view tests/test-editor-filename.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

Test temp file used with an editor has the expected suffix.

  $ hg init

Create an editor that writes its arguments to stdout and set it to $HGEDITOR.

  $ cat > editor.sh << EOF
  > echo "\$@"
  > exit 1
  > EOF
  $ hg add editor.sh
  $ HGEDITOR="sh $TESTTMP/editor.sh"
  $ export HGEDITOR

Verify that the path for a commit editor has the expected suffix.

  $ hg commit
  *.commit.hg.txt (glob)
  abort: edit failed: sh exited with status 1
  [255]

Verify that the path for a histedit editor has the expected suffix.

  $ cat >> $HGRCPATH <<EOF
  > [extensions]
  > rebase=
  > histedit=
  > EOF
  $ hg commit --message 'At least one commit for histedit.'
  $ hg histedit
  *.histedit.hg.txt (glob)
  abort: edit failed: sh exited with status 1
  [255]

Verify that when performing an action that has the side-effect of creating an
editor for a diff, the file ends in .diff.

  $ echo 1 > one
  $ echo 2 > two
  $ hg add
  adding one
  adding two
  $ hg commit --interactive --config ui.interactive=true --config ui.interface=text << EOF
  > y
  > e
  > q
  > EOF
  diff --git a/one b/one
  new file mode 100644
  examine changes to 'one'?
  (enter ? for help) [Ynesfdaq?] y
  
  @@ -0,0 +1,1 @@
  +1
  record change 1/2 to 'one'?
  (enter ? for help) [Ynesfdaq?] e
  
  *.diff (glob)
  editor exited with exit code 1
  record change 1/2 to 'one'?
  (enter ? for help) [Ynesfdaq?] q
  
  abort: user quit
  [255]