Re: [PATCH v2 0/6] Fast git status via a file system watcher

> Design
> ~~~~~~
>
> A new git hook (query-fsmonitor) must exist and be enabled
> (core.fsmonitor=true) that takes a time_t formatted as a string and
> outputs to stdout all files that have been modified since the requested
> time.

> A new 'fsmonitor' index extension has been added to store the time the
> fsmonitor hook was last queried and a ewah bitmap of the current
> 'fsmonitor-dirty' files. Unmarked entries are 'fsmonitor-clean', marked
> entries are 'fsmonitor-dirty.'
>
> As needed, git will call the query-fsmonitor hook proc for the set of
> changes since the index was last updated. Git then uses this set of
> files along with the list saved in the fsmonitor index extension to flag
> the potentially dirty index and untracked cache entries.