view tests/test-conflict.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

  $ hg init
  $ cat << EOF > a
  > Small Mathematical Series.
  > One
  > Two
  > Three
  > Four
  > Five
  > Hop we are done.
  > EOF
  $ hg add a
  $ hg commit -m ancestor
  $ cat << EOF > a
  > Small Mathematical Series.
  > 1
  > 2
  > 3
  > 4
  > 5
  > Hop we are done.
  > EOF
  $ hg commit -m branch1
  $ hg co 0
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cat << EOF > a
  > Small Mathematical Series.
  > 1
  > 2
  > 3
  > 6
  > 8
  > Hop we are done.
  > EOF
  $ hg commit -m branch2
  created new head

  $ hg merge 1
  merging a
  warning: conflicts while merging a! (edit, then use 'hg resolve --mark')
  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]

  $ hg id
  618808747361+c0c68e4fe667+ tip

  $ echo "[commands]" >> $HGRCPATH
  $ echo "status.verbose=true" >> $HGRCPATH
  $ hg status
  M a
  ? a.orig
  # The repository is in an unfinished *merge* state.
  
  # Unresolved merge conflicts:
  # 
  #     a
  # 
  # To mark files as resolved:  hg resolve --mark FILE
  
  # To continue:    hg commit
  # To abort:       hg merge --abort
  
  $ hg status -Tjson
  [
   {
    "path": "a",
    "status": "M"
   },
   {
    "path": "a.orig",
    "status": "?"
   }
  ]

  $ cat a
  Small Mathematical Series.
  1
  2
  3
  <<<<<<< working copy: 618808747361 - test: branch2
  6
  8
  =======
  4
  5
  >>>>>>> merge rev:    c0c68e4fe667 - test: branch1
  Hop we are done.

  $ hg status --config commands.status.verbose=0
  M a
  ? a.orig

Verify custom conflict markers

  $ hg up -q --clean .
  $ cat <<EOF >> .hg/hgrc
  > [ui]
  > mergemarkertemplate = '{author} {rev}'
  > EOF

  $ hg merge 1
  merging a
  warning: conflicts while merging a! (edit, then use 'hg resolve --mark')
  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]

  $ cat a
  Small Mathematical Series.
  1
  2
  3
  <<<<<<< working copy: test 2
  6
  8
  =======
  4
  5
  >>>>>>> merge rev:    test 1
  Hop we are done.

Verify line splitting of custom conflict marker which causes multiple lines

  $ hg up -q --clean .
  $ cat >> .hg/hgrc <<EOF
  > [ui]
  > mergemarkertemplate={author} {rev}\nfoo\nbar\nbaz
  > EOF

  $ hg -q merge 1
  warning: conflicts while merging a! (edit, then use 'hg resolve --mark')
  [1]

  $ cat a
  Small Mathematical Series.
  1
  2
  3
  <<<<<<< working copy: test 2
  6
  8
  =======
  4
  5
  >>>>>>> merge rev:    test 1
  Hop we are done.

Verify line trimming of custom conflict marker using multi-byte characters

  $ hg up -q --clean .
  $ "$PYTHON" <<EOF
  > fp = open('logfile', 'wb')
  > fp.write(b'12345678901234567890123456789012345678901234567890' +
  >          b'1234567890') # there are 5 more columns for 80 columns
  > 
  > # 2 x 4 = 8 columns, but 3 x 4 = 12 bytes
  > fp.write(u'\u3042\u3044\u3046\u3048'.encode('utf-8'))
  > 
  > fp.close()
  > EOF
  $ hg add logfile
  $ hg --encoding utf-8 commit --logfile logfile

  $ cat >> .hg/hgrc <<EOF
  > [ui]
  > mergemarkertemplate={desc|firstline}
  > EOF

  $ hg -q --encoding utf-8 merge 1
  warning: conflicts while merging a! (edit, then use 'hg resolve --mark')
  [1]

  $ cat a
  Small Mathematical Series.
  1
  2
  3
  <<<<<<< working copy: 1234567890123456789012345678901234567890123456789012345...
  6
  8
  =======
  4
  5
  >>>>>>> merge rev:    branch1
  Hop we are done.

Verify basic conflict markers

  $ hg up -q --clean 2
  $ printf "\n[ui]\nmergemarkers=basic\n" >> .hg/hgrc

  $ hg merge 1
  merging a
  warning: conflicts while merging a! (edit, then use 'hg resolve --mark')
  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]

  $ cat a
  Small Mathematical Series.
  1
  2
  3
  <<<<<<< working copy
  6
  8
  =======
  4
  5
  >>>>>>> merge rev
  Hop we are done.

internal:merge3

  $ hg up -q --clean .

  $ hg merge 1 --tool internal:merge3
  merging a
  warning: conflicts while merging a! (edit, then use 'hg resolve --mark')
  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]
  $ cat a
  Small Mathematical Series.
  <<<<<<< working copy
  1
  2
  3
  6
  8
  ||||||| base
  One
  Two
  Three
  Four
  Five
  =======
  1
  2
  3
  4
  5
  >>>>>>> merge rev
  Hop we are done.

Add some unconflicting changes on each head, to make sure we really
are merging, unlike :local and :other

  $ hg up -C
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  updated to "e0693e20f496: 123456789012345678901234567890123456789012345678901234567890????"
  1 other heads for branch "default"
  $ printf "\n\nEnd of file\n" >> a
  $ hg ci -m "Add some stuff at the end"
  $ hg up -r 1
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ printf "Start of file\n\n\n" > tmp
  $ cat a >> tmp
  $ mv tmp a
  $ hg ci -m "Add some stuff at the beginning"

Now test :merge-other and :merge-local

  $ hg merge
  merging a
  warning: conflicts while merging a! (edit, then use 'hg resolve --mark')
  1 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]
  $ hg resolve --tool :merge-other a
  merging a
  (no more unresolved files)
  $ cat a
  Start of file
  
  
  Small Mathematical Series.
  1
  2
  3
  6
  8
  Hop we are done.
  
  
  End of file

  $ hg up -C
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  updated to "18b51d585961: Add some stuff at the beginning"
  1 other heads for branch "default"
  $ hg merge --tool :merge-local
  merging a
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ cat a
  Start of file
  
  
  Small Mathematical Series.
  1
  2
  3
  4
  5
  Hop we are done.
  
  
  End of file