com.websudos.phantom.builder.query.ExecutableQuery.scala Maven / Gradle / Ivy
/*
* Copyright 2013-2015 Websudos, Limited.
*
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* modification, are permitted provided that the following conditions are met:
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* - Redistributions in binary form must reproduce the above copyright
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* - Explicit consent must be obtained from the copyright owner, Outworkers Limited before any redistribution is made.
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package com.websudos.phantom.builder.query
import java.util.concurrent.Executor
import java.util.{List => JavaList}
import com.datastax.driver.core._
import com.websudos.phantom.CassandraTable
import com.websudos.phantom.builder.{LimitBound, Unlimited}
import com.websudos.phantom.connectors.KeySpace
import scala.collection.JavaConverters._
import scala.concurrent.{ExecutionContextExecutor, Future => ScalaFuture}
trait RecordResult[R] {
def result: ResultSet
def pagingState: PagingState = result.getExecutionInfo.getPagingState
}
case class ListResult[R](records: List[R], result: ResultSet) extends RecordResult[R]
case class IteratorResult[R](records: Iterator[R], result: ResultSet) extends RecordResult[R]
trait ExecutableStatement extends CassandraOperations {
type Modifier = Statement => Statement
def options: QueryOptions
def qb: CQLQuery
def queryString: String = qb.terminate().queryString
def statement()(implicit session: Session): Statement = {
new SimpleStatement(qb.terminate().queryString)
.setConsistencyLevel(options.consistencyLevel.orNull)
}
/**
* Default asynchronous query execution method. This will convert the underlying
* call to Cassandra done with Google Guava ListenableFuture to a consumable
* Scala Future that will be completed once the operation is completed on the
* database end.
*
* The execution context of the transformation is provided by phantom via
* [[com.websudos.phantom.Manager.scalaExecutor]] and it is recommended to
* use [[com.websudos.phantom.dsl.context]] for operations that chain
* database calls.
*
* @param session The implicit session provided by a [[com.websudos.phantom.connectors.Connector]].
* @param keySpace The implicit keySpace definition provided by a [[com.websudos.phantom.connectors.Connector]].
* @param ec The implicit Scala execution context.
* @return An asynchronous Scala future wrapping the Datastax result set.
*/
def future()(
implicit session: Session,
keySpace: KeySpace,
ec: ExecutionContextExecutor
): ScalaFuture[ResultSet] = {
scalaQueryStringExecuteToFuture(statement)
}
/**
* This will convert the underlying call to Cassandra done with Google Guava ListenableFuture to a consumable
* Scala Future that will be completed once the operation is completed on the
* database end.
*
* The execution context of the transformation is provided by phantom via
* [[com.websudos.phantom.Manager.scalaExecutor]] and it is recommended to
* use [[com.websudos.phantom.dsl.context]] for operations that chain
* database calls.
*
* @param modifyStatement The function allowing to modify underlying [[Statement]]
* @param session The implicit session provided by a [[com.websudos.phantom.connectors.Connector]].
* @param keySpace The implicit keySpace definition provided by a [[com.websudos.phantom.connectors.Connector]].
* @param executor The implicit Scala executor.
* @return An asynchronous Scala future wrapping the Datastax result set.
*/
def future(modifyStatement: Modifier)(
implicit session: Session,
keySpace: KeySpace,
executor: ExecutionContextExecutor
): ScalaFuture[ResultSet] = {
scalaQueryStringExecuteToFuture(modifyStatement(statement))
}
}
private[phantom] class ExecutableStatementList(val queries: Seq[CQLQuery]) extends CassandraOperations {
/**
* Secondary constructor to allow passing in Sets instead of Sequences.
* Although this may appear to be fruitless and uninteresting it a necessary evil.
*
* The TwitterFuture.collect method does not support passing in arbitrary collections using the Scala API
* just as Scala.future does. Scala Futures can sequence over traversables and return a collection of the appropiate type.
*
* @param queries The list of CQL queries to execute.
* @return An instance of an ExecutableStatement with the matching sequence of CQL queries.
*/
def this(queries: Set[CQLQuery]) = this(queries.toSeq)
def add(appendable: Seq[CQLQuery]): ExecutableStatementList = {
new ExecutableStatementList(queries ++ appendable)
}
def ++(appendable: Seq[CQLQuery]): ExecutableStatementList = add(appendable)
def ++(st: ExecutableStatementList): ExecutableStatementList = add(st.queries)
def future()(
implicit session: Session,
keySpace: KeySpace,
executor: Executor,
ec: ExecutionContextExecutor
): ScalaFuture[Seq[ResultSet]] = {
ScalaFuture.sequence(queries.map(item => {
scalaQueryStringExecuteToFuture(new SimpleStatement(item.terminate().queryString))
}))
}
}
private[phantom] trait RootExecutableQuery[R] {
def fromRow(r: Row): R
protected[this] def singleResult(row: Row): Option[R] = {
if (Option(row).isDefined) Some(fromRow(row)) else None
}
protected[this] def directMapper(results: JavaList[Row]): List[R] = {
List.tabulate(results.size())(index => fromRow(results.get(index)))
}
}
/**
* An ExecutableQuery implementation, meant to retrieve results from Cassandra.
* This provides the root implementation of a Select query.
*
* @tparam T The class owning the table.
* @tparam R The record type to store.
*/
trait ExecutableQuery[T <: CassandraTable[T, _], R, Limit <: LimitBound]
extends ExecutableStatement with RootExecutableQuery[R] {
def fromRow(r: Row): R
private[phantom] def singleFetch()(
implicit session: Session,
keySpace: KeySpace,
ec: ExecutionContextExecutor
): ScalaFuture[Option[R]] = {
future() map { res => singleResult(res.one) }
}
/**
* Returns the first row from the select ignoring everything else
*
* @param session The implicit session provided by a [[com.websudos.phantom.connectors.Connector]].
* @param keySpace The implicit keySpace definition provided by a [[com.websudos.phantom.connectors.Connector]].
* @param ev The implicit limit for the query.
* @param ec The implicit Scala execution context.
* @return A Scala future guaranteed to contain a single result wrapped as an Option.
*/
def one()(
implicit session: Session,
keySpace: KeySpace,
ev: Limit =:= Unlimited,
ec: ExecutionContextExecutor
): ScalaFuture[Option[R]]
/**
* Returns a parsed sequence of [R]ows
* This is not suitable for big results set
*
* @param session The implicit session provided by a [[com.websudos.phantom.connectors.Connector]].
* @param keySpace The implicit keySpace definition provided by a [[com.websudos.phantom.connectors.Connector]].
* @param ec The implicit Scala execution context.
* @return A Scala future wrapping a list of mapped results.
*/
def fetch()(
implicit session: Session,
keySpace: KeySpace,
ec: ExecutionContextExecutor
): ScalaFuture[List[R]] = {
future() map { resultSet => directMapper(resultSet.all) }
}
/**
* Returns a parsed sequence of [R]ows
* This is not suitable for big results set
*
* @param session The implicit session provided by a [[com.websudos.phantom.connectors.Connector]].
* @param keySpace The implicit keySpace definition provided by a [[com.websudos.phantom.connectors.Connector]].
* @param ec The implicit Scala execution context.
* @return A Scala future wrapping a list of mapped results.
*/
def fetch(state: PagingState)(
implicit session: Session,
keySpace: KeySpace,
ec: ExecutionContextExecutor
): ScalaFuture[List[R]] = {
future(_.setPagingState(state)) map {
resultSet => directMapper(resultSet.all)
}
}
/**
* Returns a parsed sequence of [R]ows
* This is not suitable for big results set
*
* @param session The implicit session provided by a [[com.websudos.phantom.connectors.Connector]].
* @param keySpace The implicit keySpace definition provided by a [[com.websudos.phantom.connectors.Connector]].
* @param ec The implicit Scala execution context.
* @return A Scala future wrapping a list of mapped results.
*/
def fetch(modifyStatement : Modifier)(
implicit session: Session,
keySpace: KeySpace,
ec: ExecutionContextExecutor
): ScalaFuture[List[R]] = {
future(modifyStatement) map {
resultSet => directMapper(resultSet.all)
}
}
/**
* Returns a parsed sequence of [R]ows
* This is not suitable for big results set
*
* @param session The implicit session provided by a [[com.websudos.phantom.connectors.Connector]].
* @param keySpace The implicit keySpace definition provided by a [[com.websudos.phantom.connectors.Connector]].
* @param ec The implicit Scala execution context.
* @return A Scala future wrapping a list of mapped results.
*/
def fetchRecord()(
implicit session: Session,
keySpace: KeySpace,
ec: ExecutionContextExecutor
): ScalaFuture[ListResult[R]] = {
future() map (resultSet => ListResult(directMapper(resultSet.all), resultSet))
}
/**
* Returns a parsed sequence of [R]ows
* This is not suitable for big results set
*
* @param session The implicit session provided by a [[com.websudos.phantom.connectors.Connector]].
* @param keySpace The implicit keySpace definition provided by a [[com.websudos.phantom.connectors.Connector]].
* @param ec The implicit Scala execution context.
* @return A Scala future wrapping a list of mapped results.
*/
def fetchRecord(state: PagingState)(
implicit session: Session,
keySpace: KeySpace,
ec: ExecutionContextExecutor
): ScalaFuture[ListResult[R]] = {
future(st => st.setPagingState(state)) map {
set => ListResult(directMapper(set.all), set)
}
}
def fetchRecord(state: Option[PagingState])(
implicit session: Session,
keySpace: KeySpace,
ec: ExecutionContextExecutor
): ScalaFuture[ListResult[R]] = {
state.fold(future().map {
set => ListResult(directMapper(set.all), set)
}) (state => future(_.setPagingState(state)) map {
set => ListResult(directMapper(set.all), set)
})
}
/**
* Returns a parsed sequence of [R]ows
* This is not suitable for big results set
*
* @param session The implicit session provided by a [[com.websudos.phantom.connectors.Connector]].
* @param keySpace The implicit keySpace definition provided by a [[com.websudos.phantom.connectors.Connector]].
* @param ec The implicit Scala execution context.
* @return A Scala future wrapping a list of mapped results.
*/
def fetchRecord(modifyStatement: Modifier)(
implicit session: Session,
keySpace: KeySpace,
ec: ExecutionContextExecutor
): ScalaFuture[ListResult[R]] = {
future(modifyStatement) map {
set => ListResult(directMapper(set.all), set)
}
}
/**
* Returns a parsed iterator of [R]ows
*
* @param session The implicit session provided by a [[com.websudos.phantom.connectors.Connector]].
* @param keySpace The implicit keySpace definition provided by a [[com.websudos.phantom.connectors.Connector]].
* @param ec The implicit Scala execution context.
* @return A Scala future wrapping scala iterator of mapped results.
*/
def iterator()(
implicit session: Session,
keySpace: KeySpace,
ec: ExecutionContextExecutor
): ScalaFuture[Iterator[R]] = {
future() map { _.iterator().asScala.map(fromRow) }
}
def iteratorRecord()(
implicit session: Session,
keySpace: KeySpace,
ec: ExecutionContextExecutor
): ScalaFuture[IteratorResult[R]] = {
future() map { result => IteratorResult(result.iterator().asScala.map(fromRow), result) }
}
}
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