com.github.edgar615.util.vertx.wheel.KeepaliveCheckerImpl Maven / Gradle / Ivy
package com.github.edgar615.util.vertx.wheel;
import io.vertx.core.Vertx;
import io.vertx.core.json.JsonArray;
import io.vertx.core.json.JsonObject;
import java.util.ArrayList;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.CopyOnWriteArraySet;
import java.util.concurrent.atomic.AtomicInteger;
/**
* Created by edgar on 17-3-19.
*/
class KeepaliveCheckerImpl implements KeepaliveChecker {
private final Vertx vertx;
/**
* 多少次检测之后的心跳认为掉线
*/
private final int interval;
/**
* 每次检测的间隔时间
*/
private final int period;
/**
* 游标
*/
private final AtomicInteger cursor = new AtomicInteger(0);
/**
* 记录心跳的在环形队列中的位置，每次收到心跳都需要更新心跳在环形队列中的位置，通过location可以很快定位到心跳在环形队列中的位置
*/
private final Map location = new ConcurrentHashMap<>();
/**
* 环形队列
*/
private final Map> bucket = new ConcurrentHashMap<>();
// /**
// * 序列号
// */
// private final AtomicInteger seq = new AtomicInteger(0);
/**
* 设备掉线的事件地址
*/
private final String disConnAddress;
/**
* 设备第一次上线对事件地址
*/
private final String firstConnAddress;
KeepaliveCheckerImpl(Vertx vertx, KeepaliveOptions options) {
this.vertx = vertx;
this.interval = options.getInterval();
this.disConnAddress = options.getDisConnAddress();
this.firstConnAddress = options.getFirstConnAddress();
this.period = options.getStep();
for (int i = 0; i <= interval; i++) {
bucket.put(i, new CopyOnWriteArraySet<>());
}
vertx.setPeriodic(period, l -> {
Set oldList = forward();
if (oldList.size() > 0) {
vertx.eventBus().publish(disConnAddress,
new JsonObject().put("ids", new JsonArray(new ArrayList(oldList))));
}
});
}
/**
* 游标向前移动一格
* @return
*/
private synchronized Set forward() {
int expiredSolt = cursor
.getAndAccumulate(1, (left, right) -> left + right > interval ? 0 : left + right);
Set disConnectedIds = bucket.put(expiredSolt, new CopyOnWriteArraySet<>());
disConnectedIds.forEach(i -> location.remove(i));
return disConnectedIds;
}
/**
* 向桶中增加一个心跳．
* @param id
* @return 如果是第一次添加（或者掉线后再次添加）返回true
*/
private synchronized boolean addToBucket(Integer id) {
int solt = cursor.get() - 1;
if (solt < 0) {
solt = interval;
}
Integer oldLocaction = location.put(id, solt);
if (oldLocaction != null) {
bucket.get(oldLocaction).remove(id);
}
bucket.get(solt).add(id);
return oldLocaction == null;
}
@Override
public void add(Integer id) {
boolean firstCheck = addToBucket(id);
if (firstCheck) {
vertx.eventBus().publish(firstConnAddress,
new JsonObject().put("id", id));
}
}
@Override
public int size() {
return location.size();
}
}