TODO #26

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.

- there should be an option to detect collisions between underscorified
  tags in VCP::Dest::cvs.  Perhaps enabled by default.

- Handle differently localized timestamps

- the RevMapDB should be purged of any revisions descended from a revision
  begin 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.  Fo now, a warning is generated.

- use the upcoming -t option for p4 filelog (expected in 2002.2) to
  extract times with dates.  Issue a warning recommending an upgrade
  or enabling a metadata reading mode if not present.

- get all test suites converted from IPC::Run to TestUtils::Run
- reorder the t/9*cvs.t so t/90revml2cvs builds the repository and
  t/91cvs2revml and t/95cvs2p4 use it.
- split t/90p4.t so t/90revml2p4.t builds the repository and
  t/91p42revml.t and t/95p42cvs use it.
- p42revml.t (with TESTNUM and FATALTEST support?)
- finish off VCP::Source::cvs's simulation of the cvs (rlog) -r option
- put FATALTEST=1 support in 90p4.t and 90vss.t (see 90cvs.t)
- minimize or eliminate $self->stderr_filter, $self->ok_result_codes use
- minimize $self->command_chdir use.
- implement VCP::Source::cvs -d option
- Make it so that a dest of cvs:blah:foo is either an error or is just
  like cvs:blah:foo/...
- revml2cvs.t should use (and thus test) the new --init-cvsroot option.
- get p4 forms parsing to lex *exactly* like p4 does it.
- Add an "Options:" section to .vcp files, or add individual options for
  each of the global options.
- Allow vcp to log *everything* it outputs to make it easier for the user
  to capture things, and log it all by default.
- Store revisions on disk in db files
- 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.

- 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.

- Review cvs2p4 and (in the guest depot) vss2p4 for gotchas they catch that we
  should.

- 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.

- VCP should record its starting directory early on and then use it
  as a base directory for rel2abs().  Thinking specifically of cvsroot
  absolutification, but the sources should be grepped.

- PERHAPS checksum all non-binary files line by line, removing all \r's

- Bugfixes
  - Prevent keyword expansion on all checkouts.  Found by
    Thomas Quinot <quinot@inf.enst.fr>
  - Check for p4 >= 99.2 at runtime, since filelog -m is needed
  - Carry executable bit through (Nick Ing-Simmons)
  - Make <rev_root> and <name> escape their characters
  - VCP::Dest::cvs needs to set the binary mode properly on files it creates
    and checks in
  - VCP::Source::cvs needs to deduce binary modes correctly
  - Make test suite use an alternate port for p4d so multiple make test
    instances can be run in parallel
  - Make test suite skip cvs tests if cvs is not present (like it skips p4
    tests if p4 is not present).
  - 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.  This all must wait until IPC::Run deals
    better with IO::Pty
  - id= values should be the entire path-to-file, not relative to rev_root.

- Feature Adds
  - Need to make the transfers more transactional, so we can recover from where
    we left off when something fails.
  - Need to save some sort of state as to where the last export ended so the
    next one can start from there.
  - Offer compressed output for revml files a la tar's "z" option.
  - Consider offering <char code=0x00 repeat=34234> (david d zuhn
    <zoo@bravara.com>)
  - Allow revml to output in non-indented mode (need to see if this
    actually saves much space when compressed) (+)
  - 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.
  - An option to prefix all labels with some user-defined string Steve James
    <SJames@ariba.com>
  - Limit the number of NtLkLy queries per command to prevent server lockup.
    Steve James <SJames@ariba.com>  (possibly URGENT, need to test).


- Efficiency
  - 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::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.
  - 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.
  - 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.
  - Once a version has been used, it should be cleaned up out of the source
    directory unless it will be needed again.  This used to be the
    way things were done, but it has been changed to support branching.
    STATUS: partially implemented.  Revs now refer directly to their ancestor
    revs, and thus revs may be freed willy-nilly and needed revs won't
    disappear.  TODO: Have each ::Dest do $r->previous( undef ) as
    aggressively as possible so that older revs will be garbage collected
    as needed.

- Tests
  - rerooting revml->p4 to someplace deep in the p4 tree, to make sure that VCP
    is configuring p4 to map the files to the right place.

- Cleanup
  - Where command_stderr_filter is used to save/restore the filter, use
    stderr_filter => instead.
  - Do same for command_ok_result_codes();
  - create an init() phase after new() so new() can give immediate feedback
    on bogus command line options.  As it is, sourcing a CVS pserver causes
    a password prompt before the dest even gets a crack at the options.