IVssComponentEx::GetPrepareForBackupFailureMsg method (vswriter.h)

Article
02/22/2024

Returns the PrepareForBackup failure message string that a writer has set for a given component.

Both writers and requesters can call this method.

Syntax

HRESULT GetPrepareForBackupFailureMsg(
  [out] BSTR *pbstrFailureMsg
);

Parameters

[out] pbstrFailureMsg

A pointer to a null-terminated wide character string containing the failure message that describes an error that occurred while processing a PrepareForBackup event.

Return value

The following are the valid return codes for this method.

Value	Meaning
S_OK	The failure message was successfully obtained.
S_FALSE	No PrepareForBackup failure message was set for the component.
E_INVALIDARG	One of the parameter values is not valid.
E_OUTOFMEMORY	The caller is out of memory or other system resources.

Remarks

The caller is responsible for freeing the string that the pbstrFailureMsg parameter points to by calling the SysFreeString function.

Examples

#include <windows.h>
#include "vss.h"
#include "vsmgmt.h"

#define CHKARG_ASSERT(EXPR)  
do
{
    if(! ( EXPR ) )               
    {                       
        assert(FALSE);      
        hr = E_INVALIDARG;  
        goto exit;          
    }                        
}
while ( FALSE, FALSE );

#define  CHK(HR)                
do
{
    hr =  ( HR ) ;                
    if(FAILED(HR))          
    {                       
        hr = HR;            
        goto exit;          
    }                       
}
while ( FALSE, FALSE ); 

STDMETHODIMP CheckAsrBackupErrorMsg
(
      IVssBackupComponents           *pBackup,
      const WCHAR              *pwszWriterName
)
{
    CComPtr<IVssWriterComponentsExt> spWriter;
    CComPtr<IVssComponent>   spComponent;
    CComPtr<IVssComponentEx> spComponentEx;
    UINT    cWriterComponents = 0;
    UINT    iWriterComponent = 0;
    UINT    cComponents = 0;
    UINT    iComponent = 0;
    VSS_ID  idWriter;
    VSS_ID  idInstance;
    CComBSTR bstrFailureMsg;
    HRESULT  hr = S_OK;
    CHKARG_ASSERT( pBackup );
    CHKARG_ASSERT( pwszWriterName );

    CHK( pBackup->GetWriterComponentsCount( &cWriterComponents ) );

    for( iWriterComponent = 0; iWriterComponent < cWriterComponents; iWriterComponent++ )
    {
        spWriter.Release();
        CHK( pBackup->GetWriterComponents( iWriterComponent, &spWriter ) );
        CHK( spWriter->GetWriterInfo(&idInstance, &idWriter) );
        if( idWriter != c_ASRWriterId )
        {
            continue;
        }
        
        CHK( spWriter->GetComponentCount(&cComponents) );
        for( iComponent = 0; iComponent < cComponents; iComponent++ )
        {
            spComponent.Release();
            spComponentEx.Release();
            CHK( spWriter->GetComponent(iComponent, &spComponent) );
            CHK( spComponent->QueryInterface(__uuidof(IVssComponentEx), (void**)&spComponentEx) );

            bstrFailureMsg.Empty();
            CHK( spComponentEx->GetPrepareForBackupFailureMsg(&bstrFailureMsg) );

            if( ::SysStringLen(bstrFailureMsg) != 0 )
            {
                //  Write into the event log.
                Log_SPP_ERROR_WRITER( &ft, __LINE__, pwszWriterName, bstrFailureMsg );

                //  The ASR writer writes the same message to all components. 
                //  Log the message once.
                break;
            }
        }
    }

exit:
    return hr;
}

Requirements

Requirement	Value
Minimum supported client	Windows Vista [desktop apps only]
Minimum supported server	Windows Server 2008 [desktop apps only]
Target Platform	Windows
Header	vswriter.h (include Vss.h, VsWriter.h)
Library	VssApi.lib