view tests/test-repo-compengines.t @ 42743:8c9a6adec67a

rust-discovery: using the children cache in add_missing

The DAG range computation often needs to get back to very old
revisions, and turns out to be disproportionately long, given
that the end goal is to remove the descendents of the given
missing revisons from the undecided set.

The fast iteration capabilities available in the Rust case make
it possible to avoid the DAG range entirely, at the cost of
precomputing the children cache, and to simply iterate on
children of the given missing revisions.

This is a case where staying on the same side of the interface
between the two languages has clear benefits.

On discoveries with initial undecided sets
small enough to bypass sampling entirely, the total cost of
computing the children cache and the subsequent iteration
becomes better than the Python + C counterpart, which relies on
reachableroots2.

For example, on a repo with more than one million revisions with
an initial undecided set of 11 elements, we get these figures:

Rust version with simple iteration
  addcommons: 57.287us
  first undecided computation: 184.278334ms
  first children cache computation: 131.056us
  addmissings iteration: 42.766us
  first addinfo total: 185.24 ms

Python + C version
  first addcommons: 0.29 ms
  addcommons 0.21 ms
  first undecided computation 191.35 ms
  addmissings 45.75 ms
  first addinfo total: 237.77 ms

On discoveries with large undecided sets, the initial price paid
makes the first addinfo slower than the Python + C version,
but that's more than compensated by the gain in sampling and
subsequent iterations.
Here's an extreme example with an undecided set of a million revisions:

Rust version:
  first undecided computation: 293.842629ms
  first children cache computation: 407.911297ms
  addmissings iteration: 34.312869ms
  first addinfo total: 776.02 ms
  taking initial sample
  query 2: sampling time: 1318.38 ms
  query 2; still undecided: 1005013, sample size is: 200
  addmissings: 143.062us

Python + C version:
  first undecided computation 298.13 ms
  addmissings 80.13 ms
  first addinfo total: 399.62 ms
  taking initial sample
  query 2: sampling time: 3957.23 ms
  query 2; still undecided: 1005013, sample size is: 200
  addmissings 52.88 ms

Differential Revision: https://phab.mercurial-scm.org/D6428

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=4097
  zstd-level-22/.hg/store/data/a.i: size=4091
  zstd-level-default/.hg/store/data/a.i: size=4094

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