CVssWriter::OnPostRestore method (vswriter.h)

Article
07/12/2022

The OnPostRestore method is called by a writer following a PostRestore event. It is used to perform operations considered necessary after files are restored to disk by a requester. These operations cannot, however, modify the Backup Components Document.

OnPostRestore is a virtual method. It is implemented by the CVssWriter base class, but can be overridden by derived classes.

Syntax

bool OnPostRestore(
  [in] IVssWriterComponents *pComponent
);

Parameters

[in] pComponent

A pointer to an IVssWriterComponents object passed in by VSS to provide the method with access to the writer's component information. The value of this parameter may be NULL if the requester does not support components (if CVssWriter::AreComponentsSelected returns false).

Return value

As implemented by the base class, OnPostRestore always returns true.

Any other implementation of this method must return true except in the case of a fatal error. If a fatal error occurs, the method must call the CVssWriter::SetWriterFailure method to provide a description of the failure before returning false. If a nonfatal error occurs, the method should still call SetWriterFailure but return true. If the error is caused by a transient problem, the method should specify VSS_E_WRITERERROR_RETRYABLE in the call to SetWriterFailure.

In all cases when a failure occurs, the method should write an event to the event log to report the exact reason for the failure.

Remarks

The default implementation of this method by the CVssWriter base class returns true without performing any other operation.

If necessary, a writer should remove any temporary files and release any system resources that it needed for its participation in the restore.

Writers should never throw an exception from this method or any other CVssWriter(Ex)::OnXxx callback method.

With the generation of a PostRestore event, a requester's Backup Components Document becomes a read-only document. Therefore, attempts to modify the document through the interface (for instance, calling IVssComponent::SetRestoreMetadata) will fail in user implementations of OnPostRestore.

If this method calls the CVssWriterEx2::GetSessionId, CVssWriter::SetWriterFailure, or CVssWriterEx2::SetWriterFailureEx method, it must do so in the same thread that called this method. For more information, see Writer Event Handling.

Requirements

Requirement	Value
Minimum supported client	Windows XP [desktop apps only]
Minimum supported server	Windows Server 2003 [desktop apps only]
Target Platform	Windows
Header	vswriter.h (include Vss.h, VsWriter.h)
Library	VssApi.lib