trace data; first and last timestamp, and their difference in
  seconds; how many records had their version bit set.

 - All large numbers reported are formatted with commas
   (e.g. '1,234,567').

more.  (ZEO1 will follow after lunch.)

records.  This is much faster (the old code took 16 second to write
120,000 records on my home box, the new code takes about 2.7 seconds).

A new script, stats.py, is provided to analyze statistics.

As suggested by Toby Dickenson.

The ImmediateCommitStrategy storage is not a ZEOStorage, but a FileStorage.

when the connection is closed is called 'close()' when it doesn't
close the manager, but tells the manager that one particular
connection is closed.  Rename it to 'close_conn()'.

The previous code just called tpc_abort() on the server, but that
wouldn't restart any waiting transaction.

- Add some expository comments.

- Add some asserts documenting non-obvious assumptions.

- Make modifiedInVersion a delegated method, since it does nothing
  special.

- Fix a bug in undo(); it was passing a list of triples (oid,None,'')
  to the server.invalidate() call rather than a list of tuples
  (oid,'').  There are no unit tests for undo(), so this was never
  caught.  I guess few people care about undo() now that we have
  transactionalUndo().

- In ImmediateCommitStrategy.store(), only catch exceptions that
  inherit from Exception raised by the storage's store() call; the
  client is only checking for those in the list of serials.

- Remove unused instance variable 'invalidated' from the
  DelayedCommitStrategy class.

client.  Remove it from the stub.

names and Python method names.  (Checked this in on the trace branch
by mistake.)

Change the wire protocol back by providing aliases.

Log cache flips and non-trivial read_index statistics (at info level).

Move RCS info into docstring.

Add XXX TO DO comment at top.

Whitespace normalization.

Also, reformat the _finish() method and add some comments.

same as the serialno in the last non-version data record.

XXX This might be the only time that the serialno of a data record
does not match the transaction id.

Remove checkNewSerialOnAbortVersion and checkNewSerialOnCommitVersion.
They duplicate checkCommitVersionSerialno and checkAbortVersionSerialno.

public API.

Open the cache later to avoid scanning it twice if a connection is
made right away.

ClientStorage.close() is now idempotent.

ClientStorage stores its addr argument as self._addr so the test suite
doesn't have to dig it out of the rpc manager to reopen the storage as
readonly.

Renamed some of the callbacks into the client for clarity:
begin -> beginVerify
end -> endVerify
invalidate -> invalidateVerify
Invalidate -> invalidateTrans

Also refactor the test code to use _abortVersion() and _commitVersion().

Note that the checkModifyAfterAbortVersion() test still fails; Jeremy
wants to change abortVersion in FileStorage and DemoStorage to revert
the serialno to the last nonversion serialno instead of assigning a
brand new serialno, so I'm holding off on invalidating the cache in
ClientStorage.abortVersion.

Also note that on Red Hat 7.2, the ZEO test suite hangs in
checkCommitLock2OnAbort or checkCommitLock2OnCommit; we'll try to
debug this later today.

serials. Modified FileStorage and DemoStorage to pass this test.

In checkSize(), delete the half of the index that's no longer valid.

erase the half of the _index dict that is invalidated by the flip.