mirror of https://github.com/status-im/go-waku.git
70 lines
1.5 KiB
Go
70 lines
1.5 KiB
Go
package peer_exchange
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import (
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"bufio"
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"bytes"
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"github.com/ethereum/go-ethereum/p2p/enode"
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wenr "github.com/waku-org/go-waku/waku/v2/protocol/enr"
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"github.com/waku-org/go-waku/waku/v2/protocol/peer_exchange/pb"
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)
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// simpleLRU internal uses container/list, which is ring buffer(double linked list)
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type enrCache struct {
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// using lru, saves us from periodically cleaning the cache to mauintain a certain size
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data *shardLRU
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clusterID uint16
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}
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// err on negative size
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func newEnrCache(size int, clusterID uint16) *enrCache {
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inner := newShardLRU(int(size))
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return &enrCache{
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data: inner,
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clusterID: clusterID,
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}
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}
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// updating cache
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func (c *enrCache) updateCache(node *enode.Node) error {
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if c.clusterID != 0 {
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rs, err := wenr.RelaySharding(node.Record())
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if err != nil || rs == nil {
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// Node does not contain valid shard information, ignoring...
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return nil
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}
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if rs.ClusterID != c.clusterID {
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return nil
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}
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}
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currNode := c.data.Get(node.ID())
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if currNode == nil || node.Seq() > currNode.Seq() {
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return c.data.Add(node)
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}
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return nil
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}
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// get `numPeers` records of enr
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func (c *enrCache) getENRs(neededPeers int, clusterIndex *ShardInfo) ([]*pb.PeerInfo, error) {
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//
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nodes := c.data.GetRandomNodes(clusterIndex, neededPeers)
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result := []*pb.PeerInfo{}
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for _, node := range nodes {
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//
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var b bytes.Buffer
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writer := bufio.NewWriter(&b)
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err := node.Record().EncodeRLP(writer)
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if err != nil {
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return nil, err
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}
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writer.Flush()
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result = append(result, &pb.PeerInfo{
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Enr: b.Bytes(),
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})
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}
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return result, nil
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}
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