view tests/test-amend-subrepo.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

#testcases obsstore-off obsstore-on

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

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

Prepare parent repo
-------------------

  $ hg init r
  $ cd r

  $ echo a > a
  $ hg ci -Am0
  adding a

Link first subrepo
------------------

  $ echo 's = s' >> .hgsub
  $ hg add .hgsub
  $ hg init s

amend without .hgsub

  $ hg amend s
  abort: can't commit subrepos without .hgsub
  [255]

amend with subrepo

  $ hg amend
  saved backup bundle to * (glob) (obsstore-off !)
  $ hg status --change .
  A .hgsub
  A .hgsubstate
  A a
  $ cat .hgsubstate
  0000000000000000000000000000000000000000 s

Update subrepo
--------------

add new commit to be amended

  $ echo a >> a
  $ hg ci -m1

amend with dirty subrepo

  $ echo a >> s/a
  $ hg add -R s
  adding s/a
  $ hg amend
  abort: uncommitted changes in subrepository "s"
  (use --subrepos for recursive commit)
  [255]

amend with modified subrepo

  $ hg ci -R s -m0
  $ hg amend
  saved backup bundle to * (glob) (obsstore-off !)
  $ hg status --change .
  M .hgsubstate
  M a
  $ cat .hgsubstate
  f7b1eb17ad24730a1651fccd46c43826d1bbc2ac s

revert subrepo change

  $ hg up -R s -q null
  $ hg amend
  saved backup bundle to * (glob) (obsstore-off !)
  $ hg status --change .
  M a

Link another subrepo
--------------------

add new commit to be amended

  $ echo b >> b
  $ hg ci -qAm2

also checks if non-subrepo change is included

  $ echo a >> a

amend with another subrepo

  $ hg init t
  $ echo b >> t/b
  $ hg ci -R t -Am0
  adding b
  $ echo 't = t' >> .hgsub
  $ hg amend
  saved backup bundle to * (glob) (obsstore-off !)
  $ hg status --change .
  M .hgsub
  M .hgsubstate
  M a
  A b
  $ cat .hgsubstate
  0000000000000000000000000000000000000000 s
  bfb1a4fb358498a9533dabf4f2043d94162f1fcd t

Unlink one subrepo
------------------

add new commit to be amended

  $ echo a >> a
  $ hg ci -m3

  $ echo 't = t' > .hgsub

--interactive won't silently ignore dirty subrepos

  $ echo modified > t/b
  $ hg amend --interactive --config ui.interactive=True
  abort: uncommitted changes in subrepository "t"
  [255]
  $ hg amend --interactive --config ui.interactive=True --config ui.commitsubrepos=True
  abort: uncommitted changes in subrepository "t"
  [255]

  $ hg -R t revert -q --all --no-backup

amend with one subrepo dropped

  $ hg amend
  saved backup bundle to * (glob) (obsstore-off !)
  $ hg status --change .
  M .hgsub
  M .hgsubstate
  M a
  $ cat .hgsubstate
  bfb1a4fb358498a9533dabf4f2043d94162f1fcd t

Unlink subrepos completely
--------------------------

add new commit to be amended

  $ echo a >> a
  $ hg ci -m3

amend with .hgsub removed

  $ hg rm .hgsub
  $ hg amend
  saved backup bundle to * (glob) (obsstore-off !)
  $ hg status --change .
  M a
  R .hgsub
  R .hgsubstate

broken repositories will refuse to push

#if obsstore-off
  $ hg up -q -C 2
#else
  $ hg up -q -C 6
#endif
  $ echo c >> t/b
  $ hg amend -q -R t

  $ hg init ../dest
  $ hg init ../dest/t
  $ hg init ../dest/s
  $ hg push -q ../dest
  abort: subrepo 't' is hidden in revision 04aa62396ec6 (obsstore-on !)
  abort: subrepo 't' not found in revision 04aa62396ec6 (obsstore-off !)
  [255]

... unless forced

  $ hg push --force -q ../dest
  $ hg verify -R ../dest
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  checked 5 changesets with 12 changes to 4 files
  checking subrepo links
  subrepo 't' not found in revision 04aa62396ec6
  subrepo 't' not found in revision 6bce99600681

  $ cd ..