SERVER-39778 Create WouldChangeOwningShard exception

1 files changed, 98 insertions, 0 deletions

diff --git a/src/mongo/s/would_change_owning_shard_exception.h b/src/mongo/s/would_change_owning_shard_exception.h
new file mode 100644
index 00000000000..ad5f36081b6
--- /dev/null
+++ b/src/mongo/s/would_change_owning_shard_exception.h
@@ -0,0 +1,98 @@
+/**
+ *    Copyright (C) 2019-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/base/error_extra_info.h"
+#include "mongo/bson/bsonobj.h"
+#include "mongo/bson/bsonobjbuilder.h"
+
+namespace mongo {
+
+/**
+ * This error is thrown when an update would cause a document to be owned by a different
+ * shard. If the update is part of a multi statement transaction, we will attach the
+ * query from the original update and the post image returned by the update stage. MongoS
+ * will use these to delete the original doc and insert the new doc. If the update is a
+ * retryable write, we will attach both the query and the update fields from the original
+ * update command. MongoS will use these to start an internal transaction and re-run the
+ * update command.
+ */
+class WouldChangeOwningShardInfo final : public ErrorExtraInfo {
+public:
+    static constexpr auto code = ErrorCodes::WouldChangeOwningShard;
+
+    explicit WouldChangeOwningShardInfo(const BSONObj& originalQueryPredicate,
+                                        const boost::optional<BSONObj>& originalUpdate,
+                                        const boost::optional<BSONObj>& postImage)
+        : _originalQueryPredicate(originalQueryPredicate.getOwned()) {
+        invariant(!(originalUpdate && postImage));
+        invariant(originalUpdate || postImage);
+
+        if (originalUpdate)
+            _originalUpdate = originalUpdate->getOwned();
+        if (postImage)
+            _postImage = postImage->getOwned();
+    }
+
+    const auto& getOriginalQueryPredicate() const {
+        return _originalQueryPredicate;
+    }
+
+    const auto& getOriginalUpdate() const {
+        return _originalUpdate;
+    }
+
+    const auto& getPostImage() const {
+        return _postImage;
+    }
+
+    BSONObj toBSON() const {
+        BSONObjBuilder bob;
+        serialize(&bob);
+        return bob.obj();
+    }
+
+    void serialize(BSONObjBuilder* bob) const override;
+    static std::shared_ptr<const ErrorExtraInfo> parse(const BSONObj&);
+    static WouldChangeOwningShardInfo parseFromCommandError(const BSONObj& commandError);
+
+private:
+    // the 'q' portion of the original update comamand
+    BSONObj _originalQueryPredicate;
+
+    // The 'u' portion of the original update command
+    boost::optional<BSONObj> _originalUpdate;
+
+    // The post image returned by the update stage
+    boost::optional<BSONObj> _postImage;
+};
+using WouldChangeOwningShardException = ExceptionFor<ErrorCodes::WouldChangeOwningShard>;
+
+}  // namespace mongo