view tests/test-diff-subdir.t @ 44838:c802ec4f7196

rust-status: collect traversed directories if required

Some commands (`hg purge` notably) register the `traversedir` callback on their
matcher to run said callback every time a directory is traversed.

This is the first of three patches, further broadening Rust support for status.

Unfortunately, there is no way around collecting a full `Vec` (or any other
owned datastructure, like a radix tree) and pushing it back up the Python layer
since keeping the Python callback in a closure would mean giving up
multithreading because of the GIL, which is obviously unacceptable.

Performance is still a lot better than the Python+C path.

Running `hg clean/purge` on Netbeans' repo (100k files):

```
     | No-op | 30% unknown
--------------------------
Rust | 1.0s  | 1.67s
C    | 2.0s  | 2.87s
```

Differential Revision: https://phab.mercurial-scm.org/D8518

  $ hg init

  $ mkdir alpha
  $ touch alpha/one
  $ mkdir beta
  $ touch beta/two

  $ hg add alpha/one beta/two
  $ hg ci -m "start"

  $ echo 1 > alpha/one
  $ echo 2 > beta/two

everything

  $ hg diff --nodates
  diff -r 7d5ef1aea329 alpha/one
  --- a/alpha/one
  +++ b/alpha/one
  @@ -0,0 +1,1 @@
  +1
  diff -r 7d5ef1aea329 beta/two
  --- a/beta/two
  +++ b/beta/two
  @@ -0,0 +1,1 @@
  +2

beta only

  $ hg diff --nodates beta
  diff -r 7d5ef1aea329 beta/two
  --- a/beta/two
  +++ b/beta/two
  @@ -0,0 +1,1 @@
  +2

inside beta

  $ cd beta
  $ hg diff --nodates .
  diff -r 7d5ef1aea329 beta/two
  --- a/beta/two
  +++ b/beta/two
  @@ -0,0 +1,1 @@
  +2

relative to beta

  $ cd ..
  $ hg diff --nodates --root beta
  diff -r 7d5ef1aea329 two
  --- a/two
  +++ b/two
  @@ -0,0 +1,1 @@
  +2

inside beta

  $ cd beta
  $ hg diff --nodates --root .
  diff -r 7d5ef1aea329 two
  --- a/two
  +++ b/two
  @@ -0,0 +1,1 @@
  +2

  $ cd ..