github.com/igggame/nebulas-go@v2.1.0+incompatible/net/peer_filters.go (about)

     1  // Copyright (C) 2018 go-nebulas authors
     2  //
     3  // This file is part of the go-nebulas library.
     4  //
     5  // the go-nebulas library is free software: you can redistribute it and/or modify
     6  // it under the terms of the GNU General Public License as published by
     7  // the Free Software Foundation, either version 3 of the License, or
     8  // (at your option) any later version.
     9  //
    10  // the go-nebulas library is distributed in the hope that it will be useful,
    11  // but WITHOUT ANY WARRANTY; without even the implied warranty of
    12  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    13  // GNU General Public License for more details.
    14  //
    15  // You should have received a copy of the GNU General Public License
    16  // along with the go-nebulas library.  If not, see <http://www.gnu.org/licenses/>.
    17  //
    18  
    19  package net
    20  
    21  import (
    22  	"math"
    23  	"math/rand"
    24  )
    25  
    26  // ChainSyncPeersFilter will filter some peers randomly
    27  type ChainSyncPeersFilter struct {
    28  }
    29  
    30  // Filter implemets PeerFilterAlgorithm interface
    31  func (filter *ChainSyncPeersFilter) Filter(peers PeersSlice) PeersSlice {
    32  	if len(peers) == 0 {
    33  		return peers
    34  	}
    35  	selection := int(math.Sqrt(float64(len(peers))))
    36  	return peers[:selection]
    37  }
    38  
    39  // RandomPeerFilter will filter a peer randomly
    40  type RandomPeerFilter struct {
    41  }
    42  
    43  // Filter implemets PeerFilterAlgorithm interface
    44  func (filter *RandomPeerFilter) Filter(peers PeersSlice) PeersSlice {
    45  	if len(peers) == 0 {
    46  		return peers
    47  	}
    48  
    49  	selection := rand.Intn(len(peers))
    50  	return peers[selection : selection+1]
    51  }