FileStamp

What a build graph keeps of a path to notice that it changed.

In the namespace platform::filesystem. Declared in src/libs/libplatform/platform/FileSystem.hpp.

Detailed description

kiln's graph (build-graph §KN-BG4, §KN-BG5) compares these instead of reading content: a file whose stamp did not move is not hashed again. The identity is what makes a rename or a move recognisable as the same file.

POSIX: lstat — st_size, st_mtim to the nanosecond, st_ino. Windows: GetFileInformationByHandle — the size, the last write time in 100 ns steps, and the 64-bit file index. The index survives a rename on the same volume, as an inode does.

A path that does not exist gives exists false and zeros.