Win32: Reading directory in one kernel call

fileinfo.c

// Not sure whether it's faster than FindFirstFile, etc. - but it does it in one kernel call

#include <windows.h>
#include <stdio.h>

// to compile:
// cl fileinfo.c setargv.obj

void fileinfo(const char*name);
int main( int argc, const char* argv[] )
{
	int i;
	if( argc == 1 )
		printf( "fileinfo: Dumps GetFileInformationByHandleEx Information\n" );
	for( i=1; i<argc; i++ ) {
		fileinfo(argv[i]);
		printf("\n");
	}
	return 0;
}

void fileinfo(const char*name)
{
	int i, j;
	HANDLE h = CreateFileA(
		name, 
		GENERIC_READ, 
		FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE, 
		NULL, 
		OPEN_EXISTING,
		FILE_FLAG_BACKUP_SEMANTICS,
		NULL
	);
	if( h == INVALID_HANDLE_VALUE ) {
		fprintf( stderr, "%s: error hr=%p\n", name, GetLastError() );
		return;
	}
	for( i=0; i<256; i++ )
	{
		static __declspec(align(8)) unsigned char buffer1[64*1024*1024];
		static __declspec(align(8)) unsigned char buffer2[64*1024*1024];
		if(!GetFileInformationByHandleEx(h, (FILE_INFO_BY_HANDLE_CLASS)i, buffer1, sizeof(buffer1)) )
		    continue;
		memset(&buffer1, 0xBA, sizeof(buffer1));
		memset(&buffer2, 0xFD, sizeof(buffer2));
		if(!GetFileInformationByHandleEx(h, (FILE_INFO_BY_HANDLE_CLASS)i, buffer1, sizeof(buffer1))
		|| !GetFileInformationByHandleEx(h, (FILE_INFO_BY_HANDLE_CLASS)i, buffer2, sizeof(buffer2)))
		    continue;
		for( j=0; j<sizeof(buffer1); j++ )
		{
			if( buffer1[j] == buffer2[j] )
				continue;
			if( buffer1[j] == 0xBA && buffer2[j] == 0xFD )
				break;
			printf( "%s: info %p differs at %p\n", name, i, j );
			break;
		}
		switch( i ) {
			case FileBasicInfo: {
				PFILE_BASIC_INFO info = (PFILE_BASIC_INFO)buffer1;
				printf( "%s: FILE_BASIC_INFO (%d)\n", name, i );
				printf( "%s:   CreationTime           = %I64u\n",    name, info->CreationTime.QuadPart );
				printf( "%s:   LastAccessTime         = %I64u\n",    name, info->LastAccessTime.QuadPart );
				printf( "%s:   LastWriteTime          = %I64u\n",    name, info->LastWriteTime.QuadPart );
				printf( "%s:   ChangeTime             = %I64u\n",    name, info->ChangeTime.QuadPart );
				printf( "%s:   FileAttributes         = 0x%p\n",     name, info->FileAttributes );
			} break;
			case FileStandardInfo: {
				PFILE_STANDARD_INFO info = (PFILE_STANDARD_INFO)buffer1;
				printf( "%s: FILE_STANDARD_INFO (%d)\n", name, i );
				printf( "%s:   AllocationSize         = %I64u\n",    name, info->AllocationSize.QuadPart );
				printf( "%s:   EndOfFile              = %I64u\n",    name, info->EndOfFile.QuadPart );
				printf( "%s:   NumberOfLinks          = %d\n",       name, info->NumberOfLinks );
				printf( "%s:   DeletePending          = %d\n",       name, info->DeletePending );
				printf( "%s:   Directory              = %d\n",       name, info->Directory );
			} break;
			case FileNameInfo: {
				PFILE_NAME_INFO info = (PFILE_NAME_INFO)buffer1;
				printf( "%s: FILE_NAME_INFO (%d)\n", name, i );
				printf( "%s:   FileNameLength         = %d\n",       name, info->FileNameLength );
				printf( "%s:   FileName               = %*.*S\n",    name, info->FileNameLength/2, info->FileNameLength/2, info->FileName ); // UNICODE, hence /2
			} break;
			case FileStreamInfo: {
				int entryIndex = 0;
				PFILE_STREAM_INFO info = (PFILE_STREAM_INFO)buffer1;
				printf( "%s: FILE_STREAM_INFO (%d)\n", name, i );
				for( ;; ) {
				printf( "%s:   Stream                 = %d\n",       name, entryIndex );
				printf( "%s:     NextEntryOffset      = 0x%p\n",     name, info->NextEntryOffset );
				printf( "%s:     StreamNameLength     = %d\n",       name, info->StreamNameLength );
				printf( "%s:     StreamSize           = %I64u\n",    name, info->StreamSize.QuadPart );
				printf( "%s:     StreamAllocationSize = %I64u\n",    name, info->StreamAllocationSize.QuadPart );
				printf( "%s:     StreamName           = %*.*S\n",    name, info->StreamNameLength/2, info->StreamNameLength/2, info->StreamName ); // UNICODE, hence /2
				if( !info->NextEntryOffset )
					break;
				entryIndex ++;
				info = (PFILE_STREAM_INFO)( (char*)info + info->NextEntryOffset );
				};
			} break;
			case FileCompressionInfo: {
				PFILE_COMPRESSION_INFO info = (PFILE_COMPRESSION_INFO)buffer1;
				printf( "%s: FILE_COMPRESSION_INFO (%d)\n", name, i );
				printf( "%s:   CompressedFileSize     = %I64u\n",    name, info->CompressedFileSize.QuadPart );
				printf( "%s:   CompressionFormat      = %d\n",       name, info->CompressionFormat);
				printf( "%s:   CompressionUnitShift   = %d\n",       name, info->CompressionUnitShift);
				printf( "%s:   ChunkShift             = %d\n",       name, info->ChunkShift);
				printf( "%s:   ClusterShift           = %d\n",       name, info->ClusterShift);
				printf( "%s:   Reserved[3]            = %d %d %d\n", name, info->Reserved[0],info->Reserved[1],info->Reserved[2]);
			} break;
			case FileAttributeTagInfo: {
				PFILE_ATTRIBUTE_TAG_INFO info = (PFILE_ATTRIBUTE_TAG_INFO)buffer1;
				printf( "%s: FILE_ATTRIBUTE_TAG_INFO (%d)\n", name, i );
				printf( "%s:   FileAttributes         = 0x%p\n",     name, info->FileAttributes);
				printf( "%s:   ReparseTag             = 0x%p\n",     name, info->ReparseTag);
			} break;
			case FileIdBothDirectoryInfo:
			case FileIdBothDirectoryRestartInfo: {
				int entryIndex = 0;
				PFILE_ID_BOTH_DIR_INFO info = (PFILE_ID_BOTH_DIR_INFO)buffer1;
				printf( "%s: FILE_ID_BOTH_DIR_INFO (%d) size=%p\n", name, i, j );
				for( ;; ) {
				printf( "%s:   Entry                  = 0x%p %d 0x%p\n",  name, (char*)info - (char*)buffer1, entryIndex, (char*)info - (char*)buffer1 + sizeof(FILE_ID_BOTH_DIR_INFO)*2 );
				printf( "%s:     NextEntryOffset      = 0x%p\n",     name, info->NextEntryOffset );
				printf( "%s:     FileIndex            = %d\n",       name, info->FileIndex );
				printf( "%s:     CreationTime         = %I64u\n",    name, info->CreationTime.QuadPart );
				printf( "%s:     LastAccessTime       = %I64u\n",    name, info->LastAccessTime.QuadPart );
				printf( "%s:     LastWriteTime        = %I64u\n",    name, info->LastWriteTime.QuadPart );
				printf( "%s:     ChangeTime           = %I64u\n",    name, info->ChangeTime.QuadPart );
				printf( "%s:     EndOfFile            = %I64u\n",    name, info->EndOfFile.QuadPart );
				printf( "%s:     AllocationSize       = %I64u\n",    name, info->AllocationSize.QuadPart );
				printf( "%s:     FileAttributes       = 0x%p\n",     name, info->FileAttributes);
				printf( "%s:     FileNameLength       = %d\n",       name, info->FileNameLength );
				printf( "%s:     EaSize               = %d\n",       name, info->EaSize );
				printf( "%s:     ShortNameLength      = %d\n",       name, info->ShortNameLength );
				printf( "%s:     ShortName            = %*.*S\n",    name, info->ShortNameLength/2, info->ShortNameLength/2, info->ShortName );
				printf( "%s:     FileId               = %I64u\n",    name, info->FileId );
				printf( "%s:     FileName             = %*.*S\n",    name, info->FileNameLength/2, info->FileNameLength/2, info->FileName ); // UNICODE, hence /2
				if( !info->NextEntryOffset )
					break;
				entryIndex++;
				info = (PFILE_ID_BOTH_DIR_INFO)( (char*)info + info->NextEntryOffset );
				}
			} break;
			default: {
				printf( "%s: UKNOWN_FILE_INFO (%d) sized %d bytes\n", name, i, j );
			} break;
		}
	}
	CloseHandle(h);
}