// lookupReplica looks up replica by key [range]. Lookups are done
// by consulting each store in turn via Store.LookupRange(key).
// Returns RaftID and replica on success; RangeKeyMismatch error
// if not found.
// TODO(tschottdorf) with a very large number of stores, the LocalSender
// may want to avoid scanning the whole map of stores on each invocation.
func (ls *LocalSender) lookupReplica(start, end proto.Key) (raftID proto.RaftID, replica *proto.Replica, err error) {
ls.mu.RLock()
defer ls.mu.RUnlock()
var rng *storage.Range
for _, store := range ls.storeMap {
rng = store.LookupRange(start, end)
if rng == nil {
continue
}
if replica == nil {
raftID = rng.Desc().RaftID
replica = rng.GetReplica()
continue
}
// Should never happen outside of tests.
return 0, nil, util.Errorf(
"range %+v exists on additional store: %+v", rng, store)
}
if replica == nil {
err = proto.NewRangeKeyMismatchError(start, end, nil)
}
return raftID, replica, err
}
