view tests/test-repo-compengines.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

A new repository uses zlib storage, which doesn't need a requirement

  $ hg init default
  $ cd default
  $ cat .hg/requires
  dotencode
  fncache
  generaldelta
  revlogv1
  sparserevlog
  store
  testonly-simplestore (reposimplestore !)

  $ touch foo
  $ hg -q commit -A -m 'initial commit with a lot of repeated repeated repeated text to trigger compression'
  $ hg debugrevlog -c | grep 0x78
      0x78 (x)  :   1 (100.00%)
      0x78 (x)  : 110 (100.00%)

  $ cd ..

Unknown compression engine to format.compression aborts

  $ hg --config format.revlog-compression=unknown init unknown
  abort: compression engine unknown defined by format.revlog-compression not available
  (run "hg debuginstall" to list available compression engines)
  [255]

A requirement specifying an unknown compression engine results in bail

  $ hg init unknownrequirement
  $ cd unknownrequirement
  $ echo exp-compression-unknown >> .hg/requires
  $ hg log
  abort: repository requires features unknown to this Mercurial: exp-compression-unknown!
  (see https://mercurial-scm.org/wiki/MissingRequirement for more information)
  [255]

  $ cd ..

#if zstd

  $ hg --config format.revlog-compression=zstd init zstd
  $ cd zstd
  $ cat .hg/requires
  dotencode
  fncache
  generaldelta
  revlog-compression-zstd
  revlogv1
  sparserevlog
  store
  testonly-simplestore (reposimplestore !)

  $ touch foo
  $ hg -q commit -A -m 'initial commit with a lot of repeated repeated repeated text'

  $ hg debugrevlog -c | grep 0x28
      0x28      :  1 (100.00%)
      0x28      : 98 (100.00%)

  $ cd ..

Specifying a new format.compression on an existing repo won't introduce data
with that engine or a requirement

  $ cd default
  $ touch bar
  $ hg --config format.revlog-compression=zstd -q commit -A -m 'add bar with a lot of repeated repeated repeated text'

  $ cat .hg/requires
  dotencode
  fncache
  generaldelta
  revlogv1
  sparserevlog
  store
  testonly-simplestore (reposimplestore !)

  $ hg debugrevlog -c | grep 0x78
      0x78 (x)  :   2 (100.00%)
      0x78 (x)  : 199 (100.00%)

#endif

checking zlib options
=====================

  $ hg init zlib-level-default
  $ hg init zlib-level-1
  $ cat << EOF >> zlib-level-1/.hg/hgrc
  > [storage]
  > revlog.zlib.level=1
  > EOF
  $ hg init zlib-level-9
  $ cat << EOF >> zlib-level-9/.hg/hgrc
  > [storage]
  > revlog.zlib.level=9
  > EOF


  $ commitone() {
  >    repo=$1
  >    cp $RUNTESTDIR/bundles/issue4438-r1.hg $repo/a
  >    hg -R $repo add $repo/a
  >    hg -R $repo commit -m some-commit
  > }

  $ for repo in zlib-level-default zlib-level-1 zlib-level-9; do
  >     commitone $repo
  > done

  $ $RUNTESTDIR/f -s */.hg/store/data/*
  default/.hg/store/data/foo.i: size=64 (pure !)
  zlib-level-1/.hg/store/data/a.i: size=4146
  zlib-level-9/.hg/store/data/a.i: size=4138
  zlib-level-default/.hg/store/data/a.i: size=4138

Test error cases

  $ hg init zlib-level-invalid
  $ cat << EOF >> zlib-level-invalid/.hg/hgrc
  > [storage]
  > revlog.zlib.level=foobar
  > EOF
  $ commitone zlib-level-invalid
  abort: storage.revlog.zlib.level is not a valid integer ('foobar')
  abort: storage.revlog.zlib.level is not a valid integer ('foobar')
  [255]

  $ hg init zlib-level-out-of-range
  $ cat << EOF >> zlib-level-out-of-range/.hg/hgrc
  > [storage]
  > revlog.zlib.level=42
  > EOF

  $ commitone zlib-level-out-of-range
  abort: invalid value for `storage.revlog.zlib.level` config: 42
  abort: invalid value for `storage.revlog.zlib.level` config: 42
  [255]

#if zstd

checking zstd options
=====================

  $ hg init zstd-level-default --config format.revlog-compression=zstd
  $ hg init zstd-level-1 --config format.revlog-compression=zstd
  $ cat << EOF >> zstd-level-1/.hg/hgrc
  > [storage]
  > revlog.zstd.level=1
  > EOF
  $ hg init zstd-level-22 --config format.revlog-compression=zstd
  $ cat << EOF >> zstd-level-22/.hg/hgrc
  > [storage]
  > revlog.zstd.level=22
  > EOF


  $ commitone() {
  >    repo=$1
  >    cp $RUNTESTDIR/bundles/issue4438-r1.hg $repo/a
  >    hg -R $repo add $repo/a
  >    hg -R $repo commit -m some-commit
  > }

  $ for repo in zstd-level-default zstd-level-1 zstd-level-22; do
  >     commitone $repo
  > done

  $ $RUNTESTDIR/f -s zstd-*/.hg/store/data/*
  zstd-level-1/.hg/store/data/a.i: size=4114
  zstd-level-22/.hg/store/data/a.i: size=4091
  zstd-level-default/\.hg/store/data/a\.i: size=(4094|4102) (re)

Test error cases

  $ hg init zstd-level-invalid --config format.revlog-compression=zstd
  $ cat << EOF >> zstd-level-invalid/.hg/hgrc
  > [storage]
  > revlog.zstd.level=foobar
  > EOF
  $ commitone zstd-level-invalid
  abort: storage.revlog.zstd.level is not a valid integer ('foobar')
  abort: storage.revlog.zstd.level is not a valid integer ('foobar')
  [255]

  $ hg init zstd-level-out-of-range --config format.revlog-compression=zstd
  $ cat << EOF >> zstd-level-out-of-range/.hg/hgrc
  > [storage]
  > revlog.zstd.level=42
  > EOF

  $ commitone zstd-level-out-of-range
  abort: invalid value for `storage.revlog.zstd.level` config: 42
  abort: invalid value for `storage.revlog.zstd.level` config: 42
  [255]

#endif