new IntPtr(INVALID_HANDLE_VALUE))
            {
                var ex = new Win32Exception();
                return;
            }

            try
            {
                do
                {
                    //check is . or ..
                    if (file.cFileName == "." || file.cFileName == "..") continue;

                    callback(file);
                } while (FindNextFile(hFind, out file));
            }
            finally
            {
                FindClose(hFind);
            }
        }

        public static void LookupFilesRecursively(string dir, Action<WIN32_FIND_DATA, string> callback, string pattern = "*")
        {
            LookupFilesInternal(dir, callback, pattern: pattern);
        }

        private static void LookupFilesInternal(string dir, Action<WIN32_FIND_DATA, string> callback, string folderName = "", string pattern = "*")
        {
            var hFind = FindFirstFileEx(Path.Combine(dir, pattern), FINDEX_INFO_LEVELS.FindExInfoBasic, out var file, 0, IntPtr.Zero, 0);
            if (hFind == new IntPtr(INVALID_HANDLE_VALUE))
            {
                var ex = new Win32Exception();
                return;
            }

            try
            {
                do
                {
                    //check is . or ..
                    if (file.cFileName == "." || file.cFileName == "..") continue;

                    //check is dir re
                    if (file.IsDirectory)
                    {
                        LookupFilesInternal(Path.Combine(dir, file.cFileName), callback, folderName + "/" + file.cFileName, pattern);
                        continue;
                    }

                    callback(file, folderName);
                } while (FindNextFile(hFind, out file));
            }
            finally
            {
                FindClose(hFind);
            }
        }

        // ReSharper disable IdentifierTypo
        // ReSharper disable InconsistentNaming
        // ReSharper disable MemberCanBePrivate.Local
        // ReSharper disable FieldCanBeMadeReadOnly.Local

        [DllImport("kernel32.dll", SetLastError = true, CharSet = CharSet.Ansi)]
        private static extern IntPtr FindFirstFile(string lpFileName, out WIN32_FIND_DATA lpFindFileData);

        [DllImport("kernel32.dll", SetLastError = true, CharSet = CharSet.Unicode)]
        public static extern IntPtr FindFirstFileEx(
            string lpFileName,
            FINDEX_INFO_LEVELS fInfoLevelId,
            out WIN32_FIND_DATA lpFindFileData,
            FINDEX_SEARCH_OPS fSearchOp,
            IntPtr lpSearchFilter,
            int dwAdditionalFlags);

        [DllImport("kernel32.dll", CharSet = CharSet.Auto)]
        private static extern bool FindNextFile(IntPtr hFindFile, out WIN32_FIND_DATA lpFindFileData);

        [DllImport("kernel32.dll")]
        private static extern bool FindClose(IntPtr hFindFile);

        public const int INVALID_HANDLE_VALUE = -1;
        public const uint FILE_ATTRIBUTE_DIRECTORY = 16;

        [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]
        public struct WIN32_FIND_DATA
        {
            public uint dwFileAttributes;
            public System.Runtime.InteropServices.ComTypes.FILETIME ftCreationTime;
            public System.Runtime.InteropServices.ComTypes.FILETIME ftLastAccessTime;
            public System.Runtime.InteropServices.ComTypes.FILETIME ftLastWriteTime;
            public uint nFileSizeHigh;
            public uint nFileSizeLow;
            public uint dwReserved0;
            public uint dwReserved1;

            [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 260)]
            public string cFileName;

            [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 14)]
            public string cAlternateFileName;

            public bool IsDirectory => 0 != (dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY);
            public long FileSize => (((long)nFileSizeHigh) << 32) | nFileSizeLow;
            public DateTime CreationTime
            {
                get
                {
                    var high = (ulong)ftCreationTime.dwHighDateTime;
                    var low = (uint)ftCreationTime.dwLowDateTime;
                    var fileTime = (long)((high << 32) + low);

                    return DateTime.FromFileTimeUtc(fileTime);
                }
            }

            public DateTime LastWriteTime
            {
                get
                {
                    var high = (ulong)ftLastWriteTime.dwHighDateTime;
                    var low = (uint)ftLastWriteTime.dwLowDateTime;
                    var fileTime = (long)((high << 32) + low);

                    return DateTime.FromFileTimeUtc(fileTime);
                }
            }
        }

        public enum FINDEX_INFO_LEVELS
        {
            FindExInfoStandard = 0,
            FindExInfoBasic = 1
        }

        public enum FINDEX_SEARCH_OPS
        {
            FindExSearchNameMatch = 0,
            FindExSearchLimitToDirectories = 1,
            FindExSearchLimitToDevices = 2
        }

        // ReSharper restore FieldCanBeMadeReadOnly.Local
        // ReSharper restore MemberCanBePrivate.Local
        // ReSharper restore InconsistentNaming
        // ReSharper restore IdentifierTypo
    }
}