Files
tycho-protocol-sdk/evm/src/balancer-v2/BalancerV2SwapAdapter.sol
2024-03-27 10:43:02 +01:00

487 lines
15 KiB
Solidity

// SPDX-License-Identifier: AGPL-3.0-or-later
pragma solidity ^0.8.13;
import {IERC20, ISwapAdapter} from "src/interfaces/ISwapAdapter.sol";
// Maximum Swap In/Out Ratio - 0.3
// https://balancer.gitbook.io/balancer/core-concepts/protocol/limitations#v2-limits
uint256 constant RESERVE_LIMIT_FACTOR = 4;
uint256 constant SWAP_DEADLINE_SEC = 1000;
contract BalancerV2SwapAdapter is ISwapAdapter {
IVault immutable vault;
constructor(address payable vault_) {
vault = IVault(vault_);
}
/// @notice Calculate the price of the buy token in terms of the sell token.
/// @dev The resulting price is not scaled by the token decimals.
/// Also this function is not 'view' because Balancer V2 simulates the swap
/// and then returns the amount diff in revert data.
/// @param poolId The ID of the trading pool.
/// @param sellToken The token being sold.
/// @param buyToken The token being bought.
/// @param sellAmount The amount of tokens being sold.
/// @return calculatedPrice The price of the buy token in terms of the sell
/// as a Fraction struct.
function priceSingle(
bytes32 poolId,
IERC20 sellToken,
IERC20 buyToken,
uint256 sellAmount
) public returns (Fraction memory calculatedPrice) {
IVault.BatchSwapStep[] memory swapSteps = new IVault.BatchSwapStep[](1);
swapSteps[0] = IVault.BatchSwapStep({
poolId: poolId,
assetInIndex: 0,
assetOutIndex: 1,
amount: sellAmount,
userData: ""
});
address[] memory assets = new address[](2);
assets[0] = address(sellToken);
assets[1] = address(buyToken);
IVault.FundManagement memory funds = IVault.FundManagement({
sender: msg.sender,
fromInternalBalance: false,
recipient: payable(msg.sender),
toInternalBalance: false
});
// assetDeltas correspond to the assets array
int256[] memory assetDeltas = new int256[](2);
assetDeltas = vault.queryBatchSwap(
IVault.SwapKind.GIVEN_IN, swapSteps, assets, funds
);
// assetDeltas[1] is the amount of tokens sent from the vault (i.e.
// bought), so the sign is negative, which means the sign should be
// flipped to get the price.
calculatedPrice =
Fraction(uint256(-assetDeltas[1]), uint256(assetDeltas[0]));
}
function getSellAmount(
bytes32 poolId,
IERC20 sellToken,
IERC20 buyToken,
uint256 buyAmount
) public returns (uint256 sellAmount) {
IVault.BatchSwapStep[] memory swapSteps = new IVault.BatchSwapStep[](1);
swapSteps[0] = IVault.BatchSwapStep({
poolId: poolId,
assetInIndex: 0,
assetOutIndex: 1,
amount: buyAmount,
userData: ""
});
address[] memory assets = new address[](2);
assets[0] = address(sellToken);
assets[1] = address(buyToken);
IVault.FundManagement memory funds = IVault.FundManagement({
sender: msg.sender,
fromInternalBalance: false,
recipient: payable(msg.sender),
toInternalBalance: false
});
// assetDeltas correspond to the assets array
int256[] memory assetDeltas = new int256[](2);
assetDeltas = vault.queryBatchSwap(
IVault.SwapKind.GIVEN_OUT, swapSteps, assets, funds
);
sellAmount = uint256(assetDeltas[0]);
}
function priceBatch(
bytes32 poolId,
IERC20 sellToken,
IERC20 buyToken,
uint256[] memory specifiedAmounts
) external returns (Fraction[] memory calculatedPrices) {
for (uint256 i = 0; i < specifiedAmounts.length; i++) {
calculatedPrices[i] =
priceSingle(poolId, sellToken, buyToken, specifiedAmounts[i]);
}
}
function price(bytes32, IERC20, IERC20, uint256[] memory)
external
pure
override
returns (Fraction[] memory)
{
revert NotImplemented("BalancerV2SwapAdapter.price");
}
function swap(
bytes32 poolId,
IERC20 sellToken,
IERC20 buyToken,
OrderSide side,
uint256 specifiedAmount
) external override returns (Trade memory trade) {
uint256 sellAmount;
IVault.SwapKind kind;
uint256 limit; // TODO set this slippage limit properly
if (side == OrderSide.Sell) {
kind = IVault.SwapKind.GIVEN_IN;
sellAmount = specifiedAmount;
limit = 0;
} else {
kind = IVault.SwapKind.GIVEN_OUT;
sellAmount =
getSellAmount(poolId, sellToken, buyToken, specifiedAmount);
limit = type(uint256).max;
}
sellToken.transferFrom(msg.sender, address(this), sellAmount);
sellToken.approve(address(vault), sellAmount);
uint256 gasBefore = gasleft();
trade.calculatedAmount = vault.swap(
IVault.SingleSwap({
poolId: poolId,
kind: kind,
assetIn: address(sellToken),
assetOut: address(buyToken),
amount: specifiedAmount,
userData: ""
}),
IVault.FundManagement({
sender: address(this),
fromInternalBalance: false,
recipient: msg.sender,
toInternalBalance: false
}),
limit,
block.timestamp + SWAP_DEADLINE_SEC
);
trade.gasUsed = gasBefore - gasleft();
trade.price = priceSingle(poolId, sellToken, buyToken, specifiedAmount);
}
function getLimits(bytes32 poolId, IERC20 sellToken, IERC20 buyToken)
external
view
override
returns (uint256[] memory limits)
{
limits = new uint256[](2);
(IERC20[] memory tokens, uint256[] memory balances,) =
vault.getPoolTokens(poolId);
for (uint256 i = 0; i < tokens.length; i++) {
if (tokens[i] == sellToken) {
limits[0] = balances[i] / RESERVE_LIMIT_FACTOR;
}
if (tokens[i] == buyToken) {
limits[1] = balances[i] / RESERVE_LIMIT_FACTOR;
}
}
}
function getCapabilities(bytes32, IERC20, IERC20)
external
pure
override
returns (Capability[] memory capabilities)
{
capabilities = new Capability[](2);
capabilities[0] = Capability.SellOrder;
capabilities[1] = Capability.BuyOrder;
}
function getTokens(bytes32 poolId)
external
view
override
returns (IERC20[] memory tokens)
{
(tokens,,) = vault.getPoolTokens(poolId);
}
/// @dev Balancer V2 does not support enumerating pools, they have to be
/// indexed off-chain.
function getPoolIds(uint256, uint256)
external
pure
override
returns (bytes32[] memory)
{
revert NotImplemented("BalancerV2SwapAdapter.getPoolIds");
}
}
interface IVault {
struct BatchSwapStep {
bytes32 poolId;
uint256 assetInIndex;
uint256 assetOutIndex;
uint256 amount;
bytes userData;
}
struct FundManagement {
address sender;
bool fromInternalBalance;
address recipient;
bool toInternalBalance;
}
struct ExitPoolRequest {
address[] assets;
uint256[] minAmountsOut;
bytes userData;
bool toInternalBalance;
}
struct JoinPoolRequest {
address[] assets;
uint256[] maxAmountsIn;
bytes userData;
bool fromInternalBalance;
}
struct PoolBalanceOp {
SwapKind kind;
bytes32 poolId;
address token;
uint256 amount;
}
struct UserBalanceOp {
SwapKind kind;
address asset;
uint256 amount;
address sender;
address recipient;
}
struct SingleSwap {
bytes32 poolId;
SwapKind kind;
address assetIn;
address assetOut;
uint256 amount;
bytes userData;
}
event AuthorizerChanged(address indexed newAuthorizer);
event ExternalBalanceTransfer(
address indexed token,
address indexed sender,
address recipient,
uint256 amount
);
event FlashLoan(
address indexed recipient,
address indexed token,
uint256 amount,
uint256 feeAmount
);
event InternalBalanceChanged(
address indexed user, address indexed token, int256 delta
);
event PausedStateChanged(bool paused);
event PoolBalanceChanged(
bytes32 indexed poolId,
address indexed liquidityProvider,
address[] tokens,
int256[] deltas,
uint256[] protocolFeeAmounts
);
event PoolBalanceManaged(
bytes32 indexed poolId,
address indexed assetManager,
address indexed token,
int256 cashDelta,
int256 managedDelta
);
event PoolRegistered(
bytes32 indexed poolId,
address indexed poolAddress,
uint8 specialization
);
event RelayerApprovalChanged(
address indexed relayer, address indexed sender, bool approved
);
event Swap(
bytes32 indexed poolId,
address indexed tokenIn,
address indexed tokenOut,
uint256 amountIn,
uint256 amountOut
);
event TokensDeregistered(bytes32 indexed poolId, address[] tokens);
event TokensRegistered(
bytes32 indexed poolId, address[] tokens, address[] assetManagers
);
function WETH() external view returns (address);
function batchSwap(
SwapKind kind,
BatchSwapStep[] memory swaps,
address[] memory assets,
FundManagement memory funds,
int256[] memory limits,
uint256 deadline
) external payable returns (int256[] memory assetDeltas);
function deregisterTokens(bytes32 poolId, address[] memory tokens)
external;
function exitPool(
bytes32 poolId,
address sender,
address recipient,
ExitPoolRequest memory request
) external;
function flashLoan(
address recipient,
address[] memory tokens,
uint256[] memory amounts,
bytes memory userData
) external;
function getActionId(bytes4 selector) external view returns (bytes32);
function getAuthorizer() external view returns (address);
function getDomainSeparator() external view returns (bytes32);
function getInternalBalance(address user, address[] memory tokens)
external
view
returns (uint256[] memory balances);
function getNextNonce(address user) external view returns (uint256);
function getPausedState()
external
view
returns (
bool paused,
uint256 pauseWindowEndTime,
uint256 bufferPeriodEndTime
);
function getPool(bytes32 poolId) external view returns (address, uint8);
function getPoolTokenInfo(bytes32 poolId, address token)
external
view
returns (
uint256 cash,
uint256 managed,
uint256 lastChangeBlock,
address assetManager
);
function getProtocolFeesCollector() external view returns (address);
function hasApprovedRelayer(address user, address relayer)
external
view
returns (bool);
function joinPool(
bytes32 poolId,
address sender,
address recipient,
JoinPoolRequest memory request
) external payable;
function managePoolBalance(PoolBalanceOp[] memory ops) external;
function manageUserBalance(UserBalanceOp[] memory ops) external payable;
/**
* @dev Simulates a call to `batchSwap`, returning an array of Vault asset
* deltas. Calls to `swap` cannot be
* simulated directly, but an equivalent `batchSwap` call can and will yield
* the exact same result.
*
* Each element in the array corresponds to the asset at the same index, and
* indicates the number of tokens (or ETH)
* the Vault would take from the sender (if positive) or send to the
* recipient (if negative). The arguments it
* receives are the same that an equivalent `batchSwap` call would receive.
*
* Unlike `batchSwap`, this function performs no checks on the sender or
* recipient field in the `funds` struct.
* This makes it suitable to be called by off-chain applications via
* eth_call without needing to hold tokens,
* approve them for the Vault, or even know a user's address.
*
* Note that this function is not 'view' (due to implementation details):
* the client code must explicitly execute
* eth_call instead of eth_sendTransaction.
*/
function queryBatchSwap(
SwapKind kind,
BatchSwapStep[] memory swaps,
address[] memory assets,
FundManagement memory funds
) external returns (int256[] memory);
function registerPool(uint8 specialization) external returns (bytes32);
function registerTokens(
bytes32 poolId,
address[] memory tokens,
address[] memory assetManagers
) external;
function setAuthorizer(address newAuthorizer) external;
function setPaused(bool paused) external;
function setRelayerApproval(address sender, address relayer, bool approved)
external;
/**
* @dev Performs a swap with a single Pool.
*
* If the swap is 'given in' (the number of tokens to send to the Pool is
* known), it returns the amount of tokens
* taken from the Pool, which must be greater than or equal to `limit`.
*
* If the swap is 'given out' (the number of tokens to take from the Pool is
* known), it returns the amount of tokens
* sent to the Pool, which must be less than or equal to `limit`.
*
* Internal Balance usage and the recipient are determined by the `funds`
* struct.
*
* Emits a `Swap` event.
*/
function swap(
SingleSwap memory singleSwap,
FundManagement memory funds,
uint256 limit,
uint256 deadline
) external payable returns (uint256);
receive() external payable;
function getPoolTokens(bytes32 poolId)
external
view
returns (
IERC20[] memory tokens,
uint256[] memory balances,
uint256 lastChangeBlock
);
enum SwapKind {
/// The number of tokens to send to the Pool is known
GIVEN_IN,
/// The number of tokens to take from the Pool is known
GIVEN_OUT
}
}