If a storage doesn't support T.U. and is old enough, you need to first
check if it has a supportsTransactionalUndo attribute.

There are a few problems with Zope 2.3 that prevented the tests from
succeeding.  Since the 1.0 release must support Zope 2.3, we'll need
to hack the various tests to work around them.

    Assuming releases after 1.0 don't need to work with 2.3: After the
    1.0 final release, I'll tag both ZEO and ZODB trees and then undo
    all these silly changes.

Problems:

    - no support for transactional undo or getSerial()
    - FileStorage commitVersion() and abortVersion() didn't check for
      bogus arguments

This implementation is only faster for an object that is not modified
in a version.  For an object modified in a version, it should be about
the same as the default getSerial() in BaseStorage.

situation.

Didn't write a more interesting test in checkAbortVersion:

        # XXX Not sure I can write a test for getSerial() in the
        # presence of aborted versions, because FileStorage and
        # Berkeley storage give a different answer. I think Berkeley
        # is right and FS is wrong.

BaseStorage implements this in terms of modifiedInVersion() and
load().  Other storages may (perhaps even should) implement it more
efficiently.

now a full success :-)

(Minor change to tb handling to avoid unnecessary binding to None for
v and tb.)

Prevents memory leak for each _restore_index() call.

exceptions (this error occured when trying to access an
OOBTree with a string with non-ascii encoding e.g. latin1.
In this case Python raises a Unicode exception that has not
been caught and not propagated to the application.

Replace explicit equality tests in assert statements, which aren't
executed when running python -O, when self.assertEquals(), which also
has the side effect of producing better error messages when the test
fails.

  o Land unit test cleanup from branch.

  o Known breakage as of 2001/10/17:

    - TAL test suite is very broken (TAL is currently suppressed in
      lib/python/.testinfo).

    - AccessControl tests don't run if run first;  lib/python/.testinfo
      pushes them to the end of the queue, at which point they *do* run.
      Global side effects suck!

    - lib/python/BTrees/testBTreesUnicode.py:  weird flakiness around
      comparison of ASCII and Unicode strings;  breaks in different
      ways under Python 2.1 and 2.2.

    - lib/python/Products/PageTemplates/tests:  three tests break due
      to security asserctions.

strings as keys

Add getLogFile() method that provides hook for SpreadLog subclass.

This change includes a minor change to semantics for
reinitialization().

There are three chief performance-related changes:

    - Do not check whether logging is enabled in the actual log call.
      Instead check enviroment variables when the module is imported
      and whenever an explicit initialize() call is made.

      This might seem like it limits the user's ability to turn
      logging on and off, but I don't believe it does.  Logging is
      controlled by environment variables.  Once the Python script is
      working, the environment variables won't change.

      This change makes the case of no logging fast, instead of slow.

    - Each log call goes through a method on the stupid_log_write()
      object instead of through __call__().  It's much faster to call
      a method than an instance.

    - Use "print >> file" rather than "file.write()".  It appears to
      be a bit faster.

Replaced _set_stupid_dest() with _set_log_dest().

Also, reformat code using guidlines from the Friends of Whitespace.

Fix newTimeStamp() so that it always returns a timestamp.
XXX still not sure that it works.

Replace long multiplies with long shifts in U64() and u64().

    - use update() method where appropriate
    - don't pass None as second argument to get(). it's the default.
    - consistent space after comma between args

In tpc_vote() rename local variable id to tid.

Add doc string to read_index(), helpful but not complete yet.

In read_index(), replace an iteration over the tindex for each
transaction with a few calls that do the work with much less
overhead.

Also, add an open() method to open the storage.  Used by
PersistentStorage, too.

Raise correct exceptions in abortVersion() and commitVersion().

Spread out some code that had the vertical white space removed.

Fix the versions() implementation so that it works if the optional max
argument is not passed by the caller.

Fix commitVersion() so that it works for committing from one version
to the other.  The previous version always committed to the
non-version data even if a destination version was specified.

Fix typos.

documented exceptions.

Remove a few of the old #JF# comments that explain why some old,
commented out test code didn't work.  XXX still need to do more.

Extend a few tests with more checks of accessing non-version data via
versions that have no changes in them.

Comment -> doc string.