Augur-style data encapsulation.
library
defined for a named entity. e.g.Order
struct Data {}
within the library is the abstract data type to be passed around. e.g.Order.Data
- function
create
which returns an instance ofData
. - other related types (such as enum's and constants) are also encapsulated by this library. e.g.
Order.Types
- pure helper functions that compute higher-level information on this entity. e.g.
getOrderId
which computes the ID from the hash of the data
library Order {
struct Data {
// Contracts
IOrders orders;
IMarket market;
IAugur augur;
// Order
bytes32 id;
address creator;
uint256 outcome;
Order.Types orderType;
uint256 amount;
uint256 price;
uint256 sharesEscrowed;
uint256 moneyEscrowed;
bytes32 betterOrderId;
bytes32 worseOrderId;
}
enum Types {
Bid, Ask
}
function create(IController _controller, address _creator, uint256 _outcome, Order.Types _type, uint256 _attoshares, uint256 _price, IMarket _market, bytes32 _betterOrderId, bytes32 _worseOrderId) internal view returns (Data) {
require(_outcome < _market.getNumberOfOutcomes());
require(_price < _market.getNumTicks());
require(_attoshares > 0);
IOrders _orders = IOrders(_controller.lookup("Orders"));
IAugur _augur = _controller.getAugur();
return Data({
orders: _orders,
market: _market,
augur: _augur,
id: 0,
creator: _creator,
outcome: _outcome,
orderType: _type,
amount: _attoshares,
price: _price,
sharesEscrowed: 0,
moneyEscrowed: 0,
betterOrderId: _betterOrderId,
worseOrderId: _worseOrderId
});
}
function getOrderId(Order.Data _orderData) internal view returns (bytes32) {
if (_orderData.id == bytes32(0)) {
bytes32 _orderId = _orderData.orders.getOrderId(_orderData.orderType, _orderData.market, _orderData.amount, _orderData.price, _orderData.creator, block.number, _orderData.outcome, _orderData.moneyEscrowed, _orderData.sharesEscrowed);
require(_orderData.orders.getAmount(_orderId) == 0);
_orderData.id = _orderId;
}
return _orderData.id;
}
}