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Posted to issues@flink.apache.org by GitBox <gi...@apache.org> on 2018/07/26 09:51:44 UTC
[GitHub] asfgit closed pull request #6404: [FLINK-9928] Add LOG2 function
for table/sql API
asfgit closed pull request #6404: [FLINK-9928] Add LOG2 function for table/sql API
URL: https://github.com/apache/flink/pull/6404
This is a PR merged from a forked repository.
As GitHub hides the original diff on merge, it is displayed below for
the sake of provenance:
As this is a foreign pull request (from a fork), the diff is supplied
below (as it won't show otherwise due to GitHub magic):
diff --git a/docs/dev/table/sql.md b/docs/dev/table/sql.md
index 5b83e9d23cb..364b936fcfc 100644
--- a/docs/dev/table/sql.md
+++ b/docs/dev/table/sql.md
@@ -1409,6 +1409,17 @@ LOG10(numeric)
</td>
</tr>
+ <tr>
+ <td>
+ {% highlight text %}
+LOG2(numeric)
+{% endhighlight %}
+ </td>
+ <td>
+ <p>Returns the base 2 logarithm of <i>numeric</i>.</p>
+ </td>
+ </tr>
+
<tr>
<td>
{% highlight text %}
diff --git a/docs/dev/table/tableApi.md b/docs/dev/table/tableApi.md
index 2f651454903..80af8ee52e3 100644
--- a/docs/dev/table/tableApi.md
+++ b/docs/dev/table/tableApi.md
@@ -2067,6 +2067,17 @@ NUMERIC.log10()
</td>
</tr>
+ <tr>
+ <td>
+ {% highlight java %}
+NUMERIC.log2()
+{% endhighlight %}
+ </td>
+ <td>
+ <p>Calculates the base 2 logarithm of given value.</p>
+ </td>
+ </tr>
+
<tr>
<td>
{% highlight java %}
diff --git a/flink-libraries/flink-table/src/main/scala/org/apache/flink/table/api/scala/expressionDsl.scala b/flink-libraries/flink-table/src/main/scala/org/apache/flink/table/api/scala/expressionDsl.scala
index b0bc5b66c33..5a191243f5c 100644
--- a/flink-libraries/flink-table/src/main/scala/org/apache/flink/table/api/scala/expressionDsl.scala
+++ b/flink-libraries/flink-table/src/main/scala/org/apache/flink/table/api/scala/expressionDsl.scala
@@ -300,6 +300,11 @@ trait ImplicitExpressionOperations {
*/
def log10() = Log10(expr)
+ /**
+ * Calculates the base 2 logarithm of the given value.
+ */
+ def log2() = Log2(expr)
+
/**
* Calculates the natural logarithm of the given value.
*/
diff --git a/flink-libraries/flink-table/src/main/scala/org/apache/flink/table/codegen/calls/BuiltInMethods.scala b/flink-libraries/flink-table/src/main/scala/org/apache/flink/table/codegen/calls/BuiltInMethods.scala
index ea4f0fd2f92..11f4a1fa5e0 100644
--- a/flink-libraries/flink-table/src/main/scala/org/apache/flink/table/codegen/calls/BuiltInMethods.scala
+++ b/flink-libraries/flink-table/src/main/scala/org/apache/flink/table/codegen/calls/BuiltInMethods.scala
@@ -33,6 +33,8 @@ object BuiltInMethods {
val LOG10 = Types.lookupMethod(classOf[Math], "log10", classOf[Double])
+ val LOG2 = Types.lookupMethod(classOf[ScalarFunctions], "log2", classOf[Double])
+
val EXP = Types.lookupMethod(classOf[Math], "exp", classOf[Double])
val POWER = Types.lookupMethod(classOf[Math], "pow", classOf[Double], classOf[Double])
diff --git a/flink-libraries/flink-table/src/main/scala/org/apache/flink/table/codegen/calls/FunctionGenerator.scala b/flink-libraries/flink-table/src/main/scala/org/apache/flink/table/codegen/calls/FunctionGenerator.scala
index bd75617f474..f6c5a3d6a21 100644
--- a/flink-libraries/flink-table/src/main/scala/org/apache/flink/table/codegen/calls/FunctionGenerator.scala
+++ b/flink-libraries/flink-table/src/main/scala/org/apache/flink/table/codegen/calls/FunctionGenerator.scala
@@ -156,6 +156,12 @@ object FunctionGenerator {
DOUBLE_TYPE_INFO,
BuiltInMethods.LOG10)
+ addSqlFunctionMethod(
+ LOG2,
+ Seq(DOUBLE_TYPE_INFO),
+ DOUBLE_TYPE_INFO,
+ BuiltInMethods.LOG2)
+
addSqlFunctionMethod(
LN,
Seq(DOUBLE_TYPE_INFO),
diff --git a/flink-libraries/flink-table/src/main/scala/org/apache/flink/table/expressions/mathExpressions.scala b/flink-libraries/flink-table/src/main/scala/org/apache/flink/table/expressions/mathExpressions.scala
index 0378ce58c2a..10ba0079263 100644
--- a/flink-libraries/flink-table/src/main/scala/org/apache/flink/table/expressions/mathExpressions.scala
+++ b/flink-libraries/flink-table/src/main/scala/org/apache/flink/table/expressions/mathExpressions.scala
@@ -92,6 +92,18 @@ case class Log10(child: Expression) extends UnaryExpression with InputTypeSpec {
}
}
+case class Log2(child: Expression) extends UnaryExpression with InputTypeSpec {
+ override private[flink] def expectedTypes: Seq[TypeInformation[_]] = DOUBLE_TYPE_INFO :: Nil
+
+ override private[flink] def resultType: TypeInformation[_] = DOUBLE_TYPE_INFO
+
+ override private[flink] def toRexNode(implicit relBuilder: RelBuilder) = {
+ relBuilder.call(ScalarSqlFunctions.LOG2, child.toRexNode)
+ }
+
+ override def toString: String = s"log2($child)"
+}
+
case class Log(base: Expression, antilogarithm: Expression) extends Expression with InputTypeSpec {
def this(antilogarithm: Expression) = this(null, antilogarithm)
diff --git a/flink-libraries/flink-table/src/main/scala/org/apache/flink/table/functions/sql/ScalarSqlFunctions.scala b/flink-libraries/flink-table/src/main/scala/org/apache/flink/table/functions/sql/ScalarSqlFunctions.scala
index 69f430b399e..32e5d348277 100644
--- a/flink-libraries/flink-table/src/main/scala/org/apache/flink/table/functions/sql/ScalarSqlFunctions.scala
+++ b/flink-libraries/flink-table/src/main/scala/org/apache/flink/table/functions/sql/ScalarSqlFunctions.scala
@@ -67,6 +67,15 @@ object ScalarSqlFunctions {
OperandTypes.family(SqlTypeFamily.NUMERIC, SqlTypeFamily.NUMERIC)),
SqlFunctionCategory.NUMERIC)
+ val LOG2 = new SqlFunction(
+ "LOG2",
+ SqlKind.OTHER_FUNCTION,
+ ReturnTypes.DOUBLE_NULLABLE,
+ null,
+ OperandTypes.NUMERIC,
+ SqlFunctionCategory.NUMERIC
+ )
+
val LPAD = new SqlFunction(
"LPAD",
SqlKind.OTHER_FUNCTION,
diff --git a/flink-libraries/flink-table/src/main/scala/org/apache/flink/table/runtime/functions/ScalarFunctions.scala b/flink-libraries/flink-table/src/main/scala/org/apache/flink/table/runtime/functions/ScalarFunctions.scala
index 2e7c9f6825f..3d0e0d32542 100644
--- a/flink-libraries/flink-table/src/main/scala/org/apache/flink/table/runtime/functions/ScalarFunctions.scala
+++ b/flink-libraries/flink-table/src/main/scala/org/apache/flink/table/runtime/functions/ScalarFunctions.scala
@@ -108,6 +108,17 @@ object ScalarFunctions {
}
}
+ /**
+ * Returns the logarithm of "x" with base 2.
+ */
+ def log2(x: Double): Double = {
+ if (x <= 0.0) {
+ throw new IllegalArgumentException(s"x of 'log2(x)' must be > 0, but x = $x")
+ } else {
+ Math.log(x) / Math.log(2)
+ }
+ }
+
/**
* Returns the string str left-padded with the string pad to a length of len characters.
* If str is longer than len, the return value is shortened to len characters.
diff --git a/flink-libraries/flink-table/src/main/scala/org/apache/flink/table/validate/FunctionCatalog.scala b/flink-libraries/flink-table/src/main/scala/org/apache/flink/table/validate/FunctionCatalog.scala
index 3184e0001ea..2806e3478e4 100644
--- a/flink-libraries/flink-table/src/main/scala/org/apache/flink/table/validate/FunctionCatalog.scala
+++ b/flink-libraries/flink-table/src/main/scala/org/apache/flink/table/validate/FunctionCatalog.scala
@@ -213,6 +213,7 @@ object FunctionCatalog {
"exp" -> classOf[Exp],
"floor" -> classOf[Floor],
"log10" -> classOf[Log10],
+ "log2" -> classOf[Log2],
"ln" -> classOf[Ln],
"log" -> classOf[Log],
"power" -> classOf[Power],
@@ -397,6 +398,7 @@ class BasicOperatorTable extends ReflectiveSqlOperatorTable {
SqlStdOperatorTable.MOD,
SqlStdOperatorTable.LN,
SqlStdOperatorTable.LOG10,
+ ScalarSqlFunctions.LOG2,
SqlStdOperatorTable.ABS,
SqlStdOperatorTable.EXP,
SqlStdOperatorTable.NULLIF,
diff --git a/flink-libraries/flink-table/src/test/scala/org/apache/flink/table/expressions/ScalarFunctionsTest.scala b/flink-libraries/flink-table/src/test/scala/org/apache/flink/table/expressions/ScalarFunctionsTest.scala
index 8b0c3808f22..3687c3b2be3 100644
--- a/flink-libraries/flink-table/src/test/scala/org/apache/flink/table/expressions/ScalarFunctionsTest.scala
+++ b/flink-libraries/flink-table/src/test/scala/org/apache/flink/table/expressions/ScalarFunctionsTest.scala
@@ -553,6 +553,37 @@ class ScalarFunctionsTest extends ScalarTypesTestBase {
math.log10(4.6).toString)
}
+ @Test
+ def testLog2(): Unit = {
+ testAllApis(
+ 'f6.log2(),
+ "f6.log2",
+ "LOG2(f6)",
+ (math.log(4.6) / math.log(2)).toString
+ )
+
+ testAllApis(
+ ('f6 - 'f6 + 100).log2(),
+ "(f6 - f6 + 100).log2()",
+ "LOG2(f6 - f6 + 100)",
+ (math.log(100.0) / math.log(2)).toString
+ )
+
+ testAllApis(
+ ('f6 + 20).log2(),
+ "(f6+20).log2",
+ "LOG2(f6+20)",
+ (math.log(24.6) / math.log(2)).toString
+ )
+
+ testAllApis(
+ 10.log2(),
+ "10.log2",
+ "LOG2(10)",
+ (math.log(10.0) / math.log(2)).toString
+ )
+ }
+
@Test
def testPower(): Unit = {
// f7: int , f4: long, f6: double
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