# Orderbook
> **FUNCTIONS**
>
> exists(\_orderId)
>
> ordersLength()
>
> verifyOrdersExist(\_orderIds)
>
> verifyAllOrdersData(\_orderIds, \_isBuyOrder)
>
> verifyOrderOwners(\_orderIds, \_owner)
>
> verifyOrdersReady(\_orderIds)
>
> getOrderAmounts(\_orderIds, amountToFill, maxSpend)
>
> getPaymentTotals(\_orderIds*, \_*amounts)
>
> getOrder(\_orderId)
>
> placeOrder(\_order)
>
> fillOrders(\_orderIds, \_amounts)
>
> cancelOrders(\_orderIds)
>
> claimOrders(\_orderIds)
| exists(uint256 \_orderId) -> bool |
| ----------------------------------------------------------- |
| Verifies whether the order `_orderId` has ever been placed. |
| visibility: external |
| state mutability: view |
| ordersLength() -> uint256 |
| ------------------------------------------------------------------------- |
| Returns the total number of orders that have been placed on the exchange. |
| visibility: external |
| state mutability: view |
| verifyOrdersExist(uint256\[] \_orderIds) -> bool |
| -------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| Runs a loop of the `exists` function to verify that all the orders in `_orderIds` exist and have been placed on the exchange. |
| visibility: external |
| state mutability: view |
| verifyAllOrdersData(uint256\[] \_orderIds, bool \_isBuyOrder) -> bool |
| ------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| Verifies whether all the orders in `_orderIds` reference the same asset and token payment. And it checks that all the orders' buy/sell order type matches `_isBuyOrder`. |
| visibility: external |
| state mutability: view |
| verifyOrderOwners(uint256\[] \_orderIds, address \_owner) -> bool |
| ------------------------------------------------------------------------- |
| Verifies whether the owner of the orders in `_orderIds` matches `_owner`. |
| visibility: external |
| state mutability: view |
| verifyOrdersReady(uint256\[] \_orderIds) -> bool |
| --------------------------------------------------------------------------- |
| Verifies whether all the orders in `_orderIds` are still available to fill. |
| visibility: external |
| state mutability: view |
| getOrderAmounts(uint256\[] \_orderIds, uint256 amountToFill, uint256 maxSpend) -> uint256\[], uint256 |
| ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| Returns the amount of the asset to be filled from each order in `_orderIds`. The sum of which cannot exceed `amountToFill`, and the cumulative price cannot exceed `maxSpend`. |
| visibility: external |
| state mutability: view |
| getPaymentTotals(uint256\[] \_orderIds, uint256\[] \_amounts) -> uint256, uint256\[] |
| ----------------------------------------------------------------------------------------------------------------------- |
| Returns the token payment to be paid for each order in `orderIds` and the cumulative payment for the entire fill order. |
| visibility: external |
| state mutability: view |
| getOrder(uint256 \_orderId) -> LibOrder.Order |
| ------------------------------------------------------------------------------------------------------------------- |
| Returns the order information of `_orderId`. |
| Order structure object. See [LibOrder.sol](https://docs.rawrshak.io/developers/smart-contracts/libraries/liborder). |
| visibility: external |
| state mutability: view |
| placeOrder(LibOrder.OrderInput \_order) -> uint256 |
| --------------------------------------------------------------------------------------------------------------------------------- |
| Places an order on the exchange with order information `_order` and returns the assigned order Id. |
| `_order` OrderInput structure object. See [LibOrder.sol](https://docs.rawrshak.io/developers/smart-contracts/libraries/liborder). |
| Requirements:
- The token payment must be on the list of supported ERC20 tokens.
|
| visibility: external |
| state mutability: |
| fillOrders(uint256\[] \_orderIds, uint256\[] \_amounts) |
| --------------------------------------------------------------------------------------------------- |
| Updates the order information of `_orderIds` as to the amount of assets filled and its order state. |
| visibility: external |
| state mutability: |
| cancelOrders(uint256\[] \_orderIds) |
| ----------------------------------------------------------------------------------------------------------------- |
| Updates the order state of `_orderIds` to "CANCELLED". |
| Requirement:
- The order state of the orders must either be "READY" or "PARTIALLY\_FILLED".
|
| visibility: external |
| state mutability: |
| claimOrders(uint256\[] \_orderIds) |
| ------------------------------------------------------------------------------------------------------------------- |
| Updates the order state of `_orderIds` to "CLAIMED" if the order is completely filled and the owner has claimed it. |
| visibility: external |
| state mutability: |
---
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