PICE（1）：Programming In Clustered Environment - 集群环境内编程模式

        val ctx = JDBCQueryContext[JDBCDataRow](
          dbName = Symbol(q.dbName),
          statement = q.statement,
          parameters = params,
          fetchSize = q.fetchSize.getOrElse(100),
          autoCommit = q.autoCommit.getOrElse(false),
          queryTimeout = q.queryTimeout
        )
        jdbcAkkaStream(ctx, toRow)

message JDBCDataRow {
 string year = 1;
 string state = 2;
 string county = 3;
 string value = 4;
}

message JDBCQuery {
  string dbName = 1;
  string statement = 2;
  bytes parameters = 3;
  google.protobuf.Int32Value fetchSize= 4;
  google.protobuf.BoolValue autoCommit = 5;
  google.protobuf.Int32Value queryTimeout = 6;
}

service JDBCServices {
  rpc runQuery(JDBCQuery) returns (stream JDBCDataRow) {}
}

    parameters: _root_.com.google.protobuf.ByteString = _root_.com.google.protobuf.ByteString.EMPTY,

package protobuf.bytes
import java.io.{ByteArrayInputStream,ByteArrayOutputStream,ObjectInputStream,ObjectOutputStream}
import com.google.protobuf.ByteString
object Converter {
  def marshal(value: Any): ByteString = {
    val stream: ByteArrayOutputStream = new ByteArrayOutputStream()
    val oos = new ObjectOutputStream(stream)
    oos.writeObject(value)
    oos.close()
    ByteString.copyFrom(stream.toByteArray())
  }

  def unmarshal[A](bytes: ByteString): A = {
    val ois = new ObjectInputStream(new ByteArrayInputStream(bytes.toByteArray))
    val value = ois.readObject()
    ois.close()
    value.asInstanceOf[A]
  }
}

class JDBCStreamingServices(implicit ec: ExecutionContextExecutor) extends JdbcGrpcAkkaStream.JDBCServices {
  val logger = Logger.getLogger(classOf[JDBCStreamingServices].getName)

  val toRow = (rs: WrappedResultSet) => JDBCDataRow(
    year = rs.string("REPORTYEAR"),
    state = rs.string("STATENAME"),
    county = rs.string("COUNTYNAME"),
    value = rs.string("VALUE")
  )
  override def runQuery: Flow[JDBCQuery, JDBCDataRow, NotUsed] = {
    logger.info("**** runQuery called on service side ***")
    Flow[JDBCQuery]
      .flatMapConcat { q =>
        //unpack JDBCQuery and construct the context
        val params: Seq[Any] = unmarshal[Seq[Any]](q.parameters)
        logger.info(s"**** query parameters: ${params} ****")
        val ctx = JDBCQueryContext[JDBCDataRow](
          dbName = Symbol(q.dbName),
          statement = q.statement,
          parameters = params,
          fetchSize = q.fetchSize.getOrElse(100),
          autoCommit = q.autoCommit.getOrElse(false),
          queryTimeout = q.queryTimeout
        )
        jdbcAkkaStream(ctx, toRow)
      }
  }
}

  val query = JDBCQuery (
    dbName = "h2",
    statement = "select * from AQMRPT where STATENAME = ? and VALUE = ?",
    parameters = marshal(Seq("Arizona", 5))
  )

  def queryRows: Source[JDBCDataRow,NotUsed] = {
    logger.info(s"running queryRows ...")
    Source
      .single(query)
      .via(stub.runQuery)
  }

object QueryRows extends App {
  implicit val system = ActorSystem("QueryRows")
  implicit val mat = ActorMaterializer.create(system)

  val client = new JDBCStreamClient("localhost", 50051)

  client.queryRows.runForeach(println)

  scala.io.StdIn.readLine()
  mat.shutdown()
  system.terminate()
}

addSbtPlugin("com.thesamet" % "sbt-protoc" % "0.99.18")

resolvers += Resolver.bintrayRepo("beyondthelines", "maven")

libraryDependencies ++= Seq(
  "com.thesamet.scalapb" %% "compilerplugin" % "0.7.4",
  "beyondthelines"         %% "grpcakkastreamgenerator" % "0.0.5"
)

import scalapb.compiler.Version.scalapbVersion
import scalapb.compiler.Version.grpcJavaVersion

name := "gRPCJDBCStreaming"

version := "0.11"

scalaVersion := "2.12.6"

resolvers += Resolver.bintrayRepo("beyondthelines", "maven")

libraryDependencies ++= Seq(
  "com.thesamet.scalapb" %% "scalapb-runtime" % scalapbVersion % "protobuf",
  "io.grpc" % "grpc-netty" % grpcJavaVersion,
  "com.thesamet.scalapb" %% "scalapb-runtime-grpc" % scalapbVersion,
  "io.monix" %% "monix" % "2.3.0",
  // for GRPC Akkastream
  "beyondthelines"         %% "grpcakkastreamruntime" % "0.0.5",
  // for scalikejdbc
  "org.scalikejdbc" %% "scalikejdbc"       % "3.2.1",
  "org.scalikejdbc" %% "scalikejdbc-test"   % "3.2.1"   % "test",
  "org.scalikejdbc" %% "scalikejdbc-config"  % "3.2.1",
  "org.scalikejdbc" %% "scalikejdbc-streams" % "3.2.1",
  "org.scalikejdbc" %% "scalikejdbc-joda-time" % "3.2.1",
  "com.h2database"  %  "h2"                % "1.4.196",
  "mysql" % "mysql-connector-java" % "6.0.6",
  "org.postgresql" % "postgresql" % "42.2.0",
  "commons-dbcp" % "commons-dbcp" % "1.4",
  "org.apache.tomcat" % "tomcat-jdbc" % "9.0.2",
  "com.zaxxer" % "HikariCP" % "2.7.4",
  "com.jolbox" % "bonecp" % "0.8.0.RELEASE",
  "com.typesafe.slick" %% "slick" % "3.2.1",
  "ch.qos.logback"  %  "logback-classic"   % "1.2.3",
  "com.typesafe.akka" %% "akka-actor" % "2.5.4",
  "com.typesafe.akka" %% "akka-stream" % "2.5.4"
)

PB.targets in Compile := Seq(
  scalapb.gen() -> (sourceManaged in Compile).value,
  // generate the akka stream files
  grpc.akkastreams.generators.GrpcAkkaStreamGenerator() -> (sourceManaged in Compile).value
)

syntax = "proto3";

import "google/protobuf/wrappers.proto";
import "google/protobuf/any.proto";
import "scalapb/scalapb.proto";


package grpc.jdbc.services;

option (scalapb.options) = {
  // use a custom Scala package name
  // package_name: "io.ontherocks.introgrpc.demo"

  // don't append file name to package
  flat_package: true

  // generate one Scala file for all messages (services still get their own file)
  single_file: true

  // add imports to generated file
  // useful when extending traits or using custom types
  // import: "io.ontherocks.hellogrpc.RockingMessage"

  // code to put at the top of generated file
  // works only with `single_file: true`
  //preamble: "sealed trait SomeSealedTrait"
};

/*
 * Demoes various customization options provided by ScalaPBs.
 */


message JDBCDataRow {
 string year = 1;
 string state = 2;
 string county = 3;
 string value = 4;
}


message JDBCQuery {
  string dbName = 1;
  string statement = 2;
  bytes parameters = 3;
  google.protobuf.Int32Value fetchSize= 4;
  google.protobuf.BoolValue autoCommit = 5;
  google.protobuf.Int32Value queryTimeout = 6;
}

service JDBCServices {
  rpc runQuery(JDBCQuery) returns (stream JDBCDataRow) {}
}

# JDBC settings
test {
  db {
    h2 {
      driver = "org.h2.Driver"
      url = "jdbc:h2:tcp://localhost/~/slickdemo"
      user = ""
      password = ""
      poolInitialSize = 5
      poolMaxSize = 7
      poolConnectionTimeoutMillis = 1000
      poolValidationQuery = "select 1 as one"
      poolFactoryName = "commons-dbcp2"
    }
  }

  db.mysql.driver = "com.mysql.cj.jdbc.Driver"
  db.mysql.url = "jdbc:mysql://localhost:3306/testdb"
  db.mysql.user = "root"
  db.mysql.password = "123"
  db.mysql.poolInitialSize = 5
  db.mysql.poolMaxSize = 7
  db.mysql.poolConnectionTimeoutMillis = 1000
  db.mysql.poolValidationQuery = "select 1 as one"
  db.mysql.poolFactoryName = "bonecp"

  # scallikejdbc Global settings
  scalikejdbc.global.loggingSQLAndTime.enabled = true
  scalikejdbc.global.loggingSQLAndTime.logLevel = info
  scalikejdbc.global.loggingSQLAndTime.warningEnabled = true
  scalikejdbc.global.loggingSQLAndTime.warningThresholdMillis = 1000
  scalikejdbc.global.loggingSQLAndTime.warningLogLevel = warn
  scalikejdbc.global.loggingSQLAndTime.singleLineMode = false
  scalikejdbc.global.loggingSQLAndTime.printUnprocessedStackTrace = false
  scalikejdbc.global.loggingSQLAndTime.stackTraceDepth = 10
}
dev {
  db {
    h2 {
      driver = "org.h2.Driver"
      url = "jdbc:h2:tcp://localhost/~/slickdemo"
      user = ""
      password = ""
      poolFactoryName = "hikaricp"
      numThreads = 10
      maxConnections = 12
      minConnections = 4
      keepAliveConnection = true
    }
    mysql {
      driver = "com.mysql.cj.jdbc.Driver"
      url = "jdbc:mysql://localhost:3306/testdb"
      user = "root"
      password = "123"
      poolInitialSize = 5
      poolMaxSize = 7
      poolConnectionTimeoutMillis = 1000
      poolValidationQuery = "select 1 as one"
      poolFactoryName = "bonecp"

    }
    postgres {
      driver = "org.postgresql.Driver"
      url = "jdbc:postgresql://localhost:5432/testdb"
      user = "root"
      password = "123"
      poolFactoryName = "hikaricp"
      numThreads = 10
      maxConnections = 12
      minConnections = 4
      keepAliveConnection = true
    }
  }
  # scallikejdbc Global settings
  scalikejdbc.global.loggingSQLAndTime.enabled = true
  scalikejdbc.global.loggingSQLAndTime.logLevel = info
  scalikejdbc.global.loggingSQLAndTime.warningEnabled = true
  scalikejdbc.global.loggingSQLAndTime.warningThresholdMillis = 1000
  scalikejdbc.global.loggingSQLAndTime.warningLogLevel = warn
  scalikejdbc.global.loggingSQLAndTime.singleLineMode = false
  scalikejdbc.global.loggingSQLAndTime.printUnprocessedStackTrace = false
  scalikejdbc.global.loggingSQLAndTime.stackTraceDepth = 10
}

package sdp.jdbc.config
import scala.collection.mutable
import scala.concurrent.duration.Duration
import scala.language.implicitConversions
import com.typesafe.config._
import java.util.concurrent.TimeUnit
import java.util.Properties
import scalikejdbc.config._
import com.typesafe.config.Config
import com.zaxxer.hikari._
import scalikejdbc.ConnectionPoolFactoryRepository

/** Extension methods to make Typesafe Config easier to use */
class ConfigExtensionMethods(val c: Config) extends AnyVal {
  import scala.collection.JavaConverters._

  def getBooleanOr(path: String, default: => Boolean = false) = if(c.hasPath(path)) c.getBoolean(path) else default
  def getIntOr(path: String, default: => Int = 0) = if(c.hasPath(path)) c.getInt(path) else default
  def getStringOr(path: String, default: => String = null) = if(c.hasPath(path)) c.getString(path) else default
  def getConfigOr(path: String, default: => Config = ConfigFactory.empty()) = if(c.hasPath(path)) c.getConfig(path) else default

  def getMillisecondsOr(path: String, default: => Long = 0L) = if(c.hasPath(path)) c.getDuration(path, TimeUnit.MILLISECONDS) else default
  def getDurationOr(path: String, default: => Duration = Duration.Zero) =
    if(c.hasPath(path)) Duration(c.getDuration(path, TimeUnit.MILLISECONDS), TimeUnit.MILLISECONDS) else default

  def getPropertiesOr(path: String, default: => Properties = null): Properties =
    if(c.hasPath(path)) new ConfigExtensionMethods(c.getConfig(path)).toProperties else default

  def toProperties: Properties = {
    def toProps(m: mutable.Map[String, ConfigValue]): Properties = {
      val props = new Properties(null)
      m.foreach { case (k, cv) =>
        val v =
          if(cv.valueType() == ConfigValueType.OBJECT) toProps(cv.asInstanceOf[ConfigObject].asScala)
          else if(cv.unwrapped eq null) null
          else cv.unwrapped.toString
        if(v ne null) props.put(k, v)
      }
      props
    }
    toProps(c.root.asScala)
  }

  def getBooleanOpt(path: String): Option[Boolean] = if(c.hasPath(path)) Some(c.getBoolean(path)) else None
  def getIntOpt(path: String): Option[Int] = if(c.hasPath(path)) Some(c.getInt(path)) else None
  def getStringOpt(path: String) = Option(getStringOr(path))
  def getPropertiesOpt(path: String) = Option(getPropertiesOr(path))
}

object ConfigExtensionMethods {
  @inline implicit def configExtensionMethods(c: Config): ConfigExtensionMethods = new ConfigExtensionMethods(c)
}

trait HikariConfigReader extends TypesafeConfigReader {
  self: TypesafeConfig =>      // with TypesafeConfigReader => //NoEnvPrefix =>

  import ConfigExtensionMethods.configExtensionMethods

  def getFactoryName(dbName: Symbol): String = {
    val c: Config = config.getConfig(envPrefix + "db." + dbName.name)
    c.getStringOr("poolFactoryName", ConnectionPoolFactoryRepository.COMMONS_DBCP)
  }

  def hikariCPConfig(dbName: Symbol): HikariConfig = {

    val hconf = new HikariConfig()
    val c: Config = config.getConfig(envPrefix + "db." + dbName.name)

    // Connection settings
    if (c.hasPath("dataSourceClass")) {
      hconf.setDataSourceClassName(c.getString("dataSourceClass"))
    } else {
      Option(c.getStringOr("driverClassName", c.getStringOr("driver"))).map(hconf.setDriverClassName _)
    }
    hconf.setJdbcUrl(c.getStringOr("url", null))
    c.getStringOpt("user").foreach(hconf.setUsername)
    c.getStringOpt("password").foreach(hconf.setPassword)
    c.getPropertiesOpt("properties").foreach(hconf.setDataSourceProperties)

    // Pool configuration
    hconf.setConnectionTimeout(c.getMillisecondsOr("connectionTimeout", 1000))
    hconf.setValidationTimeout(c.getMillisecondsOr("validationTimeout", 1000))
    hconf.setIdleTimeout(c.getMillisecondsOr("idleTimeout", 600000))
    hconf.setMaxLifetime(c.getMillisecondsOr("maxLifetime", 1800000))
    hconf.setLeakDetectionThreshold(c.getMillisecondsOr("leakDetectionThreshold", 0))
    hconf.setInitializationFailFast(c.getBooleanOr("initializationFailFast", false))
    c.getStringOpt("connectionTestQuery").foreach(hconf.setConnectionTestQuery)
    c.getStringOpt("connectionInitSql").foreach(hconf.setConnectionInitSql)
    val numThreads = c.getIntOr("numThreads", 20)
    hconf.setMaximumPoolSize(c.getIntOr("maxConnections", numThreads * 5))
    hconf.setMinimumIdle(c.getIntOr("minConnections", numThreads))
    hconf.setPoolName(c.getStringOr("poolName", dbName.name))
    hconf.setRegisterMbeans(c.getBooleanOr("registerMbeans", false))

    // Equivalent of ConnectionPreparer
    hconf.setReadOnly(c.getBooleanOr("readOnly", false))
    c.getStringOpt("isolation").map("TRANSACTION_" + _).foreach(hconf.setTransactionIsolation)
    hconf.setCatalog(c.getStringOr("catalog", null))

    hconf

  }
}

import scalikejdbc._
trait ConfigDBs {
  self: TypesafeConfigReader with TypesafeConfig with HikariConfigReader =>

  def setup(dbName: Symbol = ConnectionPool.DEFAULT_NAME): Unit = {
    getFactoryName(dbName) match {
      case "hikaricp" => {
        val hconf = hikariCPConfig(dbName)
        val hikariCPSource = new HikariDataSource(hconf)
        case class HikariDataSourceCloser(src: HikariDataSource) extends DataSourceCloser {
          var closed = false
          override def close(): Unit = src.close()
        }
        if (hconf.getDriverClassName != null && hconf.getDriverClassName.trim.nonEmpty) {
          Class.forName(hconf.getDriverClassName)
        }
        ConnectionPool.add(dbName, new DataSourceConnectionPool(dataSource = hikariCPSource,settings = DataSourceConnectionPoolSettings(),
          closer = HikariDataSourceCloser(hikariCPSource)))
      }
      case _ => {
        val JDBCSettings(url, user, password, driver) = readJDBCSettings(dbName)
        val cpSettings = readConnectionPoolSettings(dbName)
        if (driver != null && driver.trim.nonEmpty) {
          Class.forName(driver)
        }
        ConnectionPool.add(dbName, url, user, password, cpSettings)
      }
    }
  }

  def setupAll(): Unit = {
    loadGlobalSettings()
    dbNames.foreach { dbName => setup(Symbol(dbName)) }
  }

  def close(dbName: Symbol = ConnectionPool.DEFAULT_NAME): Unit = {
    ConnectionPool.close(dbName)
  }

  def closeAll(): Unit = {
    ConnectionPool.closeAll
  }

}


object ConfigDBs extends ConfigDBs
  with TypesafeConfigReader
  with StandardTypesafeConfig
  with HikariConfigReader

case class ConfigDBsWithEnv(envValue: String) extends ConfigDBs
  with TypesafeConfigReader
  with StandardTypesafeConfig
  with HikariConfigReader
  with EnvPrefix {

  override val env = Option(envValue)
}

package sdp.jdbc.engine
import java.sql.PreparedStatement
import scala.collection.generic.CanBuildFrom
import akka.stream.scaladsl._
import scalikejdbc._
import scalikejdbc.streams._
import akka.NotUsed
import akka.stream._
import scala.util._
import java.time._
import scala.concurrent.duration._
import sdp.jdbc.FileStreaming._

import scalikejdbc.TxBoundary.Try._

import scala.concurrent.ExecutionContextExecutor
import java.io.InputStream

object JDBCContext {
  type SQLTYPE = Int
  val SQL_EXEDDL= 1
  val SQL_UPDATE = 2
  val RETURN_GENERATED_KEYVALUE = true
  val RETURN_UPDATED_COUNT = false

}

case class JDBCQueryContext[M](
                                dbName: Symbol,
                                statement: String,
                                parameters: Seq[Any] = Nil,
                                fetchSize: Int = 100,
                                autoCommit: Boolean = false,
                                queryTimeout: Option[Int] = None)
                               // extractor: WrappedResultSet => M)


case class JDBCContext(
                        dbName: Symbol,
                        statements: Seq[String] = Nil,
                        parameters: Seq[Seq[Any]] = Nil,
                        fetchSize: Int = 100,
                        queryTimeout: Option[Int] = None,
                        queryTags: Seq[String] = Nil,
                        sqlType: JDBCContext.SQLTYPE = JDBCContext.SQL_UPDATE,
                        batch: Boolean = false,
                        returnGeneratedKey: Seq[Option[Any]] = Nil,
                        // no return: None, return by index: Some(1), by name: Some("id")
                        preAction: Option[PreparedStatement => Unit] = None,
                        postAction: Option[PreparedStatement => Unit] = None) {

  ctx =>

  //helper functions

  def appendTag(tag: String): JDBCContext = ctx.copy(queryTags = ctx.queryTags :+ tag)

  def appendTags(tags: Seq[String]): JDBCContext = ctx.copy(queryTags = ctx.queryTags ++ tags)

  def setFetchSize(size: Int): JDBCContext = ctx.copy(fetchSize = size)

  def setQueryTimeout(time: Option[Int]): JDBCContext = ctx.copy(queryTimeout = time)

  def setPreAction(action: Option[PreparedStatement => Unit]): JDBCContext = {
    if (ctx.sqlType == JDBCContext.SQL_UPDATE &&
      !ctx.batch && ctx.statements.size == 1)
      ctx.copy(preAction = action)
    else
      throw new IllegalStateException("JDBCContex setting error: preAction not supported!")
  }

  def setPostAction(action: Option[PreparedStatement => Unit]): JDBCContext = {
    if (ctx.sqlType == JDBCContext.SQL_UPDATE &&
      !ctx.batch && ctx.statements.size == 1)
      ctx.copy(postAction = action)
    else
      throw new IllegalStateException("JDBCContex setting error: preAction not supported!")
  }

  def appendDDLCommand(_statement: String, _parameters: Any*): JDBCContext = {
    if (ctx.sqlType == JDBCContext.SQL_EXEDDL) {
      ctx.copy(
        statements = ctx.statements ++ Seq(_statement),
        parameters = ctx.parameters ++ Seq(Seq(_parameters))
      )
    } else
      throw new IllegalStateException("JDBCContex setting error: option not supported!")
  }

  def appendUpdateCommand(_returnGeneratedKey: Boolean, _statement: String, _parameters: Any*): JDBCContext = {
    if (ctx.sqlType == JDBCContext.SQL_UPDATE && !ctx.batch) {
      ctx.copy(
        statements = ctx.statements ++ Seq(_statement),
        parameters = ctx.parameters ++ Seq(_parameters),
        returnGeneratedKey = ctx.returnGeneratedKey ++ (if (_returnGeneratedKey) Seq(Some(1)) else Seq(None))
      )
    } else
      throw new IllegalStateException("JDBCContex setting error: option not supported!")
  }

  def appendBatchParameters(_parameters: Any*): JDBCContext = {
    if (ctx.sqlType != JDBCContext.SQL_UPDATE || !ctx.batch)
      throw new IllegalStateException("JDBCContex setting error: batch parameters only supported for SQL_UPDATE and batch = true!")

    var matchParams = true
    if (ctx.parameters != Nil)
      if (ctx.parameters.head.size != _parameters.size)
        matchParams = false
    if (matchParams) {
      ctx.copy(
        parameters = ctx.parameters ++ Seq(_parameters)
      )
    } else
      throw new IllegalStateException("JDBCContex setting error: batch command parameters not match!")
  }

  def setBatchReturnGeneratedKeyOption(returnKey: Boolean): JDBCContext = {
    if (ctx.sqlType != JDBCContext.SQL_UPDATE || !ctx.batch)
      throw new IllegalStateException("JDBCContex setting error: only supported in batch update commands!")
    ctx.copy(
      returnGeneratedKey = if (returnKey) Seq(Some(1)) else Nil
    )
  }

  def setDDLCommand(_statement: String, _parameters: Any*): JDBCContext = {
    ctx.copy(
      statements = Seq(_statement),
      parameters = Seq(_parameters),
      sqlType = JDBCContext.SQL_EXEDDL,
      batch = false
    )
  }

  def setUpdateCommand(_returnGeneratedKey: Boolean, _statement: String, _parameters: Any*): JDBCContext = {
    ctx.copy(
      statements = Seq(_statement),
      parameters = Seq(_parameters),
      returnGeneratedKey = if (_returnGeneratedKey) Seq(Some(1)) else Seq(None),
      sqlType = JDBCContext.SQL_UPDATE,
      batch = false
    )
  }
  def setBatchCommand(_statement: String): JDBCContext = {
    ctx.copy (
      statements = Seq(_statement),
      sqlType = JDBCContext.SQL_UPDATE,
      batch = true
    )
  }

  type JDBCDate = LocalDate
  type JDBCDateTime = LocalDateTime

  def jdbcSetDate(yyyy: Int, mm: Int, dd: Int) = LocalDate.of(yyyy,mm,dd)
  def jdbcSetNow = LocalDateTime.now()

  type JDBCBlob = InputStream

  def fileToJDBCBlob(fileName: String, timeOut: FiniteDuration = 60 seconds)(
    implicit mat: Materializer) = FileToInputStream(fileName,timeOut)

  def jdbcBlobToFile(blob: JDBCBlob, fileName: String)(
    implicit mat: Materializer) =  InputStreamToFile(blob,fileName)


}

object JDBCEngine {

  import JDBCContext._

  private def noExtractor(message: String): WrappedResultSet => Nothing = { (rs: WrappedResultSet) =>
    throw new IllegalStateException(message)
  }

  def jdbcAkkaStream[A](ctx: JDBCQueryContext[A],extractor: WrappedResultSet => A)
                       (implicit ec: ExecutionContextExecutor): Source[A,NotUsed] = {

    val publisher: DatabasePublisher[A] = NamedDB('h2) readOnlyStream {
      val rawSql = new SQLToCollectionImpl[A, NoExtractor](ctx.statement, ctx.parameters)(noExtractor(""))
      ctx.queryTimeout.foreach(rawSql.queryTimeout(_))
      val sql: SQL[A, HasExtractor] = rawSql.map(extractor)

      sql.iterator
        .withDBSessionForceAdjuster(session => {
          session.connection.setAutoCommit(ctx.autoCommit)
          session.fetchSize(ctx.fetchSize)
        })
    }
    Source.fromPublisher[A](publisher)
  }


  def jdbcQueryResult[C[_] <: TraversableOnce[_], A](ctx: JDBCQueryContext[A],
                                                     extractor: WrappedResultSet => A)(
                                                      implicit cbf: CanBuildFrom[Nothing, A, C[A]]): C[A] = {

    val rawSql = new SQLToCollectionImpl[A, NoExtractor](ctx.statement, ctx.parameters)(noExtractor(""))
    ctx.queryTimeout.foreach(rawSql.queryTimeout(_))
    rawSql.fetchSize(ctx.fetchSize)
    implicit val session = NamedAutoSession(ctx.dbName)
    val sql: SQL[A, HasExtractor] = rawSql.map(extractor)
    sql.collection.apply[C]()

  }

  def jdbcExcuteDDL(ctx: JDBCContext): Try[String] = {
    if (ctx.sqlType != SQL_EXEDDL) {
      Failure(new IllegalStateException("JDBCContex setting error: sqlType must be 'SQL_EXEDDL'!"))
    }
    else {
      NamedDB(ctx.dbName) localTx { implicit session =>
        Try {
          ctx.statements.foreach { stm =>
            val ddl = new SQLExecution(statement = stm, parameters = Nil)(
              before = WrappedResultSet => {})(
              after = WrappedResultSet => {})

            ddl.apply()
          }
          "SQL_EXEDDL executed succesfully."
        }
      }
    }
  }

  def jdbcBatchUpdate[C[_] <: TraversableOnce[_]](ctx: JDBCContext)(
    implicit cbf: CanBuildFrom[Nothing, Long, C[Long]]): Try[C[Long]] = {
    if (ctx.statements == Nil)
      throw new IllegalStateException("JDBCContex setting error: statements empty!")
    if (ctx.sqlType != SQL_UPDATE) {
      Failure(new IllegalStateException("JDBCContex setting error: sqlType must be 'SQL_UPDATE'!"))
    }
    else {
      if (ctx.batch) {
        if (noReturnKey(ctx)) {
          val usql = SQL(ctx.statements.head)
            .tags(ctx.queryTags: _*)
            .batch(ctx.parameters: _*)
          Try {
            NamedDB(ctx.dbName) localTx { implicit session =>
              ctx.queryTimeout.foreach(session.queryTimeout(_))
              usql.apply[Seq]()
              Seq.empty[Long].to[C]
            }
          }
        } else {
          val usql = new SQLBatchWithGeneratedKey(ctx.statements.head, ctx.parameters, ctx.queryTags)(None)
          Try {
            NamedDB(ctx.dbName) localTx { implicit session =>
              ctx.queryTimeout.foreach(session.queryTimeout(_))
              usql.apply[C]()
            }
          }
        }

      } else {
        Failure(new IllegalStateException("JDBCContex setting error: must set batch = true !"))
      }
    }
  }
  private def singleTxUpdateWithReturnKey[C[_] <: TraversableOnce[_]](ctx: JDBCContext)(
    implicit cbf: CanBuildFrom[Nothing, Long, C[Long]]): Try[C[Long]] = {
    val Some(key) :: xs = ctx.returnGeneratedKey
    val params: Seq[Any] = ctx.parameters match {
      case Nil => Nil
      case p@_ => p.head
    }
    val usql = new SQLUpdateWithGeneratedKey(ctx.statements.head, params, ctx.queryTags)(key)
    Try {
      NamedDB(ctx.dbName) localTx { implicit session =>
        session.fetchSize(ctx.fetchSize)
        ctx.queryTimeout.foreach(session.queryTimeout(_))
        val result = usql.apply()
        Seq(result).to[C]
      }
    }
  }

  private def singleTxUpdateNoReturnKey[C[_] <: TraversableOnce[_]](ctx: JDBCContext)(
    implicit cbf: CanBuildFrom[Nothing, Long, C[Long]]): Try[C[Long]] = {
    val params: Seq[Any] = ctx.parameters match {
      case Nil => Nil
      case p@_ => p.head
    }
    val before = ctx.preAction match {
      case None => pstm: PreparedStatement => {}
      case Some(f) => f
    }
    val after = ctx.postAction match {
      case None => pstm: PreparedStatement => {}
      case Some(f) => f
    }
    val usql = new SQLUpdate(ctx.statements.head,params,ctx.queryTags)(before)(after)
    Try {
      NamedDB(ctx.dbName) localTx {implicit session =>
        session.fetchSize(ctx.fetchSize)
        ctx.queryTimeout.foreach(session.queryTimeout(_))
        val result = usql.apply()
        Seq(result.toLong).to[C]
      }
    }

  }

  private def singleTxUpdate[C[_] <: TraversableOnce[_]](ctx: JDBCContext)(
    implicit cbf: CanBuildFrom[Nothing, Long, C[Long]]): Try[C[Long]] = {
    if (noReturnKey(ctx))
      singleTxUpdateNoReturnKey(ctx)
    else
      singleTxUpdateWithReturnKey(ctx)
  }

  private def noReturnKey(ctx: JDBCContext): Boolean = {
    if (ctx.returnGeneratedKey != Nil) {
      val k :: xs = ctx.returnGeneratedKey
      k match {
        case None => true
        case Some(k) => false
      }
    } else true
  }

  def noActon: PreparedStatement=>Unit = pstm => {}

  def multiTxUpdates[C[_] <: TraversableOnce[_]](ctx: JDBCContext)(
    implicit cbf: CanBuildFrom[Nothing, Long, C[Long]]): Try[C[Long]] = {
    Try {
      NamedDB(ctx.dbName) localTx { implicit session =>
        session.fetchSize(ctx.fetchSize)
        ctx.queryTimeout.foreach(session.queryTimeout(_))
        val keys: Seq[Option[Any]] = ctx.returnGeneratedKey match {
          case Nil => Seq.fill(ctx.statements.size)(None)
          case k@_ => k
        }
        val sqlcmd = ctx.statements zip ctx.parameters zip keys
        val results = sqlcmd.map { case ((stm, param), key) =>
          key match {
            case None =>
              new SQLUpdate(stm, param, Nil)(noActon)(noActon).apply().toLong
            case Some(k) =>
              new SQLUpdateWithGeneratedKey(stm, param, Nil)(k).apply().toLong
          }
        }
        results.to[C]
      }
    }
  }


  def jdbcTxUpdates[C[_] <: TraversableOnce[_]](ctx: JDBCContext)(
    implicit cbf: CanBuildFrom[Nothing, Long, C[Long]]): Try[C[Long]] = {
    if (ctx.statements == Nil)
      throw new IllegalStateException("JDBCContex setting error: statements empty!")
    if (ctx.sqlType != SQL_UPDATE) {
      Failure(new IllegalStateException("JDBCContex setting error: sqlType must be 'SQL_UPDATE'!"))
    }
    else {
      if (!ctx.batch) {
        if (ctx.statements.size == 1)
          singleTxUpdate(ctx)
        else
          multiTxUpdates(ctx)
      } else
        Failure(new IllegalStateException("JDBCContex setting error: must set batch = false !"))

    }
  }

  case class JDBCActionStream[R](dbName: Symbol, parallelism: Int = 1, processInOrder: Boolean = true,
                                 statement: String, prepareParams: R => Seq[Any]) {
    jas =>
    def setDBName(db: Symbol): JDBCActionStream[R] = jas.copy(dbName = db)
    def setParallelism(parLevel: Int): JDBCActionStream[R] = jas.copy(parallelism = parLevel)
    def setProcessOrder(ordered: Boolean): JDBCActionStream[R] = jas.copy(processInOrder = ordered)

    private def perform(r: R) = {
      import scala.concurrent._
      val params = prepareParams(r)
      NamedDB(dbName) autoCommit { session =>
        session.execute(statement,params: _*)
      }
      Future.successful(r)
    }
    def performOnRow(implicit session: DBSession): Flow[R, R, NotUsed] =
      if (processInOrder)
        Flow[R].mapAsync(parallelism)(perform)
      else
        Flow[R].mapAsyncUnordered(parallelism)(perform)

  }
  object JDBCActionStream {
    def apply[R](_dbName: Symbol, _statement: String, params: R => Seq[Any]): JDBCActionStream[R] =
      new JDBCActionStream[R](dbName = _dbName, statement=_statement, prepareParams = params)
  }

}

package sdp.jdbc

import java.io.{InputStream, ByteArrayInputStream}
import java.nio.ByteBuffer
import java.nio.file.Paths

import akka.stream.{Materializer}
import akka.stream.scaladsl.{FileIO, StreamConverters}

import scala.concurrent.{Await}
import akka.util._
import scala.concurrent.duration._

object FileStreaming {
  def FileToByteBuffer(fileName: String, timeOut: FiniteDuration = 60 seconds)(
    implicit mat: Materializer):ByteBuffer = {
    val fut = FileIO.fromPath(Paths.get(fileName)).runFold(ByteString()) { case (hd, bs) =>
      hd ++ bs
    }
    (Await.result(fut, timeOut)).toByteBuffer
  }

  def FileToByteArray(fileName: String, timeOut: FiniteDuration = 60 seconds)(
    implicit mat: Materializer): Array[Byte] = {
    val fut = FileIO.fromPath(Paths.get(fileName)).runFold(ByteString()) { case (hd, bs) =>
      hd ++ bs
    }
    (Await.result(fut, timeOut)).toArray
  }

  def FileToInputStream(fileName: String, timeOut: FiniteDuration = 60 seconds)(
    implicit mat: Materializer): InputStream = {
    val fut = FileIO.fromPath(Paths.get(fileName)).runFold(ByteString()) { case (hd, bs) =>
      hd ++ bs
    }
    val buf = (Await.result(fut, timeOut)).toArray
    new ByteArrayInputStream(buf)
  }

  def ByteBufferToFile(byteBuf: ByteBuffer, fileName: String)(
    implicit mat: Materializer) = {
    val ba = new Array[Byte](byteBuf.remaining())
    byteBuf.get(ba,0,ba.length)
    val baInput = new ByteArrayInputStream(ba)
    val source = StreamConverters.fromInputStream(() => baInput)  //ByteBufferInputStream(bytes))
    source.runWith(FileIO.toPath(Paths.get(fileName)))
  }

  def ByteArrayToFile(bytes: Array[Byte], fileName: String)(
    implicit mat: Materializer) = {
    val bb = ByteBuffer.wrap(bytes)
    val baInput = new ByteArrayInputStream(bytes)
    val source = StreamConverters.fromInputStream(() => baInput) //ByteBufferInputStream(bytes))
    source.runWith(FileIO.toPath(Paths.get(fileName)))
  }

  def InputStreamToFile(is: InputStream, fileName: String)(
    implicit mat: Materializer) = {
    val source = StreamConverters.fromInputStream(() => is)
    source.runWith(FileIO.toPath(Paths.get(fileName)))
  }

}

package protobuf.bytes
import java.io.{ByteArrayInputStream,ByteArrayOutputStream,ObjectInputStream,ObjectOutputStream}
import com.google.protobuf.ByteString
object Converter {

  def marshal(value: Any): ByteString = {
    val stream: ByteArrayOutputStream = new ByteArrayOutputStream()
    val oos = new ObjectOutputStream(stream)
    oos.writeObject(value)
    oos.close()
    ByteString.copyFrom(stream.toByteArray())
  }

  def unmarshal[A](bytes: ByteString): A = {
    val ois = new ObjectInputStream(new ByteArrayInputStream(bytes.toByteArray))
    val value = ois.readObject()
    ois.close()
    value.asInstanceOf[A]
  }

}

package demo.grpc.jdbc.services

import akka.NotUsed
import akka.stream.scaladsl.Flow
import grpc.jdbc.services._
import java.util.logging.Logger
import protobuf.bytes.Converter._

import sdp.jdbc.engine._
import JDBCEngine._
import scalikejdbc.WrappedResultSet

import scala.concurrent.ExecutionContextExecutor

class JDBCStreamingServices(implicit ec: ExecutionContextExecutor) extends JdbcGrpcAkkaStream.JDBCServices {
  val logger = Logger.getLogger(classOf[JDBCStreamingServices].getName)

  val toRow = (rs: WrappedResultSet) => JDBCDataRow(
    year = rs.string("REPORTYEAR"),
    state = rs.string("STATENAME"),
    county = rs.string("COUNTYNAME"),
    value = rs.string("VALUE")
  )
  override def runQuery: Flow[JDBCQuery, JDBCDataRow, NotUsed] = {
    logger.info("**** runQuery called on service side ***")
    Flow[JDBCQuery]
      .flatMapConcat { q =>
        //unpack JDBCQuery and construct the context
        val params: Seq[Any] = unmarshal[Seq[Any]](q.parameters)
        logger.info(s"**** query parameters: ${params} ****")
        val ctx = JDBCQueryContext[JDBCDataRow](
          dbName = Symbol(q.dbName),
          statement = q.statement,
          parameters = params,
          fetchSize = q.fetchSize.getOrElse(100),
          autoCommit = q.autoCommit.getOrElse(false),
          queryTimeout = q.queryTimeout
        )
        jdbcAkkaStream(ctx, toRow)
      }
  }
}

package demo.grpc.jdbc.server

import java.util.logging.Logger

import akka.actor.ActorSystem
import akka.stream.ActorMaterializer
import io.grpc.Server
import demo.grpc.jdbc.services._
import io.grpc.ServerBuilder
import grpc.jdbc.services._

class gRPCServer(server: Server) {

  val logger: Logger = Logger.getLogger(classOf[gRPCServer].getName)

  def start(): Unit = {
    server.start()
    logger.info(s"Server started, listening on ${server.getPort}")
    sys.addShutdownHook {
      // Use stderr here since the logger may has been reset by its JVM shutdown hook.
      System.err.println("*** shutting down gRPC server since JVM is shutting down")
      stop()
      System.err.println("*** server shut down")
    }
    ()
  }

  def stop(): Unit = {
    server.shutdown()
  }

  /**
    * Await termination on the main thread since the grpc library uses daemon threads.
    */
  def blockUntilShutdown(): Unit = {
    server.awaitTermination()
  }
}

object JDBCServer extends App {
  import sdp.jdbc.config._

  implicit val system = ActorSystem("JDBCServer")
  implicit val mat = ActorMaterializer.create(system)
  implicit val ec = system.dispatcher

  ConfigDBsWithEnv("dev").setup('h2)
  ConfigDBsWithEnv("dev").loadGlobalSettings()

  val server = new gRPCServer(
    ServerBuilder
      .forPort(50051)
      .addService(
        JdbcGrpcAkkaStream.bindService(
          new JDBCStreamingServices
        )
      ).build()
  )
  server.start()
  //  server.blockUntilShutdown()
  scala.io.StdIn.readLine()
  ConfigDBsWithEnv("dev").close('h2)
  mat.shutdown()
  system.terminate()
}

package demo.grpc.jdbc.client
import grpc.jdbc.services._
import java.util.logging.Logger

import protobuf.bytes.Converter._
import akka.stream.scaladsl._
import akka.NotUsed
import akka.actor.ActorSystem
import akka.stream.{ActorMaterializer, ThrottleMode}
import io.grpc._

class JDBCStreamClient(host: String, port: Int) {
  val logger: Logger = Logger.getLogger(classOf[JDBCStreamClient].getName)

  val channel = ManagedChannelBuilder
    .forAddress(host,port)
    .usePlaintext(true)
    .build()


  val stub = JdbcGrpcAkkaStream.stub(channel)
  val query = JDBCQuery (
    dbName = "h2",
    statement = "select * from AQMRPT where STATENAME = ? and VALUE = ?",
    parameters = marshal(Seq("Arizona", 5))
  )
  def queryRows: Source[JDBCDataRow,NotUsed] = {
    logger.info(s"running queryRows ...")
    Source
      .single(query)
      .via(stub.runQuery)
  }
}


object QueryRows extends App {
  implicit val system = ActorSystem("QueryRows")
  implicit val mat = ActorMaterializer.create(system)

  val client = new JDBCStreamClient("localhost", 50051)

  client.queryRows.runForeach(println)

  scala.io.StdIn.readLine()
  mat.shutdown()
  system.terminate()
}