view tests/test-stack.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

This test test the low-level definition of stack, agnostic from all formatting

Initial setup

  $ cat << EOF >> $HGRCPATH
  > [ui]
  > logtemplate = {rev} {branch} {phase} {desc|firstline}\n
  > [extensions]
  > rebase=
  > [experimental]
  > evolution=createmarkers,exchange,allowunstable
  > EOF

  $ hg init main
  $ cd main
  $ hg branch other
  marked working directory as branch other
  (branches are permanent and global, did you want a bookmark?)
  $ echo aaa > aaa
  $ hg add aaa
  $ hg commit -m c_a
  $ echo aaa > bbb
  $ hg add bbb
  $ hg commit -m c_b
  $ hg branch foo
  marked working directory as branch foo
  $ echo aaa > ccc
  $ hg add ccc
  $ hg commit -m c_c
  $ echo aaa > ddd
  $ hg add ddd
  $ hg commit -m c_d
  $ echo aaa > eee
  $ hg add eee
  $ hg commit -m c_e
  $ echo aaa > fff
  $ hg add fff
  $ hg commit -m c_f
  $ hg log -G
  @  5 foo draft c_f
  |
  o  4 foo draft c_e
  |
  o  3 foo draft c_d
  |
  o  2 foo draft c_c
  |
  o  1 other draft c_b
  |
  o  0 other draft c_a
  

Check that stack doesn't include public changesets
--------------------------------------------------

  $ hg up other
  0 files updated, 0 files merged, 4 files removed, 0 files unresolved
  $ hg log -G -r "stack()"
  @  1 other draft c_b
  |
  o  0 other draft c_a
  
  $ hg phase --public 'branch("other")'
  $ hg log -G -r "stack()"
  $ hg up foo
  4 files updated, 0 files merged, 0 files removed, 0 files unresolved

Simple test
-----------

'stack()' list all changeset in the branch

  $ hg branch
  foo
  $ hg log -G -r "stack()"
  @  5 foo draft c_f
  |
  o  4 foo draft c_e
  |
  o  3 foo draft c_d
  |
  o  2 foo draft c_c
  |
  ~

Case with some of the branch unstable
------------------------------------

  $ hg up 3
  0 files updated, 0 files merged, 2 files removed, 0 files unresolved
  $ echo bbb > ddd
  $ hg commit --amend
  2 new orphan changesets
  $ hg log -G
  @  6 foo draft c_d
  |
  | *  5 foo draft c_f
  | |
  | *  4 foo draft c_e
  | |
  | x  3 foo draft c_d
  |/
  o  2 foo draft c_c
  |
  o  1 other public c_b
  |
  o  0 other public c_a
  
  $ hg log -G -r "stack()"
  @  6 foo draft c_d
  |
  ~
  $ hg up -r "desc(c_e)"
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg log -G -r "stack()"
  @  4 foo draft c_e
  |
  x  3 foo draft c_d
  |
  ~
  $ hg up -r "desc(c_d)"
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved

  $ hg log -G -r "stack()"
  @  6 foo draft c_d
  |
  ~

Case with multiple topological heads
------------------------------------

Make things linear again

  $ hg rebase -s 'desc(c_e)' -d 'desc(c_d) - obsolete()'
  rebasing 4:4f2a69f6d380 "c_e"
  rebasing 5:913c298d8b0a "c_f"
  $ hg log -G
  o  8 foo draft c_f
  |
  o  7 foo draft c_e
  |
  @  6 foo draft c_d
  |
  o  2 foo draft c_c
  |
  o  1 other public c_b
  |
  o  0 other public c_a
  

Create the second branch

  $ hg up 'desc(c_d)'
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo aaa > ggg
  $ hg add ggg
  $ hg commit -m c_g
  created new head
  $ echo aaa > hhh
  $ hg add hhh
  $ hg commit -m c_h
  $ hg log -G
  @  10 foo draft c_h
  |
  o  9 foo draft c_g
  |
  | o  8 foo draft c_f
  | |
  | o  7 foo draft c_e
  |/
  o  6 foo draft c_d
  |
  o  2 foo draft c_c
  |
  o  1 other public c_b
  |
  o  0 other public c_a
  

Test output

  $ hg log -G -r "stack(10)"
  @  10 foo draft c_h
  |
  o  9 foo draft c_g
  |
  ~
  $ hg log -G -r "stack(8)"
  o  8 foo draft c_f
  |
  o  7 foo draft c_e
  |
  ~
  $ hg log -G -r "stack(head())"
  @  10 foo draft c_h
  |
  o  9 foo draft c_g
  |
  ~
  o  8 foo draft c_f
  |
  o  7 foo draft c_e
  |
  ~
Check the stack order
  $ hg log -r "first(stack())"
  9 foo draft c_g
  $ hg log -r "first(stack(10))"
  9 foo draft c_g
  $ hg log -r "first(stack(8))"
  7 foo draft c_e
  $ hg log -r "first(stack(head()))"
  7 foo draft c_e

Case with multiple heads with unstability involved
--------------------------------------------------

We amend the message to make sure the display base pick the right changeset

  $ hg up 'desc(c_d)'
  0 files updated, 0 files merged, 2 files removed, 0 files unresolved
  $ echo ccc > ddd
  $ hg commit --amend -m 'c_D'
  4 new orphan changesets
  $ hg rebase -d . -s 'desc(c_g)'
  rebasing 9:2ebb6e48ab8a "c_g"
  rebasing 10:634f38e27a1d "c_h"
  $ hg log -G
  o  13 foo draft c_h
  |
  o  12 foo draft c_g
  |
  @  11 foo draft c_D
  |
  | *  8 foo draft c_f
  | |
  | *  7 foo draft c_e
  | |
  | x  6 foo draft c_d
  |/
  o  2 foo draft c_c
  |
  o  1 other public c_b
  |
  o  0 other public c_a
  

We should improve stack definition to also show 12 and 13 here
  $ hg log -G -r "stack()"
  @  11 foo draft c_D
  |
  ~