fxmemorybuffer.hpp

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/*++
 
Copyright (c) Microsoft Corporation
 
Module Name:
 
    FxMemoryBuffer.hpp
 
Abstract:
 
Author:
 
Environment:
 
    kernel mode only
 
Revision History:
 
 
--*/
 
#ifndef _FXMEMORYBUFFER_H_
#define _FXMEMORYBUFFER_H_
 
class FxMemoryBuffer : public FxMemoryObject {
 
public:
 
    // Factory function
    static
    _Must_inspect_result_
    NTSTATUS
    _Create(
        __in  PFX_DRIVER_GLOBALS DriverGlobals,
        __in_opt PWDF_OBJECT_ATTRIBUTES Attributes,
        __in  ULONG PoolTag,
        __in  size_t BufferSize,
        __in POOL_TYPE PoolType,
        __out FxMemoryObject** Object
        );
 
    FxMemoryBuffer(
        __in PFX_DRIVER_GLOBALS FxDriverGlobals,
        __in size_t BufferSize
        );
 
    PVOID
    GetBuffer(
        VOID
        );
 
    PVOID
    __inline
    operator new(
        __in size_t Size,
        __in PFX_DRIVER_GLOBALS FxDriverGlobals,
        __in_opt PWDF_OBJECT_ATTRIBUTES Attributes,
        __in USHORT ExtraSize,
        __in ULONG Tag,
        __in POOL_TYPE PoolType
        )
    {
        //
        // PoolType must be non paged pool but it can be NonPagedPool
        // or NonPagedPoolNx or their variants
        //
        ASSERT(!FxIsPagedPoolType(PoolType));
 
        //
        // Specialize operator new so that we can use the caller's tag when
        // making the object allocation vs using the default driver-wide tag.
        //
        return FxObjectHandleAlloc(FxDriverGlobals,
                                   PoolType,
                                   Size,
                                   Tag,
                                   Attributes,
                                   ExtraSize,
                                   FxObjectTypeExternal);
    }
 
protected:
 
    FxMemoryBuffer(
        __in PFX_DRIVER_GLOBALS FxDriverGlobals,
        __in USHORT ObjectSize,
        __in size_t BufferSize
        );
 
    ~FxMemoryBuffer();
};
 
#endif // _FXMEMORYBUFFER_H_