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construct/include/ircd/db/delta.h
2017-09-24 18:16:37 -07:00

70 lines
2.5 KiB
C++

/*
* Copyright (C) 2016 Charybdis Development Team
* Copyright (C) 2016 Jason Volk <jason@zemos.net>
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice is present in all copies.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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
#define HAVE_IRCD_DB_DELTA_H
namespace ircd::db
{
enum op
{
GET, // no-op sentinel, do not use (debug asserts)
SET, // (batch.Put)
MERGE, // (batch.Merge)
DELETE, // (batch.Delete)
DELETE_RANGE, // (batch.DeleteRange)
SINGLE_DELETE, // (batch.SingleDelete)
};
struct delta;
// Indicates an op uses both a key and value for its operation. Some only use
// a key name so an empty value argument in a delta is okay when false.
bool value_required(const op &);
string_view reflect(const op &);
}
/// Update a database cell without `cell`, `column` or row `references`.
///
/// The cell is found by name string. This is the least efficient of the deltas
/// for many updates to the same column or cell when a reference to those can
/// be pre-resolved. This delta has to resolve those references every single
/// time it's iterated over; but that's okay for some transactions.
///
struct ircd::db::delta
:std::tuple<op, string_view, string_view, string_view>
{
enum
{
OP, COL, KEY, VAL,
};
delta(const string_view &col, const string_view &key, const string_view &val = {}, const enum op &op = op::SET)
:std::tuple<enum op, string_view, string_view, string_view>{op, col, key, val}
{}
delta(const enum op &op, const string_view &col, const string_view &key, const string_view &val = {})
:std::tuple<enum op, string_view, string_view, string_view>{op, col, key, val}
{}
delta() = default;
};