Summary on issues about PIT-CS

[zjkmxy]

Background: #38 #40

• Performance is 25-50% worse after putting expiration in the same thread. Maybe the map deletion is slow.
  Possible bottleneck:

  YaNFD/table/pit-cs-tree.go

  Line 333 in 79b7e56

  delete(curNode.parent.children, curNode.component.String())

• Till now PIT tokens are shown to be used in any tests. Not sure if it is YaNFD's problem.
• pitTokenMap seems to be wrong:

  YaNFD/table/pit-cs-tree.go

  Line 25 in 79b7e56

  pitTokenMap map[uint32]*nameTreePitEntry

• csMap does not look good. It assumes the hashes have no conflict.
  

  YaNFD/table/pit-cs-tree.go

  Line 29 in 79b7e56

  csMap map[uint64]*nameTreeCsEntry

  
  

  YaNFD/table/pit-cs-tree.go

  Line 372 in 79b7e56

  index := p.hashCsName(data.Name())