serial_ob_experiment.cc

/**
 * SPEEDEX: A Scalable, Parallelizable, and Economically Efficient Decentralized Exchange
 * Copyright (C) 2023 Geoffrey Ramseyer

 * 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/>.
 */

#include "cda/serial_ob_experiment.h"

#include "memory_database/memory_database.h"
#include "memory_database/memory_database_view.h"

using xdr::operator==;

namespace speedex {

void
SerialOrderbookExperiment::exec_one_offer(Offer const& offer)
{

	Price max_price = (((uint128_t)1) << (2*price::PRICE_RADIX)) / offer.minPrice;

	BufferedMemoryDatabaseView view(db);

	auto* user = view.lookup_user(offer.owner);

	if (user == nullptr)
	{
		throw std::runtime_error("wtf");
	}

	auto res = view.reserve_sequence_number(user, offer.offerId & 0xFFFF'FFFF'FFFF'FF00);

	if (res != TransactionProcessingStatus::SUCCESS)
	{
		throw std::runtime_error("should not happen in experiments");
		view.unwind();
		return;
	}

	res = view.escrow(user, offer.category.sellAsset, offer.amount, "cda escrow");

	if (res != TransactionProcessingStatus::SUCCESS)
	{
		view.unwind();
		return;
	}

	if (offer.category == a_to_b_cat)
	{
		auto[a_sold, b_recv] = a_to_b.try_execute(max_price, offer.amount, view);

		if (a_sold > offer.amount)
		{
			throw std::runtime_error("invalid");
		}

		view.transfer_available(user, a_to_b_cat.buyAsset, b_recv, "received amount");

		Offer to_add = offer;

		to_add.amount -= a_sold;

		if (to_add.amount > 0)
		{
			b_to_a.add_offer(to_add);
		}
	} 
	else
	{
		auto[b_sold, a_recv] = b_to_a.try_execute(max_price, offer.amount, view);

		if (b_sold > offer.amount)
		{
			throw std::runtime_error("invalid");
		}

		view.transfer_available(user, b_to_a_cat.buyAsset, a_recv, "recv amount");

		Offer to_add = offer;

		to_add.amount -= b_sold;

		if (to_add.amount > 0)
		{
			a_to_b.add_offer(to_add);
		}
	}
	view.commit();
}



} /* speedex */