Github user jerryshao commented on a diff in the pull request:
https://github.com/apache/spark/pull/2514#discussion_r17954749
--- Diff:
core/src/test/scala/org/apache/spark/util/collection/ExternalSorterSuite.scala
---
@@ -707,4 +707,53 @@ class ExternalSorterSuite extends FunSuite with
LocalSparkContext with PrivateMe
Some(agg), Some(new HashPartitioner(FEW_PARTITIONS)), None, None)
assertDidNotBypassMergeSort(sorter4)
}
+
+ test("sort without breaking sorting contracts") {
+ val conf = createSparkConf(true)
+ conf.set("spark.shuffle.memoryFraction", "0.001")
+ conf.set("spark.shuffle.manager", "sort")
+ sc = new SparkContext("local-cluster[1,1,512]", "test", conf)
+
+ val testData = Array[String](
+ "hierarch", // -1732884796
+ "variants", // -1249574770
+ "inwork", // -1183663690
+ "isohel", // -1179291542
+ "misused" // 1069518484
+ )
+ val expected = testData.map(s => (s, 200000))
+
+ def createCombiner(i: Int) = ArrayBuffer(i)
+ def mergeValue(c: ArrayBuffer[Int], i: Int) = c += i
+ def mergeCombiners(c1: ArrayBuffer[Int], c2: ArrayBuffer[Int]) = c1
++= c2
+
+ val agg = new Aggregator[String, Int, ArrayBuffer[Int]](
+ createCombiner, mergeValue, mergeCombiners)
+
+ // Using wrongHashOrdering to show that integer overflow will lead to
wrong sort result.
+ val wrongHashOrdering = new Ordering[String] {
+ override def compare(a: String, b: String) = {
+ val h1 = a.hashCode()
+ val h2 = b.hashCode()
+ h1 - h2
+ }
+ }
+ val sorter1 = new ExternalSorter[String, Int, ArrayBuffer[Int]](
+ None, None, Some(wrongHashOrdering), None)
+ sorter1.insertAll(expected.iterator)
--- End diff --
Seems these test data do not throw exception as "violates its general
contract", but only give the wrong results. I'm not familiar with TimSort,
probably this exception is not always happening, or the test data is not enough
to reproduce the exception.
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