view tests/test-convert-hg-sink.t @ 23785:cb99bacb9b4e

branchcache: introduce revbranchcache for caching of revision branch names

It is expensive to retrieve the branch name of a revision. Very expensive when
creating a changectx and calling .branch() every time - slightly less when
using changelog.branchinfo().

Now, to speed things up, provide a way to cache the results on disk in an
efficient format. Each branchname is assigned a number, and for each revision
we store the number of the corresponding branch name. The branch names are
stored in a dedicated file which is strictly append only.

Branch names are usually reused across several revisions, and the total list of
branch names will thus be so small that it is feasible to read the whole set of
names before using the cache. It will however do that it might be more
efficient to use the changelog for retrieving the branch info for a single
revision.

The revision entries are stored in another file. This file is usually append
only, but if the repository has been modified, the file will be truncated and
the relevant parts rewritten on demand.

The entries for each revision are 8 bytes each, and the whole revision file
will thus be 1/8 of 00changelog.i.

Each revision entry contains the first 4 bytes of the corresponding node hash.
This is used as a check sum that always is verified before the entry is used.
That check is relatively expensive but it makes sure history modification is
detected and handled correctly. It will also detect and handle most revision
file corruptions.

This is just a cache. A new format can always be introduced if other
requirements or ideas make that seem like a good idea. Rebuilding the cache is
not really more expensive than it was to run for example 'hg log -b branchname'
before this cache was introduced.

This new method is still unused but promise to make some operations several
times faster once it actually is used.

Abandoning Python 2.4 would make it possible to implement this more efficiently
by using struct classes and pack_into. The Python code could probably also be
micro optimized or it could be implemented very efficiently in C where it would
be easy to control the data access.

  $ cat >> $HGRCPATH <<EOF
  > [extensions]
  > convert=
  > [convert]
  > hg.saverev=False
  > EOF
  $ hg init orig
  $ cd orig
  $ echo foo > foo
  $ echo bar > bar
  $ hg ci -qAm 'add foo and bar'
  $ hg rm foo
  $ hg ci -m 'remove foo'
  $ mkdir foo
  $ echo file > foo/file
  $ hg ci -qAm 'add foo/file'
  $ hg tag some-tag
  $ hg tag -l local-tag
  $ hg log
  changeset:   3:593cbf6fb2b4
  tag:         local-tag
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     Added tag some-tag for changeset ad681a868e44
  
  changeset:   2:ad681a868e44
  tag:         some-tag
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     add foo/file
  
  changeset:   1:cbba8ecc03b7
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     remove foo
  
  changeset:   0:327daa9251fa
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     add foo and bar
  
  $ cd ..
  $ hg convert orig new 2>&1 | grep -v 'subversion python bindings could not be loaded'
  initializing destination new repository
  scanning source...
  sorting...
  converting...
  3 add foo and bar
  2 remove foo
  1 add foo/file
  0 Added tag some-tag for changeset ad681a868e44
  $ cd new
  $ hg out ../orig
  comparing with ../orig
  searching for changes
  no changes found
  [1]

dirstate should be empty:

  $ hg debugstate
  $ hg parents -q
  $ hg up -C
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg copy bar baz

put something in the dirstate:

  $ hg debugstate > debugstate
  $ grep baz debugstate
  a   0         -1 unset               baz
  copy: bar -> baz

add a new revision in the original repo

  $ cd ../orig
  $ echo baz > baz
  $ hg ci -qAm 'add baz'
  $ cd ..
  $ hg convert orig new 2>&1 | grep -v 'subversion python bindings could not be loaded'
  scanning source...
  sorting...
  converting...
  0 add baz
  $ cd new
  $ hg out ../orig
  comparing with ../orig
  searching for changes
  no changes found
  [1]

dirstate should be the same (no output below):

  $ hg debugstate > new-debugstate
  $ diff debugstate new-debugstate

no copies

  $ hg up -C
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg debugrename baz
  baz not renamed
  $ cd ..

test tag rewriting

  $ cat > filemap <<EOF
  > exclude foo
  > EOF
  $ hg convert --filemap filemap orig new-filemap 2>&1 | grep -v 'subversion python bindings could not be loaded'
  initializing destination new-filemap repository
  scanning source...
  sorting...
  converting...
  4 add foo and bar
  3 remove foo
  2 add foo/file
  1 Added tag some-tag for changeset ad681a868e44
  0 add baz
  $ cd new-filemap
  $ hg tags
  tip                                2:3c74706b1ff8
  some-tag                           0:ba8636729451
  $ cd ..


Test cases for hg-hg roundtrip

Helper

  $ glog()
  > {
  >     hg log -G --template '{rev} {node|short} "{desc}" files: {files}\n' $*
  > }

Create a tricky source repo

  $ hg init source
  $ cd source

  $ echo 0 > 0
  $ hg ci -Aqm '0: add 0'
  $ echo a > a
  $ mkdir dir
  $ echo b > dir/b
  $ hg ci -qAm '1: add a and dir/b'
  $ echo c > dir/c
  $ hg ci -qAm '2: add dir/c'
  $ hg copy a e
  $ echo b >> b
  $ hg ci -qAm '3: copy a to e, change b'
  $ hg up -qr -3
  $ echo a >> a
  $ hg ci -qAm '4: change a'
  $ hg merge
  merging a and e to e
  2 files updated, 1 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg copy b dir/d
  $ hg ci -qAm '5: merge 2 and 3, copy b to dir/d'
  $ echo a >> a
  $ hg ci -qAm '6: change a'

  $ hg mani
  0
  a
  b
  dir/b
  dir/c
  dir/d
  e
  $ glog
  @  6 0613c8e59a3d "6: change a" files: a
  |
  o    5 717e9b37cdb7 "5: merge 2 and 3, copy b to dir/d" files: dir/d e
  |\
  | o  4 86a55cb968d5 "4: change a" files: a
  | |
  o |  3 0e6e235919dd "3: copy a to e, change b" files: b e
  | |
  o |  2 0394b0d5e4f7 "2: add dir/c" files: dir/c
  |/
  o  1 333546584845 "1: add a and dir/b" files: a dir/b
  |
  o  0 d1a24e2ebd23 "0: add 0" files: 0
  
  $ cd ..

Convert excluding rev 0 and dir/ (and thus rev2):

  $ cat << EOF > filemap
  > exclude dir
  > EOF

  $ hg convert --filemap filemap source dest --config convert.hg.revs=1::
  initializing destination dest repository
  scanning source...
  sorting...
  converting...
  5 1: add a and dir/b
  4 2: add dir/c
  3 3: copy a to e, change b
  2 4: change a
  1 5: merge 2 and 3, copy b to dir/d
  0 6: change a

Verify that conversion skipped rev 2:

  $ glog -R dest
  o  4 78814e84a217 "6: change a" files: a
  |
  o    3 f7cff662c5e5 "5: merge 2 and 3, copy b to dir/d" files: e
  |\
  | o  2 ab40a95b0072 "4: change a" files: a
  | |
  o |  1 bd51f17597bf "3: copy a to e, change b" files: b e
  |/
  o  0 a4a1dae0fe35 "1: add a and dir/b" files: 0 a
  

Verify mapping correct in both directions:

  $ cat source/.hg/shamap
  a4a1dae0fe3514cefd9b8541b7abbc8f44f946d5 333546584845f70c4cfecb992341aaef0e708166
  bd51f17597bf32268e68a560b206898c3960cda2 0e6e235919dd8e9285ba8eb5adf703af9ad99378
  ab40a95b00725307e79c2fd271000aa8af9759f4 86a55cb968d51770cba2a1630d6cc637b574580a
  f7cff662c5e581e6f3f1a85ffdd2bcb35825f6ba 717e9b37cdb7eb9917ca8e30aa3f986e6d5b177d
  78814e84a217894517c2de392b903ed05e6871a4 0613c8e59a3ddb9789072ef52f1ed13496489bb4
  $ cat dest/.hg/shamap
  333546584845f70c4cfecb992341aaef0e708166 a4a1dae0fe3514cefd9b8541b7abbc8f44f946d5
  0394b0d5e4f761ced559fd0bbdc6afc16cb3f7d1 a4a1dae0fe3514cefd9b8541b7abbc8f44f946d5
  0e6e235919dd8e9285ba8eb5adf703af9ad99378 bd51f17597bf32268e68a560b206898c3960cda2
  86a55cb968d51770cba2a1630d6cc637b574580a ab40a95b00725307e79c2fd271000aa8af9759f4
  717e9b37cdb7eb9917ca8e30aa3f986e6d5b177d f7cff662c5e581e6f3f1a85ffdd2bcb35825f6ba
  0613c8e59a3ddb9789072ef52f1ed13496489bb4 78814e84a217894517c2de392b903ed05e6871a4

Verify meta data converted correctly:

  $ hg -R dest log -r 1 --debug -p --git
  changeset:   1:bd51f17597bf32268e68a560b206898c3960cda2
  phase:       draft
  parent:      0:a4a1dae0fe3514cefd9b8541b7abbc8f44f946d5
  parent:      -1:0000000000000000000000000000000000000000
  manifest:    1:040c72ed9b101773c24ac314776bfc846943781f
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  files+:      b e
  extra:       branch=default
  description:
  3: copy a to e, change b
  
  
  diff --git a/b b/b
  new file mode 100644
  --- /dev/null
  +++ b/b
  @@ -0,0 +1,1 @@
  +b
  diff --git a/a b/e
  copy from a
  copy to e
  
Verify files included and excluded correctly:

  $ hg -R dest manifest -r tip
  0
  a
  b
  e


Make changes in dest and convert back:

  $ hg -R dest up -q
  $ echo dest > dest/dest
  $ hg -R dest ci -Aqm 'change in dest'
  $ hg -R dest tip
  changeset:   5:a2e0e3cc6d1d
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     change in dest
  

(converting merges back after using a filemap will probably cause chaos so we
exclude merges.)

  $ hg convert dest source --config convert.hg.revs='!merge()'
  scanning source...
  sorting...
  converting...
  0 change in dest

Verify the conversion back:

  $ hg -R source log --debug -r tip
  changeset:   7:e6d364a69ff1248b2099e603b0c145504cade6f0
  tag:         tip
  phase:       draft
  parent:      6:0613c8e59a3ddb9789072ef52f1ed13496489bb4
  parent:      -1:0000000000000000000000000000000000000000
  manifest:    7:aa3e9542f3b76d4f1f1b2e9c7ce9dbb48b6a95ec
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  files+:      dest
  extra:       branch=default
  description:
  change in dest
  
  
Files that had been excluded are still present:

  $ hg -R source manifest -r tip
  0
  a
  b
  dest
  dir/b
  dir/c
  dir/d
  e

More source changes

  $ cd source
  $ echo 1 >> a
  $ hg ci -m '8: source first branch'
  created new head
  $ hg up -qr -2
  $ echo 2 >> a
  $ hg ci -m '9: source second branch'
  $ hg merge -q --tool internal:local
  $ hg ci -m '10: source merge'
  $ echo >> a
  $ hg ci -m '11: source change'

  $ hg mani
  0
  a
  b
  dest
  dir/b
  dir/c
  dir/d
  e

  $ glog -r 6:
  @  11 0c8927d1f7f4 "11: source change" files: a
  |
  o    10 9ccb7ee8d261 "10: source merge" files: a
  |\
  | o  9 f131b1518dba "9: source second branch" files: a
  | |
  o |  8 669cf0e74b50 "8: source first branch" files: a
  | |
  | o  7 e6d364a69ff1 "change in dest" files: dest
  |/
  o  6 0613c8e59a3d "6: change a" files: a
  |
  $ cd ..

  $ hg convert --filemap filemap source dest --config convert.hg.revs=3:
  scanning source...
  sorting...
  converting...
  3 8: source first branch
  2 9: source second branch
  1 10: source merge
  0 11: source change

  $ glog -R dest
  o  9 8432d597b263 "11: source change" files: a
  |
  o    8 632ffacdcd6f "10: source merge" files: a
  |\
  | o  7 049cfee90ee6 "9: source second branch" files: a
  | |
  o |  6 9b6845e036e5 "8: source first branch" files: a
  | |
  | @  5 a2e0e3cc6d1d "change in dest" files: dest
  |/
  o  4 78814e84a217 "6: change a" files: a
  |
  o    3 f7cff662c5e5 "5: merge 2 and 3, copy b to dir/d" files: e
  |\
  | o  2 ab40a95b0072 "4: change a" files: a
  | |
  o |  1 bd51f17597bf "3: copy a to e, change b" files: b e
  |/
  o  0 a4a1dae0fe35 "1: add a and dir/b" files: 0 a
  
  $ cd ..

Two way tests

  $ hg init 0
  $ echo f > 0/f
  $ echo a > 0/a-only
  $ echo b > 0/b-only
  $ hg -R 0 ci -Aqm0

  $ cat << EOF > filemap-a
  > exclude b-only
  > EOF
  $ cat << EOF > filemap-b
  > exclude a-only
  > EOF
  $ hg convert --filemap filemap-a 0 a
  initializing destination a repository
  scanning source...
  sorting...
  converting...
  0 0
  $ hg -R a up -q
  $ echo a > a/f
  $ hg -R a ci -ma

  $ hg convert --filemap filemap-b 0 b
  initializing destination b repository
  scanning source...
  sorting...
  converting...
  0 0
  $ hg -R b up -q
  $ echo b > b/f
  $ hg -R b ci -mb

  $ tail */.hg/shamap
  ==> 0/.hg/shamap <==
  86f3f774ffb682bffb5dc3c1d3b3da637cb9a0d6 8a028c7c77f6c7bd6d63bc3f02ca9f779eabf16a
  dd9f218eb91fb857f2a62fe023e1d64a4e7812fe 8a028c7c77f6c7bd6d63bc3f02ca9f779eabf16a
  
  ==> a/.hg/shamap <==
  8a028c7c77f6c7bd6d63bc3f02ca9f779eabf16a 86f3f774ffb682bffb5dc3c1d3b3da637cb9a0d6
  
  ==> b/.hg/shamap <==
  8a028c7c77f6c7bd6d63bc3f02ca9f779eabf16a dd9f218eb91fb857f2a62fe023e1d64a4e7812fe

  $ hg convert a 0
  scanning source...
  sorting...
  converting...
  0 a

  $ hg convert b 0
  scanning source...
  sorting...
  converting...
  0 b

  $ hg -R 0 log -G
  o  changeset:   2:637fbbbe96b6
  |  tag:         tip
  |  parent:      0:8a028c7c77f6
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     b
  |
  | o  changeset:   1:ec7b9c96e692
  |/   user:        test
  |    date:        Thu Jan 01 00:00:00 1970 +0000
  |    summary:     a
  |
  @  changeset:   0:8a028c7c77f6
     user:        test
     date:        Thu Jan 01 00:00:00 1970 +0000
     summary:     0
  
  $ hg convert --filemap filemap-b 0 a --config convert.hg.revs=1::
  scanning source...
  sorting...
  converting...

  $ hg -R 0 up -r1
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo f >> 0/f
  $ hg -R 0 ci -mx

  $ hg convert --filemap filemap-b 0 a --config convert.hg.revs=1::
  scanning source...
  sorting...
  converting...
  0 x

  $ hg -R a log -G -T '{rev} {desc|firstline} ({files})\n'
  o  2 x (f)
  |
  @  1 a (f)
  |
  o  0 0 (a-only f)
  
  $ hg -R a mani -r tip
  a-only
  f

An additional round, demonstrating that unchanged files don't get converted

  $ echo f >> 0/f
  $ echo f >> 0/a-only
  $ hg -R 0 ci -m "extra f+a-only change"

  $ hg convert --filemap filemap-b 0 a --config convert.hg.revs=1::
  scanning source...
  sorting...
  converting...
  0 extra f+a-only change

  $ hg -R a log -G -T '{rev} {desc|firstline} ({files})\n'
  o  3 extra f+a-only change (f)
  |
  o  2 x (f)
  |
  @  1 a (f)
  |
  o  0 0 (a-only f)
  

Conversion after rollback

  $ hg -R a rollback -f
  repository tip rolled back to revision 2 (undo commit)

  $ hg convert --filemap filemap-b 0 a --config convert.hg.revs=1::
  scanning source...
  sorting...
  converting...
  0 extra f+a-only change

  $ hg -R a log -G -T '{rev} {desc|firstline} ({files})\n'
  o  3 extra f+a-only change (f)
  |
  o  2 x (f)
  |
  @  1 a (f)
  |
  o  0 0 (a-only f)
  
Convert with --full adds and removes files that didn't change

  $ echo f >> 0/f
  $ hg -R 0 ci -m "f"
  $ hg convert --filemap filemap-b --full 0 a --config convert.hg.revs=1::
  scanning source...
  sorting...
  converting...
  0 f
  $ hg -R a status --change tip
  M f
  A b-only
  R a-only