com.dimajix.flowman.execution.ActivityManager.scala Maven / Gradle / Ivy

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/*
 * Copyright (C) 2021 The Flowman Authors
 *
 * 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.
 */

package com.dimajix.flowman.execution

import scala.collection.mutable

import javax.annotation.concurrent.GuardedBy


class ActivityManager(parent:Option[ActivityManager]=None) {
    @GuardedBy("opsLock")
    private val ops = new mutable.HashMap[String,Activity]()
    private val opsLock = new Object

    private val listener = new ActivityListener {
        override def onActivityTerminated(event: ActivityListener.ActivityTerminatedEvent): Unit = {
            val op = event.activity
            op.removeListener(this)
            opsLock.synchronized {
                ops.remove(op.name)
            }
        }
    }

    def this(parent:ActivityManager) = {
        this(Some(parent))
    }

    /**
     * Posts a new [[Activity]] to the manager. The activity is probably already be running.
     *
     * @param op
     */
    def post(op: Activity) : Unit = opsLock.synchronized {
        parent.foreach(_.post(op))

        if (ops.contains(op.name))
            throw new IllegalArgumentException(s"Cannot post activity with name '${op.name}', as an activity with the same name already exists")

        if (op.isActive) {
            op.addListener(listener)
            ops.put(op.name, op)
        }
    }

    /**
     * Returns a list of all Operations.
     * @return
     */
    def listAll() : Seq[Activity] = opsLock.synchronized {
        ops.values.toSeq
    }

    /**
     * Returns a list only of active Operations.
     * @return
     */
    def listActive() : Seq[Activity] = opsLock.synchronized {
        ops.values.filter(_.isActive).toSeq
    }

    /**
     * Returns true if at least one activity is running.
     * @return
     */
    def isActive : Boolean = opsLock.synchronized {
        ops.values.exists(_.isActive)
    }

    /**
     * Triggers a stop on all running activities
     */
    def stop() : Unit = {
        listActive().foreach(_.stop())
    }

    def awaitTermination(): Unit = {
        listActive().foreach(_.awaitTermination())
    }
}