145 lines
4.0 KiB
C++
145 lines
4.0 KiB
C++
/*
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* LMDB Abstraction Layer.
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* Copyright (C) 2023 Yury Gubich <blue@macaw.me>
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*
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* This program is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#ifndef LMDBAL_CURSOR_HPP
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#define LMDBAL_CURSOR_HPP
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#include "cursor.h"
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template<class K, class V>
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LMDBAL::Cursor<K, V>::Cursor(Storage<K, V>* parent):
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storage(parent),
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cursor(nullptr),
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state(closed)
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{
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}
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template<class K, class V>
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LMDBAL::Cursor<K, V>::~Cursor () {
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close();
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}
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template<class K, class V>
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void LMDBAL::Cursor<K, V>::terminated () const {
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close(); //for now it's the same, but if I ever going to make writable cursor - here is where it's gonna be different
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}
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template<class K, class V>
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void LMDBAL::Cursor<K, V>::open () const {
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storage->ensureOpened(openRecordMethodName);
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switch (state) {
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case closed: {
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TransactionID txn = storage->beginReadOnlyTransaction();
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int result = mdb_cursor_open(txn, storage->dbi, &cursor);
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if (result != MDB_SUCCESS)
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storage->throwUnknown(result, txn);
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storage->transactionStarted(txn, true);
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state = openedPrivate;
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} break;
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default:
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break;
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}
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}
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template<class K, class V>
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void LMDBAL::Cursor<K, V>::open (TransactionID txn) const {
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storage->ensureOpened(openRecordMethodName);
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switch (state) {
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case closed: {
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int result = mdb_cursor_open(txn, storage->dbi, &cursor);
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if (result != MDB_SUCCESS)
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storage->throwUnknown(result);
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state = openedPublic;
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} break;
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default:
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break;
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}
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}
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template<class K, class V>
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void LMDBAL::Cursor<K, V>::renew () const {
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storage->ensureOpened(openRecordMethodName);
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switch (state) {
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case openedPrivate: {
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TransactionID txn = mdb_cursor_txn(cursor);
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storage->abortTransaction(txn);
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storage->transactionAborted(txn);
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[[fallthrough]];
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}
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case openedPublic: {
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TransactionID txn = storage->beginReadOnlyTransaction();
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int result = mdb_cursor_renew(txn, cursor);
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if (result != MDB_SUCCESS)
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storage->throwUnknown(result, txn);
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storage->transactionStarted(txn, true);
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state = openedPrivate;
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} break;
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default:
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break;
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}
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}
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template<class K, class V>
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void LMDBAL::Cursor<K, V>::renew (TransactionID txn) const {
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storage->ensureOpened(openRecordMethodName);
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switch (state) {
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case openedPrivate: {
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TransactionID txn = mdb_cursor_txn(cursor);
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storage->abortTransaction(txn);
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storage->transactionAborted(txn);
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[[fallthrough]];
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}
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case openedPublic: {
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int result = mdb_cursor_renew(txn, cursor);
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if (result != MDB_SUCCESS)
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storage->throwUnknown(result);
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state = openedPublic;
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} break;
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default:
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break;
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}
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}
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template<class K, class V>
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void LMDBAL::Cursor<K, V>::close () const {
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switch (state) {
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case openedPublic: {
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mdb_cursor_close(cursor);
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state = closed;
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} break;
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case openedPrivate: {
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TransactionID txn = mdb_cursor_txn(cursor);
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mdb_cursor_close(cursor);
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storage->abortTransaction(txn);
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storage->transactionAborted(txn);
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state = closed;
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} break;
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default:
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break;
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}
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}
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#endif //LMDBAL_CURSOR_HPP
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