view tests/test-fix-topology.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

A script that implements uppercasing all letters in a file.

  $ UPPERCASEPY="$TESTTMP/uppercase.py"
  $ cat > $UPPERCASEPY <<EOF
  > import sys
  > from mercurial.utils.procutil import setbinary
  > setbinary(sys.stdin)
  > setbinary(sys.stdout)
  > sys.stdout.write(sys.stdin.read().upper())
  > EOF
  $ TESTLINES="foo\nbar\nbaz\n"
  $ printf $TESTLINES | "$PYTHON" $UPPERCASEPY
  FOO
  BAR
  BAZ

Tests for the fix extension's behavior around non-trivial history topologies.
Looks for correct incremental fixing and reproduction of parent/child
relationships. We indicate fixed file content by uppercasing it.

  $ cat >> $HGRCPATH <<EOF
  > [extensions]
  > fix =
  > [fix]
  > uppercase-whole-file:command="$PYTHON" $UPPERCASEPY
  > uppercase-whole-file:pattern=set:**
  > EOF

This tests the only behavior that should really be affected by obsolescence, so
we'll test it with evolution off and on. This only changes the revision
numbers, if all is well.

#testcases obsstore-off obsstore-on
#if obsstore-on
  $ cat >> $HGRCPATH <<EOF
  > [experimental]
  > evolution.createmarkers=True
  > evolution.allowunstable=True
  > EOF
#endif

Setting up the test topology. Scroll down to see the graph produced. We make it
clear which files were modified in each revision. It's enough to test at the
file granularity, because that demonstrates which baserevs were diffed against.
The computation of changed lines is orthogonal and tested separately.

  $ hg init repo
  $ cd repo

  $ printf "aaaa\n" > a
  $ hg commit -Am "change A"
  adding a
  $ printf "bbbb\n" > b
  $ hg commit -Am "change B"
  adding b
  $ printf "cccc\n" > c
  $ hg commit -Am "change C"
  adding c
  $ hg checkout 0
  0 files updated, 0 files merged, 2 files removed, 0 files unresolved
  $ printf "dddd\n" > d
  $ hg commit -Am "change D"
  adding d
  created new head
  $ hg merge -r 2
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ printf "eeee\n" > e
  $ hg commit -Am "change E"
  adding e
  $ hg checkout 0
  0 files updated, 0 files merged, 4 files removed, 0 files unresolved
  $ printf "ffff\n" > f
  $ hg commit -Am "change F"
  adding f
  created new head
  $ hg checkout 0
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ printf "gggg\n" > g
  $ hg commit -Am "change G"
  adding g
  created new head
  $ hg merge -r 5
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ printf "hhhh\n" > h
  $ hg commit -Am "change H"
  adding h
  $ hg merge -r 4
  4 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ printf "iiii\n" > i
  $ hg commit -Am "change I"
  adding i
  $ hg checkout 2
  0 files updated, 0 files merged, 6 files removed, 0 files unresolved
  $ printf "jjjj\n" > j
  $ hg commit -Am "change J"
  adding j
  created new head
  $ hg checkout 7
  3 files updated, 0 files merged, 3 files removed, 0 files unresolved
  $ printf "kkkk\n" > k
  $ hg add
  adding k

  $ hg log --graph --template '{rev} {desc}\n'
  o  9 change J
  |
  | o    8 change I
  | |\
  | | @    7 change H
  | | |\
  | | | o  6 change G
  | | | |
  | | o |  5 change F
  | | |/
  | o |  4 change E
  |/| |
  | o |  3 change D
  | |/
  o |  2 change C
  | |
  o |  1 change B
  |/
  o  0 change A
  

Fix all but the root revision and its four children.

#if obsstore-on
  $ hg fix -r '2|4|7|8|9' --working-dir
#else
  $ hg fix -r '2|4|7|8|9' --working-dir
  saved backup bundle to * (glob)
#endif

The five revisions remain, but the other revisions were fixed and replaced. All
parent pointers have been accurately set to reproduce the previous topology
(though it is rendered in a slightly different order now).

#if obsstore-on
  $ hg log --graph --template '{rev} {desc}\n'
  o  14 change J
  |
  | o    13 change I
  | |\
  | | @    12 change H
  | | |\
  | o | |  11 change E
  |/| | |
  o | | |  10 change C
  | | | |
  | | | o  6 change G
  | | | |
  | | o |  5 change F
  | | |/
  | o /  3 change D
  | |/
  o /  1 change B
  |/
  o  0 change A
  
  $ C=10
  $ E=11
  $ H=12
  $ I=13
  $ J=14
#else
  $ hg log --graph --template '{rev} {desc}\n'
  o  9 change J
  |
  | o    8 change I
  | |\
  | | @    7 change H
  | | |\
  | o | |  6 change E
  |/| | |
  o | | |  5 change C
  | | | |
  | | | o  4 change G
  | | | |
  | | o |  3 change F
  | | |/
  | o /  2 change D
  | |/
  o /  1 change B
  |/
  o  0 change A
  
  $ C=5
  $ E=6
  $ H=7
  $ I=8
  $ J=9
#endif

Change C is a root of the set being fixed, so all we fix is what has changed
since its parent. That parent, change B, is its baserev.

  $ hg cat -r $C 'set:**'
  aaaa
  bbbb
  CCCC

Change E is a merge with only one parent being fixed. Its baserevs are the
unfixed parent plus the baserevs of the other parent. This evaluates to changes
B and D. We now have to decide what it means to incrementally fix a merge
commit. We choose to fix anything that has changed versus any baserev. Only the
undisturbed content of the common ancestor, change A, is unfixed.

  $ hg cat -r $E 'set:**'
  aaaa
  BBBB
  CCCC
  DDDD
  EEEE

Change H is a merge with neither parent being fixed. This is essentially
equivalent to the previous case because there is still only one baserev for
each parent of the merge.

  $ hg cat -r $H 'set:**'
  aaaa
  FFFF
  GGGG
  HHHH

Change I is a merge that has four baserevs; two from each parent. We handle
multiple baserevs in the same way regardless of how many came from each parent.
So, fixing change H will fix any files that were not exactly the same in each
baserev.

  $ hg cat -r $I 'set:**'
  aaaa
  BBBB
  CCCC
  DDDD
  EEEE
  FFFF
  GGGG
  HHHH
  IIII

Change J is a simple case with one baserev, but its baserev is not its parent,
change C. Its baserev is its grandparent, change B.

  $ hg cat -r $J 'set:**'
  aaaa
  bbbb
  CCCC
  JJJJ

The working copy was dirty, so it is treated much like a revision. The baserevs
for the working copy are inherited from its parent, change H, because it is
also being fixed.

  $ cat *
  aaaa
  FFFF
  GGGG
  HHHH
  KKKK

Change A was never a baserev because none of its children were to be fixed.

  $ cd ..

The --all flag should fix anything that wouldn't cause a problem if you fixed
it, including the working copy. Obsolete revisions are not fixed because that
could cause divergence. Public revisions would cause an abort because they are
immutable. We can fix orphans because their successors are still just orphans
of the original obsolete parent. When obsolesence is off, we're just fixing and
replacing anything that isn't public.

  $ hg init fixall
  $ cd fixall

#if obsstore-on
  $ printf "one\n" > foo.whole
  $ hg commit -Aqm "first"
  $ hg phase --public
  $ hg tag --local root
  $ printf "two\n" > foo.whole
  $ hg commit -m "second"
  $ printf "three\n" > foo.whole
  $ hg commit -m "third" --secret
  $ hg tag --local secret
  $ hg checkout root
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ printf "four\n" > foo.whole
  $ hg commit -m "fourth"
  created new head
  $ printf "five\n" > foo.whole
  $ hg commit -m "fifth"
  $ hg tag --local replaced
  $ printf "six\n" > foo.whole
  $ hg commit -m "sixth"
  $ hg checkout replaced
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ printf "seven\n" > foo.whole
  $ hg commit --amend
  1 new orphan changesets
  $ hg checkout secret
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ printf "uncommitted\n" > foo.whole

  $ hg log --graph --template '{rev} {desc} {phase}\n'
  o  6 fifth draft
  |
  | *  5 sixth draft
  | |
  | x  4 fifth draft
  |/
  o  3 fourth draft
  |
  | @  2 third secret
  | |
  | o  1 second draft
  |/
  o  0 first public
  

  $ hg fix --all

  $ hg log --graph --template '{rev} {desc}\n' -r 'sort(all(), topo)' --hidden
  o  11 fifth
  |
  o  9 fourth
  |
  | @  8 third
  | |
  | o  7 second
  |/
  | *  10 sixth
  | |
  | | x  5 sixth
  | |/
  | x  4 fifth
  | |
  | | x  6 fifth
  | |/
  | x  3 fourth
  |/
  | x  2 third
  | |
  | x  1 second
  |/
  o  0 first
  

  $ hg cat -r 7 foo.whole
  TWO
  $ hg cat -r 8 foo.whole
  THREE
  $ hg cat -r 9 foo.whole
  FOUR
  $ hg cat -r 10 foo.whole
  SIX
  $ hg cat -r 11 foo.whole
  SEVEN
  $ cat foo.whole
  UNCOMMITTED
#else
  $ printf "one\n" > foo.whole
  $ hg commit -Aqm "first"
  $ hg phase --public
  $ hg tag --local root
  $ printf "two\n" > foo.whole
  $ hg commit -m "second"
  $ printf "three\n" > foo.whole
  $ hg commit -m "third" --secret
  $ hg tag --local secret
  $ hg checkout root
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ printf "four\n" > foo.whole
  $ hg commit -m "fourth"
  created new head
  $ printf "uncommitted\n" > foo.whole

  $ hg log --graph --template '{rev} {desc} {phase}\n'
  @  3 fourth draft
  |
  | o  2 third secret
  | |
  | o  1 second draft
  |/
  o  0 first public
  

  $ hg fix --all
  saved backup bundle to * (glob)

  $ hg log --graph --template '{rev} {desc} {phase}\n'
  @  3 fourth draft
  |
  | o  2 third secret
  | |
  | o  1 second draft
  |/
  o  0 first public
  
  $ hg cat -r 0 foo.whole
  one
  $ hg cat -r 1 foo.whole
  TWO
  $ hg cat -r 2 foo.whole
  THREE
  $ hg cat -r 3 foo.whole
  FOUR
  $ cat foo.whole
  UNCOMMITTED
#endif

  $ cd ..