The entries are written out in the top-down, depth-first order. The
first entry represents the root level of the repository, followed by the
- first subtree---let's call this A---of the root level (with its name
+ first subtree--let's call this A--of the root level (with its name
relative to the root level), followed by the first subtree of A (with
its name relative to A), ...
in the previous ewah bitmap.
- One NUL.
+
+== File System Monitor cache
+
+ The file system monitor cache tracks files for which the core.fsmonitor
+ hook has told us about changes. The signature for this extension is
+ { 'F', 'S', 'M', 'N' }.
+
+ The extension starts with
+
+ - 32-bit version number: the current supported version is 1.
+
+ - 64-bit time: the extension data reflects all changes through the given
+ time which is stored as the nanoseconds elapsed since midnight,
+ January 1, 1970.
+
+ - 32-bit bitmap size: the size of the CE_FSMONITOR_VALID bitmap.
+
+ - An ewah bitmap, the n-th bit indicates whether the n-th index entry
+ is not CE_FSMONITOR_VALID.