[#1415] Check done flag for permutation

As suggested in the review comment, the unit test is now checking if the
done flag returned by the IP range permutation is set to false when the
permutation is not done returning addresses.

Author: msiodelski

src/lib/dhcpsrv/tests/ip_range_permutation_unittest.cc

@@ -41,19 +41,24 @@ TEST(IPRangePermutationTest, ipv4) {
     std::set<IOAddress> addrs;
     bool done = false;
 
-    // Call the next() function 95 tims. The first 91 calls should return non-zero
+    // Call the next() function 95 times. The first 91 calls should return non-zero
     // IP addresses.
     for (auto i = 0; i < 95; ++i) {
         auto next = perm.next(done);
         if (!next.isV4Zero()) {
             // Make sure the returned address is within the range.
             EXPECT_LE(range.start_, next);
             EXPECT_LE(next, range.end_);
-        } else {
-            // The IPv4 zero address marks the end of the permutation. In this case
-            // the done flag should be set.
+        }
+        // If we went over all addresses in the range, the flags indicating that
+        // the permutation is exhausted should be set to true.
+        if (i >= 90) {
             EXPECT_TRUE(done);
             EXPECT_TRUE(perm.exhausted());
+        } else {
+            // We're not done yet, so these flag should still be false.
+            EXPECT_FALSE(done);
+            EXPECT_FALSE(perm.exhausted());
         }
         // Insert the address returned to the set.
         addrs.insert(next);
@@ -68,21 +73,27 @@ TEST(IPRangePermutationTest, ipv4) {
 // be generated.
 TEST(IPRangePermutationTest, ipv6) {
     AddressRange range(IOAddress("2001:db8:1::1:fea0"),
-                                    IOAddress("2001:db8:1::2:abcd"));
+                       IOAddress("2001:db8:1::2:abcd"));
     IPRangePermutation perm(range);
 
     std::set<IOAddress> addrs;
     bool done = false;
     for (auto i = 0; i < 44335; ++i) {
         auto next = perm.next(done);
         if (!next.isV6Zero()) {
-            // The IPv6 zero address marks the end of the permutation. In this case
-            // the done flag should be set.
+            // Make sure that the address is within the range.
             EXPECT_LE(range.start_, next);
             EXPECT_LE(next, range.end_);
-        } else {
+        }
+        // If we went over all addresses in the range, the flags indicating that
+        // the permutation is exhausted should be set to true.
+        if (i >= 44333) {
             EXPECT_TRUE(done);
             EXPECT_TRUE(perm.exhausted());
+        } else {
+            // We're not done yet, so these flag should still be false.
+            EXPECT_FALSE(done);
+            EXPECT_FALSE(perm.exhausted());
         }
         // Insert the address returned to the set.
         addrs.insert(next);
@@ -103,15 +114,21 @@ TEST(IPRangePermutationTest, pd) {
     for (auto i = 0; i < 257; ++i) {
         auto next = perm.next(done);
         if (!next.isV6Zero()) {
-            // The IPv6 zero address marks the end of the permutation. In this case
-            // the done flag should be set.
+            // Make sure the prefix is within the range.
             EXPECT_LE(range.start_, next);
             EXPECT_LE(next, range.end_);
-        } else {
+        }
+        // If we went over all delegated prefixes in the range, the flags indicating
+        // that the permutation is exhausted should be set to true.
+        if (i >= 255) {
             EXPECT_TRUE(done);
             EXPECT_TRUE(perm.exhausted());
+        } else {
+            // We're not done yet, so these flag should still be false.
+            EXPECT_FALSE(done);
+            EXPECT_FALSE(perm.exhausted());
         }
-        // Insert the address returned to the set.
+        // Insert the prefix returned to the set.
         addrs.insert(next);
     }