SERVER-52874 Implement validateDBMetadata command

1 files changed, 50 insertions, 0 deletions

diff --git a/src/mongo/db/commands/validate_db_metadata_common.h b/src/mongo/db/commands/validate_db_metadata_common.h
new file mode 100644
index 00000000000..400121a06a1
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+++ b/src/mongo/db/commands/validate_db_metadata_common.h
@@ -0,0 +1,50 @@
+/**
+ *    Copyright (C) 2021-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.
+ */
+
+#pragma once
+
+#include "mongo/bson/util/builder.h"
+#include "mongo/db/commands/validate_db_metadata_gen.h"
+
+namespace mongo {
+
+struct ValidateDBMetadataSizeTracker {
+    bool incrementAndCheckOverflow(const ErrorReplyElement& obj) {
+        // The field name in the array should be at most 7 digits. In addition each element will use
+        // 2 additional bytes for type byte, and null termination of the field name. Note that we
+        // are intentionally over estmating the size the delta here, so that we have sufficient
+        // space for other fields in the output.
+        currentSize += obj.toBSON().objsize() + 15;
+        return currentSize < BSONObjMaxUserSize;
+    }
+
+private:
+    size_t currentSize = 0;
+};
+}  // namespace mongo