[SPARK-2054][SQL] Code Generation for Expression Evaluation

pom.xml

@@ -114,6 +114,7 @@
     <sbt.project.name>spark</sbt.project.name>
     <scala.version>2.10.4</scala.version>
     <scala.binary.version>2.10</scala.binary.version>
+    <scala.macros.version>2.0.1</scala.macros.version>
     <mesos.version>0.18.1</mesos.version>
     <mesos.classifier>shaded-protobuf</mesos.classifier>
     <akka.group>org.spark-project.akka</akka.group>
@@ -819,6 +820,15 @@
               <javacArg>-target</javacArg>
               <javacArg>${java.version}</javacArg>
             </javacArgs>
+            <!-- The following plugin is required to use quasiquotes in Scala 2.10 and is used
+                 by Spark SQL for code generation. -->
+            <compilerPlugins>
+              <compilerPlugin>
+                  <groupId>org.scalamacros</groupId>
+                  <artifactId>paradise_${scala.version}</artifactId>
+                  <version>${scala.macros.version}</version>
+              </compilerPlugin>
+            </compilerPlugins>
           </configuration>
         </plugin>
         <plugin>

project/SparkBuild.scala

@@ -167,6 +167,9 @@ object SparkBuild extends PomBuild {
   /* Enable unidoc only for the root spark project */
   enable(Unidoc.settings)(spark)
 
+  /* Catalyst macro settings */
+  enable(Catalyst.settings)(catalyst)
+
   /* Spark SQL Core console settings */
   enable(SQL.settings)(sql)
 
@@ -183,10 +186,13 @@ object SparkBuild extends PomBuild {
 
 }
 
-object SQL {
-
+object Catalyst {
   lazy val settings = Seq(
+    addCompilerPlugin("org.scalamacros" % "paradise" % "2.0.1" cross CrossVersion.full))
+}
 
+object SQL {
+  lazy val settings = Seq(
     initialCommands in console :=
       """
         |import org.apache.spark.sql.catalyst.analysis._
@@ -201,7 +207,6 @@ object SQL {
         |import org.apache.spark.sql.test.TestSQLContext._
         |import org.apache.spark.sql.parquet.ParquetTestData""".stripMargin
   )
-
 }
 
 object Hive {

sql/catalyst/pom.xml

@@ -36,10 +36,19 @@
   </properties>
 
   <dependencies>
+    <dependency>
+      <groupId>org.scala-lang</groupId>
+      <artifactId>scala-compiler</artifactId>
+    </dependency>
     <dependency>
       <groupId>org.scala-lang</groupId>
       <artifactId>scala-reflect</artifactId>
     </dependency>
+    <dependency>
+      <groupId>org.scalamacros</groupId>
+      <artifactId>quasiquotes_${scala.binary.version}</artifactId>
+      <version>${scala.macros.version}</version>
+    </dependency>
     <dependency>
       <groupId>org.apache.spark</groupId>
       <artifactId>spark-core_${scala.binary.version}</artifactId>

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/dsl/package.scala

@@ -202,7 +202,7 @@ package object dsl {
       // Protobuf terminology
       def required = a.withNullability(false)
 
-      def at(ordinal: Int) = BoundReference(ordinal, a)
+      def at(ordinal: Int) = BoundReference(ordinal, a.dataType, a.nullable)
     }
   }
 

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/BoundAttribute.scala

@@ -17,72 +17,40 @@
 
 package org.apache.spark.sql.catalyst.expressions
 
-import org.apache.spark.sql.catalyst.trees
 import org.apache.spark.sql.catalyst.errors.attachTree
 import org.apache.spark.sql.catalyst.plans.QueryPlan
 import org.apache.spark.sql.catalyst.rules.Rule
+import org.apache.spark.sql.catalyst.types._
+import org.apache.spark.sql.catalyst.trees
+
 import org.apache.spark.sql.Logging
 
 /**
  * A bound reference points to a specific slot in the input tuple, allowing the actual value
  * to be retrieved more efficiently.  However, since operations like column pruning can change
  * the layout of intermediate tuples, BindReferences should be run after all such transformations.
  */
-case class BoundReference(ordinal: Int, baseReference: Attribute)
-  extends Attribute with trees.LeafNode[Expression] {
+case class BoundReference(ordinal: Int, dataType: DataType, nullable: Boolean)
+  extends Expression with trees.LeafNode[Expression] {
 
   type EvaluatedType = Any
 
-  override def nullable = baseReference.nullable
-  override def dataType = baseReference.dataType
-  override def exprId = baseReference.exprId
-  override def qualifiers = baseReference.qualifiers
-  override def name = baseReference.name
+  override def references = Set.empty
 
-  override def newInstance = BoundReference(ordinal, baseReference.newInstance)
-  override def withNullability(newNullability: Boolean) =
-    BoundReference(ordinal, baseReference.withNullability(newNullability))
-  override def withQualifiers(newQualifiers: Seq[String]) =
-    BoundReference(ordinal, baseReference.withQualifiers(newQualifiers))
-
-  override def toString = s"$baseReference:$ordinal"
+  override def toString = s"input[$ordinal]"
 
   override def eval(input: Row): Any = input(ordinal)
 }
 
-/**
- * Used to denote operators that do their own binding of attributes internally.
- */
-trait NoBind { self: trees.TreeNode[_] => }
-
-class BindReferences[TreeNode <: QueryPlan[TreeNode]] extends Rule[TreeNode] {
-  import BindReferences._
-
-  def apply(plan: TreeNode): TreeNode = {
-    plan.transform {
-      case n: NoBind => n.asInstanceOf[TreeNode]
-      case leafNode if leafNode.children.isEmpty => leafNode
-      case unaryNode if unaryNode.children.size == 1 => unaryNode.transformExpressions { case e =>
-        bindReference(e, unaryNode.children.head.output)
-      }
-    }
-  }
-}
-
 object BindReferences extends Logging {
   def bindReference[A <: Expression](expression: A, input: Seq[Attribute]): A = {
     expression.transform { case a: AttributeReference =>
       attachTree(a, "Binding attribute") {
         val ordinal = input.indexWhere(_.exprId == a.exprId)
         if (ordinal == -1) {
-          // TODO: This fallback is required because some operators (such as ScriptTransform)
-          // produce new attributes that can't be bound.  Likely the right thing to do is remove
-          // this rule and require all operators to explicitly bind to the input schema that
-          // they specify.
-          logger.debug(s"Couldn't find $a in ${input.mkString("[", ",", "]")}")
-          a
+          sys.error(s"Couldn't find $a in ${input.mkString("[", ",", "]")}")
         } else {
-          BoundReference(ordinal, a)
+          BoundReference(ordinal, a.dataType, a.nullable)
         }
       }
     }.asInstanceOf[A] // Kind of a hack, but safe.  TODO: Tighten return type when possible.

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/Projection.scala

@@ -17,12 +17,13 @@
 
 package org.apache.spark.sql.catalyst.expressions
 
+
 /**
- * Converts a [[Row]] to another Row given a sequence of expression that define each column of the
- * new row. If the schema of the input row is specified, then the given expression will be bound to
- * that schema.
+ * A [[Projection]] that is calculated by calling the `eval` of each of the specified expressions.
+ * @param expressions a sequence of expressions that determine the value of each column of the
+ *                    output row.
  */
-class Projection(expressions: Seq[Expression]) extends (Row => Row) {
+class InterpretedProjection(expressions: Seq[Expression]) extends Projection {
   def this(expressions: Seq[Expression], inputSchema: Seq[Attribute]) =
     this(expressions.map(BindReferences.bindReference(_, inputSchema)))
 
@@ -40,25 +41,25 @@ class Projection(expressions: Seq[Expression]) extends (Row => Row) {
 }
 
 /**
- * Converts a [[Row]] to another Row given a sequence of expression that define each column of th
- * new row. If the schema of the input row is specified, then the given expression will be bound to
- * that schema.
- *
- * In contrast to a normal projection, a MutableProjection reuses the same underlying row object
- * each time an input row is added.  This significantly reduces the cost of calculating the
- * projection, but means that it is not safe to hold on to a reference to a [[Row]] after `next()`
- * has been called on the [[Iterator]] that produced it. Instead, the user must call `Row.copy()`
- * and hold on to the returned [[Row]] before calling `next()`.
+ * A [[MutableProjection]] that is calculated by calling `eval` on each of the specified
+ * expressions.
+ * @param expressions a sequence of expressions that determine the value of each column of the
+ *                    output row.
  */
-case class MutableProjection(expressions: Seq[Expression]) extends (Row => Row) {
+case class InterpretedMutableProjection(expressions: Seq[Expression]) extends MutableProjection {
   def this(expressions: Seq[Expression], inputSchema: Seq[Attribute]) =
     this(expressions.map(BindReferences.bindReference(_, inputSchema)))
 
   private[this] val exprArray = expressions.toArray
-  private[this] val mutableRow = new GenericMutableRow(exprArray.size)
+  private[this] var mutableRow: MutableRow = new GenericMutableRow(exprArray.size)
   def currentValue: Row = mutableRow
 
-  def apply(input: Row): Row = {
+  override def target(row: MutableRow): MutableProjection = {
+    mutableRow = row
+    this
+  }
+
+  override def apply(input: Row): Row = {
     var i = 0
     while (i < exprArray.length) {
       mutableRow(i) = exprArray(i).eval(input)
@@ -76,6 +77,12 @@ class JoinedRow extends Row {
   private[this] var row1: Row = _
   private[this] var row2: Row = _
 
+  def this(left: Row, right: Row) = {
+    this()
+    row1 = left
+    row2 = right
+  }
+
   /** Updates this JoinedRow to used point at two new base rows.  Returns itself. */
   def apply(r1: Row, r2: Row): Row = {
     row1 = r1

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/Row.scala

@@ -88,15 +88,6 @@ trait MutableRow extends Row {
   def setByte(ordinal: Int, value: Byte)
   def setFloat(ordinal: Int, value: Float)
   def setString(ordinal: Int, value: String)
-
-  /**
-   * Experimental
-   *
-   * Returns a mutable string builder for the specified column.  A given row should return the
-   * result of any mutations made to the returned buffer next time getString is called for the same
-   * column.
-   */
-  def getStringBuilder(ordinal: Int): StringBuilder
 }
 
 /**
@@ -180,15 +171,42 @@ class GenericRow(protected[catalyst] val values: Array[Any]) extends Row {
     values(i).asInstanceOf[String]
   }
 
+  // Custom hashCode function that matches the efficient code generated version.
+  override def hashCode(): Int = {
+    var result: Int = 37
+
+    var i = 0
+    while (i < values.length) {
+      val update: Int =
+        if (isNullAt(i)) {
+          0
+        } else {
+          apply(i) match {
+            case b: Boolean => if (b) 0 else 1
+            case b: Byte => b.toInt
+            case s: Short => s.toInt
+            case i: Int => i
+            case l: Long => (l ^ (l >>> 32)).toInt
+            case f: Float => java.lang.Float.floatToIntBits(f)
+            case d: Double =>
+              val b = java.lang.Double.doubleToLongBits(d)
+              (b ^ (b >>> 32)).toInt
+            case other => other.hashCode()
+          }
+        }
+      result = 37 * result + update
+      i += 1
+    }
+    result
+  }
+
   def copy() = this
 }
 
 class GenericMutableRow(size: Int) extends GenericRow(size) with MutableRow {
   /** No-arg constructor for serialization. */
   def this() = this(0)
 
-  def getStringBuilder(ordinal: Int): StringBuilder = ???
-
   override def setBoolean(ordinal: Int,value: Boolean): Unit = { values(ordinal) = value }
   override def setByte(ordinal: Int,value: Byte): Unit = { values(ordinal) = value }
   override def setDouble(ordinal: Int,value: Double): Unit = { values(ordinal) = value }

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/ScalaUdf.scala

@@ -29,6 +29,7 @@ case class ScalaUdf(function: AnyRef, dataType: DataType, children: Seq[Expressi
 
   override def eval(input: Row): Any = {
     children.size match {
+      case 0 => function.asInstanceOf[() => Any]()
       case 1 => function.asInstanceOf[(Any) => Any](children(0).eval(input))
       case 2 =>
         function.asInstanceOf[(Any, Any) => Any](