Fix sort test.

https://codereview.appspot.com/7199050/

git-svn-id: http://skia.googlecode.com/svn/trunk@7364 2bbb7eff-a529-9590-31e7-b0007b416f81

diff --git a/tests/SortTest.cpp b/tests/SortTest.cpp
index 4783ba9..b9c32fd 100644 (file)
--- a/tests/SortTest.cpp
+++ b/tests/SortTest.cpp
@@ -22,34 +22,41 @@ static void rand_array(SkRandom& rand, int array[], int n) {
 }
 
 static void check_sort(skiatest::Reporter* reporter, const char label[],
-                       const int array[], int n) {
-    for (int j = 1; j < n; j++) {
-        if (array[j-1] > array[j]) {
+                       const int array[], const int reference[], int n) {
+    for (int j = 0; j < n; ++j) {
+        if (array[j] != reference[j]) {
             SkString str;
-           str.printf("%sSort [%d] failed %d %d", label, n,
-                      array[j-1], array[j]);
+            str.printf("%sSort [%d] failed %d %d", label, n, array[j], reference[j]);
             reporter->reportFailed(str);
         }
     }
 }
 
 static void TestSort(skiatest::Reporter* reporter) {
-    int         array[500];
+    /** An array of random numbers to be sorted. */
+    int randomArray[500];
+    /** The reference sort of the random numbers. */
+    int sortedArray[SK_ARRAY_COUNT(randomArray)];
+    /** The random numbers are copied into this array, sorted by an SkSort,
+        then this array is compared against the reference sort. */
+    int workingArray[SK_ARRAY_COUNT(randomArray)];
     SkRandom    rand;
 
     for (int i = 0; i < 10000; i++) {
-        int count = rand.nextRangeU(1, SK_ARRAY_COUNT(array));
+        int count = rand.nextRangeU(1, SK_ARRAY_COUNT(randomArray));
+        rand_array(rand, randomArray, count);
+ 
+        // Use qsort as the reference sort.
+        memcpy(sortedArray, randomArray, sizeof(randomArray));
+        qsort(sortedArray, count, sizeof(sortedArray[0]), compare_int);
 
-        rand_array(rand, array, count);
-        SkTHeapSort<int>(array, count);
-        check_sort(reporter, "Heap", array, count);
+        memcpy(workingArray, randomArray, sizeof(randomArray));
+        SkTHeapSort<int>(workingArray, count);
+        check_sort(reporter, "Heap", workingArray, sortedArray, count);
 
-        rand_array(rand, array, count);
-        SkTQSort<int>(array, array + count - 1);
-        check_sort(reporter, "Quick", array, count);
-    }
-    if (false) { // avoid bit rot, suppress warning
-        compare_int(array, array);
+        memcpy(workingArray, randomArray, sizeof(randomArray));
+        SkTQSort<int>(workingArray, workingArray + count - 1);
+        check_sort(reporter, "Quick", workingArray, sortedArray, count);
     }
 }