annotate tests/test-phase-archived.t @ 47120:7109a38830c9

dirstate-tree: Fold "tracked descendants" counter update in main walk

For the purpose of implementing `has_tracked_dir` (which means "has tracked
descendants) without an expensive sub-tree traversal, we maintaing a counter
of tracked descendants on each "directory" node of the tree-shaped dirstate.

Before this changeset, mutating or inserting a node at a given path would
involve:

* Walking the tree from root through ancestors to find the node or the spot
  where to insert it
* Looking at the previous node if any to decide what counter update is needed
* Performing any node mutation
* Walking the tree *again* to update counters in ancestor nodes

When profiling `hg status` on a large repo, this second walk takes times
while loading a the dirstate from disk.

It turns out we have enough information to decide before he first tree walk
what counter update is needed. This changeset merges the two walks, gaining
~10% of the total time for `hg update` (in the same hyperfine benchmark as
the previous changeset).

---

Profiling was done by compiling with this `.cargo/config`:

    [profile.release]
    debug = true

then running with:

    py-spy record -r 500 -n -o /tmp/hg.json --format speedscope -- \
    ./hg status -R $REPO --config experimental.dirstate-tree.in-memory=1

then visualizing the recorded JSON file in https://www.speedscope.app/

Differential Revision: https://phab.mercurial-scm.org/D10554

=========================================================
Test features and behaviors related to the archived phase
=========================================================

  $ cat << EOF >> $HGRCPATH
  > [format]
  > internal-phase=yes
  > [extensions]
  > strip=
  > [experimental]
  > EOF

  $ hg init repo
  $ cd repo
  $ echo  root > a
  $ hg add a
  $ hg ci -m 'root'

Test that bundle can unarchive a changeset
------------------------------------------

  $ echo foo >> a
  $ hg st
  M a
  $ hg ci -m 'unbundletesting'
  $ hg log -G
  @  changeset:   1:883aadbbf309
  |  tag:         tip
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     unbundletesting
  |
  o  changeset:   0:c1863a3840c6
     user:        test
     date:        Thu Jan 01 00:00:00 1970 +0000
     summary:     root
  
  $ hg strip --soft --rev '.'
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  saved backup bundle to $TESTTMP/repo/.hg/strip-backup/883aadbbf309-efc55adc-backup.hg
  $ hg log -G
  @  changeset:   0:c1863a3840c6
     tag:         tip
     user:        test
     date:        Thu Jan 01 00:00:00 1970 +0000
     summary:     root
  
  $ hg log -G --hidden
  o  changeset:   1:883aadbbf309
  |  tag:         tip
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     unbundletesting
  |
  @  changeset:   0:c1863a3840c6
     user:        test
     date:        Thu Jan 01 00:00:00 1970 +0000
     summary:     root
  
  $ hg unbundle .hg/strip-backup/883aadbbf309-efc55adc-backup.hg
  adding changesets
  adding manifests
  adding file changes
  added 0 changesets with 0 changes to 1 files
  (run 'hg update' to get a working copy)
  $ hg log -G
  o  changeset:   1:883aadbbf309
  |  tag:         tip
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     unbundletesting
  |
  @  changeset:   0:c1863a3840c6
     user:        test
     date:        Thu Jan 01 00:00:00 1970 +0000
     summary:     root
  

Test that history rewriting command can use the archived phase when allowed to
------------------------------------------------------------------------------

  $ hg up 'desc(unbundletesting)'
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo bar >> a
  $ hg commit --amend --config experimental.cleanup-as-archived=yes
  $ hg log -G
  @  changeset:   2:d1e73e428f29
  |  tag:         tip
  |  parent:      0:c1863a3840c6
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     unbundletesting
  |
  o  changeset:   0:c1863a3840c6
     user:        test
     date:        Thu Jan 01 00:00:00 1970 +0000
     summary:     root
  
  $ hg log -G --hidden
  @  changeset:   2:d1e73e428f29
  |  tag:         tip
  |  parent:      0:c1863a3840c6
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     unbundletesting
  |
  | o  changeset:   1:883aadbbf309
  |/   user:        test
  |    date:        Thu Jan 01 00:00:00 1970 +0000
  |    summary:     unbundletesting
  |
  o  changeset:   0:c1863a3840c6
     user:        test
     date:        Thu Jan 01 00:00:00 1970 +0000
     summary:     root
  
  $ ls -1 .hg/strip-backup/
  883aadbbf309-efc55adc-amend.hg
  883aadbbf309-efc55adc-backup.hg
  $ hg unbundle .hg/strip-backup/883aadbbf309*amend.hg
  adding changesets
  adding manifests
  adding file changes
  added 0 changesets with 0 changes to 1 files
  (run 'hg update' to get a working copy)
  $ hg log -G
  @  changeset:   2:d1e73e428f29
  |  tag:         tip
  |  parent:      0:c1863a3840c6
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     unbundletesting
  |
  | o  changeset:   1:883aadbbf309
  |/   user:        test
  |    date:        Thu Jan 01 00:00:00 1970 +0000
  |    summary:     unbundletesting
  |
  o  changeset:   0:c1863a3840c6
     user:        test
     date:        Thu Jan 01 00:00:00 1970 +0000
     summary:     root