ClfsReadLogRecord - NtDoc
Native API online documentation, based on the System Informer
(formerly Process Hacker) phnt
headers
// wdm.h
CLFSUSER_API NTSTATUS ClfsReadLogRecord(
[in] PVOID pvMarshalContext,
[in, out] PCLFS_LSN plsnFirst,
[in] CLFS_CONTEXT_MODE peContextMode,
[out] PVOID *ppvReadBuffer,
[out] PULONG pcbReadBuffer,
[out] PCLFS_RECORD_TYPE peRecordType,
[out] PCLFS_LSN plsnUndoNext,
[out] PCLFS_LSN plsnPrevious,
[out] PVOID *ppvReadContext
);
View the official Windows Driver Kit DDI referenceNo description available.
The ClfsReadLogRecord routine reads a target record in a CLFS stream and returns a read context that the caller can use to read the records preceding or following it in the stream.
pvMarshalContext [in]A pointer to an opaque context that represents a marshalling area. The caller previously obtained this pointer by calling ClfsCreateMarshallingArea.
plsnFirst [in, out]A pointer to a CLFS_LSN structure that supplies the LSN of the target record in the log.
peContextMode [in]A value from the CLFS_CONTEXT_MODE enumeration that specifies the initial mode (ClfsContextUndoNext, ClfsContextPrevious, or ClfsContextForward) of the read context returned in ppvReadContext.
ppvReadBuffer [out]A pointer to a variable that receives a pointer to the data buffer of the target record.
pcbReadBuffer [out]A pointer to a ULONG-typed variable that receives the size, in bytes, of the buffer pointed to by *ppvReadBuffer. This is the length of the data buffer of the target record.
peRecordType [out]A pointer to a variable of type CLFS_RECORD_TYPE that receives one of the following values.
| Value | Meaning |
|---|---|
| ClfsDataRecord | The target record is a data record. |
| ClfsRestartRecord | The target record is a restart record. |
plsnUndoNext [out]A pointer to a CLFS_LSN structure that receives the undo-next LSN of the target record.
plsnPrevious [out]A pointer to a CLFS_LSN structure that receives the previous LSN of the target record.
ppvReadContext [out]A pointer to a variable that receives a pointer to an opaque read context. The client repeatedly passes this context to ClfsReadNextLogRecord to read the remaining records in a sequence. After the client has read all the records in the sequence, it calls ClfsTerminateReadLog to free the read context.
ClfsReadLogRecord returns STATUS_SUCCESS if it succeeds; otherwise, it returns one of the error codes defined in Ntstatus.h.
You must call ClfsTerminateReadLog when you have finished using the read context in order to avoid a memory leak.
For an explanation of CLFS concepts and terminology, see Common Log File System.
For information about reading records from CLFS streams, see Reading Data Records from a CLFS Stream and Reading Restart Records from a CLFS Stream.
Read contexts are not thread-safe. Clients are responsible for serializing access to read contexts.