SERVER-33503: Complete timestamping multikey updates for background index builds.

1 files changed, 95 insertions, 0 deletions

diff --git a/src/mongo/db/multi_key_path_tracker_test.cpp b/src/mongo/db/multi_key_path_tracker_test.cpp
new file mode 100644
index 00000000000..ecbddb1e6ef
--- /dev/null
+++ b/src/mongo/db/multi_key_path_tracker_test.cpp
@@ -0,0 +1,95 @@
+/**
+ *    Copyright (C) 2018 MongoDB Inc.
+ *
+ *    This program is free software: you can redistribute it and/or  modify
+ *    it under the terms of the GNU Affero General Public License, version 3,
+ *    as published by the Free Software Foundation.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    GNU Affero General Public License for more details.
+ *
+ *    You should have received a copy of the GNU Affero General Public License
+ *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ *    As a special exception, the copyright holders give permission to link the
+ *    code of portions of this program with the OpenSSL library under certain
+ *    conditions as described in each individual source file and distribute
+ *    linked combinations including the program with the OpenSSL library. You
+ *    must comply with the GNU Affero General Public License in all respects
+ *    for all of the code used other than as permitted herein. If you modify
+ *    file(s) with this exception, you may extend this exception to your
+ *    version of the file(s), but you are not obligated to do so. If you do not
+ *    wish to do so, delete this exception statement from your version. If you
+ *    delete this exception statement from all source files in the program,
+ *    then also delete it in the license file.
+ */
+
+/**
+ * Unittest for MultikeyPathTracker operations.
+ */
+
+#include "mongo/platform/basic.h"
+
+#include <sstream>
+
+#include "mongo/db/multi_key_path_tracker.h"
+#include "mongo/unittest/unittest.h"
+#include "mongo/util/mongoutils/str.h"
+
+namespace mongo {
+namespace {
+
+std::string dumpMultikeyPaths(const MultikeyPaths& multikeyPaths) {
+    std::stringstream ss;
+
+    ss << "[ ";
+    for (const auto multikeyComponents : multikeyPaths) {
+        ss << "[ ";
+        for (const auto multikeyComponent : multikeyComponents) {
+            ss << multikeyComponent << " ";
+        }
+        ss << "] ";
+    }
+    ss << "]";
+
+    return ss.str();
+}
+
+void assertMultikeyPathsAreEqual(const MultikeyPaths& actual, const MultikeyPaths& expected) {
+    bool match = (expected == actual);
+    if (!match) {
+        FAIL(str::stream() << "Expected: " << dumpMultikeyPaths(expected) << ", "
+                           << "Actual: "
+                           << dumpMultikeyPaths(actual));
+    }
+    ASSERT(match);
+}
+
+TEST(MultikeyPathTracker, TestMergeMultikeyPaths) {
+    // Suppose the index key is {"a.c": 1, "a.b": 1, "c.d.b.e": 1}.
+    MultikeyPaths mutablePaths = {{}, {}, {}};
+    {
+        // `foundPaths` finds `a` to be multikey.
+        MultikeyPaths foundPaths = {{0}, {0}, {}};
+        MultikeyPathTracker::mergeMultikeyPaths(&mutablePaths, foundPaths);
+        assertMultikeyPathsAreEqual(mutablePaths, foundPaths);
+    }
+
+    {
+        // `foundPaths` finds `c` and `d` to be multikey.
+        MultikeyPaths foundPaths = {{1}, {}, {0, 1}};
+        MultikeyPathTracker::mergeMultikeyPaths(&mutablePaths, foundPaths);
+        assertMultikeyPathsAreEqual(mutablePaths, {{0, 1}, {0}, {0, 1}});
+    }
+
+    {
+        // `foundPaths` finds `b` to be multikey.
+        MultikeyPaths foundPaths = {{}, {1}, {2}};
+        MultikeyPathTracker::mergeMultikeyPaths(&mutablePaths, foundPaths);
+        assertMultikeyPathsAreEqual(mutablePaths, {{0, 1}, {0, 1}, {0, 1, 2}});
+    }
+}
+}  // namespace
+}  // namespace mongo