// Copyright (c) 2018, The Monero Project
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without modification, are
// permitted provided that the following conditions are met:
//
// 1. Redistributions of source code must retain the above copyright notice, this list of
// conditions and the following disclaimer.
//
// 2. Redistributions in binary form must reproduce the above copyright notice, this list
// of conditions and the following disclaimer in the documentation and/or other
// materials provided with the distribution.
//
// 3. Neither the name of the copyright holder nor the names of its contributors may be
// used to endorse or promote products derived from this software without specific
// prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
// THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#pragma once
#include <lmdb.h>
#include <memory>
#include "lmdb/error.h"
//! Uses C++ type system to differentiate between cursors
#define MONERO_CURSOR(name) \
struct close_ ## name : ::lmdb::close_cursor {}; \
using name = std::unique_ptr< MDB_cursor, close_ ## name >;
namespace lmdb
{
struct abort_txn
{
void operator()(MDB_txn* ptr) const noexcept
{
if (ptr)
mdb_txn_abort(ptr);
}
};
/*!
Only valid if used via `create_read_txn()`. Decrements active count in
associated `context`, and aborts a LMDB transaction (`mdb_txn_abort`).
*/
struct release_read_txn
{
void operator()(MDB_txn* ptr) const noexcept;
// implementation in database.cpp
};
/*!
Only valid if used via `create_write_txn()`. Decrements active count in
associated `context`, and aborts a LMDB transaction (`mdb_txn_abort`).
*/
struct abort_write_txn
{
void operator()(MDB_txn* ptr) const noexcept
{
release_read_txn{}(ptr);
}
};
struct close_cursor
{
void operator()(MDB_cursor* ptr) const noexcept
{
if (ptr)
mdb_cursor_close(ptr);
}
};
template<typename D>
inline expect<std::unique_ptr<MDB_cursor, D>>
open_cursor(MDB_txn& txn, MDB_dbi tbl) noexcept
{
MDB_cursor* cur = nullptr;
MONERO_LMDB_CHECK(mdb_cursor_open(&txn, tbl, &cur));
return std::unique_ptr<MDB_cursor, D>{cur};
}
// The below use the C++ type system to designate `MDB_txn` status.
using suspended_txn = std::unique_ptr<MDB_txn, abort_txn>;
using read_txn = std::unique_ptr<MDB_txn, release_read_txn>;
using write_txn = std::unique_ptr<MDB_txn, abort_write_txn>;
} // lmdb
