TODO #105

TODO for VCP

*NOTE* Doing a `grep -r TODO lib bin` will find lots of small things and
future feature ideas.  This file will grow to include the more important
of those.

- Bugfixes

    - do not attempt to convert Perforce "purged" revisions

    - VCP::Source::parse_time should pay attention to the UTC offset if
      present.

    - if vcp::source::p4 fails to create temporary p4 client,
      don't try to delete it, or at least, don't complain when
      the delete fails.

    - deduce_rev_root should be called after all metadata is extracted
      (or perhaps as it is being extracted) and deduce the root from
      all of the revisions extracted.  This will eliminate the need for
      --rev-root to be used with VCP::Source::p4's --follow-branch-into,
      for instance.

    - VCP::Source::cvs should either ignore a leading "/" before the
      module name or complain about it.

    - Clean up VCP::Dest::p4 vcp_#### integrate spec.

    - Make it so that a dest of cvs:blah:foo is either an error or is just
      like cvs:blah:foo/... (if it looks like a directory given the source
      revs or the target repository topology)

    - Prevent keyword expansion on all checkouts.  Found by
      Thomas Quinot <quinot@inf.enst.fr>

    * Carry executable bit through (Nick Ing-Simmons)

    * Make <rev_root>, <name>, etc. use binary escapes when needed

    * VCP::Dest::cvs needs to set the binary mode properly on files it creates
      and checks in [[check status]]

    * VCP::Source::cvs needs to deduce binary modes correctly [[check status]]

    - there should be an filter to detect collisions between
      underscorified names (users, files, tage) in VCP::Dest::*.

    - get p4 forms parsing to lex *exactly* like p4 does it.

    - fix docs to give .vcp file examples before command line examples

- Testing

    - Make sure all filters that can delete revs call skip_rev()

    - finish t/95vss2p4.t (all tests should pass, need to clean up RevML).

    - automate VCP-tests/

    - fully test scan/filter/transfer in test suite

    - t/99foo2bar.t "real world corner conditions" tests.

        - Test VCP::Source::cvs branching corner conditions, perhaps all
          corner conditions for this sort of thing.
            - when the first rev on a branch is a delete
            - when the first rev on a branch occurs as the first change in an
              incremental export
            - when a file is added on a branch in an incremental conversion

    - Test importing two bootstrap imports one on top of the other
        - should VCP warn when it detects this?

    - Test CVS vendor tags in cvs->p4 and cvs->cvs; not sure how to do this
      best; there is no VCP internal designation of a vendor branch.
      Such a flag would also have to be visible in RevML and would be
      needed for testing purposes.  Right now, CVS seems to make vendor
      branches appear as branches of rev 1.1, which is OK, I think, but
      it means that the first p4 integrate looks backwards.

    - Test aliased CVS tags

    - Test unlabelled CVS branches

- Feature Adds

    - support <earlier_id>s in RevML

    - Rename earlier_id to something clearer.

    - Implement --ignore-deleted-files

    - Implement --ignore-corrupted-files, which should allow VCP to
      continue if it encounters corruption by either creating revisions
      marked as corrupted or by not going further back in to history
      when it can't.  Currently, it will blow up, thus preventing any
      transfer.  We've seen corruption in both VSS and CVS
      repositoriies.

    - Implement clone support in VCP::Dest::cvs and VCP::Dest::vss.

    - Consider having clone revs carry the action of the cloned revision
      because currently we have to look back at the "previous_id" or
      "from_id" to see what the action being cloned is.

    - add a "move" action for this situation (from Gerry Thompson
      <gerry@perforce.com>, Thu, 30 Oct 2003 14:51:48 -0800):

        If VCP can detect a move from 'a' to 'b' in the ss history then we can
        do the usual Perforce dance of

        p4 integrate a b
        p4 delete a
        p4 submit

    - Detect and play back all the various VSS branching scenarios with
      minimal loss of data.  Note that VSS allows you to lose data
      before we get there with its combination of sharing, pinning,
      rollback and branching operations.  See gerry's email of Oct. 2003
      for some ideas.

    - Implement a MetaDataFudge filter to fudge missing user_id, times
      and comments.  This should perhaps be implemented as a VCP::Dest
      feature so that it could work on the aggregated comment.

    - Have VCP::Source::cvs set limits on the $r->time field on all
      branch revs to be identical within the limits possible
        - Must   be >= parent's time and <= .1 rev's time
        - Should be >  parent's time and <= .1 rev's time
        - May need to have multiple times in the case of disjoint
          timespans between parents and children on the same branch.
            - Example:
                - A#1.1     time is 2000-01-01
                - A#1.1.2.1 time is 2000-01-02
                - B#1.1     time is 2000-01-03
                - B#1.1.2.1 time is 2000-01-04
            - In this case, it's not possible for A#1.1.2.0 and
              B#1.1.2.0 to have the same timestamps.

    - Improve metadb support
        - Single flat file, named in spec
        - add RevML and SOP formats?

    - create .rep files to define repositories
        - p4 spec format

    - Prompt for repo_id in VCP.stml

    - Pay attention to case-sensitive() throughout
        - needs a code audit
            - look for compile_shellish qr, lc, eq, cmp, and uc
        - pass it in the header to all filters
        - store it in revml

    - Add the following hints for VSS-> conversions (from gerry@perforce.com)

        |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
        Subject: RE: [p4] Migration hints from Visual SourceSafe
        Date: Sun, 13 Jul 2003 09:45:37 +0200
        From: "Yariv Sheizaf" <yariv_sheizaf@bezeqint.net>
        To: <perforce-user@perforce.com>, <Thierry.Michalowski@echotech.ch>

        Hi Thierry,

        We just finished to convert to big (3GB each) VSS databases
        to Perforce using the VSS2P4 script.

        The script itself running coorrectly, and its installation is easy.
        Pay attention to two elements:

        1. Locate all components required for the conversion process:
           VSS DB, Perforce server+DB, Vss2P4 script -
           on the same machine.
           It reduces the conversion time very much (6 hours instead of 6 days).

        2. Run "analyze" and "analyze -f" if needed on the VSS DB until it fixed -
           no error messages should be appeared.
           In any case that the VSS DB is not consistent (e.g. - does not
           passing "analyze" correctly) - the conversion process will fail.

        Regards,

        Yariv
        |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||

    - Bundle HTML docs with the app, don't require HTML::Links as a
      prerequisite in the CPAN dist or vcp.pl file.

    - Allow the called executable name (cvs, p4, etc) to be set as an option.

    - Transfer and translate branch specs and other metadata on
      p4->p4 transfers.

    - Extend revml to have a <client> tag to allow p4->* conversions
      to carry the p4 client through.

    - option to lock label specs (integrate specs)?

    - Handle differently localized timestamps.  RevML should be
      in GMT or use ISO8601's tz indicators.

    - VCP::Dest::cvs Investigate running cvs as root to spoof user
      names properly
        - setting the called executable name (another todo) could
          be extended to allow multi-word invocations
        - looks like cvs calls getlogin(), might need to spoof
          wtmp to do this

    - VCP::Dest::cvs Write RCS files directly
        - only way to get accurate data in to RCS file format
            - usernames, times

    - VCP::Filter::usermap to allow usernames to be altered

    - VCP::Filter::commentedit to allow comments to be edited (post-sort
      but pre change aggregation); this is to allow cvs2p4-like comments.

    - warn when a *Map filter is used and the default <<keep>> action
      fires, because this indicates a possible missing or faulty rule.

    - improve error reporting for .vcp files. Either use recursive descent
      to delegate each value to the appropriate object or capture line and
      column with each value for error reporting.

    - give better diagnostics when the state file appears to be out of
      date:
      - when --continue is specified we can't.
      - when --continus is not specified and a revision already exists in
        the destination state files (but not in the destination rep).  We
        could keep track of the last known change to the destination in
        the state file and probe to see if that file is at the indicated
        revision.  Or just watch for revisions coming along that should be
        in the dest (according to the state file) but aren't.

    - Add a --skip-unchanged-revs option or VCP::Filter that skips
      unchanged revisions; all children of such a revision become
      children of that revision's parent.

    - Enable an "--append-revs" flag to allow a bootstrap file to be
      added.  This is dangerous (there's no checking to be sure that the
      first new version is the first version after the existing version in
      the repository) but useful.  This might be done already with
      --bootstrap specified on the source, but is completely untested

    - reports and queries against the state files to show:
      - head rev of each filebranch
      - what source revs ended up where (path & rev_id)
      - how branches got mapped
      - what the main branch_id is for foo->cvs imports.
      - what fields got edited how by StringEdit, Map, LabelMap, etc.

    - Make the transfers more transactional, so we can recover from
      where we left off when something fails.  We're part way there with
      the --continue support, but VCP needs to log what it's about to
      submit and sniff out how far the submittal got before it blew up.
      This would allow recovery by updating the state files to the
      correct state and not trying to double commit files.

    - Allow the state files to be checked in to the destination.  Probably
      as text, in order to avoid sdbm byte ordering issues if they are
      checked out on a differently byte ordered system.

    - Perhaps allow keyword expansion, but convert the expanded texts
      so that they are no longer seens as RCS style keywords.  This would
      allow imported files to have a "stamp of origin" in them.  Would
      also need an option to leave the keywords in place in this case, since
      the user might presumably want expansion to work correctly in the
      new repository too.  Suggested by Thomas Quinot <quinot@inf.enst.fr>.

    - Add a link checker to vcp html

    - An option to not bring over deleted files Steve James <SJames@ariba.com>

    - A report destination that offers a preview of what a transfer will
      do, with summary and long views.

    - Limit the number of NtLkLy queries per command to prevent server lockup.
      Steve James <SJames@ariba.com>  (possibly URGENT, need to test).

    - Set CVS_PASSFILE for all cvs invocations to prevent mucking with the
      users' current .cvspass

    - Use ptys to handle CVS login, if available.  Recomend installing
      IO::Pty if needed but not installed.

    - implement VCP::Source::cvs -d option when scanning RCS files

    - PERHAPS checksum all non-binary files line by line, removing all \r's
      in order to reduce sensitivity to varying platform settings between
      the source and the destination.

    - allow VCP::{Source,Dest}::* to "sniff" at unknown directories /
      files to see if they can detect what kind of repository is there.
      This will make schemes optional, so tab completion will work again.


- Efficiency

    - Batch cvs checkouts somehow (see clkao's patch)

    - extend VCP::Source::cvs to build revisions directly from the RCS
      files, this will probably mean memorizing the offsets of the delta
      or full text chunk for each version in the RCS file, then applying
      them all as needed to get the desired version.  They may need to be
      reversed as a speed hack since RCS files tend to store the most
      recent revision in full text and uses deltas from that to encode
      older revisions, and we'll probably want the oldest revision first.
      This means that we can build the more recent revisions from the
      older revisions by reversing the deltas as we apply them to build
      the older revisions, then apply those reversed deltas.  Or
      something; not sure what's best here.

    - VCP::Source::revml should only keep on hand the versions it needs at
      each moment in order to conserve disk space.  The problem with this
      is that the RevML may be coming from a non-seek()able byte stream,
      like STDIN, so we need to patch as we go.  One alternative is to
      cache the revml off to the side and rescan it if this happens.
      Another is to only patch- as-you-go if the input is non-seek()able.
      NOTE: P'haps VCP::Source::revml and VCP::Source::cvs can share the
      RCS file scanner.  NOTE: P'haps VCP::Source::revml and
      VCP::Source::cvs can share the an internal file revision format; RCS
      is bass ackwards for our needs.

    - in --continue mode, VCP::Source::p4 could do a p4 files to get all
      the source_filebranch_ids and then get the last_rev_in_filebranch
      for each, which would probably be a lot quicker than running a full
      filelog and throwing away most of the data (ie for a --continue on a
      large tree with lots of changes, but only one or two files have
      changed since the last export).

    - Consider offering a repeat attribute in RevML <char code="0x00"
      repeat="34234"> (david d zuhn <zoo@bravara.com>)

    - the RevMapDB should be purged of any revisions descended from a
      revision being transferred.  Right now, if you restore the set
      repository from an earlier backup and don't rewind the vcp_state
      directory, you will end up with a mix of RevMapDB entries from the
      prior transfer and the current.  For now, a warning is generated.


- Cleanup

    - Unify END{} blocks that delete/destroy resources to get stable
      cleanup ordering.  For instance, this should make sure that the
      directory a p4d is running in is not destroyed until the p4d is
      shut down (this affects t/99p4_label_branch_rev_1.t, for instance).

    - replace assert_eq (and it's *huge* reams of output on failure)
      with ok_or_diff. [Mostly done]

    - use VCP::Utils::is_win32() whereever $^O is tested for win32.

    - Refactor File::Spec->rel2abs( ..., start_dir ) calls in to a new
      VCP::Utils::start_dir();

    - Refactor $self->work_path( "co" ... ) calls in to a
      VCP::Plugin::checkout_path( ... ) or generalize the concept of a
      repository workspace.

    - use parent/child nomenclature instead of previous/next

    - Slim down the destination state; in implementing Dest::svn, it
      seemed like Dest::cvs is storing more than need be, not sure.

- Rejected

    - VCP::Source::p4 should be able to create and read a metadata dump as
      an option.  Watch out for different schemas in different p4d
      versions.  Q: Read the btree files directly? 'twould be faster and
      more space efficient.  (rejected by Perforce so as to not tie VCP to
      p4d's schema; this may still be contributed as OSS by others, but
      will not be done by the core team any time soon unless the plans
      change)

    - VCP::Dest::p4 should write a metadata file directly, and be able to
      merge new data in to a destination's exported metafile for reimport.
      Q: Write the btree files directly?  This would bypass any checking
      p4d does on recovering from a metadata file.  (rejected by Perforce
      so as to not tie VCP to p4d's schema; this may still be contributed
      as OSS by others, but will not be done by the core team any time
      soon unless the plans change)

    - An option to prefix all labels with some user-defined string Steve
      James <SJames@ariba.com> (this is no longer necessary, as vcp does
      not add its own labels by default).