optimize allocations in the memory address book

pstoremem/addr_book.go

@@ -111,7 +111,6 @@ func (mab *memoryAddrBook) gc() {
  now := time.Now()
  for _, s := range mab.segments {
  s.Lock()
- var collectedPeers []peer.ID
  for p, amap := range s.addrs {
  for k, addr := range amap {
  if addr.ExpiredBy(now) {
@@ -120,13 +119,9 @@ func (mab *memoryAddrBook) gc() {
  }
  if len(amap) == 0 {
  delete(s.addrs, p)
- collectedPeers = append(collectedPeers, p)
+ delete(s.signedPeerRecords, p)
  }
  }
- // remove signed records for peers whose signed addrs have all been removed
- for _, p := range collectedPeers {
- delete(s.signedPeerRecords, p)
- }
  s.Unlock()
  }
 }
@@ -221,23 +216,19 @@ func (mab *memoryAddrBook) addAddrsUnlocked(s *addrSegment, p peer.ID, addrs []m
  }
 
  exp := time.Now().Add(ttl)
- addrSet := make(map[string]struct{}, len(addrs))
  for _, addr := range addrs {
  if addr == nil {
  log.Warnw("was passed nil multiaddr", "peer", p)
  continue
  }
- k := string(addr.Bytes())
- addrSet[k] = struct{}{}
 
  // find the highest TTL and Expiry time between
  // existing records and function args
- a, found := amap[k] // won't allocate.
-
+ a, found := amap[string(addr.Bytes())] // won't allocate.
  if !found {
  // not found, announce it.
  entry := &expiringAddr{Addr: addr, Expires: exp, TTL: ttl}
- amap[k] = entry
+ amap[string(addr.Bytes())] = entry
  mab.subManager.BroadcastAddr(p, addr)
  } else {
  // update ttl & exp to whichever is greater between new and existing entry