cancelOrder Function

Function Type: external
Function Signature: cancelOrder(address,MetadataCancelOrder,uint256,uint256,bool,bytes)

The cancelOrder function allows order creators to cancel their existing orders and reclaim their locked tokens. This function validates ownership, returns tokens to the original creator, and provides rewards to staker executors.

Key features:

• Order Cancellation: Removes existing orders from the marketplace
• Token Recovery: Returns locked tokens to the original order creator
• Ownership Validation: Ensures only order creators can cancel their orders
• Staker Rewards: Executors who are stakers receive MATE token rewards
• Market Cleanup: Updates market statistics after order removal

Parameters

Field	Type	Description
user	address	The address that created the original order and is requesting cancellation
metadata	MetadataCancelOrder	Struct containing cancellation details and embedded signature
_priorityFee_Evvm	uint256	Priority fee for EVVM transaction processing (optional)
_nonce_Evvm	uint256	Nonce for EVVM payment transaction
_priority_Evvm	bool	Priority flag for EVVM payment (sync/async)
_signature_Evvm	bytes	EIP-191 signature for EVVM payment authorization

info

_priorityFee_Evvm is paid using principal tokens

MetadataCancelOrder Structure

Field	Type	Description
nonce	uint256	Unique nonce for P2P Swap replay protection
tokenA	address	Token that was offered in the original order
tokenB	address	Token that was requested in the original order
orderId	uint256	ID of the order to be cancelled
signature	bytes	EIP-191 signature from user authorizing the cancellation

Execution Methods

Fisher Execution

1. User signs cancellation details and optional EVVM payment authorization
2. Fisher captures the transaction and validates all signatures
3. Fisher submits the transaction and receives staker rewards if eligible
4. Order is cancelled and tokens are returned to the user

Direct Execution

1. User or authorized service calls the function directly
2. All signature validations are performed on-chain
3. Order cancellation and token return happen immediately
4. Staker benefits are distributed if executor qualifies

Workflow

1. P2P Signature Verification: Validates the embedded metadata.signature against the user address and cancellation parameters using SignatureUtils.verifyMessageSignedForCancelOrder. Reverts with "Invalid signature" on failure.

2. Market Resolution: Finds the market for the token pair using findMarket(metadata.tokenA, metadata.tokenB).

3. Nonce Validation: Checks if the P2P nonce has been used before by consulting nonceP2PSwap[user][metadata.nonce]. Reverts with "Invalid nonce" if the nonce was previously used.

4. Order Ownership Verification: Validates that:

   • The market exists (market != 0)
   • The order exists and belongs to the requesting user
   • Reverts with "Invalid order" if validation fails

5. Priority Fee Processing: If _priorityFee_Evvm > 0, processes the priority fee payment using makePay with MATE tokens.

6. Token Return: Returns the locked tokens to the order creator using makeCaPay, transferring ordersInsideMarket[market][metadata.orderId].amountA of metadata.tokenA back to user.

7. Order Removal: Marks the order as cancelled by setting the seller address to address(0).

8. Staker Reward Distribution: If the executor (msg.sender) is a registered staker:

   • MATE Token Rewards: Grants MATE tokens to the executor:
     • 3x base reward amount + priority fee if priority fee was provided
     • 2x base reward amount if no priority fee

9. Market Update: Decrements the ordersAvailable counter for the market.

10. Nonce Update: Marks the P2P nonce as used to prevent replay attacks.

Example

Scenario: User wants to cancel their order offering 100 USDC for 0.05 ETH

Parameters:

• user: 0x742c7b6b472c8f4bd58e6f9f6c82e8e6e7c82d8c
• metadata.nonce: 25
• metadata.tokenA: 0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48 (USDC)
• metadata.tokenB: 0x0000000000000000000000000000000000000000 (ETH)
• metadata.orderId: 3
• _priorityFee_Evvm: 0 (no priority fee)

Process:

1. User signs the cancellation details with their private key
2. Fisher or user submits the transaction
3. Contract validates signature and order ownership
4. 100 USDC is returned to the user's balance
5. Order #3 is marked as cancelled in the USDC/ETH market
6. Staker executor receives 2x MATE reward (no priority fee)

Market Impact:

• Market's ordersAvailable count decreases by 1
• Order slot becomes available for reuse
• Market statistics reflect the cancellation

Token Recovery:

• Original 100 USDC locked in the order is returned to user
• User can immediately use these tokens for other purposes
• No fees charged for order cancellation

info

For signature structure details, see Cancel Order Signature Structure

tip

Want to create a new order?
Use makeOrder to create a new swap order with different parameters.

Looking to fulfill someone else's order?
Check dispatchOrder to execute existing orders in the marketplace.