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

153 lines
2.3 KiB
C++

/*++
Copyright (c) 1990 Microsoft Corporation
Module Name:
hmem.hxx
Abstract:
The class HMEM is an implementation of the class MEM which uses the
memory resources of the heap.
After the first call to Acquire that succeeds, all successive calls
will return the same memory that was returned by the first call
provided that the size requested is within the bounds of the first call.
The common buffer which was created upon the first successful call to
Acquire will be available along with its size by calling GetBuf and
QuerySize.
Calling Destroy will put the object back in its initial state thus
invalidating any pointers to its memory and enabling future calls
to Acquire to succeed regardless of the size specicified.
Author:
Norbert P. Kusters (norbertk) 26-Nov-90
--*/
#if !defined(HMEM_DEFN)
#define HMEM_DEFN
#include "mem.hxx"
DECLARE_CLASS( HMEM );
class HMEM : public MEM {
public:
ULIB_EXPORT
DECLARE_CONSTRUCTOR( HMEM );
VIRTUAL
ULIB_EXPORT
~HMEM(
);
NONVIRTUAL
ULIB_EXPORT
BOOLEAN
Initialize(
);
VIRTUAL
ULIB_EXPORT
PVOID
Acquire(
IN ULONG Size,
IN ULONG AlignmentMask DEFAULT 0
);
NONVIRTUAL
PVOID
GetBuf(
) CONST;
NONVIRTUAL
ULONG
QuerySize(
) CONST;
NONVIRTUAL
ULIB_EXPORT
BOOLEAN
Resize(
IN ULONG NewSize,
IN ULONG AlignmentMask DEFAULT 0
);
private:
NONVIRTUAL
VOID
Construct (
);
NONVIRTUAL
VOID
Destroy(
);
ULONG _size;
PVOID _real_buf;
PVOID _buf;
};
INLINE
PVOID
HMEM::GetBuf(
) CONST
/*++
Routine Description:
This routine returns the memory that was previously 'Acquired'.
Arguments:
None.
Return Value:
A pointer to the beginning of the memory buffer.
--*/
{
return _buf;
}
INLINE
ULONG
HMEM::QuerySize(
) CONST
/*++
Routine Description:
This routine returns the size of the memory that was previously
'Acquired'.
Arguments:
None.
Return Value:
The size of the memory returned by 'GetBuf'.
--*/
{
return _size;
}
#endif // HMEM_DEFN