1 files changed, 69 insertions, 0 deletions
diff --git a/src/mongo/rpc/metadata.cpp b/src/mongo/rpc/metadata.cpp
new file mode 100644
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+++ b/src/mongo/rpc/metadata.cpp
@@ -0,0 +1,69 @@
+/**
+ *    Copyright (C) 2015 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.
+ */
+
+#include "mongo/platform/basic.h"
+
+#include "mongo/rpc/metadata.h"
+
+#include "mongo/client/dbclientinterface.h"
+#include "mongo/db/jsobj.h"
+
+namespace mongo {
+namespace rpc {
+namespace metadata {
+
+    BSONObj empty() {
+        return BSONObj();
+    }
+
+    const char kSecondaryOk[] = "$secondaryOk";
+
+    StatusWith<CommandAndMetadata> upconvertRequest(BSONObj legacyCmdObj, int queryFlags) {
+        BSONObjBuilder metadataBob;
+
+        // note second check may be erroneous: see SERVER-18194
+        if ((queryFlags & QueryOption_SlaveOk)) {
+            metadataBob.append(kSecondaryOk, 1);
+        }
+
+        return std::make_tuple(std::move(legacyCmdObj), std::move(metadataBob.obj()));
+    }
+
+    StatusWith<LegacyCommandAndFlags> downconvertRequest(BSONObj cmdObj, BSONObj metadata) {
+        int flags = 0;
+
+        if (metadata.hasField(kSecondaryOk)) {
+            flags |= QueryOption_SlaveOk;
+        }
+
+        return std::make_tuple(std::move(cmdObj), flags);
+    }
+
+}  // namespace metadata
+}  // namespace rpc
+}  // namespace mongo