windows-nt/Source/XPSP1/NT/base/fs/utils/ulib/inc/filestrm.hxx
2020-09-26 16:20:57 +08:00

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/*++
Copyright (c) 1991-2000 Microsoft Corporation
Module Name:
filestrm.hxx
Abstract:
This module contains the declaration for the FILE_STREAM class.
The FILE_STREAM is an abstract class derived from BUFFER_STREAM,
that models a file as a stream of data.
A FILE_STREAM class has the concept of a pointer (file poiter),
and it provides some methods that allow operations on this pointer,
such as:
.move file pointer to a particular position;
.read/write byte in a particular position;
.query the position of the file pointer;
The only way that a client has to create a FILE_STREAM is through
QueryStream() (a method in FSN_FILE).
FILE_STREAM can be has a method for initialization with two different
signatures. In one case, a PFSN_FILE is passed as parameter. This
initialization is used by QueryStream().
The other signature allows that a HANDLE is passed as parameter.
This initialization is used by GetStandardStream() during the
initialization of ulib.
Author:
Jaime Sasson (jaimes) 21-Mar-1991
Environment:
ULIB, User Mode
--*/
#if !defined( _FILE_STREAM_ )
#define _FILE_STREAM_
#include "bufstrm.hxx"
enum SEEKORIGIN {
STREAM_BEGINNING,
STREAM_CURRENT,
STREAM_END
};
//
// Forward references
//
DECLARE_CLASS( FILE_STREAM );
DECLARE_CLASS( FSN_FILE );
class FILE_STREAM : public BUFFER_STREAM {
friend class FSN_FILE;
friend class COMM_DEVICE;
friend PSTREAM GetStandardStream( HANDLE, STREAMACCESS );
public:
ULIB_EXPORT
DECLARE_CAST_MEMBER_FUNCTION( FILE_STREAM );
VIRTUAL
~FILE_STREAM(
);
VIRTUAL
BOOLEAN
MovePointerPosition(
IN LONGLONG Position,
IN SEEKORIGIN Origin
);
VIRTUAL
STREAMACCESS
QueryAccess(
) CONST;
VIRTUAL
BOOLEAN
QueryPointerPosition(
OUT PULONGLONG Position
);
NONVIRTUAL
BOOLEAN
Read(
OUT PBYTE Buffer,
IN ULONG NumberOfBytesToRead,
OUT PULONG NumberOfBytesRead
);
NONVIRTUAL
ULIB_EXPORT
BOOLEAN
ReadAt(
OUT PBYTE Buffer,
IN ULONG BytesToRead,
IN LONGLONG Position,
IN SEEKORIGIN Origin,
OUT PULONG BytesRead
);
NONVIRTUAL
BOOLEAN
Write(
IN PCBYTE Buffer,
IN ULONG BytesToWrite,
OUT PULONG BytesWritten
);
NONVIRTUAL
BOOLEAN
WriteAt(
OUT PBYTE Buffer,
IN ULONG BytesToWrite,
IN LONGLONG Position,
IN SEEKORIGIN Origin,
OUT PULONG BytesWritten
);
protected:
DECLARE_CONSTRUCTOR( FILE_STREAM );
NONVIRTUAL
BOOLEAN
Initialize(
PCFSN_FILE File,
STREAMACCESS Access,
DWORD Attributes DEFAULT 0
);
NONVIRTUAL
BOOLEAN
Initialize(
HANDLE Handle,
STREAMACCESS Access
);
VIRTUAL
BOOLEAN
AdvanceBufferPointer(
IN ULONG NumberOfBytes
);
VIRTUAL
BOOLEAN
EndOfFile(
) CONST;
NONVIRTUAL
BOOLEAN
FillBuffer(
IN PBYTE Buffer,
IN ULONG BufferSize,
OUT PULONG BytesRead
);
NONVIRTUAL
PCBYTE
GetBuffer(
PULONG BytesInBuffer
);
VIRTUAL
HANDLE
QueryHandle(
) CONST;
private:
NONVIRTUAL
VOID
Construct(
);
HANDLE _FileHandle;
HANDLE _FileMappingHandle;
STREAMACCESS _Access;
BOOLEAN _EndOfFile;
BOOLEAN _ShouldCloseHandle;
PBYTE _FileBaseAddress;
ULONG64 _FileSize;
PBYTE _CurrentByte;
BOOLEAN _EmptyFile;
BOOLEAN _MemoryMappedFile;
};
#endif // _FILE_STREAM_