view tests/test-mailmap.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

Create a repo and add some commits

  $ hg init mm
  $ cd mm
  $ echo "Test content" > testfile1
  $ hg add testfile1
  $ hg commit -m "First commit" -u "Proper <commit@m.c>"
  $ echo "Test content 2" > testfile2
  $ hg add testfile2
  $ hg commit -m "Second commit" -u "Commit Name 2 <commit2@m.c>"
  $ echo "Test content 3" > testfile3
  $ hg add testfile3
  $ hg commit -m "Third commit" -u "Commit Name 3 <commit3@m.c>"
  $ echo "Test content 4" > testfile4
  $ hg add testfile4
  $ hg commit -m "Fourth commit" -u "Commit Name 4 <commit4@m.c>"

Add a .mailmap file with each possible entry type plus comments
  $ cat > .mailmap << EOF
  > # Comment shouldn't break anything
  > <proper@m.c> <commit@m.c> # Should update email only
  > Proper Name 2 <commit2@m.c> # Should update name only
  > Proper Name 3 <proper@m.c> <commit3@m.c> # Should update name, email due to email
  > Proper Name 4 <proper@m.c> Commit Name 4 <commit4@m.c> # Should update name, email due to name, email
  > EOF
  $ hg add .mailmap
  $ hg commit -m "Add mailmap file" -u "Testuser <test123@m.c>"

Output of commits should be normal without filter
  $ hg log -T "{author}\n" -r "all()"
  Proper <commit@m.c>
  Commit Name 2 <commit2@m.c>
  Commit Name 3 <commit3@m.c>
  Commit Name 4 <commit4@m.c>
  Testuser <test123@m.c>

Output of commits with filter shows their mailmap values
  $ hg log -T "{mailmap(author)}\n" -r "all()"
  Proper <proper@m.c>
  Proper Name 2 <commit2@m.c>
  Proper Name 3 <proper@m.c>
  Proper Name 4 <proper@m.c>
  Testuser <test123@m.c>

Add new mailmap entry for testuser
  $ cat >> .mailmap << EOF
  > <newmmentry@m.c> <test123@m.c>
  > EOF

Output of commits with filter shows their updated mailmap values
  $ hg log -T "{mailmap(author)}\n" -r "all()"
  Proper <proper@m.c>
  Proper Name 2 <commit2@m.c>
  Proper Name 3 <proper@m.c>
  Proper Name 4 <proper@m.c>
  Testuser <newmmentry@m.c>

A commit with improperly formatted user field should not break the filter
  $ echo "some more test content" > testfile1
  $ hg commit -m "Commit with improper user field" -u "Improper user"
  $ hg log -T "{mailmap(author)}\n" -r "all()"
  Proper <proper@m.c>
  Proper Name 2 <commit2@m.c>
  Proper Name 3 <proper@m.c>
  Proper Name 4 <proper@m.c>
  Testuser <newmmentry@m.c>
  Improper user

No TypeError beacause of invalid input

  $ hg log -T '{mailmap(termwidth)}\n' -r0
  80