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[SPARK-34607][SQL][3.1] Add Utils.isMemberClass to fix a malformed …
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…class name error on jdk8u

This PR intends to fix a bug of `objects.NewInstance` if a user runs Spark on jdk8u and a given `cls` in `NewInstance` is a deeply-nested inner class, e.g.,.
```
  object OuterLevelWithVeryVeryVeryLongClassName1 {
    object OuterLevelWithVeryVeryVeryLongClassName2 {
      object OuterLevelWithVeryVeryVeryLongClassName3 {
        object OuterLevelWithVeryVeryVeryLongClassName4 {
          object OuterLevelWithVeryVeryVeryLongClassName5 {
            object OuterLevelWithVeryVeryVeryLongClassName6 {
              object OuterLevelWithVeryVeryVeryLongClassName7 {
                object OuterLevelWithVeryVeryVeryLongClassName8 {
                  object OuterLevelWithVeryVeryVeryLongClassName9 {
                    object OuterLevelWithVeryVeryVeryLongClassName10 {
                      object OuterLevelWithVeryVeryVeryLongClassName11 {
                        object OuterLevelWithVeryVeryVeryLongClassName12 {
                          object OuterLevelWithVeryVeryVeryLongClassName13 {
                            object OuterLevelWithVeryVeryVeryLongClassName14 {
                              object OuterLevelWithVeryVeryVeryLongClassName15 {
                                object OuterLevelWithVeryVeryVeryLongClassName16 {
                                  object OuterLevelWithVeryVeryVeryLongClassName17 {
                                    object OuterLevelWithVeryVeryVeryLongClassName18 {
                                      object OuterLevelWithVeryVeryVeryLongClassName19 {
                                        object OuterLevelWithVeryVeryVeryLongClassName20 {
                                          case class MalformedNameExample2(x: Int)
                                        }}}}}}}}}}}}}}}}}}}}
```

The root cause that Kris (@rednaxelafx) investigated is as follows (Kudos to Kris);

The reason why the test case above is so convoluted is in the way Scala generates the class name for nested classes. In general, Scala generates a class name for a nested class by inserting the dollar-sign ( `$` ) in between each level of class nesting. The problem is that this format can concatenate into a very long string that goes beyond certain limits, so Scala will change the class name format beyond certain length threshold.

For the example above, we can see that the first two levels of class nesting have class names that look like this:
```
org.apache.spark.sql.catalyst.encoders.ExpressionEncoderSuite$OuterLevelWithVeryVeryVeryLongClassName1$
org.apache.spark.sql.catalyst.encoders.ExpressionEncoderSuite$OuterLevelWithVeryVeryVeryLongClassName1$OuterLevelWithVeryVeryVeryLongClassName2$
```
If we leave out the fact that Scala uses a dollar-sign ( `$` ) suffix for the class name of the companion object, `OuterLevelWithVeryVeryVeryLongClassName1`'s full name is a prefix (substring) of `OuterLevelWithVeryVeryVeryLongClassName2`.

But if we keep going deeper into the levels of nesting, you'll find names that look like:
```
org.apache.spark.sql.catalyst.encoders.ExpressionEncoderSuite$OuterLevelWithVeryVeryVeryLongClassNam$$$$2a1321b953c615695d7442b2adb1$$$$ryVeryLongClassName8$OuterLevelWithVeryVeryVeryLongClassName9$OuterLevelWithVeryVeryVeryLongClassName10$
org.apache.spark.sql.catalyst.encoders.ExpressionEncoderSuite$OuterLevelWithVeryVeryVeryLongClassNam$$$$2a1321b953c615695d7442b2adb1$$$$ryVeryLongClassName8$OuterLevelWithVeryVeryVeryLongClassName9$OuterLevelWithVeryVeryVeryLongClassName10$OuterLevelWithVeryVeryVeryLongClassName11$
org.apache.spark.sql.catalyst.encoders.ExpressionEncoderSuite$OuterLevelWithVeryVeryVeryLongClassNam$$$$85f068777e7ecf112afcbe997d461b$$$$VeryLongClassName11$OuterLevelWithVeryVeryVeryLongClassName12$
org.apache.spark.sql.catalyst.encoders.ExpressionEncoderSuite$OuterLevelWithVeryVeryVeryLongClassNam$$$$85f068777e7ecf112afcbe997d461b$$$$VeryLongClassName11$OuterLevelWithVeryVeryVeryLongClassName12$OuterLevelWithVeryVeryVeryLongClassName13$
org.apache.spark.sql.catalyst.encoders.ExpressionEncoderSuite$OuterLevelWithVeryVeryVeryLongClassNam$$$$85f068777e7ecf112afcbe997d461b$$$$VeryLongClassName11$OuterLevelWithVeryVeryVeryLongClassName12$OuterLevelWithVeryVeryVeryLongClassName13$OuterLevelWithVeryVeryVeryLongClassName14$
org.apache.spark.sql.catalyst.encoders.ExpressionEncoderSuite$OuterLevelWithVeryVeryVeryLongClassNam$$$$5f7ad51804cb1be53938ea804699fa$$$$VeryLongClassName14$OuterLevelWithVeryVeryVeryLongClassName15$
org.apache.spark.sql.catalyst.encoders.ExpressionEncoderSuite$OuterLevelWithVeryVeryVeryLongClassNam$$$$5f7ad51804cb1be53938ea804699fa$$$$VeryLongClassName14$OuterLevelWithVeryVeryVeryLongClassName15$OuterLevelWithVeryVeryVeryLongClassName16$
org.apache.spark.sql.catalyst.encoders.ExpressionEncoderSuite$OuterLevelWithVeryVeryVeryLongClassNam$$$$5f7ad51804cb1be53938ea804699fa$$$$VeryLongClassName14$OuterLevelWithVeryVeryVeryLongClassName15$OuterLevelWithVeryVeryVeryLongClassName16$OuterLevelWithVeryVeryVeryLongClassName17$
org.apache.spark.sql.catalyst.encoders.ExpressionEncoderSuite$OuterLevelWithVeryVeryVeryLongClassNam$$$$69b54f16b1965a31e88968df1a58d8$$$$VeryLongClassName17$OuterLevelWithVeryVeryVeryLongClassName18$
org.apache.spark.sql.catalyst.encoders.ExpressionEncoderSuite$OuterLevelWithVeryVeryVeryLongClassNam$$$$69b54f16b1965a31e88968df1a58d8$$$$VeryLongClassName17$OuterLevelWithVeryVeryVeryLongClassName18$OuterLevelWithVeryVeryVeryLongClassName19$
org.apache.spark.sql.catalyst.encoders.ExpressionEncoderSuite$OuterLevelWithVeryVeryVeryLongClassNam$$$$69b54f16b1965a31e88968df1a58d8$$$$VeryLongClassName17$OuterLevelWithVeryVeryVeryLongClassName18$OuterLevelWithVeryVeryVeryLongClassName19$OuterLevelWithVeryVeryVeryLongClassName20$
```
with a hash code in the middle and various levels of nesting omitted.

The `java.lang.Class.isMemberClass` method is implemented in JDK8u as:
http://hg.openjdk.java.net/jdk8u/jdk8u/jdk/file/tip/src/share/classes/java/lang/Class.java#l1425
```
    /**
     * Returns {@code true} if and only if the underlying class
     * is a member class.
     *
     * @return {@code true} if and only if this class is a member class.
     * @SInCE 1.5
     */
    public boolean isMemberClass() {
        return getSimpleBinaryName() != null && !isLocalOrAnonymousClass();
    }

    /**
     * Returns the "simple binary name" of the underlying class, i.e.,
     * the binary name without the leading enclosing class name.
     * Returns {@code null} if the underlying class is a top level
     * class.
     */
    private String getSimpleBinaryName() {
        Class<?> enclosingClass = getEnclosingClass();
        if (enclosingClass == null) // top level class
            return null;
        // Otherwise, strip the enclosing class' name
        try {
            return getName().substring(enclosingClass.getName().length());
        } catch (IndexOutOfBoundsException ex) {
            throw new InternalError("Malformed class name", ex);
        }
    }
```
and the problematic code is `getName().substring(enclosingClass.getName().length())` -- if a class's enclosing class's full name is *longer* than the nested class's full name, this logic would end up going out of bounds.

The bug has been fixed in JDK9 by https://bugs.java.com/bugdatabase/view_bug.do?bug_id=8057919 , but still exists in the latest JDK8u release. So from the Spark side we'd need to do something to avoid hitting this problem.

This is the backport of #31733.

Bugfix on jdk8u.

No.

Added tests.
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@maropu @dongjoon-hyun
maropu authored and dongjoon-hyun committed Mar 5, 2021
1 parent 9615c0e commit f3caba1
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28 changes: 28 additions & 0 deletions core/src/main/scala/org/apache/spark/util/Utils.scala
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Original file line number Diff line number Diff line change
Expand Up @@ -2860,6 +2860,34 @@ private[spark] object Utils extends Logging {
Hex.encodeHexString(secretBytes)
}

/**
* Returns true if and only if the underlying class is a member class.
*
* Note: jdk8u throws a "Malformed class name" error if a given class is a deeply-nested
* inner class (See SPARK-34607 for details). This issue has already been fixed in jdk9+, so
* we can remove this helper method safely if we drop the support of jdk8u.
*/
def isMemberClass(cls: Class[_]): Boolean = {
try {
cls.isMemberClass
} catch {
case _: InternalError =>
// We emulate jdk8u `Class.isMemberClass` below:
// public boolean isMemberClass() {
// return getSimpleBinaryName() != null && !isLocalOrAnonymousClass();
// }
// `getSimpleBinaryName()` returns null if a given class is a top-level class,
// so we replace it with `cls.getEnclosingClass != null`. The second condition checks
// if a given class is not a local or an anonymous class, so we replace it with
// `cls.getEnclosingMethod == null` because `cls.getEnclosingMethod()` return a value
// only in either case (JVM Spec 4.8.6).
//
// Note: The newer jdk evaluates `!isLocalOrAnonymousClass()` first,
// we reorder the conditions to follow it.
cls.getEnclosingMethod == null && cls.getEnclosingClass != null
}
}

/**
* Safer than Class obj's getSimpleName which may throw Malformed class name error in scala.
* This method mimics scalatest's getSimpleNameOfAnObjectsClass.
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2 changes: 1 addition & 1 deletion sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/encoders/OuterScopes.scala
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Original file line number Diff line number Diff line change
Expand Up @@ -48,7 +48,7 @@ object OuterScopes {
* useful for inner class defined in REPL.
*/
def getOuterScope(innerCls: Class[_]): () => AnyRef = {
assert(innerCls.isMemberClass)
assert(Utils.isMemberClass(innerCls))
val outerClassName = innerCls.getDeclaringClass.getName
val outer = outerScopes.get(outerClassName)
if (outer == null) {
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2 changes: 1 addition & 1 deletion sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/objects/objects.scala
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Original file line number Diff line number Diff line change
Expand Up @@ -443,7 +443,7 @@ case class NewInstance(
// Note that static inner classes (e.g., inner classes within Scala objects) don't need
// outer pointer registration.
val needOuterPointer =
outerPointer.isEmpty && cls.isMemberClass && !Modifier.isStatic(cls.getModifiers)
outerPointer.isEmpty && Utils.isMemberClass(cls) && !Modifier.isStatic(cls.getModifiers)
childrenResolved && !needOuterPointer
}

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70 changes: 70 additions & 0 deletions ...talyst/src/test/scala/org/apache/spark/sql/catalyst/encoders/ExpressionEncoderSuite.scala
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Original file line number Diff line number Diff line change
Expand Up @@ -217,6 +217,76 @@ class ExpressionEncoderSuite extends CodegenInterpretedPlanTest with AnalysisTes
"nested Scala class should work")
}

object OuterLevelWithVeryVeryVeryLongClassName1 {
object OuterLevelWithVeryVeryVeryLongClassName2 {
object OuterLevelWithVeryVeryVeryLongClassName3 {
object OuterLevelWithVeryVeryVeryLongClassName4 {
object OuterLevelWithVeryVeryVeryLongClassName5 {
object OuterLevelWithVeryVeryVeryLongClassName6 {
object OuterLevelWithVeryVeryVeryLongClassName7 {
object OuterLevelWithVeryVeryVeryLongClassName8 {
object OuterLevelWithVeryVeryVeryLongClassName9 {
object OuterLevelWithVeryVeryVeryLongClassName10 {
object OuterLevelWithVeryVeryVeryLongClassName11 {
object OuterLevelWithVeryVeryVeryLongClassName12 {
object OuterLevelWithVeryVeryVeryLongClassName13 {
object OuterLevelWithVeryVeryVeryLongClassName14 {
object OuterLevelWithVeryVeryVeryLongClassName15 {
object OuterLevelWithVeryVeryVeryLongClassName16 {
object OuterLevelWithVeryVeryVeryLongClassName17 {
object OuterLevelWithVeryVeryVeryLongClassName18 {
object OuterLevelWithVeryVeryVeryLongClassName19 {
object OuterLevelWithVeryVeryVeryLongClassName20 {
case class MalformedNameExample(x: Int)
}}}}}}}}}}}}}}}}}}}}

{
OuterScopes.addOuterScope(
OuterLevelWithVeryVeryVeryLongClassName1
.OuterLevelWithVeryVeryVeryLongClassName2
.OuterLevelWithVeryVeryVeryLongClassName3
.OuterLevelWithVeryVeryVeryLongClassName4
.OuterLevelWithVeryVeryVeryLongClassName5
.OuterLevelWithVeryVeryVeryLongClassName6
.OuterLevelWithVeryVeryVeryLongClassName7
.OuterLevelWithVeryVeryVeryLongClassName8
.OuterLevelWithVeryVeryVeryLongClassName9
.OuterLevelWithVeryVeryVeryLongClassName10
.OuterLevelWithVeryVeryVeryLongClassName11
.OuterLevelWithVeryVeryVeryLongClassName12
.OuterLevelWithVeryVeryVeryLongClassName13
.OuterLevelWithVeryVeryVeryLongClassName14
.OuterLevelWithVeryVeryVeryLongClassName15
.OuterLevelWithVeryVeryVeryLongClassName16
.OuterLevelWithVeryVeryVeryLongClassName17
.OuterLevelWithVeryVeryVeryLongClassName18
.OuterLevelWithVeryVeryVeryLongClassName19
.OuterLevelWithVeryVeryVeryLongClassName20)
encodeDecodeTest(
OuterLevelWithVeryVeryVeryLongClassName1
.OuterLevelWithVeryVeryVeryLongClassName2
.OuterLevelWithVeryVeryVeryLongClassName3
.OuterLevelWithVeryVeryVeryLongClassName4
.OuterLevelWithVeryVeryVeryLongClassName5
.OuterLevelWithVeryVeryVeryLongClassName6
.OuterLevelWithVeryVeryVeryLongClassName7
.OuterLevelWithVeryVeryVeryLongClassName8
.OuterLevelWithVeryVeryVeryLongClassName9
.OuterLevelWithVeryVeryVeryLongClassName10
.OuterLevelWithVeryVeryVeryLongClassName11
.OuterLevelWithVeryVeryVeryLongClassName12
.OuterLevelWithVeryVeryVeryLongClassName13
.OuterLevelWithVeryVeryVeryLongClassName14
.OuterLevelWithVeryVeryVeryLongClassName15
.OuterLevelWithVeryVeryVeryLongClassName16
.OuterLevelWithVeryVeryVeryLongClassName17
.OuterLevelWithVeryVeryVeryLongClassName18
.OuterLevelWithVeryVeryVeryLongClassName19
.OuterLevelWithVeryVeryVeryLongClassName20
.MalformedNameExample(42),
"deeply nested Scala class should work")
}

productTest(PrimitiveData(1, 1, 1, 1, 1, 1, true))

productTest(
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