SERVER-37593 Make wildcard index multikey path set retrieval more efficient

3 files changed, 82 insertions, 3 deletions

diff --git a/src/mongo/dbtests/SConscript b/src/mongo/dbtests/SConscript
index 60f08f368e4..3d45de4cafe 100644
--- a/src/mongo/dbtests/SConscript
+++ b/src/mongo/dbtests/SConscript
@@ -109,6 +109,7 @@ dbtest = env.Program(
         'threadedtests.cpp',
         'updatetests.cpp',
         'validate_tests.cpp',
+        'wildcard_access_method_test.cpp',
         'wildcard_multikey_persistence_test.cpp',
     ],
     LIBDEPS=[
@@ -119,6 +120,7 @@ dbtest = env.Program(
         "$BUILD_DIR/mongo/db/commands/mongod",
         "$BUILD_DIR/mongo/db/commands/test_commands_enabled",
         "$BUILD_DIR/mongo/db/concurrency/deferred_writer",
+        "$BUILD_DIR/mongo/db/index/index_access_methods",
         "$BUILD_DIR/mongo/db/logical_clock",
         "$BUILD_DIR/mongo/db/logical_time_metadata_hook",
         "$BUILD_DIR/mongo/db/pipeline/document_value_test_util",
diff --git a/src/mongo/dbtests/wildcard_access_method_test.cpp b/src/mongo/dbtests/wildcard_access_method_test.cpp
new file mode 100644
index 00000000000..2f24954378a
--- /dev/null
+++ b/src/mongo/dbtests/wildcard_access_method_test.cpp
@@ -0,0 +1,74 @@
+/**
+ *    Copyright (C) 2018-present MongoDB, Inc.
+ *
+ *    This program is free software: you can redistribute it and/or modify
+ *    it under the terms of the Server Side Public License, version 1,
+ *    as published by MongoDB, Inc.
+ *
+ *    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
+ *    Server Side Public License for more details.
+ *
+ *    You should have received a copy of the Server Side Public License
+ *    along with this program. If not, see
+ *    <http://www.mongodb.com/licensing/server-side-public-license>.
+ *
+ *    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 Server Side 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.
+ */
+
+#include "mongo/platform/basic.h"
+
+#include "mongo/bson/json.h"
+#include "mongo/db/index/wildcard_access_method.h"
+#include "mongo/db/query/query_planner_test_lib.h"
+#include "mongo/unittest/unittest.h"
+
+namespace mongo {
+namespace {
+
+void assertCorrectMultikeyMetadataPathBoundsGenerated(StringData field,
+                                                      const BSONObj& expectedBounds) {
+    IndexBounds indexBounds;
+
+    OrderedIntervalList orderedIntervalList;
+    FieldRef fieldRef(field);
+    orderedIntervalList.intervals =
+        WildcardAccessMethod::getMultikeyPathIndexIntervalsForField(std::move(fieldRef));
+
+    indexBounds.fields.push_back(std::move(orderedIntervalList));
+
+    const bool kDoNotRelaxBoundsCheck = false;
+    ASSERT(QueryPlannerTestLib::boundsMatch(
+        expectedBounds, std::move(indexBounds), kDoNotRelaxBoundsCheck));
+}
+
+TEST(WildcardAccessMethodTest, FieldGeneratesExpectedMultikeyPathBounds) {
+    assertCorrectMultikeyMetadataPathBoundsGenerated("foo",
+                                                     fromjson("{'': [['foo','foo',true,true]]}"));
+    assertCorrectMultikeyMetadataPathBoundsGenerated(
+        "foo.bar", fromjson("{'': [['foo','foo',true,true], ['foo.bar','foo.bar',true,true]]}"));
+    assertCorrectMultikeyMetadataPathBoundsGenerated(
+        "foo.0", fromjson("{'': [['foo','foo',true,true], ['foo.','foo/',true,false]]}"));
+    assertCorrectMultikeyMetadataPathBoundsGenerated(
+        "foo.0.bar", fromjson("{'': [['foo','foo',true,true], ['foo.','foo/',true,false]]}"));
+    assertCorrectMultikeyMetadataPathBoundsGenerated(
+        "foo.bar.0",
+        fromjson("{'': [['foo','foo',true,true], ['foo.bar','foo.bar',true,true], "
+                 "['foo.bar.','foo.bar/',true,false]]}"));
+    assertCorrectMultikeyMetadataPathBoundsGenerated(
+        "foo.0.bar.1", fromjson("{'': [['foo','foo',true,true], ['foo.','foo/',true,false]]}"));
+}
+
+}  // namespace
+}  // namespace mongo
diff --git a/src/mongo/dbtests/wildcard_multikey_persistence_test.cpp b/src/mongo/dbtests/wildcard_multikey_persistence_test.cpp
index e7b48c4f98e..0c167e340f4 100644
--- a/src/mongo/dbtests/wildcard_multikey_persistence_test.cpp
+++ b/src/mongo/dbtests/wildcard_multikey_persistence_test.cpp
@@ -35,7 +35,9 @@
 #include "mongo/db/catalog/multi_index_block.h"
 #include "mongo/db/catalog/multi_index_block_impl.h"
 #include "mongo/db/db_raii.h"
+#include "mongo/db/index/wildcard_access_method.h"
 #include "mongo/db/repl/storage_interface_impl.h"
+#include "mongo/db/storage/sorted_data_interface.h"
 #include "mongo/unittest/unittest.h"
 #include "mongo/util/log.h"
 
@@ -138,7 +140,8 @@ protected:
         AutoGetCollectionForRead autoColl(opCtx(), nss);
         auto collection = autoColl.getCollection();
         auto indexAccessMethod = getIndex(collection, indexName);
-        auto multikeyPathSet = indexAccessMethod->getMultikeyPathSet(opCtx());
+        MultikeyMetadataAccessStats stats;
+        auto multikeyPathSet = indexAccessMethod->getMultikeyPathSet(opCtx(), &stats);
 
         ASSERT(expectedFieldRefs == multikeyPathSet);
     }
@@ -218,11 +221,11 @@ protected:
         return collection->getIndexCatalog()->findIndexByName(opCtx(), indexName);
     }
 
-    const IndexAccessMethod* getIndex(const Collection* collection, const StringData indexName) {
+    IndexAccessMethod* getIndex(Collection* collection, const StringData indexName) {
         return collection->getIndexCatalog()->getIndex(getIndexDesc(collection, indexName));
     }
 
-    std::unique_ptr<SortedDataInterface::Cursor> getIndexCursor(const Collection* collection,
+    std::unique_ptr<SortedDataInterface::Cursor> getIndexCursor(Collection* collection,
                                                                 const StringData indexName) {
         return getIndex(collection, indexName)->newCursor(opCtx());
     }