Contract Name:
ExchangeProxy
Contract Source Code:
File 1 of 1 : ExchangeProxy
// SPDX-License-Identifier: MIT
pragma solidity 0.6.12;
pragma experimental ABIEncoderV2;
/**
* @dev Interface of the ERC20 standard as defined in the EIP.
*/
interface IERC20 {
/**
* @dev Returns the amount of tokens in existence.
*/
function totalSupply() external view returns (uint256);
/**
* @dev Returns the amount of tokens owned by `account`.
*/
function balanceOf(address account) external view returns (uint256);
/**
* @dev Moves `amount` tokens from the caller's account to `recipient`.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* Emits a {Transfer} event.
*/
function transfer(address recipient, uint256 amount) external returns (bool);
/**
* @dev Returns the remaining number of tokens that `spender` will be
* allowed to spend on behalf of `owner` through {transferFrom}. This is
* zero by default.
*
* This value changes when {approve} or {transferFrom} are called.
*/
function allowance(address owner, address spender) external view returns (uint256);
/**
* @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* IMPORTANT: Beware that changing an allowance with this method brings the risk
* that someone may use both the old and the new allowance by unfortunate
* transaction ordering. One possible solution to mitigate this race
* condition is to first reduce the spender's allowance to 0 and set the
* desired value afterwards:
* https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
*
* Emits an {Approval} event.
*/
function approve(address spender, uint256 amount) external returns (bool);
/**
* @dev Moves `amount` tokens from `sender` to `recipient` using the
* allowance mechanism. `amount` is then deducted from the caller's
* allowance.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* Emits a {Transfer} event.
*/
function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);
/**
* @dev Emitted when `value` tokens are moved from one account (`from`) to
* another (`to`).
*
* Note that `value` may be zero.
*/
event Transfer(address indexed from, address indexed to, uint256 value);
/**
* @dev Emitted when the allowance of a `spender` for an `owner` is set by
* a call to {approve}. `value` is the new allowance.
*/
event Approval(address indexed owner, address indexed spender, uint256 value);
}
/**
* @dev Wrappers over Solidity's arithmetic operations with added overflow
* checks.
*
* Arithmetic operations in Solidity wrap on overflow. This can easily result
* in bugs, because programmers usually assume that an overflow raises an
* error, which is the standard behavior in high level programming languages.
* `SafeMath` restores this intuition by reverting the transaction when an
* operation overflows.
*
* Using this library instead of the unchecked operations eliminates an entire
* class of bugs, so it's recommended to use it always.
*/
library SafeMath {
/**
* @dev Returns the addition of two unsigned integers, reverting on
* overflow.
*
* Counterpart to Solidity's `+` operator.
*
* Requirements:
*
* - Addition cannot overflow.
*/
function add(uint256 a, uint256 b) internal pure returns (uint256) {
uint256 c = a + b;
require(c >= a, "SafeMath: addition overflow");
return c;
}
/**
* @dev Returns the subtraction of two unsigned integers, reverting on
* overflow (when the result is negative).
*
* Counterpart to Solidity's `-` operator.
*
* Requirements:
*
* - Subtraction cannot overflow.
*/
function sub(uint256 a, uint256 b) internal pure returns (uint256) {
return sub(a, b, "SafeMath: subtraction overflow");
}
/**
* @dev Returns the subtraction of two unsigned integers, reverting with custom message on
* overflow (when the result is negative).
*
* Counterpart to Solidity's `-` operator.
*
* Requirements:
*
* - Subtraction cannot overflow.
*/
function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
require(b <= a, errorMessage);
uint256 c = a - b;
return c;
}
/**
* @dev Returns the multiplication of two unsigned integers, reverting on
* overflow.
*
* Counterpart to Solidity's `*` operator.
*
* Requirements:
*
* - Multiplication cannot overflow.
*/
function mul(uint256 a, uint256 b) internal pure returns (uint256) {
// Gas optimization: this is cheaper than requiring 'a' not being zero, but the
// benefit is lost if 'b' is also tested.
// See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
if (a == 0) {
return 0;
}
uint256 c = a * b;
require(c / a == b, "SafeMath: multiplication overflow");
return c;
}
/**
* @dev Returns the integer division of two unsigned integers. Reverts on
* division by zero. The result is rounded towards zero.
*
* Counterpart to Solidity's `/` operator. Note: this function uses a
* `revert` opcode (which leaves remaining gas untouched) while Solidity
* uses an invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
*
* - The divisor cannot be zero.
*/
function div(uint256 a, uint256 b) internal pure returns (uint256) {
return div(a, b, "SafeMath: division by zero");
}
/**
* @dev Returns the integer division of two unsigned integers. Reverts with custom message on
* division by zero. The result is rounded towards zero.
*
* Counterpart to Solidity's `/` operator. Note: this function uses a
* `revert` opcode (which leaves remaining gas untouched) while Solidity
* uses an invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
*
* - The divisor cannot be zero.
*/
function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
require(b > 0, errorMessage);
uint256 c = a / b;
// assert(a == b * c + a % b); // There is no case in which this doesn't hold
return c;
}
/**
* @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
* Reverts when dividing by zero.
*
* Counterpart to Solidity's `%` operator. This function uses a `revert`
* opcode (which leaves remaining gas untouched) while Solidity uses an
* invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
*
* - The divisor cannot be zero.
*/
function mod(uint256 a, uint256 b) internal pure returns (uint256) {
return mod(a, b, "SafeMath: modulo by zero");
}
/**
* @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
* Reverts with custom message when dividing by zero.
*
* Counterpart to Solidity's `%` operator. This function uses a `revert`
* opcode (which leaves remaining gas untouched) while Solidity uses an
* invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
*
* - The divisor cannot be zero.
*/
function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
require(b != 0, errorMessage);
return a % b;
}
}
/**
* @dev Collection of functions related to the address type
*/
library Address {
/**
* @dev Returns true if `account` is a contract.
*
* [IMPORTANT]
* ====
* It is unsafe to assume that an address for which this function returns
* false is an externally-owned account (EOA) and not a contract.
*
* Among others, `isContract` will return false for the following
* types of addresses:
*
* - an externally-owned account
* - a contract in construction
* - an address where a contract will be created
* - an address where a contract lived, but was destroyed
* ====
*/
function isContract(address account) internal view returns (bool) {
// This method relies in extcodesize, which returns 0 for contracts in
// construction, since the code is only stored at the end of the
// constructor execution.
uint256 size;
// solhint-disable-next-line no-inline-assembly
assembly { size := extcodesize(account) }
return size > 0;
}
/**
* @dev Replacement for Solidity's `transfer`: sends `amount` wei to
* `recipient`, forwarding all available gas and reverting on errors.
*
* https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
* of certain opcodes, possibly making contracts go over the 2300 gas limit
* imposed by `transfer`, making them unable to receive funds via
* `transfer`. {sendValue} removes this limitation.
*
* https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
*
* IMPORTANT: because control is transferred to `recipient`, care must be
* taken to not create reentrancy vulnerabilities. Consider using
* {ReentrancyGuard} or the
* https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
*/
function sendValue(address payable recipient, uint256 amount) internal {
require(address(this).balance >= amount, "Address: insufficient balance");
// solhint-disable-next-line avoid-low-level-calls, avoid-call-value
(bool success, ) = recipient.call{ value: amount }("");
require(success, "Address: unable to send value, recipient may have reverted");
}
/**
* @dev Performs a Solidity function call using a low level `call`. A
* plain`call` is an unsafe replacement for a function call: use this
* function instead.
*
* If `target` reverts with a revert reason, it is bubbled up by this
* function (like regular Solidity function calls).
*
* Returns the raw returned data. To convert to the expected return value,
* use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
*
* Requirements:
*
* - `target` must be a contract.
* - calling `target` with `data` must not revert.
*
* _Available since v3.1._
*/
function functionCall(address target, bytes memory data) internal returns (bytes memory) {
return functionCall(target, data, "Address: low-level call failed");
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
* `errorMessage` as a fallback revert reason when `target` reverts.
*
* _Available since v3.1._
*/
function functionCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
return _functionCallWithValue(target, data, 0, errorMessage);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but also transferring `value` wei to `target`.
*
* Requirements:
*
* - the calling contract must have an ETH balance of at least `value`.
* - the called Solidity function must be `payable`.
*
* _Available since v3.1._
*/
function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {
return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
}
/**
* @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
* with `errorMessage` as a fallback revert reason when `target` reverts.
*
* _Available since v3.1._
*/
function functionCallWithValue(address target, bytes memory data, uint256 value, string memory errorMessage) internal returns (bytes memory) {
require(address(this).balance >= value, "Address: insufficient balance for call");
return _functionCallWithValue(target, data, value, errorMessage);
}
function _functionCallWithValue(address target, bytes memory data, uint256 weiValue, string memory errorMessage) private returns (bytes memory) {
require(isContract(target), "Address: call to non-contract");
// solhint-disable-next-line avoid-low-level-calls
(bool success, bytes memory returndata) = target.call{ value: weiValue }(data);
if (success) {
return returndata;
} else {
// Look for revert reason and bubble it up if present
if (returndata.length > 0) {
// The easiest way to bubble the revert reason is using memory via assembly
// solhint-disable-next-line no-inline-assembly
assembly {
let returndata_size := mload(returndata)
revert(add(32, returndata), returndata_size)
}
} else {
revert(errorMessage);
}
}
}
}
/**
* @title SafeERC20
* @dev Wrappers around ERC20 operations that throw on failure (when the token
* contract returns false). Tokens that return no value (and instead revert or
* throw on failure) are also supported, non-reverting calls are assumed to be
* successful.
* To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
* which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
*/
library SafeERC20 {
using SafeMath for uint256;
using Address for address;
function safeTransfer(IERC20 token, address to, uint256 value) internal {
_callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
}
function safeTransferFrom(IERC20 token, address from, address to, uint256 value) internal {
_callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
}
/**
* @dev Deprecated. This function has issues similar to the ones found in
* {IERC20-approve}, and its usage is discouraged.
*
* Whenever possible, use {safeIncreaseAllowance} and
* {safeDecreaseAllowance} instead.
*/
function safeApprove(IERC20 token, address spender, uint256 value) internal {
// safeApprove should only be called when setting an initial allowance,
// or when resetting it to zero. To increase and decrease it, use
// 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
// solhint-disable-next-line max-line-length
require((value == 0) || (token.allowance(address(this), spender) == 0),
"SafeERC20: approve from non-zero to non-zero allowance"
);
_callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
}
function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal {
uint256 newAllowance = token.allowance(address(this), spender).add(value);
_callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
}
function safeDecreaseAllowance(IERC20 token, address spender, uint256 value) internal {
uint256 newAllowance = token.allowance(address(this), spender).sub(value, "SafeERC20: decreased allowance below zero");
_callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
}
/**
* @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
* on the return value: the return value is optional (but if data is returned, it must not be false).
* @param token The token targeted by the call.
* @param data The call data (encoded using abi.encode or one of its variants).
*/
function _callOptionalReturn(IERC20 token, bytes memory data) private {
// We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
// we're implementing it ourselves. We use {Address.functionCall} to perform this call, which verifies that
// the target address contains contract code and also asserts for success in the low-level call.
bytes memory returndata = address(token).functionCall(data, "SafeERC20: low-level call failed");
if (returndata.length > 0) { // Return data is optional
// solhint-disable-next-line max-line-length
require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
}
}
}
interface IBPool is IERC20 {
function version() external view returns(uint);
function swapExactAmountIn(address, uint, address, uint, uint) external returns (uint, uint);
function swapExactAmountOut(address, uint, address, uint, uint) external returns (uint, uint);
function calcInGivenOut(uint, uint, uint, uint, uint, uint) external pure returns (uint);
function calcOutGivenIn(uint, uint, uint, uint, uint, uint) external pure returns (uint);
function getDenormalizedWeight(address) external view returns (uint);
function swapFee() external view returns (uint);
function setSwapFee(uint _swapFee) external;
function bind(address token, uint balance, uint denorm) external;
function rebind(address token, uint balance, uint denorm) external;
function finalize(
uint _swapFee,
uint _initPoolSupply,
address[] calldata _bindTokens,
uint[] calldata _bindDenorms
) external;
function setPublicSwap(bool _publicSwap) external;
function setController(address _controller) external;
function setExchangeProxy(address _exchangeProxy) external;
function getFinalTokens() external view returns (address[] memory tokens);
function getTotalDenormalizedWeight() external view returns (uint);
function getBalance(address token) external view returns (uint);
function joinPool(uint poolAmountOut, uint[] calldata maxAmountsIn) external;
function joinPoolFor(address account, uint rewardAmountOut, uint[] calldata maxAmountsIn) external;
function joinswapPoolAmountOut(address tokenIn, uint poolAmountOut, uint maxAmountIn) external returns (uint tokenAmountIn);
function exitPool(uint poolAmountIn, uint[] calldata minAmountsOut) external;
function exitswapPoolAmountIn(address tokenOut, uint poolAmountIn, uint minAmountOut) external returns (uint tokenAmountOut);
function exitswapExternAmountOut(address tokenOut, uint tokenAmountOut, uint maxPoolAmountIn) external returns (uint poolAmountIn);
function joinswapExternAmountIn(
address tokenIn,
uint tokenAmountIn,
uint minPoolAmountOut
) external returns (uint poolAmountOut);
}
interface IFreeFromUpTo {
function freeFromUpTo(address from, uint256 value) external returns (uint256 freed);
}
interface IBFactory {
function newBPool() external returns (IBPool);
}
interface IValueLiquidRegistry {
function getBestPoolsWithLimit(address, address, uint) external view returns (address[] memory);
}
interface IWETH {
function deposit() external payable;
function allowance(address owner, address spender) external view returns (uint256);
function transfer(address to, uint value) external returns (bool);
function withdraw(uint) external;
function balanceOf(address account) external view returns (uint256);
}
contract ExchangeProxy {
using SafeMath for uint256;
using SafeERC20 for IERC20;
using Address for address;
IFreeFromUpTo public constant chi = IFreeFromUpTo(0x0000000000004946c0e9F43F4Dee607b0eF1fA1c);
modifier discountCHI(uint8 flag) {
if ((flag & 0x1) == 0) {
_;
} else {
uint256 gasStart = gasleft();
_;
uint256 gasSpent = 21000 + gasStart - gasleft() + 16 * msg.data.length;
chi.freeFromUpTo(msg.sender, (gasSpent + 14154) / 41130);
}
}
struct Pool {
address pool;
uint tokenBalanceIn;
uint tokenWeightIn;
uint tokenBalanceOut;
uint tokenWeightOut;
uint swapFee;
uint effectiveLiquidity;
}
struct Swap {
address pool;
address tokenIn;
address tokenOut;
uint swapAmount; // tokenInAmount / tokenOutAmount
uint limitReturnAmount; // minAmountOut / maxAmountIn
uint maxPrice;
}
IWETH weth;
IValueLiquidRegistry registry;
address private constant ETH_ADDRESS = address(0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE);
uint private constant BONE = 10 ** 18;
address public governance;
constructor(address _weth) public {
weth = IWETH(_weth);
governance = tx.origin;
}
function setGovernance(address _governance) external {
require(msg.sender == governance, "!governance");
governance = _governance;
}
function setRegistry(address _registry) external {
require(msg.sender == governance, "!governance");
registry = IValueLiquidRegistry(_registry);
}
function batchSwapExactIn(
Swap[] memory swaps,
IERC20 tokenIn,
IERC20 tokenOut,
uint totalAmountIn,
uint minTotalAmountOut,
uint8 flag
)
public payable discountCHI(flag)
returns (uint totalAmountOut)
{
transferFromAll(tokenIn, totalAmountIn);
for (uint i = 0; i < swaps.length; i++) {
Swap memory swap = swaps[i];
IERC20 SwapTokenIn = IERC20(swap.tokenIn);
IBPool pool = IBPool(swap.pool);
if (SwapTokenIn.allowance(address(this), swap.pool) > 0) {
SwapTokenIn.safeApprove(swap.pool, 0);
}
SwapTokenIn.safeApprove(swap.pool, swap.swapAmount);
(uint tokenAmountOut,) = pool.swapExactAmountIn(
swap.tokenIn,
swap.swapAmount,
swap.tokenOut,
swap.limitReturnAmount,
swap.maxPrice
);
totalAmountOut = tokenAmountOut.add(totalAmountOut);
}
require(totalAmountOut >= minTotalAmountOut, "ERR_LIMIT_OUT");
transferAll(tokenOut, totalAmountOut);
transferAll(tokenIn, getBalance(tokenIn));
}
function batchSwapExactOut(
Swap[] memory swaps,
IERC20 tokenIn,
IERC20 tokenOut,
uint maxTotalAmountIn,
uint8 flag
)
public payable discountCHI(flag)
returns (uint totalAmountIn)
{
transferFromAll(tokenIn, maxTotalAmountIn);
for (uint i = 0; i < swaps.length; i++) {
Swap memory swap = swaps[i];
IERC20 SwapTokenIn = IERC20(swap.tokenIn);
IBPool pool = IBPool(swap.pool);
if (SwapTokenIn.allowance(address(this), swap.pool) > 0) {
SwapTokenIn.safeApprove(swap.pool, 0);
}
SwapTokenIn.safeApprove(swap.pool, swap.limitReturnAmount);
(uint tokenAmountIn,) = pool.swapExactAmountOut(
swap.tokenIn,
swap.limitReturnAmount,
swap.tokenOut,
swap.swapAmount,
swap.maxPrice
);
totalAmountIn = tokenAmountIn.add(totalAmountIn);
}
require(totalAmountIn <= maxTotalAmountIn, "ERR_LIMIT_IN");
transferAll(tokenOut, getBalance(tokenOut));
transferAll(tokenIn, getBalance(tokenIn));
}
function multihopBatchSwapExactIn(
Swap[][] memory swapSequences,
IERC20 tokenIn,
IERC20 tokenOut,
uint totalAmountIn,
uint minTotalAmountOut,
uint8 flag
)
public payable discountCHI(flag)
returns (uint totalAmountOut)
{
transferFromAll(tokenIn, totalAmountIn);
for (uint i = 0; i < swapSequences.length; i++) {
uint tokenAmountOut;
for (uint k = 0; k < swapSequences[i].length; k++) {
Swap memory swap = swapSequences[i][k];
IERC20 SwapTokenIn = IERC20(swap.tokenIn);
if (k == 1) {
// Makes sure that on the second swap the output of the first was used
// so there is not intermediate token leftover
swap.swapAmount = tokenAmountOut;
}
IBPool pool = IBPool(swap.pool);
if (SwapTokenIn.allowance(address(this), swap.pool) > 0) {
SwapTokenIn.safeApprove(swap.pool, 0);
}
SwapTokenIn.safeApprove(swap.pool, swap.swapAmount);
(tokenAmountOut,) = pool.swapExactAmountIn(
swap.tokenIn,
swap.swapAmount,
swap.tokenOut,
swap.limitReturnAmount,
swap.maxPrice
);
}
// This takes the amountOut of the last swap
totalAmountOut = tokenAmountOut.add(totalAmountOut);
}
require(totalAmountOut >= minTotalAmountOut, "ERR_LIMIT_OUT");
transferAll(tokenOut, totalAmountOut);
transferAll(tokenIn, getBalance(tokenIn));
}
function multihopBatchSwapExactOut(
Swap[][] memory swapSequences,
IERC20 tokenIn,
IERC20 tokenOut,
uint maxTotalAmountIn,
uint8 flag
)
public payable discountCHI(flag)
returns (uint totalAmountIn)
{
transferFromAll(tokenIn, maxTotalAmountIn);
for (uint i = 0; i < swapSequences.length; i++) {
uint tokenAmountInFirstSwap;
// Specific code for a simple swap and a multihop (2 swaps in sequence)
if (swapSequences[i].length == 1) {
Swap memory swap = swapSequences[i][0];
IERC20 SwapTokenIn = IERC20(swap.tokenIn);
IBPool pool = IBPool(swap.pool);
if (SwapTokenIn.allowance(address(this), swap.pool) > 0) {
SwapTokenIn.safeApprove(swap.pool, 0);
}
SwapTokenIn.safeApprove(swap.pool, swap.limitReturnAmount);
(tokenAmountInFirstSwap,) = pool.swapExactAmountOut(
swap.tokenIn,
swap.limitReturnAmount,
swap.tokenOut,
swap.swapAmount,
swap.maxPrice
);
} else {
// Consider we are swapping A -> B and B -> C. The goal is to buy a given amount
// of token C. But first we need to buy B with A so we can then buy C with B
// To get the exact amount of C we then first need to calculate how much B we'll need:
uint intermediateTokenAmount;
// This would be token B as described above
Swap memory secondSwap = swapSequences[i][1];
IBPool poolSecondSwap = IBPool(secondSwap.pool);
intermediateTokenAmount = poolSecondSwap.calcInGivenOut(
poolSecondSwap.getBalance(secondSwap.tokenIn),
poolSecondSwap.getDenormalizedWeight(secondSwap.tokenIn),
poolSecondSwap.getBalance(secondSwap.tokenOut),
poolSecondSwap.getDenormalizedWeight(secondSwap.tokenOut),
secondSwap.swapAmount,
poolSecondSwap.swapFee()
);
//// Buy intermediateTokenAmount of token B with A in the first pool
Swap memory firstSwap = swapSequences[i][0];
IERC20 FirstSwapTokenIn = IERC20(firstSwap.tokenIn);
IBPool poolFirstSwap = IBPool(firstSwap.pool);
if (FirstSwapTokenIn.allowance(address(this), firstSwap.pool) < uint(- 1)) {
FirstSwapTokenIn.safeApprove(firstSwap.pool, uint(- 1));
}
(tokenAmountInFirstSwap,) = poolFirstSwap.swapExactAmountOut(
firstSwap.tokenIn,
firstSwap.limitReturnAmount,
firstSwap.tokenOut,
intermediateTokenAmount, // This is the amount of token B we need
firstSwap.maxPrice
);
//// Buy the final amount of token C desired
IERC20 SecondSwapTokenIn = IERC20(secondSwap.tokenIn);
if (SecondSwapTokenIn.allowance(address(this), secondSwap.pool) < uint(- 1)) {
SecondSwapTokenIn.safeApprove(secondSwap.pool, uint(- 1));
}
poolSecondSwap.swapExactAmountOut(
secondSwap.tokenIn,
secondSwap.limitReturnAmount,
secondSwap.tokenOut,
secondSwap.swapAmount,
secondSwap.maxPrice
);
}
totalAmountIn = tokenAmountInFirstSwap.add(totalAmountIn);
}
require(totalAmountIn <= maxTotalAmountIn, "ERR_LIMIT_IN");
transferAll(tokenOut, getBalance(tokenOut));
transferAll(tokenIn, getBalance(tokenIn));
}
function smartSwapExactIn(
IERC20 tokenIn,
IERC20 tokenOut,
uint totalAmountIn,
uint minTotalAmountOut,
uint nPools,
uint8 flag
)
public payable discountCHI(flag)
returns (uint totalAmountOut)
{
Swap[] memory swaps;
if (isETH(tokenIn)) {
(swaps,) = viewSplitExactIn(address(weth), address(tokenOut), totalAmountIn, nPools);
} else if (isETH(tokenOut)) {
(swaps,) = viewSplitExactIn(address(tokenIn), address(weth), totalAmountIn, nPools);
} else {
(swaps,) = viewSplitExactIn(address(tokenIn), address(tokenOut), totalAmountIn, nPools);
}
totalAmountOut = batchSwapExactIn(swaps, tokenIn, tokenOut, totalAmountIn, minTotalAmountOut, 0x0);
}
function smartSwapExactOut(
IERC20 tokenIn,
IERC20 tokenOut,
uint totalAmountOut,
uint maxTotalAmountIn,
uint nPools,
uint8 flag
)
public payable discountCHI(flag)
returns (uint totalAmountIn)
{
Swap[] memory swaps;
if (isETH(tokenIn)) {
(swaps,) = viewSplitExactOut(address(weth), address(tokenOut), totalAmountOut, nPools);
} else if (isETH(tokenOut)) {
(swaps,) = viewSplitExactOut(address(tokenIn), address(weth), totalAmountOut, nPools);
} else {
(swaps,) = viewSplitExactOut(address(tokenIn), address(tokenOut), totalAmountOut, nPools);
}
totalAmountIn = batchSwapExactOut(swaps, tokenIn, tokenOut, maxTotalAmountIn, 0x0);
}
function viewSplitExactIn(
address tokenIn,
address tokenOut,
uint swapAmount,
uint nPools
)
public view
returns (Swap[] memory swaps, uint totalOutput)
{
address[] memory poolAddresses = registry.getBestPoolsWithLimit(tokenIn, tokenOut, nPools);
Pool[] memory pools = new Pool[](poolAddresses.length);
uint sumEffectiveLiquidity;
for (uint i = 0; i < poolAddresses.length; i++) {
pools[i] = getPoolData(tokenIn, tokenOut, poolAddresses[i]);
sumEffectiveLiquidity = sumEffectiveLiquidity.add(pools[i].effectiveLiquidity);
}
uint[] memory bestInputAmounts = new uint[](pools.length);
uint totalInputAmount;
for (uint i = 0; i < pools.length; i++) {
bestInputAmounts[i] = swapAmount.mul(pools[i].effectiveLiquidity).div(sumEffectiveLiquidity);
totalInputAmount = totalInputAmount.add(bestInputAmounts[i]);
}
if (totalInputAmount < swapAmount) {
bestInputAmounts[0] = bestInputAmounts[0].add(swapAmount.sub(totalInputAmount));
} else {
bestInputAmounts[0] = bestInputAmounts[0].sub(totalInputAmount.sub(swapAmount));
}
swaps = new Swap[](pools.length);
for (uint i = 0; i < pools.length; i++) {
swaps[i] = Swap({
pool : pools[i].pool,
tokenIn : tokenIn,
tokenOut : tokenOut,
swapAmount : bestInputAmounts[i],
limitReturnAmount : 0,
maxPrice : uint(- 1)
});
}
totalOutput = calcTotalOutExactIn(bestInputAmounts, pools);
return (swaps, totalOutput);
}
function viewSplitExactOut(
address tokenIn,
address tokenOut,
uint swapAmount,
uint nPools
)
public view
returns (Swap[] memory swaps, uint totalOutput)
{
address[] memory poolAddresses = registry.getBestPoolsWithLimit(tokenIn, tokenOut, nPools);
Pool[] memory pools = new Pool[](poolAddresses.length);
uint sumEffectiveLiquidity;
for (uint i = 0; i < poolAddresses.length; i++) {
pools[i] = getPoolData(tokenIn, tokenOut, poolAddresses[i]);
sumEffectiveLiquidity = sumEffectiveLiquidity.add(pools[i].effectiveLiquidity);
}
uint[] memory bestInputAmounts = new uint[](pools.length);
uint totalInputAmount;
for (uint i = 0; i < pools.length; i++) {
bestInputAmounts[i] = swapAmount.mul(pools[i].effectiveLiquidity).div(sumEffectiveLiquidity);
totalInputAmount = totalInputAmount.add(bestInputAmounts[i]);
}
if (totalInputAmount < swapAmount) {
bestInputAmounts[0] = bestInputAmounts[0].add(swapAmount.sub(totalInputAmount));
} else {
bestInputAmounts[0] = bestInputAmounts[0].sub(totalInputAmount.sub(swapAmount));
}
swaps = new Swap[](pools.length);
for (uint i = 0; i < pools.length; i++) {
swaps[i] = Swap({
pool : pools[i].pool,
tokenIn : tokenIn,
tokenOut : tokenOut,
swapAmount : bestInputAmounts[i],
limitReturnAmount : uint(- 1),
maxPrice : uint(- 1)
});
}
totalOutput = calcTotalOutExactOut(bestInputAmounts, pools);
return (swaps, totalOutput);
}
function getPoolData(
address tokenIn,
address tokenOut,
address poolAddress
)
internal view
returns (Pool memory)
{
IBPool pool = IBPool(poolAddress);
uint tokenBalanceIn = pool.getBalance(tokenIn);
uint tokenBalanceOut = pool.getBalance(tokenOut);
uint tokenWeightIn = pool.getDenormalizedWeight(tokenIn);
uint tokenWeightOut = pool.getDenormalizedWeight(tokenOut);
uint swapFee = pool.swapFee();
uint effectiveLiquidity = calcEffectiveLiquidity(
tokenWeightIn,
tokenBalanceOut,
tokenWeightOut
);
Pool memory returnPool = Pool({
pool : poolAddress,
tokenBalanceIn : tokenBalanceIn,
tokenWeightIn : tokenWeightIn,
tokenBalanceOut : tokenBalanceOut,
tokenWeightOut : tokenWeightOut,
swapFee : swapFee,
effectiveLiquidity : effectiveLiquidity
});
return returnPool;
}
function calcEffectiveLiquidity(
uint tokenWeightIn,
uint tokenBalanceOut,
uint tokenWeightOut
)
internal pure
returns (uint effectiveLiquidity)
{
// Bo * wi/(wi+wo)
effectiveLiquidity =
tokenWeightIn.mul(BONE).div(
tokenWeightOut.add(tokenWeightIn)
).mul(tokenBalanceOut).div(BONE);
return effectiveLiquidity;
}
function calcTotalOutExactIn(
uint[] memory bestInputAmounts,
Pool[] memory bestPools
)
internal pure
returns (uint totalOutput)
{
totalOutput = 0;
for (uint i = 0; i < bestInputAmounts.length; i++) {
uint output = IBPool(bestPools[i].pool).calcOutGivenIn(
bestPools[i].tokenBalanceIn,
bestPools[i].tokenWeightIn,
bestPools[i].tokenBalanceOut,
bestPools[i].tokenWeightOut,
bestInputAmounts[i],
bestPools[i].swapFee
);
totalOutput = totalOutput.add(output);
}
return totalOutput;
}
function calcTotalOutExactOut(
uint[] memory bestInputAmounts,
Pool[] memory bestPools
)
internal pure
returns (uint totalOutput)
{
totalOutput = 0;
for (uint i = 0; i < bestInputAmounts.length; i++) {
uint output = IBPool(bestPools[i].pool).calcInGivenOut(
bestPools[i].tokenBalanceIn,
bestPools[i].tokenWeightIn,
bestPools[i].tokenBalanceOut,
bestPools[i].tokenWeightOut,
bestInputAmounts[i],
bestPools[i].swapFee
);
totalOutput = totalOutput.add(output);
}
return totalOutput;
}
function transferFromAll(IERC20 token, uint amount) internal returns (bool) {
if (isETH(token)) {
weth.deposit{value : msg.value}();
} else {
token.safeTransferFrom(msg.sender, address(this), amount);
}
return true;
}
function getBalance(IERC20 token) internal view returns (uint) {
if (isETH(token)) {
return weth.balanceOf(address(this));
} else {
return token.balanceOf(address(this));
}
}
function transferAll(IERC20 token, uint amount) internal returns (bool) {
if (amount == 0) {
return true;
}
if (isETH(token)) {
weth.withdraw(amount);
(bool xfer,) = msg.sender.call{value : amount}("");
require(xfer, "ERR_ETH_FAILED");
} else {
token.safeTransfer(msg.sender, amount);
}
return true;
}
function isETH(IERC20 token) internal pure returns (bool) {
return (address(token) == ETH_ADDRESS);
}
/**
* This function allows governance to take unsupported tokens out of the contract.
* This is in an effort to make someone whole, should they seriously mess up.
* There is no guarantee governance will vote to return these.
* It also allows for removal of airdropped tokens.
*/
function governanceRecoverUnsupported(IERC20 _token, uint _amount, address _to) external {
require(msg.sender == governance, "!governance");
if (isETH(_token)) {
(bool xfer,) = _to.call{value : _amount}("");
require(xfer, "ERR_ETH_FAILED");
} else {
_token.safeTransfer(_to, _amount);
}
}
receive() external payable {}
function create(
IBFactory factory,
address[] memory tokens,
uint[] calldata balances,
uint[] calldata denorms,
uint swapFee,
uint initPoolSupply,
uint8 flag
) payable external discountCHI(flag) returns (IBPool pool) {
require(tokens.length == balances.length, "ERR_LENGTH_MISMATCH");
require(tokens.length == denorms.length, "ERR_LENGTH_MISMATCH");
pool = factory.newBPool();
bool containsETH = false;
for (uint i = 0; i < tokens.length; i++) {
if (transferFromAllTo(tokens[i], balances[i], address(pool))) {
containsETH = true;
tokens[i] = address(weth);
}
}
require(msg.value == 0 || containsETH, "!invalid payable");
pool.finalize(swapFee, initPoolSupply, tokens, denorms);
pool.setExchangeProxy(address(this));
pool.setController(msg.sender);
uint lpAmount = pool.balanceOf(address(this));
if (lpAmount > 0) {
IERC20(pool).safeTransfer(msg.sender, lpAmount);
}
}
function joinPool(
IBPool pool,
uint poolAmountOut,
uint[] calldata maxAmountsIn,
uint8 flag
) payable external discountCHI(flag) {
address[] memory tokens = pool.getFinalTokens();
require(maxAmountsIn.length == tokens.length, "ERR_LENGTH_MISMATCH");
bool containsETH = false;
for (uint i = 0; i < tokens.length; i++) {
if (transferFromAllAndApprove(tokens[i], maxAmountsIn[i], address(pool))) {
containsETH = true;
}
}
require(msg.value == 0 || containsETH, "!invalid payable");
if (pool.version() == 1001) {
pool.joinPool(poolAmountOut, maxAmountsIn);
} else {
pool.joinPoolFor(msg.sender, poolAmountOut, maxAmountsIn);
}
for (uint i = 0; i < tokens.length; i++) {
transferAll(IERC20(tokens[i]), getBalance(IERC20(tokens[i])));
}
uint lpAmount = pool.balanceOf(address(this));
transferAll(pool, lpAmount);
}
function joinswapExternAmountIn(
IBPool pool,
address tokenIn,
uint tokenAmountIn,
uint minPoolAmountOut,
uint8 flag
) payable external discountCHI(flag) {
bool containsETH = false;
if (transferFromAllAndApprove(tokenIn, tokenAmountIn, address(pool))) {
containsETH = true;
}
require(msg.value == 0 || containsETH, "!invalid payable");
uint poolAmountOut = pool.joinswapExternAmountIn(tokenIn, tokenAmountIn, minPoolAmountOut);
IERC20(pool).safeTransfer(msg.sender, poolAmountOut);
}
function transferFromAllTo(address token, uint amount, address to) internal returns (bool containsETH) {
if (isETH(IERC20(token))) {
require(amount == msg.value, "!invalid amount");
weth.deposit{value : amount}();
weth.transfer(to,amount);
containsETH = true;
} else {
IERC20(token).safeTransferFrom(msg.sender, to, amount);
}
return containsETH;
}
function transferFromAllAndApprove(address token, uint amount, address spender) internal returns (bool containsETH) {
if (isETH(IERC20(token))) {
require(amount == msg.value, "!invalid amount");
weth.deposit{value : amount}();
if (weth.allowance(address(this), spender) > 0) {
IERC20(address(weth)).safeApprove(address(spender), 0);
}
IERC20(address(weth)).safeApprove(spender, amount);
containsETH = true;
} else {
IERC20(token).safeTransferFrom(msg.sender, address(this), amount);
if (IERC20(token).allowance(address(this), spender) > 0) {
IERC20(token).safeApprove(spender, 0);
}
IERC20(token).safeApprove(spender, amount);
}
return containsETH;
}
}