Deleting GpuPartition#prefixSum and its unit test cases

#23: Delete unnecessary methods from GpuPartition

Task-Url: http://github.com/meisam/spark/issues/issue/23

core/src/main/scala/org/apache/spark/rdd/GpuPartition.scala

@@ -400,38 +400,6 @@ class GpuPartition[T <: Product : ClassTag]
     clReleaseMemObject(col)
   }
 
-  def prefixSum(counts: Array[Int], prefixSums: Array[Int]): Unit = {
-
-    if (counts.length != prefixSums.length) {
-      throw new IllegalArgumentException("Input and output arrays should have the same size (%,12d != %,12d)".format(counts.length, prefixSums.length))
-    }
-
-    val globalSize = POW_2_S.filter(_ >= counts.length).head
-    val localSize = Math.min(globalSize, BLOCK_SIZE)
-    val global_work_size = Array[Long](globalSize)
-    val local_work_size = Array[Long](localSize)
-
-    // using double buffers to avoid copying data
-    val buffer1 = createReadWriteBuffer[Int](globalSize.toInt)
-    val buffer2 = createReadWriteBuffer[Int](globalSize.toInt)
-    hostToDeviceCopy[Int](Pointer.to(counts), buffer1, counts.length)
-    val kernel = clCreateKernel(context.getOpenCLProgram, "prefix_sum_stage", null)
-    var stride: Int = 0
-
-    var switchedBuffers = true
-
-    while (stride <= counts.length) {
-      clSetKernelArg(kernel, if (switchedBuffers) 0 else 1, Sizeof.cl_mem, Pointer.to(buffer1))
-      clSetKernelArg(kernel, if (switchedBuffers) 1 else 0, Sizeof.cl_mem, Pointer.to(buffer2))
-      clSetKernelArg(kernel, 2, Sizeof.cl_int, Pointer.to(Array[Int](stride)))
-      clEnqueueNDRangeKernel(context.getOpenCLQueue, kernel, 1, null, global_work_size, local_work_size, 0, null, null)
-      switchedBuffers = !switchedBuffers
-      stride = if (stride == 0) 1 else stride << 1
-    }
-    val results = if (switchedBuffers) buffer1 else buffer2
-    deviceToHostCopy[Int](results, Pointer.to(prefixSums), globalSize)
-  }
-
   def getColumn[V: ClassTag](columnIndex: Int): Array[V] = {
     val typeAwareColumnIndex = toTypeAwareColumnIndex(columnIndex)
 

core/src/test/scala/org/apache/spark/gpu/GpuFilteredRDDSuit.scala

@@ -144,50 +144,6 @@ class GpuFilteredRDDSuit extends FunSuite with SharedSparkContext {
     }
   }
 
-  test("kernel.my prefixSum test") {
-    val TEST_DATA_SIZE = 3 + (1 << 14)
-
-    // the test sequence is     (0,1,0,0,1,0,0,1,0,0,1,0,0,1,0,0,1,0,0,...)
-    // the prefix sum should be (0,1,1,1,2,2,2,3,3,3,4,4,4,5,5,5,6,6,6,...)
-    val testData = (0 until TEST_DATA_SIZE).map(_ % 3).map(_ % 2).zipWithIndex
-
-    val chunk = new GpuPartition[(Int, Int)](openCLContext, Array("INT", "INT"), DEFAULT_CAPACITY)
-    chunk.fill(testData.toIterator)
-
-    assert(chunk.intData(0) !== null)
-
-    val expectedResults = (0 until TEST_DATA_SIZE).map(x => (2 + x) / 3).toArray
-    val actualResults = new Array[Int](chunk.intData(0).length)
-
-    chunk.prefixSum(chunk.intData(0), actualResults)
-
-    assert(actualResults !== null)
-    assert(actualResults.length !== expectedResults.length)
-    expectedResults.zip(actualResults).zipWithIndex.foreach { case ((expected, actual), i) =>
-      assert(expected === actual, "The %sths expected %,12d <> %,12d actual".format(i, expected, actual))
-    }
-  }
-
-  test("kernel.my prefixSum small range test test") {
-    val count = 10
-    val testData = (0 until count).map(_ % 2).zipWithIndex
-
-    val chunk = new GpuPartition[(Int, Int)](openCLContext, Array("INT", "INT"), DEFAULT_CAPACITY)
-
-    chunk.fill(testData.toIterator)
-    assert(chunk.intData(0) !== null)
-
-    val expectedResults = Array(0, 1, 1, 2, 2, 3, 3, 4, 4, 5)
-    val actualResults = new Array[Int](chunk.intData(0).length)
-    chunk.prefixSum(chunk.intData(0), actualResults)
-
-    assert(actualResults !== null)
-    assert(actualResults.length !== expectedResults.length)
-    expectedResults.zip(actualResults).zipWithIndex.foreach { case ((expected, actual), i) =>
-      assert(expected === actual, "The %sths expected %,12d <> %,12d actual".format(i, expected, actual))
-    }
-  }
-
   test("org.apache.spark.rdd.GpuRDD.filter test") {
     // This crashes  the OpenCL device
     val testData: IndexedSeq[(Int, Int)] = (0 to 10).reverse.zipWithIndex