Use new algorithm to get fixed random order of disks (#2147)

xl-v1_test.go

@@ -19,6 +19,7 @@ package main
 import (
 	"os"
 	"path/filepath"
+	"reflect"
 	"testing"
 )
 
@@ -136,3 +137,30 @@ func TestNewXL(t *testing.T) {
 		t.Fatalf("Unable to initialize erasure, %s", err)
 	}
 }
+
+// TestHashOrder - test order of ints in array
+func TestHashOrder(t *testing.T) {
+	testCases := []struct {
+		objectName  string
+		hashedOrder []int
+	}{
+		// cases which should pass the test.
+		// passing in valid object name.
+		{"object", []int{15, 16, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14}},
+		{"The Shining Script <v1>.pdf", []int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16}},
+		{"Cost Benefit Analysis (2009-2010).pptx", []int{15, 16, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14}},
+		{"117Gn8rfHL2ACARPAhaFd0AGzic9pUbIA/5OCn5A", []int{3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 1, 2}},
+		{"SHØRT", []int{11, 12, 13, 14, 15, 16, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10}},
+		{"There are far too many object names, and far too few bucket names!", []int{15, 16, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14}},
+		{"a/b/c/", []int{3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 1, 2}},
+		{"/a/b/c", []int{7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 1, 2, 3, 4, 5, 6}},
+		{string([]byte{0xff, 0xfe, 0xfd}), []int{15, 16, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14}},
+	}
+
+	for i, testCase := range testCases {
+		hashedOrder := hashOrder(testCase.objectName, 16)
+		if !reflect.DeepEqual(testCase.hashedOrder, hashedOrder) {
+			t.Errorf("Test case %d: Expected \"%#v\" but failed \"%#v\"", i+1, testCase.hashedOrder, hashedOrder)
+		}
+	}
+}