interchain-token-service

Solidity API

FlowLimit

Implements flow limit logic for interchain token transfers.

This contract implements low-level assembly for optimization purposes.

FLOW_LIMIT_SLOT

uint256 FLOW_LIMIT_SLOT

PREFIX_FLOW_OUT_AMOUNT

uint256 PREFIX_FLOW_OUT_AMOUNT

PREFIX_FLOW_IN_AMOUNT

uint256 PREFIX_FLOW_IN_AMOUNT

epochTime

function epochTime() internal view virtual returns (uint256)

Returns the epoch duration for which the flow limit is applied

Return Values

Name	Type	Description
[0]	uint256	The epoch time

flowLimit

function flowLimit() public view returns (uint256 flowLimit_)

Returns the current flow limit.

Return Values

Name	Type	Description
flowLimit_	uint256	The current flow limit value.

_setFlowLimit

function _setFlowLimit(uint256 flowLimit_, bytes32 tokenId) internal

Internal function to set the flow limit.

Parameters

Name	Type	Description
flowLimit_	uint256	The value to set the flow limit to.
tokenId	bytes32	The id of the token to set the flow limit for.

_getFlowOutSlot

function _getFlowOutSlot(uint256 epoch) internal pure returns (uint256 slot)

Returns the slot which is used to get the flow out amount for a specific epoch.

Parameters

Name	Type	Description
epoch	uint256	The epoch to get the flow out amount for.

Return Values

Name	Type	Description
slot	uint256	The slot to get the flow out amount from.

_getFlowInSlot

function _getFlowInSlot(uint256 epoch) internal pure returns (uint256 slot)

Returns the slot which is used to get the flow in amount for a specific epoch.

Parameters

Name	Type	Description
epoch	uint256	The epoch to get the flow in amount for.

Return Values

Name	Type	Description
slot	uint256	The slot to get the flow in amount from.

flowOutAmount

function flowOutAmount() external view returns (uint256 flowOutAmount_)

Returns the current flow out amount.

Return Values

Name	Type	Description
flowOutAmount_	uint256	The current flow out amount.

flowInAmount

function flowInAmount() external view returns (uint256 flowInAmount_)

Returns the current flow in amount.

Return Values

Name	Type	Description
flowInAmount_	uint256	The current flow in amount.

_addFlow

function _addFlow(uint256 flowSlot, uint256 reverseFlowSlot, uint256 flowAmount, uint256 flowLimit_) internal

Adds flow amount in the specified direction (in/out) for a token, and applies the flow limit.

_Reverts if:

• Flow amount exceeds the flow limit
• The flow in either direction exceeds uint256::MAX

• Net flow (difference between in and out) exceeds the flow limit, i.e.

  flow - reverse_flow

  > flow_limit_

Parameters

Name	Type	Description
flowSlot	uint256	The storage slot for the current direction’s flow (in or out).
reverseFlowSlot	uint256	The storage slot for the opposite direction’s flow.
flowAmount	uint256	The amount of flow to add.
flowLimit_	uint256	The allowed maximum net flow during the epoch.

_addFlowOut

function _addFlowOut(uint256 flowOutAmount_) internal

Adds a flow out amount.

Parameters

Name	Type	Description
flowOutAmount_	uint256	The flow out amount to add.

_addFlowIn

function _addFlowIn(uint256 flowInAmount_) internal

Adds a flow in amount.

Parameters

Name	Type	Description
flowInAmount_	uint256	The flow in amount to add.