pub const GD_AT_END: u64 = 0xffff_ffff_ffff_ffff;Expand description
Sentinel gdOffset in the primary header of a streamOptimized extent.
When gdOffset == GD_AT_END the real GD location is in the footer header
appended to the end of the file: SparseExtentHeader at file_end − 1024,
followed by an EOS marker at file_end − 512 (VDF 1.1 §4.6).