view tests/test-convert-svn-source.t @ 16120:47ee41fcf42b

largefiles: optimize update speed by only updating changed largefiles

Historically, during 'hg update', every largefile in the working copy was
hashed (which is a very expensive operation on big files) and any
largefiles that did not have a hash that matched their standin were
updated.

This patch optimizes 'hg update' by keeping track of what standins have
changed between the old and new revisions, and only updating the largefiles
that have changed.  This saves a lot of time by avoiding the unecessary
calculation of a list of sha1 hashes for big files.

With this patch, the time 'hg update' takes to complete is a function of
how many largefiles need to be updated and what their size is.

Performance tests on a repository with about 80 largefiles ranging from
a few MB to about 97 MB are shown below.  The tests show how long it takes
to run 'hg update' with no changes actually being updated.

Mercurial 2.1 release:

$ time hg update
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
getting changed largefiles
0 largefiles updated, 0 removed

real    0m10.045s
user    0m9.367s
sys    0m0.674s

With this patch:

$ time hg update
0 files updated, 0 files merged, 0 files removed, 0 files unresolved

real    0m0.965s
user    0m0.845s
sys    0m0.115s

The same repsoitory, without the largefiles extension enabled:

$ time hg update
0 files updated, 0 files merged, 0 files removed, 0 files unresolved

real    0m0.799s
user    0m0.684s
sys    0m0.111s

So before the patch, 'hg update' with no changes was approximately 9.25s
slower with largefiles enabled.  With this patch, it is approximately 0.165s
slower.

  $ "$TESTDIR/hghave" svn svn-bindings || exit 80

  $ fixpath()
  > {
  >     tr '\\' /
  > }
  $ cat >> $HGRCPATH <<EOF
  > [extensions]
  > convert = 
  > graphlog =
  > [convert]
  > svn.trunk = mytrunk
  > EOF

  $ svnadmin create svn-repo
  $ svnpath=`pwd | fixpath`


  $ expr "$svnpath" : "\/" > /dev/null
  > if [ $? -ne 0 ]; then
  >   svnpath="/$svnpath"
  > fi
  > svnurl="file://$svnpath/svn-repo"

Now test that it works with trunk/tags layout, but no branches yet.

Initial svn import

  $ mkdir projB
  $ cd projB
  $ mkdir mytrunk
  $ mkdir tags
  $ cd ..

  $ svnurl="file://$svnpath/svn-repo/proj%20B"
  $ svn import -m "init projB" projB "$svnurl" | fixpath
  Adding         projB/mytrunk
  Adding         projB/tags
  
  Committed revision 1.

Update svn repository

  $ svn co "$svnurl"/mytrunk B | fixpath
  Checked out revision 1.
  $ cd B
  $ echo hello > 'letter .txt'
  $ svn add 'letter .txt'
  A         letter .txt
  $ svn ci -m hello
  Adding         letter .txt
  Transmitting file data .
  Committed revision 2.

  $ "$TESTDIR/svn-safe-append.py" world 'letter .txt'
  $ svn ci -m world
  Sending        letter .txt
  Transmitting file data .
  Committed revision 3.

  $ svn copy -m "tag v0.1" "$svnurl"/mytrunk "$svnurl"/tags/v0.1
  
  Committed revision 4.

  $ "$TESTDIR/svn-safe-append.py" 'nice day today!' 'letter .txt'
  $ svn ci -m "nice day"
  Sending        letter .txt
  Transmitting file data .
  Committed revision 5.
  $ cd ..

Convert to hg once

  $ hg convert "$svnurl" B-hg
  initializing destination B-hg repository
  scanning source...
  sorting...
  converting...
  3 init projB
  2 hello
  1 world
  0 nice day
  updating tags

Update svn repository again

  $ cd B
  $ "$TESTDIR/svn-safe-append.py" "see second letter" 'letter .txt'
  $ echo "nice to meet you" > letter2.txt
  $ svn add letter2.txt
  A         letter2.txt
  $ svn ci -m "second letter"
  Sending        letter .txt
  Adding         letter2.txt
  Transmitting file data ..
  Committed revision 6.

  $ svn copy -m "tag v0.2" "$svnurl"/mytrunk "$svnurl"/tags/v0.2
  
  Committed revision 7.

  $ "$TESTDIR/svn-safe-append.py" "blah-blah-blah" letter2.txt
  $ svn ci -m "work in progress"
  Sending        letter2.txt
  Transmitting file data .
  Committed revision 8.
  $ cd ..

  $ hg convert -s svn "$svnurl/non-existent-path" dest
  initializing destination dest repository
  abort: no revision found in module /proj B/non-existent-path
  [255]

########################################

Test incremental conversion

  $ hg convert "$svnurl" B-hg
  scanning source...
  sorting...
  converting...
  1 second letter
  0 work in progress
  updating tags

  $ cd B-hg
  $ hg glog --template '{rev} {desc|firstline} files: {files}\n'
  o  7 update tags files: .hgtags
  |
  o  6 work in progress files: letter2.txt
  |
  o  5 second letter files: letter .txt letter2.txt
  |
  o  4 update tags files: .hgtags
  |
  o  3 nice day files: letter .txt
  |
  o  2 world files: letter .txt
  |
  o  1 hello files: letter .txt
  |
  o  0 init projB files:
  
  $ hg tags -q
  tip
  v0.2
  v0.1
  $ cd ..

Test filemap
  $ echo 'include letter2.txt' > filemap
  $ hg convert --filemap filemap "$svnurl"/mytrunk fmap
  initializing destination fmap repository
  scanning source...
  sorting...
  converting...
  5 init projB
  4 hello
  3 world
  2 nice day
  1 second letter
  0 work in progress
  $ hg -R fmap branch -q
  default
  $ hg glog -R fmap --template '{rev} {desc|firstline} files: {files}\n'
  o  1 work in progress files: letter2.txt
  |
  o  0 second letter files: letter2.txt
  

Test stop revision
  $ hg convert --rev 1 "$svnurl"/mytrunk stoprev
  initializing destination stoprev repository
  scanning source...
  sorting...
  converting...
  0 init projB
  $ hg -R stoprev branch -q
  default

Check convert_revision extra-records.
This is also the only place testing more than one extra field in a revision.

  $ cd stoprev
  $ hg tip --debug | grep extra
  extra:       branch=default
  extra:       convert_revision=svn:........-....-....-....-............/proj B/mytrunk@1 (re)
  $ cd ..