view tests/test-sparse-merges.t @ 42743:8c9a6adec67a

rust-discovery: using the children cache in add_missing

The DAG range computation often needs to get back to very old
revisions, and turns out to be disproportionately long, given
that the end goal is to remove the descendents of the given
missing revisons from the undecided set.

The fast iteration capabilities available in the Rust case make
it possible to avoid the DAG range entirely, at the cost of
precomputing the children cache, and to simply iterate on
children of the given missing revisions.

This is a case where staying on the same side of the interface
between the two languages has clear benefits.

On discoveries with initial undecided sets
small enough to bypass sampling entirely, the total cost of
computing the children cache and the subsequent iteration
becomes better than the Python + C counterpart, which relies on
reachableroots2.

For example, on a repo with more than one million revisions with
an initial undecided set of 11 elements, we get these figures:

Rust version with simple iteration
  addcommons: 57.287us
  first undecided computation: 184.278334ms
  first children cache computation: 131.056us
  addmissings iteration: 42.766us
  first addinfo total: 185.24 ms

Python + C version
  first addcommons: 0.29 ms
  addcommons 0.21 ms
  first undecided computation 191.35 ms
  addmissings 45.75 ms
  first addinfo total: 237.77 ms

On discoveries with large undecided sets, the initial price paid
makes the first addinfo slower than the Python + C version,
but that's more than compensated by the gain in sampling and
subsequent iterations.
Here's an extreme example with an undecided set of a million revisions:

Rust version:
  first undecided computation: 293.842629ms
  first children cache computation: 407.911297ms
  addmissings iteration: 34.312869ms
  first addinfo total: 776.02 ms
  taking initial sample
  query 2: sampling time: 1318.38 ms
  query 2; still undecided: 1005013, sample size is: 200
  addmissings: 143.062us

Python + C version:
  first undecided computation 298.13 ms
  addmissings 80.13 ms
  first addinfo total: 399.62 ms
  taking initial sample
  query 2: sampling time: 3957.23 ms
  query 2; still undecided: 1005013, sample size is: 200
  addmissings 52.88 ms

Differential Revision: https://phab.mercurial-scm.org/D6428

test merging things outside of the sparse checkout

  $ hg init myrepo
  $ cd myrepo
  $ cat > .hg/hgrc <<EOF
  > [extensions]
  > sparse=
  > EOF

  $ echo foo > foo
  $ echo bar > bar
  $ hg add foo bar
  $ hg commit -m initial

  $ hg branch feature
  marked working directory as branch feature
  (branches are permanent and global, did you want a bookmark?)
  $ echo bar2 >> bar
  $ hg commit -m 'feature - bar2'

  $ hg update -q default
  $ hg debugsparse --exclude 'bar**'

  $ hg merge feature
  temporarily included 1 file(s) in the sparse checkout for merging
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

Verify bar was merged temporarily

  $ ls
  bar
  foo
  $ hg status
  M bar

Verify bar disappears automatically when the working copy becomes clean

  $ hg commit -m "merged"
  cleaned up 1 temporarily added file(s) from the sparse checkout
  $ hg status
  $ ls
  foo

  $ hg cat -r . bar
  bar
  bar2

Test merging things outside of the sparse checkout that are not in the working
copy

  $ hg strip -q -r . --config extensions.strip=
  $ hg up -q feature
  $ touch branchonly
  $ hg ci -Aqm 'add branchonly'

  $ hg up -q default
  $ hg debugsparse -X branchonly
  $ hg merge feature
  temporarily included 2 file(s) in the sparse checkout for merging
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

  $ cd ..

Tests merging a file which is modified in one branch and deleted in another and
file is excluded from sparse checkout

  $ hg init ytest
  $ cd ytest
  $ echo "syntax: glob" >> .hgignore
  $ echo "*.orig" >> .hgignore
  $ hg ci -Aqm "added .hgignore"
  $ for ch in a d; do echo foo > $ch; hg ci -Aqm "added "$ch; done;
  $ cat >> .hg/hgrc <<EOF
  > [alias]
  > glog = log -GT "{rev}:{node|short} {desc}"
  > [extensions]
  > sparse =
  > EOF

  $ hg glog
  @  2:f29feff37cfc added d
  |
  o  1:617125d27d6b added a
  |
  o  0:53f3774ed939 added .hgignore
  
  $ hg rm d
  $ hg ci -m "removed d"

  $ hg up '.^'
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg debugsparse --reset
  $ echo bar >> d
  $ hg ci -Am "added bar to d"
  created new head

  $ hg glog
  @  4:6527874a90e4 added bar to d
  |
  | o  3:372c8558de45 removed d
  |/
  o  2:f29feff37cfc added d
  |
  o  1:617125d27d6b added a
  |
  o  0:53f3774ed939 added .hgignore
  
  $ hg debugsparse --exclude "d"
  $ ls
  a

  $ hg merge
  temporarily included 1 file(s) in the sparse checkout for merging
  file 'd' was deleted in other [merge rev] but was modified in local [working copy].
  You can use (c)hanged version, (d)elete, or leave (u)nresolved.
  What do you want to do? u
  0 files updated, 0 files merged, 0 files removed, 1 files unresolved
  use 'hg resolve' to retry unresolved file merges or 'hg merge --abort' to abandon
  [1]

  $ cd ..

Testing merging of a file which is renamed+modified on one side and modified on
another

  $ hg init mvtest
  $ cd mvtest
  $ echo "syntax: glob" >> .hgignore
  $ echo "*.orig" >> .hgignore
  $ hg ci -Aqm "added .hgignore"
  $ for ch in a d; do echo foo > $ch; hg ci -Aqm "added "$ch; done;
  $ cat >> .hg/hgrc <<EOF
  > [alias]
  > glog = log -GT "{rev}:{node|short} {desc}"
  > [extensions]
  > sparse =
  > EOF

  $ hg glog
  @  2:f29feff37cfc added d
  |
  o  1:617125d27d6b added a
  |
  o  0:53f3774ed939 added .hgignore
  
  $ echo babar >> a
  $ hg ci -m "added babar to a"

  $ hg up '.^'
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg mv a amove
  $ hg ci -m "moved a to amove"
  created new head

  $ hg up 3
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ hg glog
  o  4:5d1e85955f6d moved a to amove
  |
  | @  3:a06e41a6c16c added babar to a
  |/
  o  2:f29feff37cfc added d
  |
  o  1:617125d27d6b added a
  |
  o  0:53f3774ed939 added .hgignore
  
  $ hg debugsparse --exclude "a"
  $ ls
  d

  $ hg merge
  temporarily included 1 file(s) in the sparse checkout for merging
  merging a and amove to amove
  0 files updated, 1 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

  $ hg up -C 4
  cleaned up 1 temporarily added file(s) from the sparse checkout
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ hg merge
  merging amove and a to amove
  abort: cannot add 'a' - it is outside the sparse checkout
  (include file with `hg debugsparse --include <pattern>` or use `hg add -s <file>` to include file directory while adding)
  [255]