reduce complexity in update addr book method

pstoreds/addr_book.go

@@ -15,6 +15,7 @@ import (
 
  "github.com/libp2p/go-libp2p-core/peer"
  pstore "github.com/libp2p/go-libp2p-core/peerstore"
+ "github.com/libp2p/go-libp2p-core/record"
  pb "github.com/libp2p/go-libp2p-peerstore/pb"
  "github.com/libp2p/go-libp2p-peerstore/pstoremem"
 
@@ -467,36 +468,40 @@ func (ab *dsAddrBook) setAddrs(p peer.ID, addrs []ma.Multiaddr, ttl time.Duratio
  // }
 
  newExp := time.Now().Add(ttl).Unix()
- // TODO this is very inefficient O(m*n); we could build a map to use as an
- // index, and test against it. That would turn it into O(m+n). This code
- // will be refactored entirely anyway, and it's not being used by users
- // (that we know of); so OK to keep it for now.
- updateExisting := func(entryList []*pb.AddrBookRecord_AddrEntry, incoming ma.Multiaddr) *pb.AddrBookRecord_AddrEntry {
- for _, have := range entryList {
- if incoming.Equal(have.Addr) {
- switch mode {
- case ttlOverride:
- have.Ttl = int64(ttl)
- have.Expiry = newExp
- case ttlExtend:
- if int64(ttl) > have.Ttl {
- have.Ttl = int64(ttl)
- }
- if newExp > have.Expiry {
- have.Expiry = newExp
- }
- default:
- panic("BUG: unimplemented ttl mode")
- }
- return have
+ var addrsMap map[string]*pb.AddrBookRecord_AddrEntry
+ if len(addrs) > 0 {
+ addrsMap = make(map[string]*pb.AddrBookRecord_AddrEntry, len(pr.Addrs))
+ for _, addr := range pr.Addrs {
+ addrsMap[addr.Addr.String()] = addr
+ }
+ }
+
+ updateExisting := func(incoming ma.Multiaddr) *pb.AddrBookRecord_AddrEntry {
+ existingEntry := addrsMap[incoming.String()]
+ if existingEntry == nil {
+ return nil
+ }
+
+ switch mode {
+ case ttlOverride:
+ existingEntry.Ttl = int64(ttl)
+ existingEntry.Expiry = newExp
+ case ttlExtend:
+ if int64(ttl) > existingEntry.Ttl {
+ existingEntry.Ttl = int64(ttl)
  }
+ if newExp > existingEntry.Expiry {
+ existingEntry.Expiry = newExp
+ }
+ default:
+ panic("BUG: unimplemented ttl mode")
  }
- return nil
+ return existingEntry
  }
 
  var entries []*pb.AddrBookRecord_AddrEntry
  for _, incoming := range addrs {
- existingEntry := updateExisting(pr.Addrs, incoming)
+ existingEntry := updateExisting(incoming)
 
  if existingEntry == nil {
  // if signed {