[SPARK-9100] [SQL] Adds DataFrame reader/writer shortcut methods for ORC

This PR adds DataFrame reader/writer shortcut methods for ORC in both Scala and Python.

Author: Cheng Lian <lian@databricks.com>

Closes #7444 from liancheng/spark-9100 and squashes the following commits:

284d043 [Cheng Lian] Fixes PySpark test cases and addresses PR comments
e0b09fb [Cheng Lian] Adds DataFrame reader/writer shortcut methods for ORC

6 files changed, 38 insertions, 20 deletions

diff --git a/sql/core/src/main/scala/org/apache/spark/sql/DataFrameReader.scala b/sql/core/src/main/scala/org/apache/spark/sql/DataFrameReader.scala
index 0e37ad3e12..f1c1ddf898 100644
--- a/sql/core/src/main/scala/org/apache/spark/sql/DataFrameReader.scala
+++ b/sql/core/src/main/scala/org/apache/spark/sql/DataFrameReader.scala
@@ -265,6 +265,15 @@ class DataFrameReader private[sql](sqlContext: SQLContext) extends Logging {
   }
 
   /**
+   * Loads an ORC file and returns the result as a [[DataFrame]].
+   *
+   * @param path input path
+   * @since 1.5.0
+   * @note Currently, this method can only be used together with `HiveContext`.
+   */
+  def orc(path: String): DataFrame = format("orc").load(path)
+
+  /**
    * Returns the specified table as a [[DataFrame]].
    *
    * @since 1.4.0
diff --git a/sql/core/src/main/scala/org/apache/spark/sql/DataFrameWriter.scala b/sql/core/src/main/scala/org/apache/spark/sql/DataFrameWriter.scala
index 5548b26cb8..3e7b9cd797 100644
--- a/sql/core/src/main/scala/org/apache/spark/sql/DataFrameWriter.scala
+++ b/sql/core/src/main/scala/org/apache/spark/sql/DataFrameWriter.scala
@@ -280,6 +280,18 @@ final class DataFrameWriter private[sql](df: DataFrame) {
    */
   def parquet(path: String): Unit = format("parquet").save(path)
 
+  /**
+   * Saves the content of the [[DataFrame]] in ORC format at the specified path.
+   * This is equivalent to:
+   * {{{
+   *   format("orc").save(path)
+   * }}}
+   *
+   * @since 1.5.0
+   * @note Currently, this method can only be used together with `HiveContext`.
+   */
+  def orc(path: String): Unit = format("orc").save(path)
+
   ///////////////////////////////////////////////////////////////////////////////////////
   // Builder pattern config options
   ///////////////////////////////////////////////////////////////////////////////////////
diff --git a/sql/hive/src/test/scala/org/apache/spark/sql/hive/orc/OrcHadoopFsRelationSuite.scala b/sql/hive/src/test/scala/org/apache/spark/sql/hive/orc/OrcHadoopFsRelationSuite.scala
index 080af5bb23..af3f468aaa 100644
--- a/sql/hive/src/test/scala/org/apache/spark/sql/hive/orc/OrcHadoopFsRelationSuite.scala
+++ b/sql/hive/src/test/scala/org/apache/spark/sql/hive/orc/OrcHadoopFsRelationSuite.scala
@@ -41,8 +41,7 @@ class OrcHadoopFsRelationSuite extends HadoopFsRelationTest {
           .parallelize(for (i <- 1 to 3) yield (i, s"val_$i", p1))
           .toDF("a", "b", "p1")
           .write
-          .format("orc")
-          .save(partitionDir.toString)
+          .orc(partitionDir.toString)
       }
 
       val dataSchemaWithPartition =
diff --git a/sql/hive/src/test/scala/org/apache/spark/sql/hive/orc/OrcPartitionDiscoverySuite.scala b/sql/hive/src/test/scala/org/apache/spark/sql/hive/orc/OrcPartitionDiscoverySuite.scala
index 3c2efe329b..d463e8fd62 100644
--- a/sql/hive/src/test/scala/org/apache/spark/sql/hive/orc/OrcPartitionDiscoverySuite.scala
+++ b/sql/hive/src/test/scala/org/apache/spark/sql/hive/orc/OrcPartitionDiscoverySuite.scala
@@ -49,13 +49,13 @@ class OrcPartitionDiscoverySuite extends QueryTest with BeforeAndAfterAll {
 
   def makeOrcFile[T <: Product: ClassTag: TypeTag](
       data: Seq[T], path: File): Unit = {
-    data.toDF().write.format("orc").mode("overwrite").save(path.getCanonicalPath)
+    data.toDF().write.mode("overwrite").orc(path.getCanonicalPath)
   }
 
 
   def makeOrcFile[T <: Product: ClassTag: TypeTag](
       df: DataFrame, path: File): Unit = {
-    df.write.format("orc").mode("overwrite").save(path.getCanonicalPath)
+    df.write.mode("overwrite").orc(path.getCanonicalPath)
   }
 
   protected def withTempTable(tableName: String)(f: => Unit): Unit = {
@@ -90,7 +90,7 @@ class OrcPartitionDiscoverySuite extends QueryTest with BeforeAndAfterAll {
           makePartitionDir(base, defaultPartitionName, "pi" -> pi, "ps" -> ps))
       }
 
-      read.format("orc").load(base.getCanonicalPath).registerTempTable("t")
+      read.orc(base.getCanonicalPath).registerTempTable("t")
 
       withTempTable("t") {
         checkAnswer(
@@ -137,7 +137,7 @@ class OrcPartitionDiscoverySuite extends QueryTest with BeforeAndAfterAll {
           makePartitionDir(base, defaultPartitionName, "pi" -> pi, "ps" -> ps))
       }
 
-      read.format("orc").load(base.getCanonicalPath).registerTempTable("t")
+      read.orc(base.getCanonicalPath).registerTempTable("t")
 
       withTempTable("t") {
         checkAnswer(
@@ -187,9 +187,8 @@ class OrcPartitionDiscoverySuite extends QueryTest with BeforeAndAfterAll {
       }
 
       read
-        .format("orc")
         .option(ConfVars.DEFAULTPARTITIONNAME.varname, defaultPartitionName)
-        .load(base.getCanonicalPath)
+        .orc(base.getCanonicalPath)
         .registerTempTable("t")
 
       withTempTable("t") {
@@ -230,9 +229,8 @@ class OrcPartitionDiscoverySuite extends QueryTest with BeforeAndAfterAll {
       }
 
       read
-        .format("orc")
         .option(ConfVars.DEFAULTPARTITIONNAME.varname, defaultPartitionName)
-        .load(base.getCanonicalPath)
+        .orc(base.getCanonicalPath)
         .registerTempTable("t")
 
       withTempTable("t") {
diff --git a/sql/hive/src/test/scala/org/apache/spark/sql/hive/orc/OrcQuerySuite.scala b/sql/hive/src/test/scala/org/apache/spark/sql/hive/orc/OrcQuerySuite.scala
index ca131faaee..744d462938 100644
--- a/sql/hive/src/test/scala/org/apache/spark/sql/hive/orc/OrcQuerySuite.scala
+++ b/sql/hive/src/test/scala/org/apache/spark/sql/hive/orc/OrcQuerySuite.scala
@@ -63,14 +63,14 @@ class OrcQuerySuite extends QueryTest with BeforeAndAfterAll with OrcTest {
 
     withOrcFile(data) { file =>
       checkAnswer(
-        sqlContext.read.format("orc").load(file),
+        sqlContext.read.orc(file),
         data.toDF().collect())
     }
   }
 
   test("Read/write binary data") {
     withOrcFile(BinaryData("test".getBytes("utf8")) :: Nil) { file =>
-      val bytes = read.format("orc").load(file).head().getAs[Array[Byte]](0)
+      val bytes = read.orc(file).head().getAs[Array[Byte]](0)
       assert(new String(bytes, "utf8") === "test")
     }
   }
@@ -88,7 +88,7 @@ class OrcQuerySuite extends QueryTest with BeforeAndAfterAll with OrcTest {
 
     withOrcFile(data) { file =>
       checkAnswer(
-        read.format("orc").load(file),
+        read.orc(file),
         data.toDF().collect())
     }
   }
@@ -158,7 +158,7 @@ class OrcQuerySuite extends QueryTest with BeforeAndAfterAll with OrcTest {
 
     withOrcFile(data) { file =>
       checkAnswer(
-        read.format("orc").load(file),
+        read.orc(file),
         Row(Seq.fill(5)(null): _*))
     }
   }
@@ -310,7 +310,7 @@ class OrcQuerySuite extends QueryTest with BeforeAndAfterAll with OrcTest {
              """.stripMargin)
 
           val errorMessage = intercept[AnalysisException] {
-            sqlContext.read.format("orc").load(path)
+            sqlContext.read.orc(path)
           }.getMessage
 
           assert(errorMessage.contains("Failed to discover schema from ORC files"))
@@ -323,7 +323,7 @@ class OrcQuerySuite extends QueryTest with BeforeAndAfterAll with OrcTest {
                |SELECT key, value FROM single
              """.stripMargin)
 
-          val df = sqlContext.read.format("orc").load(path)
+          val df = sqlContext.read.orc(path)
           assert(df.schema === singleRowDF.schema.asNullable)
           checkAnswer(df, singleRowDF)
         }
diff --git a/sql/hive/src/test/scala/org/apache/spark/sql/hive/orc/OrcTest.scala b/sql/hive/src/test/scala/org/apache/spark/sql/hive/orc/OrcTest.scala
index 5daf691aa8..9d76d6503a 100644
--- a/sql/hive/src/test/scala/org/apache/spark/sql/hive/orc/OrcTest.scala
+++ b/sql/hive/src/test/scala/org/apache/spark/sql/hive/orc/OrcTest.scala
@@ -39,7 +39,7 @@ private[sql] trait OrcTest extends SQLTestUtils {
       (data: Seq[T])
       (f: String => Unit): Unit = {
     withTempPath { file =>
-      sparkContext.parallelize(data).toDF().write.format("orc").save(file.getCanonicalPath)
+      sparkContext.parallelize(data).toDF().write.orc(file.getCanonicalPath)
       f(file.getCanonicalPath)
     }
   }
@@ -51,7 +51,7 @@ private[sql] trait OrcTest extends SQLTestUtils {
   protected def withOrcDataFrame[T <: Product: ClassTag: TypeTag]
       (data: Seq[T])
       (f: DataFrame => Unit): Unit = {
-    withOrcFile(data)(path => f(sqlContext.read.format("orc").load(path)))
+    withOrcFile(data)(path => f(sqlContext.read.orc(path)))
   }
 
   /**
@@ -70,11 +70,11 @@ private[sql] trait OrcTest extends SQLTestUtils {
 
   protected def makeOrcFile[T <: Product: ClassTag: TypeTag](
       data: Seq[T], path: File): Unit = {
-    data.toDF().write.format("orc").mode(SaveMode.Overwrite).save(path.getCanonicalPath)
+    data.toDF().write.mode(SaveMode.Overwrite).orc(path.getCanonicalPath)
   }
 
   protected def makeOrcFile[T <: Product: ClassTag: TypeTag](
       df: DataFrame, path: File): Unit = {
-    df.write.format("orc").mode(SaveMode.Overwrite).save(path.getCanonicalPath)
+    df.write.mode(SaveMode.Overwrite).orc(path.getCanonicalPath)
   }
 }