IDedupReadFileCallback::PreviewContainerRead method (ddpbackup.h)
Provides the application with a preview of the sequence of reads that are pending for a given container file extent.
Syntax
HRESULT PreviewContainerRead(
[in] BSTR FileFullPath,
[in] ULONG NumberOfReads,
[in] DDP_FILE_EXTENT *ReadOffsets
);
Parameters
[in] FileFullPath
The full path from the root directory of the volume to the container file.
[in] NumberOfReads
Number of DDP_FILE_EXTENT structures in the array that the ReadOffsets parameter points to.
[in] ReadOffsets
Pointer to an array of DDP_FILE_EXTENT structures.
Return value
This method can return standard HRESULT values, such as S_OK. It can also return converted system error codes using the HRESULT_FROM_WIN32 macro. Possible return values include the following.
Remarks
PreviewContainerRead is called for each container file extent reported by IDedupReadFileCallback::OrderContainersRestore. The application may use this preview as a per-container extent read plan to increase the efficiency of the pending reads. For example, the application may choose to perform read-ahead to improve throughput or to cache read buffers to improve overall performance across parallel file restore operations.
Requirements
| Requirement | Value |
|---|---|
| Minimum supported client | None supported |
| Minimum supported server | Windows Server 2012 |
| Target Platform | Windows |
| Header | ddpbackup.h |