func (fo *frameOpen) createRollClientTxn() (*cmsgs.ClientTxn, map[common.VarUUId]*common.Positions) {
var origWrite *msgs.Action
vUUIdBytes := fo.v.UUId[:]
for idx, l := 0, fo.frameTxnActions.Len(); idx < l; idx++ {
action := fo.frameTxnActions.At(idx)
if bytes.Equal(action.VarId(), vUUIdBytes) {
origWrite = &action
break
}
}
seg := capn.NewBuffer(nil)
ctxn := cmsgs.NewClientTxn(seg)
ctxn.SetRetry(false)
actions := cmsgs.NewClientActionList(seg, 1)
ctxn.SetActions(actions)
action := actions.At(0)
action.SetVarId(fo.v.UUId[:])
action.SetRoll()
roll := action.Roll()
roll.SetVersion(fo.frameTxnId[:])
var refs msgs.VarIdPos_List
switch origWrite.Which() {
case msgs.ACTION_WRITE:
ow := origWrite.Write()
roll.SetValue(ow.Value())
refs = ow.References()
case msgs.ACTION_READWRITE:
owr := origWrite.Readwrite()
roll.SetValue(owr.Value())
refs = owr.References()
case msgs.ACTION_CREATE:
oc := origWrite.Create()
roll.SetValue(oc.Value())
refs = oc.References()
case msgs.ACTION_ROLL:
owr := origWrite.Roll()
roll.SetValue(owr.Value())
refs = owr.References()
default:
panic(fmt.Sprintf("%v unexpected action type when building roll: %v", fo.frame, origWrite.Which()))
}
posMap := make(map[common.VarUUId]*common.Positions)
posMap[*fo.v.UUId] = fo.v.positions
refVarList := seg.NewDataList(refs.Len())
roll.SetReferences(refVarList)
for idx, l := 0, refs.Len(); idx < l; idx++ {
ref := refs.At(idx)
vUUId := common.MakeVarUUId(ref.Id())
pos := common.Positions(ref.Positions())
posMap[*vUUId] = &pos
refVarList.Set(idx, vUUId[:])
}
return &ctxn, posMap
}
func (s *store) LoadTopology() error {
res, err := s.db.ReadonlyTransaction(func(rtxn *mdbs.RTxn) interface{} {
bites, err := rtxn.Get(s.db.Vars, configuration.TopologyVarUUId[:])
if err != nil {
rtxn.Error(err)
return nil
}
seg, _, err := capn.ReadFromMemoryZeroCopy(bites)
if err != nil {
rtxn.Error(err)
return nil
}
varCap := msgs.ReadRootVar(seg)
txnId := common.MakeTxnId(varCap.WriteTxnId())
bites = s.db.ReadTxnBytesFromDisk(rtxn, txnId)
if bites == nil {
rtxn.Error(fmt.Errorf("Unable to find txn for topology: %v", txnId))
return nil
}
seg, _, err = capn.ReadFromMemoryZeroCopy(bites)
if err != nil {
rtxn.Error(err)
return nil
}
txnCap := msgs.ReadRootTxn(seg)
actions := txnCap.Actions()
if actions.Len() != 1 {
rtxn.Error(fmt.Errorf("Topology txn has %v actions; expected 1", actions.Len()))
return nil
}
action := actions.At(0)
var refs msgs.VarIdPos_List
switch action.Which() {
case msgs.ACTION_WRITE:
w := action.Write()
bites = w.Value()
refs = w.References()
case msgs.ACTION_READWRITE:
rw := action.Readwrite()
bites = rw.Value()
refs = rw.References()
case msgs.ACTION_CREATE:
c := action.Create()
bites = c.Value()
refs = c.References()
default:
rtxn.Error(fmt.Errorf("Expected topology txn action to be w, rw, or c; found %v", action.Which()))
return nil
}
if refs.Len() != 1 {
rtxn.Error(fmt.Errorf("Topology txn action has %v references; expected 1", refs.Len()))
return nil
}
rootRef := refs.At(0)
seg, _, err = capn.ReadFromMemoryZeroCopy(bites)
if err != nil {
rtxn.Error(err)
return nil
}
topology, err := configuration.TopologyFromCap(txnId, &rootRef, bites)
if err != nil {
rtxn.Error(err)
return nil
}
return topology
}).ResultError()
if err != nil {
return err
}
s.topology = res.(*configuration.Topology)
return nil
}