Summary:
It was starting to get pretty complex to manage locking across the
inodes, filedata, overlay and soon the journal, so as a simplifying step, this
folds data that was tracked by the overlay into the TreeInode itself.
This is the first diff in a short series for this. This one:
1. Breaks the persistent overlay information, so shutting down eden and
bringing it back up will lose your changes (to be restored in the
following diff)
2. Allows deferring materialization of file data in more cases
3. Allows renaming dirs.
The approach here is now to keep just one source of information about the
directory contents; when we construct a TreeInode we import this data from the
Tree and then apply mutations to it locally.
Each inode can be mutated indepdently from others; we only need to lock the 1,
2 or 3 participating inodes in the various mutation operations.
I'll tackle persistence of the mutations in the following diff, but the high
level plan for that (to help understand this diff) is to always keep the
directory inodes for mutations alive as inode objects. We make use of the
canForget functionality introduced by D3774269 to ensure that these don't
get evicted early. On startup we'll load this information from the overlay
area.
This model simplifies some of the processing around reading dirs and looking up
children.
Since the overlay data now tracks the appropriate tree or content hash
we can be much more lazy at materializing data, especially in the rename
case. For example, renaming "fbcode" to "fbcod" doesn't require us to
recursively materialize the "fbcode" tree.
Depends on D3653706
Reviewed By: simpkins
Differential Revision: D3657894
fbshipit-source-id: d4561639845ca93b93487dc84bf11ad795927b1f
Summary:
If a directory is present in the overlay, we still need to check if a TreeEntry
exists from the source control data structures. Previously this was causing us
to incorrectly report directories as empty if they exist in the local overlay,
even when they had contents from the main Tree.
Reviewed By: wez
Differential Revision: D3434219
fbshipit-source-id: f872f90075602dfdc7b217f50eefcd7c248512e7
Summary:
We look this up via the mount point or eden mount object instead.
I've also removed the mercurial library stuff that was added to support the now defunct lamehg fuse we had in the earlier days.
simpkins' new importer doesn't use these and it resolves our CI mismatch issue.
Reviewed By: bolinfest
Differential Revision: D3349698
fbshipit-source-id: 5f4ec16b76042959cd1e3184f46bb3526fbaf74c
