view tests/test-convert-svn-encoding.t @ 42621:99ebde4fec99

commit: improve the files field of changelog for merges

Currently, the files list of merge commits repeats all the deletions
(either actual deletions, or files that got renamed) that happened
between base and p2 of the merge. If p2 is the main branch, the list
can easily be much bigger than the change being merged.

This results in various problems worth improving:
- changelog is bigger than necessary
- `hg log directory` lists many unrelated merge commits, and `hg log
  -v -r commit` frequently fills multiple screens worth of files
- it possibly slows down adjustlinkrev, by forcing it to read more
  manifests, and that function can certainly be a bottleneck
- the server side of pulls can waste a lot of time simply opening the
  filelogs for pointless files (the constant factors for opening even
  a tiny filelog is apparently pretty bad)

So stop listing such files as described in the code.  Impacted merge
commits and their descendants get a different hash than they would
have without this. This doesn't seem problematic, except for
convert. The previous commit helped with that in the hg->hg case (but
if you do svn->hg twice from scratch, hashes can still change).

The rest of the description is numbers. I don't have much to report,
because recreating the files list of existing repositories is not
easy:
- debugupgradeformat and bundle/unbundle don't recreate the list
- export/import tends to choke quickly applying patches or on
  description that contain diffs,
- merge commits from the convert extension don't have the right files
  list for reasons orthogonal to the current commit
- replaying the merge with hg update/hg merge/hg revert --all/hg
  commit can end up failing in hg revert
- I wasn't sure that using debugsetparents + debugrebuilddirstate
  would really build the right thing

I measured commit time before and after this change, in a case with no
files filtered out, several files filtered out (no difference) and 5k
files filtered out (+1% time).

Recreating the 100 more recent merges in a private repo, the
concatenated uncompressed files lists goes from 1.12MB to
0.52MB. Excluding 3 merges that are not representative, then the size
goes from 570k to 15k.
I converted part of mozilla-central, and observed file list shrinking
quite a bit too, starting at the very first merge, 733641d9feaf, going
from 550 files to 10 files (although they have relatively few merges,
so they probably wouldn't care).

Differential Revision: https://phab.mercurial-scm.org/D6613

#require svn svn-bindings

  $ cat >> $HGRCPATH <<EOF
  > [extensions]
  > convert =
  > EOF

  $ svnadmin create svn-repo
  $ svnadmin load -q svn-repo < "$TESTDIR/svn/encoding.svndump"

Convert while testing all possible outputs

  $ hg --debug convert svn-repo A-hg --config progress.debug=1
  initializing destination A-hg repository
  reparent to file:/*/$TESTTMP/svn-repo (glob)
  run hg sink pre-conversion action
  scanning source...
  found trunk at 'trunk'
  found tags at 'tags'
  found branches at 'branches'
  found branch branch\xc3\xa9 at 5 (esc)
  found branch branch\xc3\xa9e at 6 (esc)
  scanning: 1/4 revisions (25.00%)
  reparent to file:/*/$TESTTMP/svn-repo/trunk (glob)
  fetching revision log for "/trunk" from 4 to 0
  parsing revision 4 (2 changes)
  parsing revision 3 (4 changes)
  parsing revision 2 (3 changes)
  parsing revision 1 (3 changes)
  no copyfrom path, don't know what to do.
  '/branches' is not under '/trunk', ignoring
  '/tags' is not under '/trunk', ignoring
  scanning: 2/4 revisions (50.00%)
  reparent to file:/*/$TESTTMP/svn-repo/branches/branch%C3%A9 (glob)
  fetching revision log for "/branches/branch\xc3\xa9" from 5 to 0 (esc)
  parsing revision 5 (1 changes)
  reparent to file:/*/$TESTTMP/svn-repo (glob)
  reparent to file:/*/$TESTTMP/svn-repo/branches/branch%C3%A9 (glob)
  found parent of branch /branches/branch\xc3\xa9 at 4: /trunk (esc)
  scanning: 3/4 revisions (75.00%)
  reparent to file:/*/$TESTTMP/svn-repo/branches/branch%C3%A9e (glob)
  fetching revision log for "/branches/branch\xc3\xa9e" from 6 to 0 (esc)
  parsing revision 6 (1 changes)
  reparent to file:/*/$TESTTMP/svn-repo (glob)
  reparent to file:/*/$TESTTMP/svn-repo/branches/branch%C3%A9e (glob)
  found parent of branch /branches/branch\xc3\xa9e at 5: /branches/branch\xc3\xa9 (esc)
  scanning: 4/4 revisions (100.00%)
  scanning: 5/4 revisions (125.00%)
  scanning: 6/4 revisions (150.00%)
  sorting...
  converting...
  5 init projA
  source: svn:afeb9c47-92ff-4c0c-9f72-e1f6eb8ac9af/trunk@1
  converting: 0/6 revisions (0.00%)
  reusing manifest from p1 (no file change)
  committing changelog
  updating the branch cache
  4 hello
  source: svn:afeb9c47-92ff-4c0c-9f72-e1f6eb8ac9af/trunk@2
  converting: 1/6 revisions (16.67%)
  reparent to file:/*/$TESTTMP/svn-repo/trunk (glob)
  scanning paths: /trunk/\xc3\xa0 0/3 paths (0.00%) (esc)
  scanning paths: /trunk/\xc3\xa0/e\xcc\x81 1/3 paths (33.33%) (esc)
  scanning paths: /trunk/\xc3\xa9 2/3 paths (66.67%) (esc)
  committing files:
  \xc3\xa0/e\xcc\x81 (esc)
  getting files: \xc3\xa0/e\xcc\x81 1/2 files (50.00%) (esc)
  \xc3\xa9 (esc)
  getting files: \xc3\xa9 2/2 files (100.00%) (esc)
  committing manifest
  committing changelog
  updating the branch cache
  3 copy files
  source: svn:afeb9c47-92ff-4c0c-9f72-e1f6eb8ac9af/trunk@3
  converting: 2/6 revisions (33.33%)
  scanning paths: /trunk/\xc3\xa0 0/4 paths (0.00%) (esc)
  gone from -1
  reparent to file:/*/$TESTTMP/svn-repo (glob)
  reparent to file:/*/$TESTTMP/svn-repo/trunk (glob)
  scanning paths: /trunk/\xc3\xa8 1/4 paths (25.00%) (esc)
  copied to \xc3\xa8 from \xc3\xa9@2 (esc)
  scanning paths: /trunk/\xc3\xa9 2/4 paths (50.00%) (esc)
  gone from -1
  reparent to file:/*/$TESTTMP/svn-repo (glob)
  reparent to file:/*/$TESTTMP/svn-repo/trunk (glob)
  scanning paths: /trunk/\xc3\xb9 3/4 paths (75.00%) (esc)
  mark /trunk/\xc3\xb9 came from \xc3\xa0:2 (esc)
  getting files: \xc3\xa0/e\xcc\x81 1/4 files (25.00%) (esc)
  getting files: \xc3\xa9 2/4 files (50.00%) (esc)
  committing files:
  \xc3\xa8 (esc)
  getting files: \xc3\xa8 3/4 files (75.00%) (esc)
   \xc3\xa8: copy \xc3\xa9:6b67ccefd5ce6de77e7ead4f5292843a0255329f (esc)
  \xc3\xb9/e\xcc\x81 (esc)
  getting files: \xc3\xb9/e\xcc\x81 4/4 files (100.00%) (esc)
   \xc3\xb9/e\xcc\x81: copy \xc3\xa0/e\xcc\x81:a9092a3d84a37b9993b5c73576f6de29b7ea50f6 (esc)
  committing manifest
  committing changelog
  updating the branch cache
  2 remove files
  source: svn:afeb9c47-92ff-4c0c-9f72-e1f6eb8ac9af/trunk@4
  converting: 3/6 revisions (50.00%)
  scanning paths: /trunk/\xc3\xa8 0/2 paths (0.00%) (esc)
  gone from -1
  reparent to file:/*/$TESTTMP/svn-repo (glob)
  reparent to file:/*/$TESTTMP/svn-repo/trunk (glob)
  scanning paths: /trunk/\xc3\xb9 1/2 paths (50.00%) (esc)
  gone from -1
  reparent to file:/*/$TESTTMP/svn-repo (glob)
  reparent to file:/*/$TESTTMP/svn-repo/trunk (glob)
  getting files: \xc3\xa8 1/2 files (50.00%) (esc)
  getting files: \xc3\xb9/e\xcc\x81 2/2 files (100.00%) (esc)
  committing files:
  committing manifest
  committing changelog
  updating the branch cache
  1 branch to branch?
  source: svn:afeb9c47-92ff-4c0c-9f72-e1f6eb8ac9af/branches/branch?@5
  converting: 4/6 revisions (66.67%)
  reparent to file:/*/$TESTTMP/svn-repo/branches/branch%C3%A9 (glob)
  scanning paths: /branches/branch\xc3\xa9 0/1 paths (0.00%) (esc)
  reusing manifest from p1 (no file change)
  committing changelog
  updating the branch cache
  0 branch to branch?e
  source: svn:afeb9c47-92ff-4c0c-9f72-e1f6eb8ac9af/branches/branch?e@6
  converting: 5/6 revisions (83.33%)
  reparent to file:/*/$TESTTMP/svn-repo/branches/branch%C3%A9e (glob)
  scanning paths: /branches/branch\xc3\xa9e 0/1 paths (0.00%) (esc)
  reusing manifest from p1 (no file change)
  committing changelog
  updating the branch cache
  reparent to file:/*/$TESTTMP/svn-repo (glob)
  reparent to file:/*/$TESTTMP/svn-repo/branches/branch%C3%A9e (glob)
  reparent to file:/*/$TESTTMP/svn-repo (glob)
  reparent to file:/*/$TESTTMP/svn-repo/branches/branch%C3%A9e (glob)
  updating tags
  committing files:
  .hgtags
  committing manifest
  committing changelog
  updating the branch cache
  run hg sink post-conversion action
  $ cd A-hg
  $ hg up
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

Check tags are in UTF-8

  $ cat .hgtags
  e94e4422020e715add80525e8f0f46c9968689f1 branch\xc3\xa9e (esc)
  f7e66f98380ed1e53a797c5c7a7a2616a7ab377d branch\xc3\xa9 (esc)

  $ cd ..