Forwarder

Forwarder

Each offer posted via this contract are managed by their offer maker, not by this contract's admin. This class implements IForwarder, which contains specific Forwarder logic functions in additions to IOfferLogic interface.

GAS_APPROX

uint256 GAS_APPROX

approx of amount of gas units required to complete __posthookFallback__ when evaluating penalty.

OwnerData

data associated to each offer published on Mangrove by this contract.

OwnerData packs into one word.

Parameters

Name	Type	Description

struct OwnerData {
  address owner;
  uint96 weiBalance;
}

ownerData

mapping(bytes32 => mapping(uint256 => struct Forwarder.OwnerData)) ownerData

Owner data mapping.

mapping is olKeyHash -> offerId -> OwnerData 'ownerData[olKeyHash][offerId].owner == makerifmakeris offer owner ofofferIdin the(out, in)` offer list.

onlyOwner

modifier onlyOwner(bytes32 olKeyHash, uint256 offerId)

modifier to enforce function caller to be offer owner

mgvOrOwner

modifier mgvOrOwner(bytes32 olKeyHash, uint256 offerId)

modifier to enforce function caller to be offer owner or MGV (for use in the offer logic)

constructor

constructor(contract IMangrove mgv, contract AbstractRouter router) internal

Forwarder constructor

Parameters

Name	Type	Description
mgv	contract IMangrove	the deployed Mangrove contract on which this contract will post offers.
router	contract AbstractRouter	the router that this contract will use to pull/push liquidity from offer maker's reserve. This must not be NO_ROUTER.

setRouter

function setRouter(contract AbstractRouter router) public virtual

offerOwners

function offerOwners(bytes32 olKeyHash, uint256[] offerIds) public view returns (address[] offerOwners_)

view on offer owners.

if offerIds[i]==address(0) if and only if this offer has no owner.

Parameters

Name	Type	Description
olKeyHash	bytes32	the hash of the offer list key.
offerIds	uint256[]	an array of offer identifiers on the offer list.

Return Values

Name	Type	Description
offerOwners_	address[]

addOwner

function addOwner(bytes32 olKeyHash, uint256 offerId, address owner, uint256 leftover) internal

grants managing (update/retract) rights on a particular offer.

Parameters

Name	Type	Description
olKeyHash	bytes32	the hash of the offer list key.
offerId	uint256	the offer identifier in the offer list.
owner	address	the address of the offer maker.
leftover	uint256	the fraction of msg.value that is not locked in the offer provision due to rounding error (see _newOffer).

deriveGasprice

function deriveGasprice(uint256 gasreq, uint256 provision, uint256 offerGasbase) internal pure returns (uint256 gasprice, uint256 leftover)

computes the maximum gasprice that can be covered by the amount of provision given in argument.

the returned gasprice is slightly lower than the real gasprice that the provision can cover because of the rounding error due to division

Parameters

Name	Type	Description
gasreq	uint256	the gas required by the offer
provision	uint256	the amount of native token one wishes to use, to provision the offer on Mangrove.
offerGasbase	uint256	Mangrove's offer_gasbase.

Return Values

Name	Type	Description
gasprice	uint256	the gas price that is covered by provision - leftover.
leftover	uint256	the sub amount of provision that is not used to provision the offer.

ownerOf

function ownerOf(bytes32 olKeyHash, uint256 offerId) public view returns (address owner)

view on an offer owner.

ownerOf(in,out,id) is equivalent to offerOwners(in, out, [id]) but more gas efficient.

Parameters

Name	Type	Description
olKeyHash	bytes32	the hash of the offer list key.
offerId	uint256	the offer identifier on the offer list.

Return Values

Name	Type	Description
owner	address	the offer maker that can manage the offer.

deriveAndCheckGasprice

function deriveAndCheckGasprice(struct IOfferLogic.OfferArgs args) internal view returns (uint256 gasprice, uint256 leftover)

Derives the gas price for the new offer and verifies it against the global configuration.

the returned gasprice is slightly lower than the real gasprice that the provision can cover because of the rounding error due to division

Parameters

Name	Type	Description
args	struct IOfferLogic.OfferArgs	function's arguments in memory

Return Values

Name	Type	Description
gasprice	uint256	the gas price that is covered by provision - leftover.
leftover	uint256	the sub amount of provision that is not used to provision the offer.

_newOffer

function _newOffer(struct IOfferLogic.OfferArgs args, address owner) internal returns (uint256 offerId, bytes32 status)

Inserts a new offer on a Mangrove Offer List.

_If inside a hook, one should call _newOffer to create a new offer and not directly MGV.newOffer to make sure one is correctly dealing with:

• offer ownership
• offer provisions and gasprice_

Parameters

Name	Type	Description
args	struct IOfferLogic.OfferArgs	function's arguments in memory
owner	address	the address of the offer owner

Return Values

Name	Type	Description
offerId	uint256	the identifier of the new offer on the offer list. Can be 0 if posting was rejected by Mangrove and args.noRevert is true.
status	bytes32	the status of the new offer on Mangrove if the call has not reverted. It may be NEW_OFFER_SUCCESS or Mangrove's revert reason if args.noRevert was set to true. Forwarder logic does not manage user funds on Mangrove, as a consequence: An offer maker's redeemable provisions on Mangrove is just the sum $S_locked(maker)$ of locked provision in all live offers it owns plus the sum $S_free(maker)$ of weiBalance's in all dead offers it owns (see OwnerData.weiBalance). Notice $\sum_i S_free(maker_i)$ <= MGV.balanceOf(address(this)). Any fund of an offer maker on Mangrove that is either not locked on Mangrove or stored in the OwnerDatafree wei's is thus not recoverable by the offer maker (although it is admin recoverable). Therefore we need to make sure that allmsg.valueis either used to provision the offer atgaspriceor stored in the offer data underweiBalance. To do so, we do not let offer maker fix a gasprice. Rather we derive the gasprice based on msg.value. Because of rounding errors in deriveGaspricea small amount of WEIs will accumulate in mangrove's balance ofthiscontract We assign this leftover to the correspondingweiBalanceofOwnerData`.

UpdateOfferVars

struct UpdateOfferVars {
  uint256 leftover;
  Global global;
  Local local;
  OfferDetail offerDetail;
}

_updateOffer

function _updateOffer(struct IOfferLogic.OfferArgs args, uint256 offerId) internal returns (bytes32 reason)

Internal updateOffer, using arguments and variables on memory to avoid stack too deep.

Parameters

Name	Type	Description
args	struct IOfferLogic.OfferArgs	A memory struct containing the offer parameters to update.
offerId	uint256	An unsigned integer representing the identifier of the offer to be updated.

Return Values

Name	Type	Description
reason	bytes32	Either REPOST_SUCCESS or Mangrove's revert reason if update was rejected by Mangrove and args.noRevert is true.

provisionOf

function provisionOf(struct OLKey olKey, uint256 offerId) external view returns (uint256 provision)

computes the amount of native tokens that can be redeemed when deprovisioning a given offer.

Parameters

Name	Type	Description
olKey	struct OLKey	the offer list key.
offerId	uint256	the identifier of the offer in the offer list

Return Values

Name	Type	Description
provision	uint256	the amount of native tokens that can be redeemed when deprovisioning the offer

_retractOffer

function _retractOffer(struct OLKey olKey, uint256 offerId, bool deprovision) internal returns (uint256 freeWei)

Retracts an offer from an Offer List of Mangrove.

An offer that is retracted without deprovision is retracted from the offer list, but still has its provisions locked by Mangrove. Calling this function, with the deprovision flag, on an offer that is already retracted must be used to retrieve the locked provisions.

Parameters

Name	Type	Description
olKey	struct OLKey	the offer list key.
offerId	uint256	the identifier of the offer in the offer list
deprovision	bool	if set to true if offer owner wishes to redeem the offer's provision.

Return Values

Name	Type	Description
freeWei	uint256	the amount of native tokens (in WEI) that have been retrieved by retracting the offer.

put

function __put__(uint256 amount, struct MgvLib.SingleOrder order) internal virtual returns (uint256)

Hook that implements where the inbound token, which are brought by the Offer Taker, should go during Taker Order's execution.

put received inbound tokens on offer maker's reserve during makerExecute if nothing is done at that stage then it could still be done during makerPosthook. However one would then need to pay attention to the following fact: if order.olKey.inbound_tkn is not pushed to reserve during makerExecute, in the posthook of this offer execution, the order.olKey.inbound_tkn balance of this contract would then contain the sum of all payments of offers managed by this that are in a better position in the offer list (because posthook is called in the call stack order). here we maintain an invariant that this balance is empty (both for order.olKey.inbound_tkn and order.olKey.outbound_tkn) at the end of makerExecute.

Parameters

Name	Type	Description
amount	uint256	of inbound tokens that are on this contract's balance and still need to be deposited somewhere
order	struct MgvLib.SingleOrder	is a recall of the taker order that is at the origin of the current trade.

Return Values

Name	Type	Description
[0]	uint256

get

function __get__(uint256 amount, struct MgvLib.SingleOrder order) internal virtual returns (uint256)

Hook that implements where the outbound token, which are promised to the taker, should be fetched from, during Taker Order's execution.

get outbound tokens from offer owner reserve

Parameters

Name	Type	Description
amount	uint256	of outbound tokens that still needs to be brought to the balance of this contract when entering this function
order	struct MgvLib.SingleOrder	is a recall of the taker order that is at the origin of the current trade.

Return Values

Name	Type	Description
[0]	uint256

handleResidualProvision

function __handleResidualProvision__(struct MgvLib.SingleOrder order) internal virtual

Hook that defines what needs to be done to the part of an offer provision that was added to the balance of this on Mangrove after an offer has failed.

if offer failed to execute, Mangrove retracts and deprovisions it after the posthook call. As a consequence if this hook is reached, this balance on Mangrove will increase, after the posthook, of some amount $n$ of native tokens. We evaluate here an underapproximation $~n$ in order to credit the offer maker in a pull based manner: failed offer owner can retrieve $~n$ by calling retractOffer on the failed offer. because $~n<n$ a small amount of WEIs will accumulate on the balance of this on Mangrove over time. Note that these WEIs are not burnt since they can be admin retrieved using withdrawFromMangrove.

Parameters

Name	Type	Description
order	struct MgvLib.SingleOrder	is a recall of the taker order that failed

checkList

function __checkList__(contract IERC20 token) internal view virtual

verifies that msg.sender is an allowed reserve id to trade tokens with this contract

Parameters

Name	Type	Description
token	contract IERC20	a token that is traded by this contract