view tests/test-mq-qpush-fail.t @ 30442:41a8106789ca

util: implement zstd compression engine

Now that zstd is vendored and being built (in some configurations), we
can implement a compression engine for zstd!

The zstd engine is a little different from existing engines. Because
it may not always be present, we have to defer load the module in case
importing it fails. We facilitate this via a cached property that holds
a reference to the module or None. The "available" method is
implemented to reflect reality.

The zstd engine declares its ability to handle bundles using the
"zstd" human name and the "ZS" internal name. The latter was chosen
because internal names are 2 characters (by only convention I think)
and "ZS" seems reasonable.

The engine, like others, supports specifying the compression level.
However, there are no consumers of this API that yet pass in that
argument. I have plans to change that, so stay tuned.

Since all we need to do to support bundle generation with a new
compression engine is implement and register the compression engine,
bundle generation with zstd "just works!" Tests demonstrating this
have been added.

How does performance of zstd for bundle generation compare? On the
mozilla-unified repo, `hg bundle --all -t <engine>-v2` yields the
following on my i7-6700K on Linux:

engine        CPU time     bundle size   vs orig size   throughput
none            97.0s     4,054,405,584     100.0%       41.8 MB/s
bzip2 (l=9)    393.6s       975,343,098      24.0%       10.3 MB/s
gzip (l=6)     184.0s     1,140,533,074      28.1%       22.0 MB/s
zstd (l=1)     108.2s     1,119,434,718      27.6%       37.5 MB/s
zstd (l=2)     111.3s     1,078,328,002      26.6%       36.4 MB/s
zstd (l=3)     113.7s     1,011,823,727      25.0%       35.7 MB/s
zstd (l=4)     116.0s     1,008,965,888      24.9%       35.0 MB/s
zstd (l=5)     121.0s       977,203,148      24.1%       33.5 MB/s
zstd (l=6)     131.7s       927,360,198      22.9%       30.8 MB/s
zstd (l=7)     139.0s       912,808,505      22.5%       29.2 MB/s
zstd (l=12)    198.1s       854,527,714      21.1%       20.5 MB/s
zstd (l=18)    681.6s       789,750,690      19.5%        5.9 MB/s

On compression, zstd for bundle generation delivers:

* better compression than gzip with significantly less CPU utilization
* better than bzip2 compression ratios while still being significantly
  faster than gzip
* ability to aggressively tune compression level to achieve
  significantly smaller bundles

That last point is important. With clone bundles, a server can
pre-generate a bundle file, upload it to a static file server, and
redirect clients to transparently download it during clone. The server
could choose to produce a zstd bundle with the highest compression
settings possible. This would take a very long time - a magnitude
longer than a typical zstd bundle generation - but the result would
be hundreds of megabytes smaller! For the clone volume we do at
Mozilla, this could translate to petabytes of bandwidth savings
per year and faster clones (due to smaller transfer size).

I don't have detailed numbers to report on decompression. However,
zstd decompression is fast: >1 GB/s output throughput on this machine,
even through the Python bindings. And it can do that regardless of the
compression level of the input. By the time you have enough data to
worry about overhead of decompression, you have plenty of other things
to worry about performance wise.

zstd is wins all around. I can't wait to implement support for it
on the wire protocol and in revlogs.

Test that qpush cleans things up if it doesn't complete

  $ echo "[extensions]" >> $HGRCPATH
  $ echo "mq=" >> $HGRCPATH
  $ hg init repo
  $ cd repo
  $ echo foo > foo
  $ hg ci -Am 'add foo'
  adding foo
  $ touch untracked-file
  $ echo 'syntax: glob' > .hgignore
  $ echo '.hgignore' >> .hgignore
  $ hg qinit

test qpush on empty series

  $ hg qpush
  no patches in series
  $ hg qnew patch1
  $ echo >> foo
  $ hg qrefresh -m 'patch 1'
  $ hg qnew patch2
  $ echo bar > bar
  $ hg add bar
  $ hg qrefresh -m 'patch 2'
  $ hg qnew --config 'mq.plain=true' -U bad-patch
  $ echo >> foo
  $ hg qrefresh
  $ hg qpop -a
  popping bad-patch
  popping patch2
  popping patch1
  patch queue now empty
  $ $PYTHON -c 'print "\xe9"' > message
  $ cat .hg/patches/bad-patch >> message
  $ mv message .hg/patches/bad-patch
  $ cat > $TESTTMP/wrapplayback.py <<EOF
  > import os
  > from mercurial import extensions, transaction
  > def wrapplayback(orig,
  >                  journal, report, opener, vfsmap, entries, backupentries,
  >                  unlink=True):
  >     orig(journal, report, opener, vfsmap, entries, backupentries, unlink)
  >     # Touching files truncated at "transaction.abort" causes
  >     # forcible re-loading invalidated filecache properties
  >     # (including repo.changelog)
  >     for f, o, _ignore in entries:
  >         if o or not unlink:
  >             os.utime(opener.join(f), (0.0, 0.0))
  > def extsetup(ui):
  >     extensions.wrapfunction(transaction, '_playback', wrapplayback)
  > EOF
  $ hg qpush -a --config extensions.wrapplayback=$TESTTMP/wrapplayback.py  && echo 'qpush succeeded?!'
  applying patch1
  applying patch2
  applying bad-patch
  transaction abort!
  rollback completed
  cleaning up working directory...
  reverting foo
  done
  abort: decoding near '\xe9': 'ascii' codec can't decode byte 0xe9 in position 0: ordinal not in range(128)! (esc)
  [255]
  $ hg parents
  changeset:   0:bbd179dfa0a7
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     add foo
  

test corrupt status file
  $ hg qpush
  applying patch1
  now at: patch1
  $ cp .hg/patches/status .hg/patches/status.orig
  $ hg qpop
  popping patch1
  patch queue now empty
  $ cp .hg/patches/status.orig .hg/patches/status
  $ hg qpush
  abort: working directory revision is not qtip
  [255]
  $ rm .hg/patches/status .hg/patches/status.orig


bar should be gone; other unknown/ignored files should still be around

  $ hg status -A
  ? untracked-file
  I .hgignore
  C foo

preparing qpush of a missing patch

  $ hg qpop -a
  no patches applied
  $ hg qpush
  applying patch1
  now at: patch1
  $ rm .hg/patches/patch2

now we expect the push to fail, but it should NOT complain about patch1

  $ hg qpush
  applying patch2
  unable to read patch2
  now at: patch1
  [1]

preparing qpush of missing patch with no patch applied

  $ hg qpop -a
  popping patch1
  patch queue now empty
  $ rm .hg/patches/patch1

qpush should fail the same way as below

  $ hg qpush
  applying patch1
  unable to read patch1
  [1]

Test qpush to a patch below the currently applied patch.

  $ hg qq -c guardedseriesorder
  $ hg qnew a
  $ hg qguard +block
  $ hg qnew b
  $ hg qnew c

  $ hg qpop -a
  popping c
  popping b
  popping a
  patch queue now empty

try to push and pop while a is guarded

  $ hg qpush a
  cannot push 'a' - guarded by '+block'
  [1]
  $ hg qpush -a
  applying b
  patch b is empty
  applying c
  patch c is empty
  now at: c

now try it when a is unguarded, and we're at the top of the queue

  $ hg qapplied -v
  0 G a
  1 A b
  2 A c
  $ hg qsel block
  $ hg qpush b
  abort: cannot push to a previous patch: b
  [255]
  $ hg qpush a
  abort: cannot push to a previous patch: a
  [255]

and now we try it one more time with a unguarded, while we're not at the top of the queue

  $ hg qpop b
  popping c
  now at: b
  $ hg qpush a
  abort: cannot push to a previous patch: a
  [255]

test qpop --force and backup files

  $ hg qpop -a
  popping b
  patch queue now empty
  $ hg qq --create force
  $ echo a > a
  $ echo b > b
  $ echo c > c
  $ hg ci -Am add a b c
  $ echo a >> a
  $ hg rm b
  $ hg rm c
  $ hg qnew p1
  $ echo a >> a
  $ echo bb > b
  $ hg add b
  $ echo cc > c
  $ hg add c
  $ hg qpop --force --verbose
  saving current version of a as a.orig
  saving current version of b as b.orig
  saving current version of c as c.orig
  popping p1
  patch queue now empty
  $ hg st
  ? a.orig
  ? b.orig
  ? c.orig
  ? untracked-file
  $ cat a.orig
  a
  a
  a
  $ cat b.orig
  bb
  $ cat c.orig
  cc

test qpop --force --no-backup

  $ hg qpush
  applying p1
  now at: p1
  $ rm a.orig
  $ echo a >> a
  $ hg qpop --force --no-backup --verbose
  popping p1
  patch queue now empty
  $ test -f a.orig && echo 'error: backup with --no-backup'
  [1]

test qpop --keep-changes

  $ hg qpush
  applying p1
  now at: p1
  $ hg qpop --keep-changes --force
  abort: cannot use both --force and --keep-changes
  [255]
  $ echo a >> a
  $ hg qpop --keep-changes
  abort: local changes found, qrefresh first
  [255]
  $ hg revert -qa a
  $ rm a
  $ hg qpop --keep-changes
  abort: local changes found, qrefresh first
  [255]
  $ hg rm -A a
  $ hg qpop --keep-changes
  abort: local changes found, qrefresh first
  [255]
  $ hg revert -qa a
  $ echo b > b
  $ hg add b
  $ hg qpop --keep-changes
  abort: local changes found, qrefresh first
  [255]
  $ hg forget b
  $ echo d > d
  $ hg add d
  $ hg qpop --keep-changes
  popping p1
  patch queue now empty
  $ hg forget d
  $ rm d

test qpush --force and backup files

  $ echo a >> a
  $ hg qnew p2
  $ echo b >> b
  $ echo d > d
  $ echo e > e
  $ hg add d e
  $ hg rm c
  $ hg qnew p3
  $ hg qpop -a
  popping p3
  popping p2
  patch queue now empty
  $ echo a >> a
  $ echo b1 >> b
  $ echo d1 > d
  $ hg add d
  $ echo e1 > e
  $ hg qpush -a --force --verbose
  applying p2
  saving current version of a as a.orig
  patching file a
  committing files:
  a
  committing manifest
  committing changelog
  applying p3
  saving current version of b as b.orig
  saving current version of d as d.orig
  patching file b
  patching file c
  patching file d
  file d already exists
  1 out of 1 hunks FAILED -- saving rejects to file d.rej
  patching file e
  file e already exists
  1 out of 1 hunks FAILED -- saving rejects to file e.rej
  patch failed to apply
  committing files:
  b
  committing manifest
  committing changelog
  patch failed, rejects left in working directory
  errors during apply, please fix and qrefresh p3
  [2]
  $ cat a.orig
  a
  a
  $ cat b.orig
  b
  b1
  $ cat d.orig
  d1

test qpush --force --no-backup

  $ hg revert -qa
  $ hg qpop -a
  popping p3
  popping p2
  patch queue now empty
  $ echo a >> a
  $ rm a.orig
  $ hg qpush --force --no-backup --verbose
  applying p2
  patching file a
  committing files:
  a
  committing manifest
  committing changelog
  now at: p2
  $ test -f a.orig && echo 'error: backup with --no-backup'
  [1]

test qgoto --force --no-backup

  $ hg qpop
  popping p2
  patch queue now empty
  $ echo a >> a
  $ hg qgoto --force --no-backup p2 --verbose
  applying p2
  patching file a
  committing files:
  a
  committing manifest
  committing changelog
  now at: p2
  $ test -f a.orig && echo 'error: backup with --no-backup'
  [1]

test qpush --keep-changes

  $ hg qpush --keep-changes --force
  abort: cannot use both --force and --keep-changes
  [255]
  $ hg qpush --keep-changes --exact
  abort: cannot use --exact and --keep-changes together
  [255]
  $ echo b >> b
  $ hg qpush --keep-changes
  applying p3
  abort: conflicting local changes found
  (did you forget to qrefresh?)
  [255]
  $ rm b
  $ hg qpush --keep-changes
  applying p3
  abort: conflicting local changes found
  (did you forget to qrefresh?)
  [255]
  $ hg rm -A b
  $ hg qpush --keep-changes
  applying p3
  abort: conflicting local changes found
  (did you forget to qrefresh?)
  [255]
  $ hg revert -aq b
  $ echo d > d
  $ hg add d
  $ hg qpush --keep-changes
  applying p3
  abort: conflicting local changes found
  (did you forget to qrefresh?)
  [255]
  $ hg forget d
  $ rm d
  $ hg qpop
  popping p2
  patch queue now empty
  $ echo b >> b
  $ hg qpush -a --keep-changes
  applying p2
  applying p3
  abort: conflicting local changes found
  (did you forget to qrefresh?)
  [255]
  $ hg qtop
  p2
  $ hg parents --template "{rev} {desc}\n"
  2 imported patch p2
  $ hg st b
  M b
  $ cat b
  b
  b

test qgoto --keep-changes

  $ hg revert -aq b
  $ rm e
  $ hg qgoto --keep-changes --force p3
  abort: cannot use both --force and --keep-changes
  [255]
  $ echo a >> a
  $ hg qgoto --keep-changes p3
  applying p3
  now at: p3
  $ hg st a
  M a
  $ hg qgoto --keep-changes p2
  popping p3
  now at: p2
  $ hg st a
  M a

test mq.keepchanges setting

  $ hg --config mq.keepchanges=1 qpush
  applying p3
  now at: p3
  $ hg st a
  M a
  $ hg --config mq.keepchanges=1 qpop
  popping p3
  now at: p2
  $ hg st a
  M a
  $ hg --config mq.keepchanges=1 qgoto p3
  applying p3
  now at: p3
  $ hg st a
  M a
  $ echo b >> b
  $ hg --config mq.keepchanges=1 qpop --force --config 'ui.origbackuppath=.hg/origbackups'
  popping p3
  now at: p2
  $ hg st b
  $ hg --config mq.keepchanges=1 qpush --exact
  abort: local changes found, qrefresh first
  [255]
  $ hg revert -qa a
  $ hg qpop
  popping p2
  patch queue now empty
  $ echo a >> a
  $ hg --config mq.keepchanges=1 qpush --force
  applying p2
  now at: p2
  $ hg st a

test previous qpop (with --force and --config) saved .orig files to where user
wants them
  $ ls .hg/origbackups
  b.orig
  $ rm -rf .hg/origbackups

  $ cd ..