view tests/test-histedit-fold-non-commute.t @ 44363:f7459da77f23

nodemap: introduce an option to use mmap to read the nodemap mapping

The performance and memory benefit is much greater if we don't have to copy all
the data in memory for each information. So we introduce an option (on by
default) to read the data using mmap.

This changeset is the last one definition the API for index support nodemap
data. (they have to be able to use the mmaping).

Below are some benchmark comparing the best we currently have in 5.3 with the
final step of this series (using the persistent nodemap implementation in
Rust). The benchmark run `hg perfindex` with various revset and the following
variants:

Before:

 * do not use the persistent nodemap
 * use the CPython implementation of the index for nodemap
 * use mmapping of the changelog index

After:

 * use the MixedIndex Rust code, with the NodeTree object for nodemap access
   (still in review)
 * use the persistent nodemap data from disk
 * access the persistent nodemap data through mmap
 * use mmapping of the changelog index

The persistent nodemap greatly speed up  most operation on very large
repositories. Some of the previously very fast lookup end up a bit slower because
the persistent nodemap has to be setup. However the absolute slowdown is very
small and won't matters in the big picture.

Here are some numbers (in seconds) for the reference copy of mozilla-try:

Revset            Before   After     abs-change speedup

-10000:           0.004622 0.005532   0.000910  ×   0.83
-10:              0.000050 0.000132   0.000082  ×   0.37
tip               0.000052 0.000085   0.000033  ×   0.61
0 + (-10000:)     0.028222 0.005337  -0.022885  ×   5.29
0                 0.023521 0.000084  -0.023437  × 280.01
(-10000:) + 0     0.235539 0.005308  -0.230231  ×  44.37
(-10:) + :9       0.232883 0.000180  -0.232703  ×1293.79
(-10000:) + (:99) 0.238735 0.005358  -0.233377  ×  44.55
:99 + (-10000:)   0.317942 0.005593  -0.312349  ×  56.84
:9 + (-10:)       0.313372 0.000179  -0.313193  ×1750.68
:9                0.316450 0.000143  -0.316307  ×2212.93


On smaller repositories, the cost of nodemap related operation is not as big, so
the win is much more modest. Yet it helps shaving a handful of millisecond here
and there.

Here are some numbers (in seconds) for the reference copy of mercurial:

Revset            Before   After     abs-change speedup
-10:              0.000065 0.000097   0.000032  × 0.67
tip               0.000063 0.000078   0.000015  × 0.80
0                 0.000561 0.000079  -0.000482  × 7.10
-10000:           0.004609 0.003648  -0.000961  × 1.26
0 + (-10000:)     0.005023 0.003715  -0.001307  × 1.35
(-10:) + :9       0.002187 0.000108  -0.002079  ×20.25
(-10000:) + 0     0.006252 0.003716  -0.002536  × 1.68
(-10000:) + (:99) 0.006367 0.003707  -0.002660  × 1.71
:9 + (-10:)       0.003846 0.000110  -0.003736  ×34.96
:9                0.003854 0.000099  -0.003755  ×38.92
:99 + (-10000:)   0.007644 0.003778  -0.003866  × 2.02

Differential Revision: https://phab.mercurial-scm.org/D7894

  $ . "$TESTDIR/histedit-helpers.sh"

  $ cat >> $HGRCPATH <<EOF
  > [extensions]
  > histedit=
  > EOF

  $ modwithdate ()
  > {
  >     echo $1 > $1
  >     hg ci -m $1 -d "$2 0"
  > }

  $ initrepo ()
  > {
  >     hg init $1
  >     cd $1
  >     for x in a b c d e f ; do
  >         echo $x$x$x$x$x > $x
  >         hg add $x
  >     done
  >     hg ci -m 'Initial commit'
  >     modwithdate a 1
  >     modwithdate b 2
  >     modwithdate c 3
  >     modwithdate d 4
  >     modwithdate e 5
  >     modwithdate f 6
  >     echo 'I can haz no commute' > e
  >     hg ci -m 'does not commute with e' -d '7 0'
  >     cd ..
  > }

  $ initrepo r
  $ cd r
Initial generation of the command files

  $ EDITED="$TESTTMP/editedhistory"
  $ hg log --template 'pick {node|short} {rev} {desc}\n' -r 3 >> $EDITED
  $ hg log --template 'pick {node|short} {rev} {desc}\n' -r 4 >> $EDITED
  $ hg log --template 'fold {node|short} {rev} {desc}\n' -r 7 >> $EDITED
  $ hg log --template 'pick {node|short} {rev} {desc}\n' -r 5 >> $EDITED
  $ hg log --template 'pick {node|short} {rev} {desc}\n' -r 6 >> $EDITED
  $ cat $EDITED
  pick 092e4ce14829 3 c
  pick ae78f4c9d74f 4 d
  fold 42abbb61bede 7 does not commute with e
  pick 7f3755409b00 5 e
  pick dd184f2faeb0 6 f

log before edit
  $ hg log --graph
  @  changeset:   7:42abbb61bede
  |  tag:         tip
  |  user:        test
  |  date:        Thu Jan 01 00:00:07 1970 +0000
  |  summary:     does not commute with e
  |
  o  changeset:   6:dd184f2faeb0
  |  user:        test
  |  date:        Thu Jan 01 00:00:06 1970 +0000
  |  summary:     f
  |
  o  changeset:   5:7f3755409b00
  |  user:        test
  |  date:        Thu Jan 01 00:00:05 1970 +0000
  |  summary:     e
  |
  o  changeset:   4:ae78f4c9d74f
  |  user:        test
  |  date:        Thu Jan 01 00:00:04 1970 +0000
  |  summary:     d
  |
  o  changeset:   3:092e4ce14829
  |  user:        test
  |  date:        Thu Jan 01 00:00:03 1970 +0000
  |  summary:     c
  |
  o  changeset:   2:40ccdd8beb95
  |  user:        test
  |  date:        Thu Jan 01 00:00:02 1970 +0000
  |  summary:     b
  |
  o  changeset:   1:cd997a145b29
  |  user:        test
  |  date:        Thu Jan 01 00:00:01 1970 +0000
  |  summary:     a
  |
  o  changeset:   0:1715188a53c7
     user:        test
     date:        Thu Jan 01 00:00:00 1970 +0000
     summary:     Initial commit
  

edit the history
  $ hg histedit 3 --commands $EDITED 2>&1 | fixbundle
  merging e
  warning: conflicts while merging e! (edit, then use 'hg resolve --mark')
  Fix up the change (fold 42abbb61bede)
  (hg histedit --continue to resume)

fix up
  $ echo 'I can haz no commute' > e
  $ hg resolve --mark e
  (no more unresolved files)
  continue: hg histedit --continue
  $ HGEDITOR=cat hg histedit --continue 2>&1 | fixbundle | grep -v '2 files removed'
  d
  ***
  does not commute with e
  
  
  
  HG: Enter commit message.  Lines beginning with 'HG:' are removed.
  HG: Leave message empty to abort commit.
  HG: --
  HG: user: test
  HG: branch 'default'
  HG: changed d
  HG: changed e
  merging e
  warning: conflicts while merging e! (edit, then use 'hg resolve --mark')
  Fix up the change (pick 7f3755409b00)
  (hg histedit --continue to resume)

just continue this time
keep the non-commuting change, and thus the pending change will be dropped
  $ hg revert -r 'p1()' e
  $ hg resolve --mark e
  (no more unresolved files)
  continue: hg histedit --continue
  $ hg diff
  $ hg histedit --continue 2>&1 | fixbundle
  7f3755409b00: skipping changeset (no changes)

log after edit
  $ hg log --graph
  @  changeset:   5:1300355b1a54
  |  tag:         tip
  |  user:        test
  |  date:        Thu Jan 01 00:00:06 1970 +0000
  |  summary:     f
  |
  o  changeset:   4:e2ac33269083
  |  user:        test
  |  date:        Thu Jan 01 00:00:07 1970 +0000
  |  summary:     d
  |
  o  changeset:   3:092e4ce14829
  |  user:        test
  |  date:        Thu Jan 01 00:00:03 1970 +0000
  |  summary:     c
  |
  o  changeset:   2:40ccdd8beb95
  |  user:        test
  |  date:        Thu Jan 01 00:00:02 1970 +0000
  |  summary:     b
  |
  o  changeset:   1:cd997a145b29
  |  user:        test
  |  date:        Thu Jan 01 00:00:01 1970 +0000
  |  summary:     a
  |
  o  changeset:   0:1715188a53c7
     user:        test
     date:        Thu Jan 01 00:00:00 1970 +0000
     summary:     Initial commit
  

contents of e
  $ hg cat e
  I can haz no commute

manifest
  $ hg manifest
  a
  b
  c
  d
  e
  f

  $ cd ..

Repeat test using "roll", not "fold". "roll" folds in changes but drops message and date

  $ initrepo r2
  $ cd r2

Initial generation of the command files

  $ EDITED="$TESTTMP/editedhistory.2"
  $ hg log --template 'pick {node|short} {rev} {desc}\n' -r 3 >> $EDITED
  $ hg log --template 'pick {node|short} {rev} {desc}\n' -r 4 >> $EDITED
  $ hg log --template 'roll {node|short} {rev} {desc}\n' -r 7 >> $EDITED
  $ hg log --template 'pick {node|short} {rev} {desc}\n' -r 5 >> $EDITED
  $ hg log --template 'pick {node|short} {rev} {desc}\n' -r 6 >> $EDITED
  $ cat $EDITED
  pick 092e4ce14829 3 c
  pick ae78f4c9d74f 4 d
  roll 42abbb61bede 7 does not commute with e
  pick 7f3755409b00 5 e
  pick dd184f2faeb0 6 f

log before edit
  $ hg log --graph
  @  changeset:   7:42abbb61bede
  |  tag:         tip
  |  user:        test
  |  date:        Thu Jan 01 00:00:07 1970 +0000
  |  summary:     does not commute with e
  |
  o  changeset:   6:dd184f2faeb0
  |  user:        test
  |  date:        Thu Jan 01 00:00:06 1970 +0000
  |  summary:     f
  |
  o  changeset:   5:7f3755409b00
  |  user:        test
  |  date:        Thu Jan 01 00:00:05 1970 +0000
  |  summary:     e
  |
  o  changeset:   4:ae78f4c9d74f
  |  user:        test
  |  date:        Thu Jan 01 00:00:04 1970 +0000
  |  summary:     d
  |
  o  changeset:   3:092e4ce14829
  |  user:        test
  |  date:        Thu Jan 01 00:00:03 1970 +0000
  |  summary:     c
  |
  o  changeset:   2:40ccdd8beb95
  |  user:        test
  |  date:        Thu Jan 01 00:00:02 1970 +0000
  |  summary:     b
  |
  o  changeset:   1:cd997a145b29
  |  user:        test
  |  date:        Thu Jan 01 00:00:01 1970 +0000
  |  summary:     a
  |
  o  changeset:   0:1715188a53c7
     user:        test
     date:        Thu Jan 01 00:00:00 1970 +0000
     summary:     Initial commit
  

edit the history
  $ hg histedit 3 --commands $EDITED 2>&1 | fixbundle
  merging e
  warning: conflicts while merging e! (edit, then use 'hg resolve --mark')
  Fix up the change (roll 42abbb61bede)
  (hg histedit --continue to resume)

fix up
  $ echo 'I can haz no commute' > e
  $ hg resolve --mark e
  (no more unresolved files)
  continue: hg histedit --continue
  $ hg histedit --continue 2>&1 | fixbundle | grep -v '2 files removed'
  merging e
  warning: conflicts while merging e! (edit, then use 'hg resolve --mark')
  Fix up the change (pick 7f3755409b00)
  (hg histedit --continue to resume)

just continue this time
  $ hg revert -r 'p1()' e
  $ hg resolve --mark e
  (no more unresolved files)
  continue: hg histedit --continue
  $ hg histedit --continue 2>&1 | fixbundle
  7f3755409b00: skipping changeset (no changes)

log after edit
  $ hg log --graph
  @  changeset:   5:b538bcb461be
  |  tag:         tip
  |  user:        test
  |  date:        Thu Jan 01 00:00:06 1970 +0000
  |  summary:     f
  |
  o  changeset:   4:317e37cb6d66
  |  user:        test
  |  date:        Thu Jan 01 00:00:04 1970 +0000
  |  summary:     d
  |
  o  changeset:   3:092e4ce14829
  |  user:        test
  |  date:        Thu Jan 01 00:00:03 1970 +0000
  |  summary:     c
  |
  o  changeset:   2:40ccdd8beb95
  |  user:        test
  |  date:        Thu Jan 01 00:00:02 1970 +0000
  |  summary:     b
  |
  o  changeset:   1:cd997a145b29
  |  user:        test
  |  date:        Thu Jan 01 00:00:01 1970 +0000
  |  summary:     a
  |
  o  changeset:   0:1715188a53c7
     user:        test
     date:        Thu Jan 01 00:00:00 1970 +0000
     summary:     Initial commit
  

contents of e
  $ hg cat e
  I can haz no commute

manifest
  $ hg manifest
  a
  b
  c
  d
  e
  f

description is taken from rollup target commit

  $ hg log --debug --rev 4
  changeset:   4:317e37cb6d66c1c84628c00e5bf4c8c292831951
  phase:       draft
  parent:      3:092e4ce14829f4974399ce4316d59f64ef0b6725
  parent:      -1:0000000000000000000000000000000000000000
  manifest:    4:b068a323d969f22af1296ec6a5ea9384cef437ac
  user:        test
  date:        Thu Jan 01 00:00:04 1970 +0000
  files:       d e
  extra:       branch=default
  extra:       histedit_source=ae78f4c9d74ffa4b6cb5045001c303fe9204e890,42abbb61bede6f4366fa1e74a664343e5d558a70
  description:
  d
  
  

done with repo r2

  $ cd ..