view tests/test-convert-cvs-synthetic.t @ 42406:f385ba70e4af

changelog: optionally store added and removed files in changeset extras

As mentioned in an earlier patch, copies._chain() is used a lot in the
changeset-centric version of pathcopies(). It is expensive because it
needs to look at the manifest in order to filter out copies whose
target file has since been removed. I want to store the sets of added
and removed files in the changeset in order to speed that up. This
patch does the writing part of that. It could easily be a separate
config, but it's currently tied to experimental.copies.write-to since
that's the only real use case (it will also make the {file_*} template
keywords faster, but I doubt that anyone cares enough about those to
write extra metadata for them).

The new information is stored in the changeset extras. Since they're
always subsets of the changeset's "files" list, they're stored as
indexes into that list. I've stored the indexes as stringified ints
separated by NUL bytes. The size of 00changelog.d for the hg repo
increased in size by 0.28% percent (compared to the size with only
copy information in the changesets, which in turn is 0.17% larger than
without copy information). We could store only the delta between the
indexes and we could store them in binary, but the chosen format is
more readable.

We could also have implemented this as a cache outside the
changelog. One advantage of doing it that way is that we would get the
speedups from the {file_*} template keywords also on old
repos. Another advantage is that it we can rewrite the cache if we
find a bug in how we calculate the set of files. A disadvantage is
that it would be more complex. Another is that it would surely use
more space. We already write the copy information to the changeset
extras, so it seems like a small step to also write these file sets.

Differential Revision: https://phab.mercurial-scm.org/D6416

#require cvs112

This feature requires use of builtin cvsps!

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

create cvs repository with one project

  $ mkdir cvsrepo
  $ cd cvsrepo
  $ CVSROOT=`pwd`
  $ export CVSROOT
  $ CVS_OPTIONS=-f
  $ export CVS_OPTIONS
  $ cd ..
  $ rmdir cvsrepo
  $ cvscall()
  > {
  >     cvs -f "$@"
  > }

output of 'cvs ci' varies unpredictably, so just discard it

  $ cvsci()
  > {
  >     sleep 1
  >     cvs -f ci "$@" >/dev/null
  > }
  $ cvscall -d "$CVSROOT" init
  $ mkdir cvsrepo/proj
  $ cvscall -q co proj

create file1 on the trunk

  $ cd proj
  $ touch file1
  $ cvscall -Q add file1
  $ cvsci -m"add file1 on trunk" file1

create two branches

  $ cvscall -q tag -b v1_0
  T file1
  $ cvscall -q tag -b v1_1
  T file1

create file2 on branch v1_0

  $ cvscall -Q up -rv1_0
  $ touch file2
  $ cvscall -Q add file2
  $ cvsci -m"add file2" file2

create file3, file4 on branch v1_1

  $ cvscall -Q up -rv1_1
  $ touch file3
  $ touch file4
  $ cvscall -Q add file3 file4
  $ cvsci -m"add file3, file4 on branch v1_1" file3 file4

merge file2 from v1_0 to v1_1

  $ cvscall -Q up -jv1_0
  $ cvsci -m"MERGE from v1_0: add file2"
  cvs commit: Examining .

Step things up a notch: now we make the history really hairy, with
changes bouncing back and forth between trunk and v1_2 and merges
going both ways.  (I.e., try to model the real world.)
create branch v1_2

  $ cvscall -Q up -A
  $ cvscall -q tag -b v1_2
  T file1

create file5 on branch v1_2

  $ cvscall -Q up -rv1_2
  $ touch file5
  $ cvs -Q add file5
  $ cvsci -m"add file5 on v1_2"
  cvs commit: Examining .

create file6 on trunk post-v1_2

  $ cvscall -Q up -A
  $ touch file6
  $ cvscall -Q add file6
  $ cvsci -m"add file6 on trunk post-v1_2"
  cvs commit: Examining .

merge file5 from v1_2 to trunk

  $ cvscall -Q up -A
  $ cvscall -Q up -jv1_2 file5
  $ cvsci -m"MERGE from v1_2: add file5"
  cvs commit: Examining .

merge file6 from trunk to v1_2

  $ cvscall -Q up -rv1_2
  $ cvscall up -jHEAD file6
  U file6
  $ cvsci -m"MERGE from HEAD: add file6"
  cvs commit: Examining .

cvs rlog output

  $ cvscall -q rlog proj | egrep '^(RCS file|revision)'
  RCS file: $TESTTMP/cvsrepo/proj/file1,v
  revision 1.1
  RCS file: $TESTTMP/cvsrepo/proj/Attic/file2,v
  revision 1.1
  revision 1.1.4.2
  revision 1.1.4.1
  revision 1.1.2.1
  RCS file: $TESTTMP/cvsrepo/proj/Attic/file3,v
  revision 1.1
  revision 1.1.2.1
  RCS file: $TESTTMP/cvsrepo/proj/Attic/file4,v
  revision 1.1
  revision 1.1.2.1
  RCS file: $TESTTMP/cvsrepo/proj/file5,v
  revision 1.2
  revision 1.1
  revision 1.1.2.1
  RCS file: $TESTTMP/cvsrepo/proj/file6,v
  revision 1.1
  revision 1.1.2.2
  revision 1.1.2.1

convert to hg (#1)

  $ cd ..
  $ hg convert --datesort proj proj.hg
  initializing destination proj.hg repository
  connecting to $TESTTMP/cvsrepo
  scanning source...
  collecting CVS rlog
  15 log entries
  creating changesets
  9 changeset entries
  sorting...
  converting...
  8 add file1 on trunk
  7 add file2
  6 MERGE from v1_0: add file2
  5 file file3 was initially added on branch v1_1.
  4 add file3, file4 on branch v1_1
  3 add file5 on v1_2
  2 add file6 on trunk post-v1_2
  1 MERGE from HEAD: add file6
  0 MERGE from v1_2: add file5

hg log -G output (#1)

  $ hg -R proj.hg log -G --template "{rev} {desc}\n"
  o  8 MERGE from v1_2: add file5
  |
  | o  7 MERGE from HEAD: add file6
  | |
  o |  6 add file6 on trunk post-v1_2
  | |
  | o  5 add file5 on v1_2
  | |
  | | o  4 add file3, file4 on branch v1_1
  | | |
  o | |  3 file file3 was initially added on branch v1_1.
  |/ /
  | o  2 MERGE from v1_0: add file2
  |/
  | o  1 add file2
  |/
  o  0 add file1 on trunk
  

convert to hg (#2: with merge detection)

  $ hg convert \
  >   --config convert.cvsps.mergefrom='"^MERGE from (\S+):"' \
  >   --datesort \
  >   proj proj.hg2
  initializing destination proj.hg2 repository
  connecting to $TESTTMP/cvsrepo
  scanning source...
  collecting CVS rlog
  15 log entries
  creating changesets
  9 changeset entries
  sorting...
  converting...
  8 add file1 on trunk
  7 add file2
  6 MERGE from v1_0: add file2
  5 file file3 was initially added on branch v1_1.
  4 add file3, file4 on branch v1_1
  3 add file5 on v1_2
  2 add file6 on trunk post-v1_2
  1 MERGE from HEAD: add file6
  0 MERGE from v1_2: add file5

hg log -G output (#2)

  $ hg -R proj.hg2 log -G --template "{rev} {desc}\n"
  o  8 MERGE from v1_2: add file5
  |
  | o  7 MERGE from HEAD: add file6
  | |
  o |  6 add file6 on trunk post-v1_2
  | |
  | o  5 add file5 on v1_2
  | |
  | | o  4 add file3, file4 on branch v1_1
  | | |
  o | |  3 file file3 was initially added on branch v1_1.
  |/ /
  | o  2 MERGE from v1_0: add file2
  |/
  | o  1 add file2
  |/
  o  0 add file1 on trunk