diff options
Diffstat (limited to 'test/files/run/t6261.scala')
-rw-r--r-- | test/files/run/t6261.scala | 91 |
1 files changed, 91 insertions, 0 deletions
diff --git a/test/files/run/t6261.scala b/test/files/run/t6261.scala index 873875285d..bf6d640de3 100644 --- a/test/files/run/t6261.scala +++ b/test/files/run/t6261.scala @@ -27,6 +27,97 @@ object Test extends App { if(y.getClass.getSimpleName != "HashMap1") println("HashMap of size 1 should use HashMap1" + y.getClass) } + def test3() { + // finds an int x such that improved(x) differs in the first bit to improved(0), + // which is the worst case for the HashTrieSet + def findWorstCaseInts() { + // copy of improve from HashSet + def improve(hcode: Int) = { + var h: Int = hcode + ~(hcode << 9) + h = h ^ (h >>> 14) + h = h + (h << 4) + h ^ (h >>> 10) + } + + // find two hashes which have a large separation + val x = 0 + var y = 1 + val ix = improve(x) + while(y!=0 && improve(y)!=ix+(1<<31)) + y+=1 + printf("%s %s %x %x\n",x,y,improve(x), improve(y)) + } + // this is not done every test run since it would slow down ant test.suite too much. + // findWorstCaseInts() + + // two numbers that are immediately adiacent when fed through HashSet.improve + val h0 = 0 + val h1 = 1270889724 + + // h is the hashcode, i is ignored for the hashcode but relevant for equality + case class Collision(h:Int, i:Int) { + override def hashCode = h + } + val a = Collision(h0,0)->0 + val b = Collision(h0,1)->0 + val c = Collision(h1,0)->0 + + // create a HashSetCollision1 + val x = HashMap(a) + b + if(x.getClass.getSimpleName != "HashMapCollision1") + println("x should be a HashMapCollision") + StructureTests.validate(x) + //StructureTests.printStructure(x) + require(x.size==2 && x.contains(a._1) && x.contains(b._1)) + + // go from a HashSetCollision1 to a HashTrieSet with maximum depth + val y = x + c + if(y.getClass.getSimpleName != "HashTrieMap") + println("y should be a HashTrieMap") + StructureTests.validate(y) + // StructureTests.printStructure(y) + require(y.size==3 && y.contains(a._1) && y.contains(b._1) && y.contains(c._1)) + + // go from a HashSet1 directly to a HashTrieSet with maximum depth + val z = HashMap(a) + c + if(y.getClass.getSimpleName != "HashTrieMap") + println("y should be a HashTrieMap") + StructureTests.validate(z) + // StructureTests.printStructure(z) + require(z.size == 2 && z.contains(a._1) && z.contains(c._1)) + } test1() test2() + test3() +} + + +package scala.collection.immutable { + object StructureTests { + def printStructure(x:HashMap[_,_], prefix:String="") { + x match { + case m:HashMap.HashTrieMap[_,_] => + println(prefix+m.getClass.getSimpleName + " " + m.size) + m.elems.foreach(child => printStructure(child, prefix + " ")) + case m:HashMap.HashMapCollision1[_,_] => + println(prefix+m.getClass.getSimpleName + " " + m.kvs.size) + case m:HashMap.HashMap1[_,_] => + println(prefix+m.getClass.getSimpleName + " " + m.head) + case _ => + println(prefix+"empty") + } + } + + def validate(x:HashMap[_,_]) { + x match { + case m:HashMap.HashTrieMap[_,_] => + require(m.elems.size>1 || (m.elems.size==1 && m.elems(0).isInstanceOf[HashMap.HashTrieMap[_,_]])) + m.elems.foreach(validate _) + case m:HashMap.HashMapCollision1[_,_] => + require(m.kvs.size>1) + case m:HashMap.HashMap1[_,_] => + case _ => + } + } + } } |