view tests/test-exchange-obsmarkers-case-A6.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

============================================
Testing obsolescence markers push: Cases A.6
============================================

Mercurial pushes obsolescences markers relevant to the "pushed-set", the set of
all changesets that requested to be "in sync" after the push (even if they are
already on both side).

This test belongs to a series of tests checking such set is properly computed
and applied. This does not tests "obsmarkers" discovery capabilities.

Category A: simple cases
TestCase 6: new markers between changesets already known on both side
Variants:
# a: explicit push
# b: bare push

A.6  new markers between changesets already known on both side
==============================================================

.. {{{
..   A ◕⇠● B
..     |/
..     ● O
.. }}}
..
.. Marker exist from:
..
..  * `A◕⇠● B`
..
.. Command runs:
..
..  * hg push -r B
..  * hg push
..
.. Expected exchange:
..
..  * `A◕⇠● B`

Setup
-----

  $ . $TESTDIR/testlib/exchange-obsmarker-util.sh

initial

  $ setuprepos A.6
  creating test repo for test case A.6
  - pulldest
  - main
  - pushdest
  cd into `main` and proceed with env setup
  $ cd main
  $ mkcommit A0
  $ hg update -q 0
  $ mkcommit A1
  created new head

make both changeset known in remote

  $ hg push -qf ../pushdest
  $ hg push -qf ../pulldest

create a marker after this

  $ hg debugobsolete `getid 'desc(A0)'` `getid 'desc(A1)'`
  1 new obsolescence markers
  obsoleted 1 changesets
  $ hg log -G --hidden
  @  e5ea8f9c7314 (draft): A1
  |
  | x  28b51eb45704 (draft): A0
  |/
  o  a9bdc8b26820 (public): O
  
  $ inspect_obsmarkers
  obsstore content
  ================
  28b51eb45704506b5c603decd6bf7ac5e0f6a52f e5ea8f9c73143125d36658e90ef70c6d2027a5b7 0 (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
  $ cd ..
  $ cd ..

  $ cp -R A.6 A.6.a
  $ cp -R A.6 A.6.b

Actual Test (explicit push version)
-----------------------------------

  $ dotest A.6.a A1
  ## Running testcase A.6.a
  # testing echange of "A1" (e5ea8f9c7314)
  ## initial state
  # obstore: main
  28b51eb45704506b5c603decd6bf7ac5e0f6a52f e5ea8f9c73143125d36658e90ef70c6d2027a5b7 0 (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
  # obstore: pushdest
  # obstore: pulldest
  ## pushing "A1" from main to pushdest
  pushing to pushdest
  searching for changes
  no changes found
  remote: 1 new obsolescence markers
  remote: obsoleted 1 changesets
  ## post push state
  # obstore: main
  28b51eb45704506b5c603decd6bf7ac5e0f6a52f e5ea8f9c73143125d36658e90ef70c6d2027a5b7 0 (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
  # obstore: pushdest
  28b51eb45704506b5c603decd6bf7ac5e0f6a52f e5ea8f9c73143125d36658e90ef70c6d2027a5b7 0 (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
  # obstore: pulldest
  ## pulling "e5ea8f9c7314" from main into pulldest
  pulling from main
  no changes found
  1 new obsolescence markers
  obsoleted 1 changesets
  ## post pull state
  # obstore: main
  28b51eb45704506b5c603decd6bf7ac5e0f6a52f e5ea8f9c73143125d36658e90ef70c6d2027a5b7 0 (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
  # obstore: pushdest
  28b51eb45704506b5c603decd6bf7ac5e0f6a52f e5ea8f9c73143125d36658e90ef70c6d2027a5b7 0 (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
  # obstore: pulldest
  28b51eb45704506b5c603decd6bf7ac5e0f6a52f e5ea8f9c73143125d36658e90ef70c6d2027a5b7 0 (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}

Actual Test (bare push version)
-------------------------------

  $ dotest A.6.b
  ## Running testcase A.6.b
  ## initial state
  # obstore: main
  28b51eb45704506b5c603decd6bf7ac5e0f6a52f e5ea8f9c73143125d36658e90ef70c6d2027a5b7 0 (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
  # obstore: pushdest
  # obstore: pulldest
  ## pushing from main to pushdest
  pushing to pushdest
  searching for changes
  no changes found
  remote: 1 new obsolescence markers
  remote: obsoleted 1 changesets
  ## post push state
  # obstore: main
  28b51eb45704506b5c603decd6bf7ac5e0f6a52f e5ea8f9c73143125d36658e90ef70c6d2027a5b7 0 (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
  # obstore: pushdest
  28b51eb45704506b5c603decd6bf7ac5e0f6a52f e5ea8f9c73143125d36658e90ef70c6d2027a5b7 0 (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
  # obstore: pulldest
  ## pulling from main into pulldest
  pulling from main
  searching for changes
  no changes found
  1 new obsolescence markers
  obsoleted 1 changesets
  ## post pull state
  # obstore: main
  28b51eb45704506b5c603decd6bf7ac5e0f6a52f e5ea8f9c73143125d36658e90ef70c6d2027a5b7 0 (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
  # obstore: pushdest
  28b51eb45704506b5c603decd6bf7ac5e0f6a52f e5ea8f9c73143125d36658e90ef70c6d2027a5b7 0 (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
  # obstore: pulldest
  28b51eb45704506b5c603decd6bf7ac5e0f6a52f e5ea8f9c73143125d36658e90ef70c6d2027a5b7 0 (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}