RETRIEVAL_POINTERS_BUFFER structure (winioctl.h)

Contains the output for the FSCTL_GET_RETRIEVAL_POINTERS control code.

Syntax

typedef struct RETRIEVAL_POINTERS_BUFFER {
  DWORD                    ExtentCount;
  LARGE_INTEGER            StartingVcn;
  struct {
    LARGE_INTEGER NextVcn;
    LARGE_INTEGER Lcn;
  };
  __unnamed_struct_1931_64 Extents[1];
} RETRIEVAL_POINTERS_BUFFER, *PRETRIEVAL_POINTERS_BUFFER;

Members

ExtentCount

The count of elements in the Extents array.

StartingVcn

The starting VCN returned by the function call. This is not necessarily the VCN requested by the function call, as the file system driver may round down to the first VCN of the extent in which the requested starting VCN is found.

NextVcn

Lcn

Extents[1]

Array of Extents structures. For the number of members in the array, see ExtentCount. Each member of the array has the following members.

NextVcn

The VCN at which the next extent begins. This value minus either StartingVcn (for the first Extents array member) or the NextVcn of the previous member of the array (for all other Extents array members) is the length, in clusters, of the current extent. The length is an input to the FSCTL_MOVE_FILE operation.

Lcn

The LCN at which the current extent begins on the volume. This value is an input to the FSCTL_MOVE_FILE operation. On the NTFS file system, the value (LONGLONG) –1 indicates either a compression unit that is partially allocated, or an unallocated region of a sparse file.

Requirements

Requirement	Value
Minimum supported client	Windows XP [desktop apps only]
Minimum supported server	Windows Server 2003 [desktop apps only]
Header	winioctl.h (include Windows.h)

See also

Defragmentation

FSCTL_GET_RETRIEVAL_POINTERS

FSCTL_MOVE_FILE