Interface IWbemObjectInternals

The IWbemObjectInternals interface is intended to allow direct access to and manipulation of binary data underlying an instance of IWbemClassObject.   For instance, if you have a series of IWbemClassObjects that are all instances of the same class, in order to limit consumption of memory, you can use IWbemObjectInternals::MergeClassPart to cause all objects to use a shared piece of data for the class part information, since this piece of data cannot be modified for instances.

This interface is derived from IUnknown and supports its methods.

IWbemCallResult Methods Description
QueryObjectInfo Returns a bitmask containing information regarding availability of various pieces of data in the object..
SetObjectMemory Sets the object's binary data to the supplied buffer.
GetObjectMemory Returns the object's underlying binary data in the supplied buffer.
IsObjectInstance Returns whether or not the object's underlying binary data describes an instance or a class.
SetObjectParts Sets the specified portions of the object's binary data to the data in the supplied buffer.
GetObjectParts Gets the specified portions of the object's binary data and copies the data into the supplied buffer
StripClassPart Removes the class part of an Instance object.
SetClassPart Sets the class part of an Instance object to the data pointed to by the supplied buffer.
MergeClassPart Merges the current Instance with the class part of the supplied IWbemClassObject.   IWbemClassObject::AddRef() is called on the supplied object.

 

IWbemObjectInternals::QueryObjectInfo

The IWbemObjectInternals::QueryObjectInfo method returns a bitmap that describes the actual data underlying an IWbemClassObject.   At this time, for Class Objects, this function will not return any data.

HRESULT QueryObjectInfo(
    [out] DWORD* pdwInfo,
   );

Parameters

pdwInfo
Provides storage for the returned flags..

Return Values

WBEM_S_NO_ERROR The object successfully returned .

Notes

Note that for class objects, although the call will succeed, at this time, the flags will not contain any useful information.

The flags that can be returned in pdwInfo are as follows:

WBEM_OBJ_DECORATION_PART The decoration part is available.
WBEM_OBJ_INSTANCE_PART The instance part is available.
WBEM_OBJ_CLASS_PART The class part is available.
WBEM_OBJ_CLASS_PART_INTERNAL The class part is contained internally by the object.
WBEM_OBJ_CLASS_PART_SHARED The class part information is held outside of the object and is shared with another object.

The first three flags indicate whether or not specific parts are available from the object.  The last two flags pertain to the class part and indicate whether or not the part is contained internally, or points to a shared piece of data.  Please note that the behavior of instance objects that do not have all three parts available, is undefined.


See Also

IWbemServices::IsObjectInstance
IWbemServices::SetObjectParts
IWbemServices::GetObjectParts
IWbemServices::MergeClassPart

IWbemObjectInternals::SetObjectMemory

The IWbemObjectInternals::SetObjectMemory method sets the underlying data of an IWbemClassObject to point to a supplied buffer.

HRESULT SetObjectMemory(
    [in] LPVOID pMem,
    [in] DWORD dwMemSize
   );

Parameters

pMem
Specifies the underlying buffer for use by the IWbemClassObject.

dwMemSize
Specifies the size of the buffer pMem points to.

Return Values

WBEM_S_NO_ERROR The object path was retrieved.
WBEM_E_INVALID_PARAMETER An invalid parameter was specified.

Note that the object memory is what defines an IWbemClassObject.   The memory must contain information understood by the IWbemClassObject code or the behavior of the object will be undefined.

See Also

IWbemServices::GetObjectMemory
IWbemServices::SetObjectParts
IWbemServices::GetObjectParts

IWbemObjectInternals::GetObjectMemory

You can use the IWbemObjectInternals::GetObjectMemory method to retrieve a copy of the block of memory underlying an IWbemClassObject.

HRESULT GetObjectMemory(
    [out] LPVOID pDestination,
    [in] DWORD dwDestBuffSize,
    [out] DWORD* pdwUsed
   );

Parameters

pDestination
Buffer to copy data into.

dwDestBuffSize
Size of the destination buffer.

pdwUsed
Number of bytes used in the destination buffer.

Return Values

WBEM_S_NO_ERROR The call succeeded and returned an IWbemServices pointer.
WBEM_E_BUFFER_TOO_SMALL The supplied buffer was too small to copy data into.
WBEM_E_INVALID_PARAMETER An invalid parameter was specified.

To get the size of the buffer required to copy the data into, pass a NULL for pDestination and a 0 for dwDestBuffSize.  pdwUsed will be filled with the size of the internal buffer.  The function will return WBEM_E_BUFFER_TOO_SMALL.  Note that whenever WBEM_E_BUFFER_TOO_SMALL is returned, pdwUsed will contain the size of the internal buffer.

See Also

IWbemServices::SetObjectMemory
IWbemServices::SetObjectParts
IWbemServices::GetObjectParts

IWbemObjectInternals::IsObjectInstance

You can use the IWbemObjectInternals::IsObjectInstance method to quickly determine if an IWbemClassObject is an instance or a class.

HRESULT IsObjectInstance(
    void
   );

Parameters

None.

Return Values

WBEM_S_NO_ERROR The object is an instance.
WBEM_S_FALSE The object is not an instance..

This function directly accesses the Decoration Part of an IWbemClassObject to quickly determine if the object is an Instance or not.

See Also

IWbemServices::QueryObjectInfo

IWbemObjectInternals::SetObjectParts

You can use the IWbemObjectInternals::SetObjectParts method to quickly set the underlying memory for an IWbemClassObject to point to partial or full object data.

HRESULT SetObjectParts(
    [in] LPVOID pMem,
    [in] DWORD dwMemSize,
    [in] DWORD dwParts,
   );

Parameters

pMem
Buffer to copy data from.

dwMemSize
Size of the buffer pointed to by pMem.

dwParts
Bitmask of flags describing the data pointed to by pMem .

Return Values

WBEM_S_NO_ERROR The call succeeded and reset the memory underlying the object.
WBEM_E_INVALID_OPERATION An invalid operation was specified.
WBEM_E_INVALID_PARAMETER An invalid parameter was specified.

pMem must not be NULL for this operation to succeed, and it must contain the Decoration Part (specified by dwParts).

Valid flags for dwParts are as follows:

WBEM_OBJ_DECORATION_PART The decoration part is available.
WBEM_OBJ_INSTANCE_PART The instance part is available.
WBEM_OBJ_CLASS_PART The class part is available.

If dwParts does not specify WBEM_OBJ_DECORATION_PART, the operation will return WBEM_E_INVALID_OPERATION.

See Also

IWbemServices::GetObjectParts
IWbemServices::SetObjectMemory
IWbemServices::GetObjectMemory

IWbemObjectInternals::GetObjectParts

You can use the IWbemObjectInternals::GetObjectParts method to retrieve a copy of the specified underlying parts from an IWbemClassObject.   These parts will be placed one after the other in the destinatio buffer.

HRESULT GetObjectParts(
    [out] LPVOID pDestination,
    [in] DWORD dwDestBuffSize,
    [in] DWORD dwParts,
    [out] DWORD* pdwUsed
   );

Parameters

pDestination
Buffer to copy data into.

dwDestBuffSize
Size of the destination buffer.

dwParts
Parts to copy into the supplied buffer.  Values described below.

pdwUsed
Number of bytes used in the destination buffer.

Return Values

WBEM_S_NO_ERROR The call succeeded and returned appropriate data in the supplied buffer.
WBEM_E_BUFFER_TOO_SMALL The supplied buffer was too small to copy data into.
WBEM_E_INVALID_PARAMETER An invalid parameter was specified.
WBEM_E_INVALID_OPERATION An invalid operation was requested.

To get the size of the buffer required to copy the data into, pass a NULL for pDestination and a 0 for dwDestBuffSize.   pdwUsed will be filled with the size required to copy the specified parts.   The function will return WBEM_E_BUFFER_TOO_SMALL.  Note that whenever WBEM_E_BUFFER_TOO_SMALL is returned, pdwUsed will contain the size required to copy the specified parts.

To specify the parts, you can use any or all of the following flags:

WBEM_OBJ_DECORATION_PART The decoration part.
WBEM_OBJ_INSTANCE_PART The instance part..
WBEM_OBJ_CLASS_PART The class part.

The data will be copied out Decoration, Class then Instance, maintaining that order in terms of the actual parts copied out.

The requested part(s) must be avaliable or the operation will return WBEM_E_INVALID_OPERATION.

See Also

IWbemServices::SetObjectParts
IWbemServices::SetObjectMemory
IWbemServices::GetObjectMemory

IWbemObjectInternals::StripClassPart

You can use the IWbemObjectInternals::StripClassPart method to remove the class part from the IWbemClassObject.  Behavior of the object until a class part is reapplied is undefined.

HRESULT StripClassPart(
    void
   );

Parameters

None.

Return Values

WBEM_S_NO_ERROR The call succeeded and the class part was stripped from the underlying buffer.
WBEM_E_OUT_OF_MEMORY Unable to reallocate the buffer.
WBEM_E_INVALID_OPERATION An invalid operation was specified.

For this operation to succeed, the class part MUST be internal.  If it is not, WBEM_E_INVALID_OPERATION will be returned.

See Also

IWbemServices::SetClassPart
IWbemServices::MergeClassPart

IWbemObjectInternals::SetClassPart

You can use the IWbemObjectInternals::SetClassPart method to set the class part in an IWbemClassObject.

HRESULT StripClassPart(
    [in] LPVOID pClassPart,
    [in] DWORD dwSize
   );

Parameters

pClassPart
Buffer to copy class part data from.

dwSize
Size of the buffer we are copying from.

Return Values

WBEM_S_NO_ERROR The call succeeded and the class part was stripped from the underlying buffer.
WBEM_E_OUT_OF_MEMORY Unable to reallocate the buffer.
WBEM_E_INVALID_PARAMETER An invalid parameter was specified.

This operation will resize the underlying buffer to accomodate the class part.  The class part will be copied into the resized buffer.

See Also

IWbemServices::StripClassPart
IWbemServices::MergeClassPart

IWbemObjectInternals::MergeClassPart

You can use the IWbemObjectInternals::MergeClassPart method to set the class part in an IWbemClassObject to point to the class part of another IWbemClassObject.

HRESULT MergeClassPart(
    [in] IWbemClassObject* pObj
   );

Parameters

pObj
Pointer to an IWbemClassObject whose class part the current object will merge with.

Return Values

WBEM_S_NO_ERROR The call succeeded and the class part was stripped from the underlying buffer.
WBEM_E_OUT_OF_MEMORY Unable to reallocate the buffer.
WBEM_E_INVALID_PARAMETER An invalid parameter was specified.
WBEM_E_INVALID_OPERATION An invalid operation was specified.

This operation will point the class part of the current object at the class part of the specified object.  The specified object must be an Instance object, and it must contain a class part, or WBEM_E_INVALID_OPERATION will be returned.  This function will call IWbemClassObject::AddRef() on the supplied object.  When the current object is destroyed, it will call IWbemClassObject::Release() on the object it is merged with.

See Also

IWbemServices::StripClassPart
IWbemServices::SetClassPart
IWbemServices::QueryObjectInfo
IWbemServices::SetObjectParts
IWbemServices::GetObjectParts