view tests/test-narrow-debugrebuilddirstate.t @ 44861:065421e12248

files: speed up `hg files` when no flags change display

It's not the first time I see slowness from this command slow down
tools built on top of hg.

The majority of the time is spent merely printing the result before
this change, which is clearly not how it should be (especially since
the computation of the result also looks slow).

Running `hg files` in mozilla-central:

parent revision: 1,260s
this commit: 0,683s
this commit without batching ui.write: 0,931s
this commit replacing the body of the loop with `pass`: 0,566s

This looks like a prime candidate for a rust fast path, but until
then, it seems reasonable to optimize the python.

Differential Revision: https://phab.mercurial-scm.org/D8586

  $ . "$TESTDIR/narrow-library.sh"
  $ hg init master
  $ cd master
  $ echo treemanifest >> .hg/requires
  $ echo 'contents of file' > file
  $ mkdir foo
  $ echo 'contents of foo/bar' > foo/bar
  $ hg ci -Am 'some change'
  adding file
  adding foo/bar

  $ cd ..
  $ hg clone --narrow ssh://user@dummy/master copy --include=foo
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files
  new changesets * (glob)
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd copy

  $ hg debugdirstate --no-dates
  n *         20 *               foo/bar (glob)
  $ mv .hg/dirstate .hg/old_dirstate
  $ dd bs=40 count=1 if=.hg/old_dirstate of=.hg/dirstate 2>/dev/null
  $ hg debugdirstate
  $ hg debugrebuilddirstate
  $ hg debugdirstate
  n *         * unset               foo/bar (glob)