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FILE_ALLOCATED_RANGE_BUFFER structure (ntifs.h)

  • Article

FILE_ALLOCATED_RANGE_BUFFER structures are used as input and output during a FSCTL_QUERY_ALLOCATED_RANGES control code request.

Syntax

typedef struct _FILE_ALLOCATED_RANGE_BUFFER {
  LARGE_INTEGER FileOffset;
  LARGE_INTEGER Length;
} FILE_ALLOCATED_RANGE_BUFFER, *PFILE_ALLOCATED_RANGE_BUFFER;

Members

FileOffset

On FSCTL input, contains the file offset in bytes of the start of a range of bytes in a file. FileOffset must be greater than or equal to 0.

On FSCTL output, contains the file offset in bytes from the start of the file; the start of a range of bytes to which storage is allocated. If the file is a sparse file, FileOffset can contain ranges of bytes for which storage is not allocated; these ranges will be excluded from the list of allocated ranges returned by FSCTL_QUERY_ALLOCATED_RANGES. Because an application using a sparse file can choose whether or not to allocate disk space for each sequence of 0x00-valued bytes, the allocated ranges can contain 0x00-valued bytes. This value must be greater than or equal to 0 on output.

Length

Contains the size in bytes of the range. On FSCTL input, Length must be greater than or equal to 0. On FSCTL output, Length must be greater than 0.

Requirements

Requirement Value
Minimum supported client Windows 2000
Header ntifs.h

See also

FSCTL_QUERY_ALLOCATED_RANGES