/
sorting.go
55 lines (48 loc) · 1.24 KB
/
sorting.go
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package kbucket
import (
"container/list"
peer "gx/ipfs/QmbyvM8zRFDkbFdYyt1MnevUMJ62SiSGbfDFZ3Z8nkrzr4/go-libp2p-peer"
"sort"
)
// A helper struct to sort peers by their distance to the local node
type peerDistance struct {
p peer.ID
distance ID
}
// peerSorterArr implements sort.Interface to sort peers by xor distance
type peerSorterArr []*peerDistance
func (p peerSorterArr) Len() int { return len(p) }
func (p peerSorterArr) Swap(a, b int) { p[a], p[b] = p[b], p[a] }
func (p peerSorterArr) Less(a, b int) bool {
return p[a].distance.less(p[b].distance)
}
//
func copyPeersFromList(target ID, peerArr peerSorterArr, peerList *list.List) peerSorterArr {
for e := peerList.Front(); e != nil; e = e.Next() {
p := e.Value.(peer.ID)
pID := ConvertPeerID(p)
pd := peerDistance{
p: p,
distance: xor(target, pID),
}
peerArr = append(peerArr, &pd)
}
return peerArr
}
func SortClosestPeers(peers []peer.ID, target ID) []peer.ID {
var psarr peerSorterArr
for _, p := range peers {
pID := ConvertPeerID(p)
pd := &peerDistance{
p: p,
distance: xor(target, pID),
}
psarr = append(psarr, pd)
}
sort.Sort(psarr)
var out []peer.ID
for _, p := range psarr {
out = append(out, p.p)
}
return out
}