SERVER-48816 Make a TenantDatabaseCloner skeleton class

1 files changed, 106 insertions, 0 deletions

diff --git a/src/mongo/db/repl/tenant_collection_cloner.h b/src/mongo/db/repl/tenant_collection_cloner.h
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+/**
+ *    Copyright (C) 2020-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 <memory>
+#include <vector>
+
+#include "mongo/db/repl/base_cloner.h"
+#include "mongo/db/repl/task_runner.h"
+#include "mongo/util/progress_meter.h"
+
+namespace mongo {
+namespace repl {
+
+class TenantCollectionCloner : public BaseCloner {
+public:
+    struct Stats {
+        static constexpr StringData kDocumentsToCopyFieldName = "documentsToCopy"_sd;
+        static constexpr StringData kDocumentsCopiedFieldName = "documentsCopied"_sd;
+
+        std::string ns;
+        Date_t start;
+        Date_t end;
+        size_t documentToCopy{0};
+        size_t documentsCopied{0};
+        size_t indexes{0};
+        size_t insertedBatches{0};
+        size_t receivedBatches{0};
+
+        std::string toString() const;
+        BSONObj toBSON() const;
+        void append(BSONObjBuilder* builder) const;
+    };
+
+    TenantCollectionCloner(const NamespaceString& ns,
+                           const CollectionOptions& collectionOptions,
+                           InitialSyncSharedData* sharedData,
+                           const HostAndPort& source,
+                           DBClientConnection* client,
+                           StorageInterface* storageInterface,
+                           ThreadPool* dbPool);
+
+    virtual ~TenantCollectionCloner() = default;
+
+    Stats getStats() const;
+
+protected:
+    ClonerStages getStages() final;
+
+private:
+    std::string describeForFuzzer(BaseClonerStage* stage) const final {
+        return _sourceNss.db() + " db: { " + stage->getName() + ": UUID(\"" +
+            _sourceDbAndUuid.uuid()->toString() + "\") coll: " + _sourceNss.coll() + " }";
+    }
+
+    /**
+     * Temporary no-op stage.
+     */
+    AfterStageBehavior placeholderStage();
+
+    // All member variables are labeled with one of the following codes indicating the
+    // synchronization rules for accessing them.
+    //
+    // (R)  Read-only in concurrent operation; no synchronization required.
+    // (S)  Self-synchronizing; access according to class's own rules.
+    // (M)  Reads and writes guarded by _mutex (defined in base class).
+    // (X)  Access only allowed from the main flow of control called from run() or constructor.
+    const NamespaceString _sourceNss;            // (R)
+    const CollectionOptions _collectionOptions;  // (R)
+    // Despite the type name, this member must always contain a UUID.
+    NamespaceStringOrUUID _sourceDbAndUuid;  // (R)
+
+    ClonerStage<TenantCollectionCloner> _placeholderStage;  // (R)
+
+    Stats _stats;  // (M)
+};
+
+}  // namespace repl
+}  // namespace mongo
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