forked from cerc-io/ipld-eth-server
62 lines
1.4 KiB
Go
62 lines
1.4 KiB
Go
package kbucket
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import (
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"container/list"
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"sort"
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peer "github.com/libp2p/go-libp2p-peer"
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)
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// A helper struct to sort peers by their distance to the local node
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type peerDistance struct {
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p peer.ID
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distance ID
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}
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// peerSorterArr implements sort.Interface to sort peers by xor distance
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type peerSorterArr []*peerDistance
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func (p peerSorterArr) Len() int { return len(p) }
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func (p peerSorterArr) Swap(a, b int) { p[a], p[b] = p[b], p[a] }
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func (p peerSorterArr) Less(a, b int) bool {
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return p[a].distance.less(p[b].distance)
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}
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//
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func copyPeersFromList(target ID, peerArr peerSorterArr, peerList *list.List) peerSorterArr {
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if cap(peerArr) < len(peerArr)+peerList.Len() {
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newArr := make(peerSorterArr, len(peerArr), len(peerArr)+peerList.Len())
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copy(newArr, peerArr)
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peerArr = newArr
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}
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for e := peerList.Front(); e != nil; e = e.Next() {
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p := e.Value.(peer.ID)
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pID := ConvertPeerID(p)
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pd := peerDistance{
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p: p,
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distance: xor(target, pID),
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}
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peerArr = append(peerArr, &pd)
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}
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return peerArr
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}
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func SortClosestPeers(peers []peer.ID, target ID) []peer.ID {
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psarr := make(peerSorterArr, 0, len(peers))
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for _, p := range peers {
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pID := ConvertPeerID(p)
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pd := &peerDistance{
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p: p,
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distance: xor(target, pID),
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}
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psarr = append(psarr, pd)
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}
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sort.Sort(psarr)
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out := make([]peer.ID, 0, len(psarr))
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for _, p := range psarr {
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out = append(out, p.p)
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}
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return out
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}
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