[SPARK-8214] [SQL] Add function hex

cc chenghao-intel  adrian-wang

Author: zhichao.li <zhichao.li@intel.com>

Closes #6976 from zhichao-li/hex and squashes the following commits:

e218d1b [zhichao.li] turn off scalastyle for non-ascii
de3f5ea [zhichao.li] non-ascii char
cf9c936 [zhichao.li] give separated buffer for each hex method
967ec90 [zhichao.li] Make 'value' as a feild of Hex
3b2fa13 [zhichao.li] tiny fix
a647641 [zhichao.li] remove duplicate null check
7cab020 [zhichao.li] tiny refactoring
35ecfe5 [zhichao.li] add function hex

2 files changed, 29 insertions, 0 deletions

diff --git a/sql/core/src/main/scala/org/apache/spark/sql/functions.scala b/sql/core/src/main/scala/org/apache/spark/sql/functions.scala
index ef92801548..5422e066af 100644
--- a/sql/core/src/main/scala/org/apache/spark/sql/functions.scala
+++ b/sql/core/src/main/scala/org/apache/spark/sql/functions.scala
@@ -1047,6 +1047,22 @@ object functions {
   def floor(columnName: String): Column = floor(Column(columnName))
 
   /**
+   * Computes hex value of the given column
+   *
+   * @group math_funcs
+   * @since 1.5.0
+   */
+  def hex(column: Column): Column = Hex(column.expr)
+
+  /**
+   * Computes hex value of the given input
+   *
+   * @group math_funcs
+   * @since 1.5.0
+   */
+  def hex(colName: String): Column = hex(Column(colName))
+
+  /**
    * Computes `sqrt(a^2^ + b^2^)` without intermediate overflow or underflow.
    *
    * @group math_funcs
diff --git a/sql/core/src/test/scala/org/apache/spark/sql/MathExpressionsSuite.scala b/sql/core/src/test/scala/org/apache/spark/sql/MathExpressionsSuite.scala
index 2768d7dfc8..d6331aa4ff 100644
--- a/sql/core/src/test/scala/org/apache/spark/sql/MathExpressionsSuite.scala
+++ b/sql/core/src/test/scala/org/apache/spark/sql/MathExpressionsSuite.scala
@@ -212,6 +212,19 @@ class MathExpressionsSuite extends QueryTest {
     )
   }
 
+  test("hex") {
+    val data = Seq((28, -28, 100800200404L, "hello")).toDF("a", "b", "c", "d")
+    checkAnswer(data.select(hex('a)), Seq(Row("1C")))
+    checkAnswer(data.select(hex('b)), Seq(Row("FFFFFFFFFFFFFFE4")))
+    checkAnswer(data.select(hex('c)), Seq(Row("177828FED4")))
+    checkAnswer(data.select(hex('d)), Seq(Row("68656C6C6F")))
+    checkAnswer(data.selectExpr("hex(a)"), Seq(Row("1C")))
+    checkAnswer(data.selectExpr("hex(b)"), Seq(Row("FFFFFFFFFFFFFFE4")))
+    checkAnswer(data.selectExpr("hex(c)"), Seq(Row("177828FED4")))
+    checkAnswer(data.selectExpr("hex(d)"), Seq(Row("68656C6C6F")))
+    checkAnswer(data.selectExpr("hex(cast(d as binary))"), Seq(Row("68656C6C6F")))
+  }
+
   test("hypot") {
     testTwoToOneMathFunction(hypot, hypot, math.hypot)
   }