view tests/test-convert-mtn.t @ 33207:895ecec31c70

revlog: add an experimental option to mitigated delta issues (issue5480)

The general delta heuristic to select a delta do not scale with the number of
branch. The delta base is frequently too far away to be able to reuse a chain
according to the "distance" criteria. This leads to insertion of larger delta (or
even full text) that themselves push the bases for the next delta further away
leading to more large deltas and full texts. This full text and frequent
recomputation throw Mercurial performance in disarray.

For example of a slightly large repository

  280 000 files (2 150 000 versions)
  430 000 changesets (10 000 topological heads)

Number below compares repository with and without the distance criteria:

manifest size:
    with:    21.4 GB
    without:  0.3 GB

store size:
    with:    28.7 GB
    without   7.4 GB

bundle last 15 00 revisions:
    with:    800 seconds
             971 MB
    without:  50 seconds
              73 MB

unbundle time (of the last 15K revisions):
    with:    1150 seconds (~19 minutes)
    without:   35 seconds

Similar issues has been observed in other repositories.


Adding a new option or "feature" on stable is uncommon. However, given that this
issues is making Mercurial practically unusable, I'm exceptionally targeting
this patch for stable.

What is actually needed is a full rework of the delta building and reading
logic. However, that will be a longer process and churn not suitable for stable.

In the meantime, we introduces a quick and dirty mitigation of this in the
'experimental' config space. The new option introduces a way to set the maximum
amount of memory usable to store a diff in memory. This extend the ability for
Mercurial to create chains without removing all safe guard regarding memory
access. The option should be phased out when core has a more proper solution
available.

Setting the limit to '0' remove all limits, setting it to '-1' use the default
limit (textsize x 4).

#require mtn

Monotone directory is called .monotone on *nix and monotone
on Windows.

#if windows

  $ mtndir=monotone

#else

  $ mtndir=.monotone

#endif

  $ echo "[extensions]" >> $HGRCPATH
  $ echo "convert=" >> $HGRCPATH

Windows version of monotone home

  $ APPDATA=$HOME; export APPDATA

tedious monotone keys configuration
The /dev/null redirection is necessary under Windows, or
it complains about home directory permissions

  $ mtn --quiet genkey [e-mail] 1>/dev/null 2>&1 <<EOF
  > passphrase
  > passphrase
  > EOF
  $ cat >> $HOME/$mtndir/monotonerc <<EOF
  > function get_passphrase(keypair_id)
  >     return "passphrase"
  > end
  > EOF

create monotone repository

  $ mtn db init --db=repo.mtn
  $ mtn --db=repo.mtn --branch=com.selenic.test setup workingdir
  $ cd workingdir
  $ echo a > a
  $ mkdir dir
  $ echo b > dir/b
  $ echo d > dir/d
  $ $PYTHON -c 'file("bin", "wb").write("a\\x00b")'
  $ echo c > c
  $ mtn add a dir/b dir/d c bin
  mtn: adding 'a' to workspace manifest
  mtn: adding 'bin' to workspace manifest
  mtn: adding 'c' to workspace manifest
  mtn: adding 'dir' to workspace manifest
  mtn: adding 'dir/b' to workspace manifest
  mtn: adding 'dir/d' to workspace manifest
  $ mtn ci -m initialize
  mtn: beginning commit on branch 'com.selenic.test'
  mtn: committed revision 0f6e5e4f2e7d2a8ef312408f57618abf026afd90

update monotone working directory

  $ mtn mv a dir/a
  mtn: skipping 'dir', already accounted for in workspace
  mtn: renaming 'a' to 'dir/a' in workspace manifest
  $ echo a >> dir/a
  $ echo b >> dir/b
  $ mtn drop c
  mtn: dropping 'c' from workspace manifest
  $ $PYTHON -c 'file("bin", "wb").write("b\\x00c")'
  $ mtn ci -m update1
  mtn: beginning commit on branch 'com.selenic.test'
  mtn: committed revision 51d0a982464573a2a2cf5ee2c9219c652aaebeff
  $ cd ..

convert once

  $ hg convert -s mtn repo.mtn
  assuming destination repo.mtn-hg
  initializing destination repo.mtn-hg repository
  scanning source...
  sorting...
  converting...
  1 initialize
  0 update1
  $ cd workingdir
  $ echo e > e
  $ mtn add e
  mtn: adding 'e' to workspace manifest
  $ mtn drop dir/b
  mtn: dropping 'dir/b' from workspace manifest
  $ mtn mv bin bin2
  mtn: renaming 'bin' to 'bin2' in workspace manifest
  $ mtn ci -m 'update2 "with" quotes'
  mtn: beginning commit on branch 'com.selenic.test'
  mtn: committed revision ebe58335d85d8cb176b6d0a12be04f5314b998da

test directory move

  $ mkdir -p dir1/subdir1
  $ mkdir -p dir1/subdir2_other
  $ echo file1 > dir1/subdir1/file1
  $ echo file2 > dir1/subdir2_other/file1
  $ mtn add dir1/subdir1/file1 dir1/subdir2_other/file1
  mtn: adding 'dir1' to workspace manifest
  mtn: adding 'dir1/subdir1' to workspace manifest
  mtn: adding 'dir1/subdir1/file1' to workspace manifest
  mtn: adding 'dir1/subdir2_other' to workspace manifest
  mtn: adding 'dir1/subdir2_other/file1' to workspace manifest
  $ mtn ci -m createdir1
  mtn: beginning commit on branch 'com.selenic.test'
  mtn: committed revision a8d62bc04fee4d2936d28e98bbcc81686dd74306
  $ mtn rename dir1/subdir1 dir1/subdir2
  mtn: skipping 'dir1', already accounted for in workspace
  mtn: renaming 'dir1/subdir1' to 'dir1/subdir2' in workspace manifest
  $ mtn ci -m movedir1
  mtn: beginning commit on branch 'com.selenic.test'
  mtn: committed revision 2c3d241bbbfe538b1b51d910f5676407e3f4d3a6

test subdirectory move

  $ mtn mv dir dir2
  mtn: renaming 'dir' to 'dir2' in workspace manifest
  $ echo newfile > dir2/newfile
  $ mtn drop dir2/d
  mtn: dropping 'dir2/d' from workspace manifest
  $ mtn add dir2/newfile
  mtn: adding 'dir2/newfile' to workspace manifest
  $ mtn ci -m movedir
  mtn: beginning commit on branch 'com.selenic.test'
  mtn: committed revision fdb5a02dae8bfce3a79b3393680af471016e1b4c

Test directory removal with empty directory

  $ mkdir dir2/dir
  $ mkdir dir2/dir/subdir
  $ echo f > dir2/dir/subdir/f
  $ mkdir dir2/dir/emptydir
  $ mtn add --quiet -R dir2/dir
  $ mtn ci -m emptydir
  mtn: beginning commit on branch 'com.selenic.test'
  mtn: committed revision 8bbf76d717001d24964e4604739fdcd0f539fc88
  $ mtn drop -R dir2/dir
  mtn: dropping 'dir2/dir/subdir/f' from workspace manifest
  mtn: dropping 'dir2/dir/subdir' from workspace manifest
  mtn: dropping 'dir2/dir/emptydir' from workspace manifest
  mtn: dropping 'dir2/dir' from workspace manifest
  $ mtn ci -m dropdirectory
  mtn: beginning commit on branch 'com.selenic.test'
  mtn: committed revision 2323d4bc324e6c82628dc04d47a9fd32ad24e322

test directory and file move

  $ mkdir -p dir3/d1
  $ echo a > dir3/a
  $ mtn add dir3/a dir3/d1
  mtn: adding 'dir3' to workspace manifest
  mtn: adding 'dir3/a' to workspace manifest
  mtn: adding 'dir3/d1' to workspace manifest
  $ mtn ci -m dirfilemove
  mtn: beginning commit on branch 'com.selenic.test'
  mtn: committed revision 47b192f720faa622f48c68d1eb075b26d405aa8b
  $ mtn mv dir3/a dir3/d1/a
  mtn: skipping 'dir3/d1', already accounted for in workspace
  mtn: renaming 'dir3/a' to 'dir3/d1/a' in workspace manifest
  $ mtn mv dir3/d1 dir3/d2
  mtn: skipping 'dir3', already accounted for in workspace
  mtn: renaming 'dir3/d1' to 'dir3/d2' in workspace manifest
  $ mtn ci -m dirfilemove2
  mtn: beginning commit on branch 'com.selenic.test'
  mtn: committed revision 8b543a400d3ee7f6d4bb1835b9b9e3747c8cb632

test directory move into another directory move

  $ mkdir dir4
  $ mkdir dir5
  $ echo a > dir4/a
  $ mtn add dir4/a dir5
  mtn: adding 'dir4' to workspace manifest
  mtn: adding 'dir4/a' to workspace manifest
  mtn: adding 'dir5' to workspace manifest
  $ mtn ci -m dirdirmove
  mtn: beginning commit on branch 'com.selenic.test'
  mtn: committed revision 466e0b2afc7a55aa2b4ab2f57cb240bb6cd66fc7
  $ mtn mv dir5 dir6
  mtn: renaming 'dir5' to 'dir6' in workspace manifest
  $ mtn mv dir4 dir6/dir4
  mtn: skipping 'dir6', already accounted for in workspace
  mtn: renaming 'dir4' to 'dir6/dir4' in workspace manifest
  $ mtn ci -m dirdirmove2
  mtn: beginning commit on branch 'com.selenic.test'
  mtn: committed revision 3d1f77ebad0c23a5d14911be3b670f990991b749

test diverging directory moves

  $ mkdir -p dir7/dir9/dir8
  $ echo a > dir7/dir9/dir8/a
  $ echo b > dir7/dir9/b
  $ echo c > dir7/c
  $ mtn add -R dir7
  mtn: adding 'dir7' to workspace manifest
  mtn: adding 'dir7/c' to workspace manifest
  mtn: adding 'dir7/dir9' to workspace manifest
  mtn: adding 'dir7/dir9/b' to workspace manifest
  mtn: adding 'dir7/dir9/dir8' to workspace manifest
  mtn: adding 'dir7/dir9/dir8/a' to workspace manifest
  $ mtn ci -m divergentdirmove
  mtn: beginning commit on branch 'com.selenic.test'
  mtn: committed revision 08a08511f18b428d840199b062de90d0396bc2ed
  $ mtn mv dir7 dir7-2
  mtn: renaming 'dir7' to 'dir7-2' in workspace manifest
  $ mtn mv dir7-2/dir9 dir9-2
  mtn: renaming 'dir7-2/dir9' to 'dir9-2' in workspace manifest
  $ mtn mv dir9-2/dir8 dir8-2
  mtn: renaming 'dir9-2/dir8' to 'dir8-2' in workspace manifest
  $ mtn ci -m divergentdirmove2
  mtn: beginning commit on branch 'com.selenic.test'
  mtn: committed revision 4a736634505795f17786fffdf2c9cbf5b11df6f6

test large file support (> 32kB)

  >>> fp = file('large-file', 'wb')
  >>> for x in xrange(10000): fp.write('%d\n' % x)
  >>> fp.close()
  $ md5sum.py large-file
  5d6de8a95c3b6bf9e0ffb808ba5299c1  large-file
  $ mtn add large-file
  mtn: adding 'large-file' to workspace manifest
  $ mtn ci -m largefile
  mtn: beginning commit on branch 'com.selenic.test'
  mtn: committed revision f0a20fecd10dc4392d18fe69a03f1f4919d3387b

test suspending (closing a branch)

  $ mtn suspend f0a20fecd10dc4392d18fe69a03f1f4919d3387b 2> /dev/null
  $ cd ..

convert incrementally

  $ hg convert -s mtn repo.mtn
  assuming destination repo.mtn-hg
  scanning source...
  sorting...
  converting...
  12 update2 "with" quotes
  11 createdir1
  10 movedir1
  9 movedir
  8 emptydir
  7 dropdirectory
  6 dirfilemove
  5 dirfilemove2
  4 dirdirmove
  3 dirdirmove2
  2 divergentdirmove
  1 divergentdirmove2
  0 largefile
  $ glog()
  > {
  >     hg log -G --template '{rev} "{desc|firstline}" files: {files}\n' "$@"
  > }
  $ cd repo.mtn-hg
  $ hg up -C
  12 files updated, 0 files merged, 0 files removed, 0 files unresolved
  no open descendant heads on branch "com.selenic.test", updating to a closed head
  (committing will reopen branch "com.selenic.test")
  $ glog
  @  14 "largefile" files: large-file
  |
  o  13 "divergentdirmove2" files: dir7-2/c dir7/c dir7/dir9/b dir7/dir9/dir8/a dir8-2/a dir9-2/b
  |
  o  12 "divergentdirmove" files: dir7/c dir7/dir9/b dir7/dir9/dir8/a
  |
  o  11 "dirdirmove2" files: dir4/a dir6/dir4/a
  |
  o  10 "dirdirmove" files: dir4/a
  |
  o  9 "dirfilemove2" files: dir3/a dir3/d2/a
  |
  o  8 "dirfilemove" files: dir3/a
  |
  o  7 "dropdirectory" files: dir2/dir/subdir/f
  |
  o  6 "emptydir" files: dir2/dir/subdir/f
  |
  o  5 "movedir" files: dir/a dir/d dir2/a dir2/newfile
  |
  o  4 "movedir1" files: dir1/subdir1/file1 dir1/subdir2/file1
  |
  o  3 "createdir1" files: dir1/subdir1/file1 dir1/subdir2_other/file1
  |
  o  2 "update2 "with" quotes" files: bin bin2 dir/b e
  |
  o  1 "update1" files: a bin c dir/a dir/b
  |
  o  0 "initialize" files: a bin c dir/b dir/d
  

manifest

  $ hg manifest
  bin2
  dir1/subdir2/file1
  dir1/subdir2_other/file1
  dir2/a
  dir2/newfile
  dir3/d2/a
  dir6/dir4/a
  dir7-2/c
  dir8-2/a
  dir9-2/b
  e
  large-file

contents

  $ cat dir2/a
  a
  a
  $ test -d dir2/dir && echo 'removed dir2/dir is still there!'
  [1]

file move

  $ hg log -v -C -r 1 | grep copies
  copies:      dir/a (a)

check directory move

  $ hg manifest -r 4
  bin2
  dir/a
  dir/d
  dir1/subdir2/file1
  dir1/subdir2_other/file1
  e
  $ test -d dir1/subdir2 || echo 'new dir1/subdir2 does not exist!'
  $ test -d dir1/subdir1 && echo 'renamed dir1/subdir1 is still there!'
  [1]
  $ hg log -v -C -r 4 | grep copies
  copies:      dir1/subdir2/file1 (dir1/subdir1/file1)

check file remove with directory move

  $ hg manifest -r 5
  bin2
  dir1/subdir2/file1
  dir1/subdir2_other/file1
  dir2/a
  dir2/newfile
  e

check file move with directory move

  $ hg manifest -r 9
  bin2
  dir1/subdir2/file1
  dir1/subdir2_other/file1
  dir2/a
  dir2/newfile
  dir3/d2/a
  e

check file directory directory move

  $ hg manifest -r 11
  bin2
  dir1/subdir2/file1
  dir1/subdir2_other/file1
  dir2/a
  dir2/newfile
  dir3/d2/a
  dir6/dir4/a
  e

check divergent directory moves

  $ hg manifest -r 13
  bin2
  dir1/subdir2/file1
  dir1/subdir2_other/file1
  dir2/a
  dir2/newfile
  dir3/d2/a
  dir6/dir4/a
  dir7-2/c
  dir8-2/a
  dir9-2/b
  e

test large file support (> 32kB)

  $ md5sum.py large-file
  5d6de8a95c3b6bf9e0ffb808ba5299c1  large-file

check branch closing

  $ hg branches -a
  $ hg branches -c
  com.selenic.test              14:* (closed) (glob)