lmdbal/src/storagecommon.h

/*
 * LMDB Abstraction Layer.
 * Copyright (C) 2023  Yury Gubich <blue@macaw.me>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#pragma once

#include <string>
#include <stdint.h>

#include <lmdb.h>

#include "base.h"
#include "transaction.h"

namespace LMDBAL {

class CursorCommon;

class StorageCommon {
    friend class Base;
    friend class CursorCommon;
public:
protected:
    StorageCommon(Base* parent, const std::string& name, bool duplicates = false);
    virtual ~ StorageCommon();

    /**
    * \brief A private virtual function I need to open each storage in the database
    *
    * \param[in] transaction   - lmdb transaction to call <a class="el" href="http://www.lmdb.tech/doc/group__mdb.html#gac08cad5b096925642ca359a6d6f0562a">mdb_dbi_open</a>
    * \returns MDB_SUCCESS if everything went smooth or MDB_<error> -like error code
    */
    virtual int open(MDB_txn * transaction) = 0;
    virtual void close();
    virtual void handleDrop();

    bool isDBOpened() const;
    const std::string& dbName() const;

    void ensureOpened(const std::string& methodName) const;
    void throwDuplicateOrUnknown(int rc, const std::string& key) const;
    void throwDuplicateOrUnknown(int rc, TransactionID txn, const std::string& key) const;
    void throwNotFoundOrUnknown(int rc, const std::string& key) const;
    void throwNotFoundOrUnknown(int rc, TransactionID txn, const std::string& key) const;
    void throwUnknown(int rc, TransactionID txn) const;
    void throwUnknown(int rc) const;
    void throwUnknown(const std::string& message) const;
    void throwDuplicate(const std::string& key) const;
    void throwNotFound(const std::string& key) const;
    void throwCursorNotReady(const std::string& method) const;

    TransactionID extractTransactionId(const Transaction& txn, const std::string& action = "") const;
    TransactionID beginReadOnlyTransaction() const;
    TransactionID beginTransaction() const;
    void commitTransaction(TransactionID id);
    void abortTransaction(TransactionID id) const;
    virtual void transactionStarted(TransactionID txn, bool readOnly) const;
    virtual void transactionCommited(TransactionID txn);
    virtual void transactionAborted(TransactionID txn) const;
    virtual int drop(TransactionID transaction);
    virtual SizeType count(TransactionID txn) const;

    void openCursorTransaction(MDB_cursor** cursor, bool renew = false) const;
    void closeCursorTransaction(MDB_cursor* cursor, bool closeCursor = false) const;
    void attachCursorToTransaction(uint32_t cursorId, MDB_cursor* cursorHandle, CursorCommon* pointer) const;
    void disconnectCursorFromTransaction(uint32_t cursorId, MDB_cursor* cursorHandle) const;

    int _mdbOpen(MDB_txn* txn, unsigned int flags = 0);

    int _mdbPut(MDB_txn* txn, MDB_val& key, MDB_val& data, unsigned int flags = 0);
    int _mdbGet(MDB_txn* txn, MDB_val& key, MDB_val& data) const;
    int _mdbDel(MDB_txn* txn, MDB_val& key);
    int _mdbDel(MDB_txn* txn, MDB_val& key, MDB_val& data);

    int _mdbStat(MDB_txn* txn, MDB_stat& stat) const;
    int _mdbFlags(MDB_txn* txn, uint32_t& flags) const;

    int _mdbCursorOpen(MDB_txn* txn, MDB_cursor** cursor) const;
    void _mdbCursorClose(MDB_cursor* cursor) const;
    int _mdbCursorGet(MDB_cursor* cursor, MDB_val& key, MDB_val& data, MDB_cursor_op operation) const;
    int _mdbCursorSet(MDB_cursor* cursor, MDB_val& key) const;
    int _mdbCursorDel(MDB_cursor* cursor, unsigned int flags = 0);
    int _mdbCursorPut(MDB_cursor* cursor, MDB_val& key, MDB_val& data, unsigned int flags = 0);

    int _mdbCursorRenew(MDB_txn* txn, MDB_cursor* cursor) const;
    MDB_txn* _mdbCursorTxn(MDB_cursor* cursor) const;

public:
    virtual void drop();
    virtual int drop(const WriteTransaction& txn);
    virtual SizeType count() const;
    virtual SizeType count(const Transaction& txn) const;

protected:
    MDB_dbi dbi;                /**<\brief lmdb storage handle*/
    Base* db;                   /**<\brief parent database pointer (borrowed)*/
    const std::string name;     /**<\brief this storage name*/
    const bool duplicates;      /**<\brief true if storage supports duplicates*/

    inline static const std::string dropMethodName = "drop";                                    /**<\brief member function name, just for exceptions*/
    inline static const std::string countMethodName = "count";                                  /**<\brief member function name, just for exceptions*/
    inline static const std::string flagsMethodName = "flags";                                  /**<\brief member function name, just for exceptions*/

    inline static const std::string addRecordMethodName = "addRecord";                          /**<\brief member function name, just for exceptions*/
    inline static const std::string forceRecordMethodName = "forceRecord";                      /**<\brief member function name, just for exceptions*/
    inline static const std::string changeRecordMethodName = "changeRecord";                    /**<\brief member function name, just for exceptions*/
    inline static const std::string removeRecordMethodName = "removeRecord";                    /**<\brief member function name, just for exceptions*/
    inline static const std::string checkRecordMethodName = "checkRecord";                      /**<\brief member function name, just for exceptions*/
    inline static const std::string getRecordMethodName = "getRecord";                          /**<\brief member function name, just for exceptions*/
    inline static const std::string readAllMethodName = "readAllRecord";                        /**<\brief member function name, just for exceptions*/
    inline static const std::string replaceAllMethodName = "replaceAll";                        /**<\brief member function name, just for exceptions*/
    inline static const std::string addRecordsMethodName = "addRecords";                        /**<\brief member function name, just for exceptions*/
    inline static const std::string openCursorTransactionMethodName = "openCursorTransaction";  /**<\brief member function name, just for exceptions*/

protected:
    template <class K, class V>
    int makeStorage(MDB_txn* transaction, bool duplicates = false);

    template <class T>
    static std::string toString(const T& value);
};

}

#include "storagecommon.hpp"