When the virtualfilesystem is enabled the previous implementation of
clear_ce_flags would iterate all of the cache entries and query whether
each one is in the virtual filesystem to determine whether to clear one
of the SKIP_WORKTREE bits. For each cache entry, we would do a hash
lookup for each parent directory in the is_included_in_virtualfilesystem
function.
The former approach is slow for a typical Windows OS enlistment with
3 million files where only a small percentage is in the virtual
filesystem. The cost is
O(n_index_entries * n_chars_per_path * n_parent_directories_per_path).
In this change, we use the same approach as apply_virtualfilesystem,
which iterates the set of entries in the virtualfilesystem and searches
in the cache for the corresponding entries in order to clear their
flags. This approach has a cost of
O(n_virtual_filesystem_entries * n_chars_per_path * log(n_index_entries)).
The apply_virtualfilesystem code was refactored a bit and modified to
clear flags for all names that 'alias' a given virtual filesystem name
when ignore_case is set.
n_virtual_filesystem_entries is typically much less than
n_index_entries, in which case the new approach is much faster. We wind
up building the name hash for the index, but this occurs quickly thanks
to the multi-threading.
Signed-off-by: Neeraj Singh <neerajsi@ntdev.microsoft.com>
The vfs does not correctly handle the case when there is a file
that begins with the same prefix as a directory. For example, the
following setup would encounter this issue:
A directory contains a file named `dir1.sln` and a directory
named `dir1/`.
The directory `dir1` contains other files.
The directory `dir1` is in the virtual file system list
The contents of `dir1` should be in the virtual file system, but
it is not. The contents of this directory do not have the skip
worktree bit cleared as expected. The problem is in the
`apply_virtualfilesystem(...)` function where it does not include
the trailing slash of the directory name when looking up the
position in the index to start clearing the skip worktree bit.
This fix is it include the trailing slash when finding the first
index entry from `index_name_pos(...)`.
Add check to see if a directory is included in the virtualfilesystem
before checking the directory hashmap. This allows a directory entry
like foo/ to find all untracked files in subdirectories.
The virtual file system code incorrectly treated symlinks as directories
instead of regular files. This meant symlinks were not included even if
they are listed in the list of files returned by the core.virtualFilesystem
hook proc. Fixes#25
Signed-off-by: Ben Peart <Ben.Peart@microsoft.com>
On index load, clear/set the skip worktree bits based on the virtual
file system data. Use virtual file system data to update skip-worktree
bit in unpack-trees. Use virtual file system data to exclude files and
folders not explicitly requested.
Update 2022-04-05: disable the "present-despite-SKIP_WORKTREE" file removal
behavior when 'core.virtualfilesystem' is enabled.
Signed-off-by: Ben Peart <benpeart@microsoft.com>
Neeraj Singh
Jeff Hostetler
Jameson Miller
Kevin Willford
Ben Peart