SnapShot OOPS editing team with 13000 members

[Diogo Matsubara]

As seen in OOPS-1420EA331 a ShortListTooBigError: Hard limit of 5000 exceeded was raised while editing the team's description.

[Curtis Hovey (sinzui)]

This is like the branches problem that launchpad and u1 had. In this case, there are too many members. The core of the problem is not that the hard limit was exceeded, but that the automated rules for snapshots (the interface) is copying the attributes that are into intrinsic to the object. The specific attributes in this case appear to be activemember, allmembers, deactivatedmembers, approvedmembers, expiredmembers, inactivemembers, invited_members, member_memberships, pending_memberships, proposed_memberships. These fileds are often CollectionField...Snapshot should not be coying these fields.

[Curtis Hovey (sinzui)]

My idea about ignoring CollectionField is BAD in all caps. We need a explicit way to tell snapshot what can be ignored. Maybe.

1. Define IDoNotSnapShot in lazr.lifecycle.snapshot.

2. Update laz.lifecycle.snapshot.Snapshot ignores any field that provides IDoNotSnapShot eg.
    if IField.providedBy(field) and not IDoNotSnapShot.providedBy(field):

3. Update the problem fields in Launchpad (eg. Person.allmembers, Product.branches, ...) by adding the interface to the instance attribute eg.
    IPublicPerson:
        allmembers = Exported(...)
        alsoProvides( allmembers, IDoNotSnapShot)

[Diogo Matsubara (matsubara)]

Fixed in devel r9973 <http://bazaar.launchpad.net/~launchpad-pqm/launchpad/devel/revision/9973>

[Brad Crittenden (bac)]

r 9973