SERVER-23092 Collation-aware index key generation

1 files changed, 126 insertions, 0 deletions

diff --git a/src/mongo/db/index/hash_key_generator_test.cpp b/src/mongo/db/index/hash_key_generator_test.cpp
new file mode 100644
index 00000000000..047c59b9994
--- /dev/null
+++ b/src/mongo/db/index/hash_key_generator_test.cpp
@@ -0,0 +1,126 @@
+/**
+ *    Copyright (C) 2014 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.
+ */
+
+#define MONGO_LOG_DEFAULT_COMPONENT ::mongo::logger::LogComponent::kIndex
+
+#include "mongo/platform/basic.h"
+
+#include "mongo/db/index/expression_keys_private.h"
+
+#include "mongo/bson/bsonobjbuilder.h"
+#include "mongo/db/hasher.h"
+#include "mongo/db/json.h"
+#include "mongo/db/query/collation/collator_interface_mock.h"
+#include "mongo/unittest/unittest.h"
+#include "mongo/util/log.h"
+
+using namespace mongo;
+
+namespace {
+
+const HashSeed kHashSeed = 0;
+const int kHashVersion = 0;
+
+std::string dumpKeyset(const BSONObjSet& objs) {
+    std::stringstream ss;
+    ss << "[ ";
+    for (BSONObjSet::iterator i = objs.begin(); i != objs.end(); ++i) {
+        ss << i->toString() << " ";
+    }
+    ss << "]";
+
+    return ss.str();
+}
+
+bool assertKeysetsEqual(const BSONObjSet& expectedKeys, const BSONObjSet& actualKeys) {
+    if (expectedKeys != actualKeys) {
+        log() << "Expected: " << dumpKeyset(expectedKeys) << ", "
+              << "Actual: " << dumpKeyset(actualKeys);
+        return false;
+    }
+    return true;
+}
+
+BSONObj makeHashKey(BSONElement elt) {
+    return BSON("" << BSONElementHasher::hash64(elt, kHashSeed));
+}
+
+TEST(HashKeyGeneratorTest, CollationAppliedBeforeHashing) {
+    BSONObj obj = fromjson("{a: 'string'}");
+    BSONObjSet actualKeys;
+    CollatorInterfaceMock collator(CollatorInterfaceMock::MockType::kReverseString);
+    ExpressionKeysPrivate::getHashKeys(
+        obj, "a", kHashSeed, kHashVersion, false, &collator, &actualKeys);
+
+    BSONObj backwardsObj = fromjson("{a: 'gnirts'}");
+    BSONObjSet expectedKeys;
+    expectedKeys.insert(makeHashKey(backwardsObj["a"]));
+
+    ASSERT(assertKeysetsEqual(expectedKeys, actualKeys));
+}
+
+TEST(HashKeyGeneratorTest, CollationDoesNotAffectNonStringFields) {
+    BSONObj obj = fromjson("{a: 5}");
+    BSONObjSet actualKeys;
+    CollatorInterfaceMock collator(CollatorInterfaceMock::MockType::kReverseString);
+    ExpressionKeysPrivate::getHashKeys(
+        obj, "a", kHashSeed, kHashVersion, false, &collator, &actualKeys);
+
+    BSONObjSet expectedKeys;
+    expectedKeys.insert(makeHashKey(obj["a"]));
+
+    ASSERT(assertKeysetsEqual(expectedKeys, actualKeys));
+}
+
+// TODO SERVER-23172: remove test.
+TEST(HashKeyGeneratorTest, CollationDoesNotAffectStringsInEmbeddedDocuments) {
+    BSONObj obj = fromjson("{a: {b: 'string'}}");
+    BSONObjSet actualKeys;
+    CollatorInterfaceMock collator(CollatorInterfaceMock::MockType::kReverseString);
+    ExpressionKeysPrivate::getHashKeys(
+        obj, "a", kHashSeed, kHashVersion, false, &collator, &actualKeys);
+
+    BSONObjSet expectedKeys;
+    expectedKeys.insert(makeHashKey(obj["a"]));
+
+    ASSERT(assertKeysetsEqual(expectedKeys, actualKeys));
+}
+
+TEST(HashKeyGeneratorTest, NoCollation) {
+    BSONObj obj = fromjson("{a: 'string'}");
+    BSONObjSet actualKeys;
+    ExpressionKeysPrivate::getHashKeys(
+        obj, "a", kHashSeed, kHashVersion, false, nullptr, &actualKeys);
+
+    BSONObjSet expectedKeys;
+    expectedKeys.insert(makeHashKey(obj["a"]));
+
+    ASSERT(assertKeysetsEqual(expectedKeys, actualKeys));
+}
+
+}  // namespace