Deep-checking forward extremities (#1698)

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Neil Alexander 2021-01-11 12:47:25 +00:00 committed by GitHub
parent 0fbebecd41
commit e1e34b8994
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@ -259,34 +259,8 @@ func (u *latestEventsUpdater) calculateLatest(
// First of all, get a list of all of the events in our current // First of all, get a list of all of the events in our current
// set of forward extremities. // set of forward extremities.
existingRefs := make(map[string]*types.StateAtEventAndReference) existingRefs := make(map[string]*types.StateAtEventAndReference)
existingNIDs := make([]types.EventNID, len(oldLatest))
for i, old := range oldLatest { for i, old := range oldLatest {
existingRefs[old.EventID] = &oldLatest[i] existingRefs[old.EventID] = &oldLatest[i]
existingNIDs[i] = old.EventNID
}
// Look up the old extremity events. This allows us to find their
// prev events.
events, err := u.api.DB.Events(u.ctx, existingNIDs)
if err != nil {
return false, fmt.Errorf("u.api.DB.Events: %w", err)
}
// Make a list of all of the prev events as referenced by all of
// the current forward extremities.
existingPrevs := make(map[string]struct{})
for _, old := range events {
for _, prevEventID := range old.PrevEventIDs() {
existingPrevs[prevEventID] = struct{}{}
}
}
// If the "new" event is already referenced by a forward extremity
// then do nothing - it's not a candidate to be a new extremity if
// it has been referenced.
if _, ok := existingPrevs[newEvent.EventID()]; ok {
u.latest = oldLatest
return false, nil
} }
// If the "new" event is already a forward extremity then stop, as // If the "new" event is already a forward extremity then stop, as
@ -296,6 +270,29 @@ func (u *latestEventsUpdater) calculateLatest(
return false, nil return false, nil
} }
// If the "new" event is already referenced by an existing event
// then do nothing - it's not a candidate to be a new extremity if
// it has been referenced.
if referenced, err := u.updater.IsReferenced(newEvent.EventReference()); err != nil {
return false, fmt.Errorf("u.updater.IsReferenced(new): %w", err)
} else if referenced {
u.latest = oldLatest
return false, nil
}
// Then let's see if any of the existing forward extremities now
// have entries in the previous events table. If they do then we
// will no longer include them as forward extremities.
existingPrevs := make(map[string]struct{})
for _, l := range existingRefs {
referenced, err := u.updater.IsReferenced(l.EventReference)
if err != nil {
return false, fmt.Errorf("u.updater.IsReferenced: %w", err)
} else if referenced {
existingPrevs[l.EventID] = struct{}{}
}
}
// Include our new event in the extremities. // Include our new event in the extremities.
newLatest := []types.StateAtEventAndReference{newStateAndRef} newLatest := []types.StateAtEventAndReference{newStateAndRef}