Re: [PATCH 21/23] fsmonitor: optimize processing of directory events

> From: Jeff Hostetler <jeffhost@microsoft.com>
> 
> Teach Git to perform binary search over the cache-entries for a directory
> notification and then linearly scan forward to find the immediate children.
> 
> Previously, when the FSMonitor reported a modified directory Git would
> perform a linear search on the entire cache-entry array for all
> entries matching that directory prefix and invalidate them.  Since the
> cache-entry array is already sorted, we can use a binary search to
> find the first matching entry and then only linearly walk forward and
> invalidate entries until the prefix changes.
> 
> Also, the original code would invalidate anything having the same
> directory prefix.  Since a directory event should only be received for
> items that are immediately within the directory (and not within
> sub-directories of it), only invalidate those entries and not the
> whole subtree.