func buildCirc(tgt directory.ChordKey) (*core2core.Client, error) {
// find the closest neighbor to the destination
circPool.Lock()
nxt := circPool.neighs[0]
for _, v := range circPool.neighs[1:] {
var vkee directory.ChordKey
var xkee directory.ChordKey
vkee.FromBytes(v.PubKey)
xkee.FromBytes(nxt.PubKey)
if vkee.Distance(tgt).Cmp(xkee.Distance(tgt)) == -1 {
nxt = v
}
}
circPool.Unlock()
kilog.Debug("circ: closest neighbor to %x is %v", tgt.ToBytes(), nxt.PubKey)
// begin to route
spider, err := core2core.NewClient(nxt)
if err != nil {
return nil, err
}
//defer spider.Destroy()
// loop
closest := false
for !closest {
neighs, err := spider.ListNeighs()
if err != nil {
spider.Destroy()
return nil, err
}
if len(neighs) == 0 {
kilog.Warning("circ: topology anomaly! node with no neighbors!")
spider.Destroy()
return nil, err
}
better := spider.CurrentPublic()
closest = true
// can we find a closer one?
for _, cand := range neighs {
var candkee directory.ChordKey
var currkee directory.ChordKey
candkee.FromBytes(cand)
currkee.FromBytes(better)
if candkee.Distance(tgt).Cmp(currkee.Distance(tgt)) == -1 {
better = cand
closest = false
}
}
// connect to the next hop
if !closest {
kilog.Debug("circ: circuit to %x extending to %v", tgt.ToBytes(), better)
err = spider.ConnectNext(better)
if err != nil {
spider.Destroy()
return nil, err
}
}
}
return spider, nil
}
