package com.shentu.dht.peer;
import io.netty.util.CharsetUtil;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.SneakyThrows;
import org.apache.commons.collections.CollectionUtils;
import org.apache.commons.lang3.RandomUtils;
import org.springframework.beans.BeanUtils;
import java.net.InetSocketAddress;
import java.util.*;
import java.util.concurrent.ConcurrentHashMap;
import java.util.stream.Collectors;
/**
* Created by styb on 2019/3/13.
*/
@Data
public class RoutingTable {
private byte[] nodeId= RandomUtils.nextBytes(20);
private String nodeIdStr=new String(nodeId, CharsetUtil.ISO_8859_1);
private Map<Integer,PriorityQueue<Node>> tableMap=new ConcurrentHashMap<>();
private Bucket bucket=new Bucket(0,null);
public List<Node> getSlef(){
return Arrays.asList(new Node(nodeId,new InetSocketAddress("127.0.0.1",7000),0));
}
/**
* 根据nodeid 查找最近的8个node
* @param trargetBytes 需要查找目标id
* @return
*/
public List<Node> getForTop8(byte[] trargetBytes){
int bucketIndex = getBucketIndex(trargetBytes);
List<Node> l=new ArrayList<>();
PriorityQueue<Node> pq = tableMap.get(bucketIndex);
if(CollectionUtils.isEmpty(pq)){
while(bucket.next != null){
if(bucketIndex > bucket.getK()
&& bucketIndex < bucket.next.getK()){
tableMap.get(bucket.next.getK()).stream().forEach(x->{
if(l.size()<8){
l.add(x);
}
});
}
bucket=bucket.next;
}
if(CollectionUtils.isEmpty(l)){
tableMap.get(bucket.getK()).stream().forEach(x->{
if(l.size()<8){
l.add(x);
}
});
}
}else{//如果不空 那么直接加 简单点来吧
l.addAll(pq.stream().collect(Collectors.toList()));
}
return l;
}
public static void main(String[] args) {
RoutingTable routingTable = new RoutingTable();
Map<Integer, PriorityQueue<Node>> tableMap = routingTable.getTableMap();
tableMap.put(0,new PriorityQueue<>());
byte[] bytes = RandomUtils.nextBytes(26);
Node node = new Node(bytes);
node.setRank(1);
for(int i=0;i<100;i++)
routingTable.put(node);
}
public void put(Node node) {
int bucketIndex = getBucketIndex(node);
if(bucketIndex==0){//是自己就不用加入了
return;
}
PriorityQueue<Node> pq = tableMap.get(bucketIndex);
if(CollectionUtils.isEmpty(pq)){
//如果是空 那么找最近的那个节点加入
boolean isAdd=false;
while(bucket.next != null){
if(bucketIndex > bucket.getK()
&& bucketIndex < bucket.next.getK()){
//先往小的里面放
node.setCurrentK(bucket.getK());
isAdd=putAccurate(tableMap.get(bucket.getK()),node,false,bucket,tableMap);
if(!isAdd){
node.setCurrentK(bucket.next.getK());
isAdd=putAccurate(tableMap.get(bucket.next.getK()),node,true,bucket,tableMap);
}
}
bucket=bucket.next;
}
if(!isAdd){
//没有添加成功 那么往最后一个节点添加
node.setCurrentK(bucket.getK());
putAccurate(tableMap.get(bucket.getK()),node,true,bucket,tableMap);
}
}else{//如果不空 那么直接加 简单点来吧
if(pq.size()<8){
if(!pq.contains(node)){
node.setCurrentK(node.getK());
pq.add(node);
}else{
reAdd(pq,node);
}
}else{
pq.add(node);
pq.poll();
}
}
}
public boolean reAdd(PriorityQueue<Node> pq,Node node){
Node reAdd=new Node(RandomUtils.nextBytes(26));
pq.stream().forEach(x->{
if(x.getNodeId().equals(node.getNodeId())){
x.setRank(x.getRank()+node.getRank());
BeanUtils.copyProperties(x,reAdd);
}
});
pq.remove(reAdd);
pq.add(reAdd);
return true;
}
/**
* @param pq 当前bucket
* @param node 需要插入的node
* @param isSplit 是否需要分裂
* @param bucket 需要插入的bucket的位置
* @param tableMap 路由表
* @return 返回是否添加成功
*/
@SneakyThrows
public boolean putAccurate(PriorityQueue<Node> pq,Node node,boolean isSplit,Bucket bucket,Map<Integer,PriorityQueue<Node>> tableMap){
boolean isAdd=false;
if(pq.contains(node)){
return reAdd(pq,node);
}
if(pq.size()<8){
pq.add(node);
isAdd=true;
}
if(isSplit && !isAdd){
PriorityQueue<Node> priorityQueue=new PriorityQueue<Node>((x,y)->x.getRank()-y.getRank());
priorityQueue.add(node);
tableMap.putIfAbsent(node.getK(),priorityQueue);
//创建新的k桶后需要把两边的bucket距离比较近的都放到自己的k桶里面 如果超过8个就丢了 最好是可以ping一下
//先从小的开始放
PriorityQueue<Node> collect1 = new PriorityQueue<>();
collect1.addAll(tableMap.get(bucket.getK()).stream().filter(n -> {
if (priorityQueue.size() < 8 &&
Math.abs(n.getK() - n.getCurrentK()) > Math.abs(n.getK() - node.getK())) {
n.setCurrentK(node.getK());
priorityQueue.add(n);
return false;
}
return true;
}).collect(Collectors.toSet()));
tableMap.put(bucket.getK(),CollectionUtils.isNotEmpty(collect1)?collect1:new PriorityQueue<Node>());
if(bucket.next!=null && CollectionUtils.isNotEmpty(tableMap.get(bucket.next.getK()))){
PriorityQueue<Node> collect = new PriorityQueue<>();
collect.addAll(tableMap.get(bucket.next.getK()).stream().filter(n -> {
if (priorityQueue.size() < 8 &&
Math.abs(n.getK() - n.getCurrentK()) > Math.abs(n.getK() - node.getK())) {
n.setCurrentK(node.getK());
priorityQueue.add(n);
return false;
}
return true;
}).collect(Collectors.toSet()));
tableMap.put(bucket.next.getK(),CollectionUtils.isNotEmpty(collect)?collect:new PriorityQueue<Node>());
}
Bucket b=new Bucket(node.getK(),bucket.next);
bucket.next=b;
isAdd=true;
node.setCurrentK(node.getK());
}
return isAdd;
}
public int getBucketIndex(Node node) {
int index=160;
byte[] bytes = getAllBit(node.getNodeIdBytes());
byte[] nodeAllBit = getAllBit(nodeId);
for(int i=0;i<bytes.length;i++){
//高位一样距离越近
if(bytes[i]==nodeAllBit[i]){
index--;
}else{
break;
}
}
node.setK(index);
return index;
}
public int getBucketIndex(byte[] b) {
int index=160;
byte[] bytes = getAllBit(b);
byte[] nodeAllBit = getAllBit(nodeId);
for(int i=0;i<bytes.length;i++){
//高位一样距离越近
if(bytes[i]==nodeAllBit[i]){
index--;
}else{
break;
}
}
return index;
}
@Data
@AllArgsConstructor
public static class Bucket{
private int k;
private Bucket next;
}
/**
* 转化为160位的bit
* @param bytes
* @return
*/
public static byte[] getAllBit(byte[] bytes) {
byte[] result = new byte[160];
int index = 0;
for (int i = 0; i < 20; i++) {
byte b = bytes[i];
//0-7 8-15
int count=index+7;
for (int j = 0; j < 8; j++) {
result[count] = (byte) (b & 0x1);
b = (byte) (b >> 1);
count--;
}
index+=8;
}
return result;
}
}
