gateway/gateway-httpclient-support/src/main/scala/com/webank/wedatasphere/linkis/httpclient/dws/discovery/DWSGatewayDiscovery.scala

/*
 * Copyright 2019 WeBank
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

/*
 * created by cooperyang on 2019/07/24.
 */

package com.webank.wedatasphere.linkis.httpclient.dws.discovery

import com.webank.wedatasphere.linkis.httpclient.discovery.{AbstractDiscovery, HeartbeatAction, HeartbeatResult}
import com.webank.wedatasphere.linkis.httpclient.dws.request.DWSHeartbeatAction
import com.webank.wedatasphere.linkis.httpclient.dws.response.DWSHeartbeatResult
import org.apache.http.HttpResponse

import scala.util.Random

/**
  * created by cooperyang on 2019/5/22.
  */
class DWSGatewayDiscovery extends AbstractDiscovery {

  override protected def discovery(): Array[String] = {
    val serverUrl = if(getServerInstances.isEmpty) getServerUrl
      else Random.shuffle(getServerInstances.toList).head
    info("discovery to gateway " + serverUrl)
    getClient.execute(getHeartbeatAction(serverUrl)) match {
      case dws: DWSHeartbeatResult => dws.getGatewayList
    }
  }

  override protected def getHeartbeatAction(serverUrl: String): HeartbeatAction = new DWSHeartbeatAction(serverUrl)

  override def getHeartbeatResult(response: HttpResponse, requestAction: HeartbeatAction): HeartbeatResult = requestAction match {
    case h: DWSHeartbeatAction => new DWSHeartbeatResult(response, h.serverUrl)
  }
}