view tests/test-histedit-outgoing.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

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

  $ initrepos ()
  > {
  >     hg init r
  >     cd r
  >     for x in a b c ; do
  >         echo $x > $x
  >         hg add $x
  >         hg ci -m $x
  >     done
  >     cd ..
  >     hg clone r r2 | grep -v updating
  >     cd r2
  >     for x in d e f ; do
  >         echo $x > $x
  >         hg add $x
  >         hg ci -m $x
  >     done
  >     cd ..
  >     hg init r3
  >     cd r3
  >     for x in g h i ; do
  >         echo $x > $x
  >         hg add $x
  >         hg ci -m $x
  >     done
  >     cd ..
  > }

  $ initrepos
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved

show the edit commands offered by outgoing
  $ cd r2
  $ HGEDITOR=cat hg histedit --outgoing ../r | grep -v comparing | grep -v searching
  pick 055a42cdd887 3 d
  pick e860deea161a 4 e
  pick 652413bf663e 5 f
  
  # Edit history between 055a42cdd887 and 652413bf663e
  #
  # Commits are listed from least to most recent
  #
  # You can reorder changesets by reordering the lines
  #
  # Commands:
  #
  #  e, edit = use commit, but stop for amending
  #  m, mess = edit commit message without changing commit content
  #  p, pick = use commit
  #  b, base = checkout changeset and apply further changesets from there
  #  d, drop = remove commit from history
  #  f, fold = use commit, but combine it with the one above
  #  r, roll = like fold, but discard this commit's description and date
  #
  $ cd ..

show the error from unrelated repos
  $ cd r3
  $ HGEDITOR=cat hg histedit --outgoing ../r | grep -v comparing | grep -v searching
  abort: repository is unrelated
  [1]
  $ cd ..

show the error from unrelated repos
  $ cd r3
  $ HGEDITOR=cat hg histedit --force --outgoing ../r
  comparing with ../r
  searching for changes
  warning: repository is unrelated
  pick 2a4042b45417 0 g
  pick 68c46b4927ce 1 h
  pick 51281e65ba79 2 i
  
  # Edit history between 2a4042b45417 and 51281e65ba79
  #
  # Commits are listed from least to most recent
  #
  # You can reorder changesets by reordering the lines
  #
  # Commands:
  #
  #  e, edit = use commit, but stop for amending
  #  m, mess = edit commit message without changing commit content
  #  p, pick = use commit
  #  b, base = checkout changeset and apply further changesets from there
  #  d, drop = remove commit from history
  #  f, fold = use commit, but combine it with the one above
  #  r, roll = like fold, but discard this commit's description and date
  #
  $ cd ..

test sensitivity to branch in URL:

  $ cd r2
  $ hg -q update 2
  $ hg -q branch foo
  $ hg commit -m 'create foo branch'
  $ HGEDITOR=cat hg histedit --outgoing '../r#foo' | grep -v comparing | grep -v searching
  pick f26599ee3441 6 create foo branch
  
  # Edit history between f26599ee3441 and f26599ee3441
  #
  # Commits are listed from least to most recent
  #
  # You can reorder changesets by reordering the lines
  #
  # Commands:
  #
  #  e, edit = use commit, but stop for amending
  #  m, mess = edit commit message without changing commit content
  #  p, pick = use commit
  #  b, base = checkout changeset and apply further changesets from there
  #  d, drop = remove commit from history
  #  f, fold = use commit, but combine it with the one above
  #  r, roll = like fold, but discard this commit's description and date
  #

test to check number of roots in outgoing revisions

  $ hg -q outgoing -G --template '{node|short}({branch})' '../r'
  @  f26599ee3441(foo)
  
  o  652413bf663e(default)
  |
  o  e860deea161a(default)
  |
  o  055a42cdd887(default)
  
  $ HGEDITOR=cat hg -q histedit --outgoing '../r'
  abort: there are ambiguous outgoing revisions
  (see 'hg help histedit' for more detail)
  [255]

  $ hg -q update -C 2
  $ echo aa >> a
  $ hg -q commit -m 'another head on default'
  $ hg -q outgoing -G --template '{node|short}({branch})' '../r#default'
  @  3879dc049647(default)
  
  o  652413bf663e(default)
  |
  o  e860deea161a(default)
  |
  o  055a42cdd887(default)
  
  $ HGEDITOR=cat hg -q histedit --outgoing '../r#default'
  abort: there are ambiguous outgoing revisions
  (see 'hg help histedit' for more detail)
  [255]

  $ cd ..