tests/test-no-symlinks.t
author Gregory Szorc <gregory.szorc@gmail.com>
Wed, 04 Apr 2018 21:27:02 -0700
changeset 37438 7b7ca9ba2de5
parent 34814 2d49d2eb1ff2
child 39520 0612e4c6fda0
permissions -rw-r--r--
commands: don't violate storage abstractions in `manifest --all` Previously, we asked the store to emit its data files. For modern repos, this would use fncache to resolve the set of files then would stat() each file. For my copy of the mozilla-unified repository, this took 3.3-10s depending on the state of my filesystem cache to render 449,790 items. The previous behavior was a massive layering violation because it assumed tracked files would have specific filenames in specific directories. Alternate storage backends would violate this assumption. The new behavior scans the changelog entries for the set of files changed by each commit. It aggregates them into a set and then sorts and prints the result. This reliably takes ~16.3s on my machine. ~80% of the time is spent in zlib decompression. The performance regression is unfortunate. If we want to claw it back, we can create a proper storage API to query for the set of tracked files. I'm not opposed to doing that. But I'm in no hurry because I suspect ~0 people care about the performance of `hg manifest --all`. .. perf:: `hg manifest --all` is likely slower due to changing its implementation to respect storage interface boundaries. If you are impacted by this regression in a meaningful way, please make noise on the development mailing list and it can be dealt with. Differential Revision: https://phab.mercurial-scm.org/D3119

#require no-symlink

# The following script was used to create the bundle:
#
# hg init symlinks
# cd symlinks
# echo a > a
# mkdir d
# echo b > d/b
# ln -s a a.lnk
# ln -s d/b d/b.lnk
# hg ci -Am t
# hg bundle --base null ../test-no-symlinks.hg

Extract a symlink on a platform not supporting them

  $ hg init t
  $ cd t
  $ hg pull -q "$TESTDIR/bundles/test-no-symlinks.hg"
  $ hg update
  4 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cat a.lnk && echo
  a
  $ cat d/b.lnk && echo
  d/b

Copy a symlink and move another

  $ hg copy a.lnk d/a2.lnk
  $ hg mv d/b.lnk b2.lnk
  $ hg ci -Am copy
  $ cat d/a2.lnk && echo
  a
  $ cat b2.lnk && echo
  d/b

Bundle and extract again

  $ hg bundle --base null ../symlinks.hg
  2 changesets found
  $ cd ..
  $ hg init t2
  $ cd t2
  $ hg pull ../symlinks.hg
  pulling from ../symlinks.hg
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 2 changesets with 6 changes to 6 files
  new changesets d326ae2d01ee:71d85cf3ba90
  (run 'hg update' to get a working copy)
  $ hg update
  5 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cat a.lnk && echo
  a
  $ cat d/a2.lnk && echo
  a
  $ cat b2.lnk && echo
  d/b