data/src/main/scala/org/apache/predictionio/data/store/LEventStore.scala

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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 org.apache.predictionio.data.store

import org.apache.predictionio.data.storage.Storage
import org.apache.predictionio.data.storage.Event
import org.joda.time.DateTime

import scala.concurrent.{Await, ExecutionContext, Future}
import scala.concurrent.duration.Duration

/** This object provides a set of operation to access Event Store
  * without going through Spark's parallelization.
  *
  * Note that blocking methods of this object uses
  * `scala.concurrent.ExecutionContext.Implicits.global` internally.
  * Since this is a thread pool which has a number of threads equal to available
  * processors, parallelism is limited up to the number of processors.
  *
  * If this limitation become bottleneck of resource usage, you can increase the
  * number of threads by declaring following VM options before calling "pio deploy":
  *
  * <pre>
  * export JAVA_OPTS="$JAVA_OPTS \
  *   -Dscala.concurrent.context.numThreads=1000 \
  *   -Dscala.concurrent.context.maxThreads=1000"
  * </pre>
  *
  * You can learn more about the global execution context in the Scala documentation:
  * [[https://docs.scala-lang.org/overviews/core/futures.html#the-global-execution-context]]
  */
object LEventStore {

  private val defaultTimeout = Duration(60, "seconds")

  @transient lazy private val eventsDb = Storage.getLEvents()

  /** Reads events of the specified entity. May use this in Algorithm's predict()
    * or Serving logic to have fast event store access.
    *
    * @param appName return events of this app
    * @param entityType return events of this entityType
    * @param entityId return events of this entityId
    * @param channelName return events of this channel (default channel if it's None)
    * @param eventNames return events with any of these event names.
    * @param targetEntityType return events of this targetEntityType:
    *   - None means no restriction on targetEntityType
    *   - Some(None) means no targetEntityType for this event
    *   - Some(Some(x)) means targetEntityType should match x.
    * @param targetEntityId return events of this targetEntityId
    *   - None means no restriction on targetEntityId
    *   - Some(None) means no targetEntityId for this event
    *   - Some(Some(x)) means targetEntityId should match x.
    * @param startTime return events with eventTime >= startTime
    * @param untilTime return events with eventTime < untilTime
    * @param limit Limit number of events. Get all events if None or Some(-1)
    * @param latest Return latest event first (default true)
    * @return Iterator[Event]
    */
  def findByEntity(
    appName: String,
    entityType: String,
    entityId: String,
    channelName: Option[String] = None,
    eventNames: Option[Seq[String]] = None,
    targetEntityType: Option[Option[String]] = None,
    targetEntityId: Option[Option[String]] = None,
    startTime: Option[DateTime] = None,
    untilTime: Option[DateTime] = None,
    limit: Option[Int] = None,
    latest: Boolean = true,
    timeout: Duration = defaultTimeout): Iterator[Event] = {

    // Import here to ensure ExecutionContext.Implicits.global is used only in this method
    import scala.concurrent.ExecutionContext.Implicits.global

    Await.result(findByEntityAsync(
      appName = appName,
      entityType = entityType,
      entityId = entityId,
      channelName = channelName,
      eventNames = eventNames,
      targetEntityType = targetEntityType,
      targetEntityId = targetEntityId,
      startTime = startTime,
      untilTime = untilTime,
      limit = limit,
      latest = latest),
      timeout)
  }

  /** Reads events of the specified entity. May use this in Algorithm's predict()
    * or Serving logic to have fast event store access.
    *
    * @param appName return events of this app
    * @param entityType return events of this entityType
    * @param entityId return events of this entityId
    * @param channelName return events of this channel (default channel if it's None)
    * @param eventNames return events with any of these event names.
    * @param targetEntityType return events of this targetEntityType:
    *   - None means no restriction on targetEntityType
    *   - Some(None) means no targetEntityType for this event
    *   - Some(Some(x)) means targetEntityType should match x.
    * @param targetEntityId return events of this targetEntityId
    *   - None means no restriction on targetEntityId
    *   - Some(None) means no targetEntityId for this event
    *   - Some(Some(x)) means targetEntityId should match x.
    * @param startTime return events with eventTime >= startTime
    * @param untilTime return events with eventTime < untilTime
    * @param limit Limit number of events. Get all events if None or Some(-1)
    * @param latest Return latest event first (default true)
    * @return Future[Iterator[Event]]
    */
  def findByEntityAsync(
    appName: String,
    entityType: String,
    entityId: String,
    channelName: Option[String] = None,
    eventNames: Option[Seq[String]] = None,
    targetEntityType: Option[Option[String]] = None,
    targetEntityId: Option[Option[String]] = None,
    startTime: Option[DateTime] = None,
    untilTime: Option[DateTime] = None,
    limit: Option[Int] = None,
    latest: Boolean = true)(implicit ec: ExecutionContext): Future[Iterator[Event]] = {

    val (appId, channelId) = Common.appNameToId(appName, channelName)

    eventsDb.futureFind(
      appId = appId,
      channelId = channelId,
      startTime = startTime,
      untilTime = untilTime,
      entityType = Some(entityType),
      entityId = Some(entityId),
      eventNames = eventNames,
      targetEntityType = targetEntityType,
      targetEntityId = targetEntityId,
      limit = limit,
      reversed = Some(latest))
  }

  /** Reads events generically. If entityType or entityId is not specified, it
    * results in table scan.
    *
    * @param appName return events of this app
    * @param entityType return events of this entityType
    *   - None means no restriction on entityType
    *   - Some(x) means entityType should match x.
    * @param entityId return events of this entityId
    *   - None means no restriction on entityId
    *   - Some(x) means entityId should match x.
    * @param channelName return events of this channel (default channel if it's None)
    * @param eventNames return events with any of these event names.
    * @param targetEntityType return events of this targetEntityType:
    *   - None means no restriction on targetEntityType
    *   - Some(None) means no targetEntityType for this event
    *   - Some(Some(x)) means targetEntityType should match x.
    * @param targetEntityId return events of this targetEntityId
    *   - None means no restriction on targetEntityId
    *   - Some(None) means no targetEntityId for this event
    *   - Some(Some(x)) means targetEntityId should match x.
    * @param startTime return events with eventTime >= startTime
    * @param untilTime return events with eventTime < untilTime
    * @param limit Limit number of events. Get all events if None or Some(-1)
    * @return Iterator[Event]
    */
  def find(
    appName: String,
    entityType: Option[String] = None,
    entityId: Option[String] = None,
    channelName: Option[String] = None,
    eventNames: Option[Seq[String]] = None,
    targetEntityType: Option[Option[String]] = None,
    targetEntityId: Option[Option[String]] = None,
    startTime: Option[DateTime] = None,
    untilTime: Option[DateTime] = None,
    limit: Option[Int] = None,
    timeout: Duration = defaultTimeout): Iterator[Event] = {

    // Import here to ensure ExecutionContext.Implicits.global is used only in this method
    import scala.concurrent.ExecutionContext.Implicits.global

    Await.result(findAsync(
      appName = appName,
      entityType = entityType,
      entityId = entityId,
      channelName = channelName,
      eventNames = eventNames,
      targetEntityType = targetEntityType,
      targetEntityId = targetEntityId,
      startTime = startTime,
      untilTime = untilTime,
      limit = limit), timeout)
  }

  /** Reads events generically. If entityType or entityId is not specified, it
    * results in table scan.
    *
    * @param appName return events of this app
    * @param entityType return events of this entityType
    *   - None means no restriction on entityType
    *   - Some(x) means entityType should match x.
    * @param entityId return events of this entityId
    *   - None means no restriction on entityId
    *   - Some(x) means entityId should match x.
    * @param channelName return events of this channel (default channel if it's None)
    * @param eventNames return events with any of these event names.
    * @param targetEntityType return events of this targetEntityType:
    *   - None means no restriction on targetEntityType
    *   - Some(None) means no targetEntityType for this event
    *   - Some(Some(x)) means targetEntityType should match x.
    * @param targetEntityId return events of this targetEntityId
    *   - None means no restriction on targetEntityId
    *   - Some(None) means no targetEntityId for this event
    *   - Some(Some(x)) means targetEntityId should match x.
    * @param startTime return events with eventTime >= startTime
    * @param untilTime return events with eventTime < untilTime
    * @param limit Limit number of events. Get all events if None or Some(-1)
    * @return Future[Iterator[Event]]
    */
  def findAsync(
    appName: String,
    entityType: Option[String] = None,
    entityId: Option[String] = None,
    channelName: Option[String] = None,
    eventNames: Option[Seq[String]] = None,
    targetEntityType: Option[Option[String]] = None,
    targetEntityId: Option[Option[String]] = None,
    startTime: Option[DateTime] = None,
    untilTime: Option[DateTime] = None,
    limit: Option[Int] = None)(implicit ec: ExecutionContext): Future[Iterator[Event]] = {

    val (appId, channelId) = Common.appNameToId(appName, channelName)

    eventsDb.futureFind(
      appId = appId,
      channelId = channelId,
      startTime = startTime,
      untilTime = untilTime,
      entityType = entityType,
      entityId = entityId,
      eventNames = eventNames,
      targetEntityType = targetEntityType,
      targetEntityId = targetEntityId,
      limit = limit)
  }

}