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BPool.sol

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// This program is free software: you can redistribute it and/or modify

// it under the terms of the GNU General Public License as published by

// the Free Software Foundation, either version 3 of the License, or

// (at your option) any later version.

// This program is distributed in the hope that it will be useful,

// but WITHOUT ANY WARRANTY; without even the implied warranty of

// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the

// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License

// along with this program. If not, see <http://www.gnu.org/licenses/>.

pragma solidity 0.5.12;

import "./BToken.sol";

import "./BMath.sol";

contract BPool is BBronze, BToken, BMath {

struct Record {

bool bound; // is token bound to pool

uint index; // private

uint denorm; // denormalized weight

uint balance;

}

event LOG_SWAP(

address indexed caller,

address indexed tokenIn,

address indexed tokenOut,

uint256 tokenAmountIn,

uint256 tokenAmountOut

uint256 tokenAmountOut,

uint256 reservesAmount

);

event LOG_JOIN(

address indexed caller,

address indexed tokenIn,

uint256 tokenAmountIn

uint256 tokenAmountIn,

uint256 reservesAmount

);

event LOG_EXIT(

address indexed caller,

address indexed tokenOut,

uint256 tokenAmountOut,

uint256 reservesAmount

);

event LOG_DRAIN_RESERVES(

address indexed caller,

address indexed tokenOut,

uint256 tokenAmountOut

);

event LOG_ADD_RESERVES(

address indexed token,

uint256 reservesAmount

);

event LOG_CALL(

bytes4 indexed sig,

address indexed caller,

bytes data

) anonymous;

modifier _logs_() {

emit LOG_CALL(msg.sig, msg.sender, msg.data);

}

modifier _lock_() {

require(!_mutex, "ERR_REENTRY");

require(!_mutex);

_mutex = true;

_mutex = false;

}

modifier _viewlock_() {

require(!_mutex, "ERR_REENTRY");

require(!_mutex);

}

bool private _mutex;

address private _factory; // BFactory address to push token exitFee to

address private _controller; // has CONTROL role

bool private _publicSwap; // true if PUBLIC can call SWAP functions

// `setSwapFee` and `finalize` require CONTROL

// `finalize` sets `PUBLIC can SWAP`, `PUBLIC can JOIN`

uint private _swapFee;

uint private _reservesRatio;

bool private _finalized;

address[] private _tokens;

mapping(address=>Record) private _records;

mapping(address=>uint) public totalReserves;

uint private _totalWeight;

constructor() public {

_controller = msg.sender;

_factory = msg.sender;

_swapFee = MIN_FEE;

_reservesRatio = DEFAULT_RESERVES_RATIO;

_publicSwap = false;

_finalized = false;

}

function isPublicSwap()

external view

returns (bool)

{

return _publicSwap;

}

function isFinalized()

external view

returns (bool)

{

return _finalized;

}

function isBound(address t)

external view

returns (bool)

{

return _records[t].bound;

}

function getNumTokens()

external view

returns (uint)

{

return _tokens.length;

}

function getCurrentTokens()

external view _viewlock_

returns (address[] memory tokens)

{

return _tokens;

}

function getFinalTokens()

external view

_viewlock_

returns (address[] memory tokens)

{

require(_finalized, "ERR_NOT_FINALIZED");

require(_finalized);

return _tokens;

}

function getDenormalizedWeight(address token)

external view

_viewlock_

returns (uint)

{

require(_records[token].bound, "ERR_NOT_BOUND");

require(_records[token].bound);

return _records[token].denorm;

}

function getTotalDenormalizedWeight()

external view

_viewlock_

returns (uint)

{

return _totalWeight;

}

function getNormalizedWeight(address token)

external view

_viewlock_

returns (uint)

{

require(_records[token].bound, "ERR_NOT_BOUND");

require(_records[token].bound);

uint denorm = _records[token].denorm;

return bdiv(denorm, _totalWeight);

}

function getBalance(address token)

external view

_viewlock_

returns (uint)

{

require(_records[token].bound, "ERR_NOT_BOUND");

require(_records[token].bound);

return _records[token].balance;

}

function getSwapFee()

external view

_viewlock_

returns (uint)

{

return _swapFee;

}

function getReservesRatio()

external view

_viewlock_

returns (uint)

{

return _reservesRatio;

}

function getController()

external view

_viewlock_

returns (address)

{

return _controller;

}

function setSwapFee(uint swapFee)

external

_logs_

_lock_

{

require(!_finalized, "ERR_IS_FINALIZED");

require(!_finalized);

require(msg.sender == _controller, "ERR_NOT_CONTROLLER");

require(msg.sender == _controller);

require(swapFee >= MIN_FEE, "ERR_MIN_FEE");

require(swapFee >= MIN_FEE);

require(swapFee <= MAX_FEE, "ERR_MAX_FEE");

require(swapFee <= MAX_FEE);

_swapFee = swapFee;

}

function setReservesRatio(uint reservesRatio)

external

_logs_

_lock_

{

require(!_finalized);

require(msg.sender == _controller);

require(reservesRatio <= BONE);

require(reservesRatio >= DEFAULT_RESERVES_RATIO);

_reservesRatio = reservesRatio;

}

function setController(address manager)

external

_logs_

_lock_

{

require(msg.sender == _controller, "ERR_NOT_CONTROLLER");

require(msg.sender == _controller);

_controller = manager;

}

function setPublicSwap(bool public_)

external

_logs_

_lock_

{

require(!_finalized, "ERR_IS_FINALIZED");

require(!_finalized);

require(msg.sender == _controller, "ERR_NOT_CONTROLLER");

require(msg.sender == _controller);

_publicSwap = public_;

}

function finalize()

external

_logs_

_lock_

{

require(msg.sender == _controller, "ERR_NOT_CONTROLLER");

require(msg.sender == _controller);

require(!_finalized, "ERR_IS_FINALIZED");

require(!_finalized);

require(_tokens.length >= MIN_BOUND_TOKENS, "ERR_MIN_TOKENS");

require(_tokens.length >= MIN_BOUND_TOKENS);

_finalized = true;

_publicSwap = true;

_mintPoolShare(INIT_POOL_SUPPLY);

_pushPoolShare(msg.sender, INIT_POOL_SUPPLY);

}

function bind(address token, uint balance, uint denorm)

external

_logs_

// _lock_ Bind does not lock because it jumps to `rebind`, which does

{

require(msg.sender == _controller, "ERR_NOT_CONTROLLER");

require(msg.sender == _controller);

require(!_records[token].bound, "ERR_IS_BOUND");

require(!_records[token].bound);

require(!_finalized, "ERR_IS_FINALIZED");

require(!_finalized);

require(_tokens.length < MAX_BOUND_TOKENS, "ERR_MAX_TOKENS");

require(_tokens.length < MAX_BOUND_TOKENS);

_records[token] = Record({

bound: true,

index: _tokens.length,

denorm: 0, // balance and denorm will be validated

balance: 0 // and set by `rebind`

});

_tokens.push(token);

rebind(token, balance, denorm);

}

function rebind(address token, uint balance, uint denorm)

public

_logs_

_lock_

{

require(msg.sender == _controller, "ERR_NOT_CONTROLLER");

require(msg.sender == _controller);

require(_records[token].bound, "ERR_NOT_BOUND");

require(_records[token].bound);

require(!_finalized, "ERR_IS_FINALIZED");

require(!_finalized);

require(denorm >= MIN_WEIGHT, "ERR_MIN_WEIGHT");

require(denorm >= MIN_WEIGHT);

require(denorm <= MAX_WEIGHT, "ERR_MAX_WEIGHT");

require(denorm <= MAX_WEIGHT);

require(balance >= MIN_BALANCE, "ERR_MIN_BALANCE");

require(balance >= MIN_BALANCE);

// Adjust the denorm and totalWeight

uint oldWeight = _records[token].denorm;

if (denorm > oldWeight) {

_totalWeight = badd(_totalWeight, bsub(denorm, oldWeight));

require(_totalWeight <= MAX_TOTAL_WEIGHT, "ERR_MAX_TOTAL_WEIGHT");

require(_totalWeight <= MAX_TOTAL_WEIGHT);

} else if (denorm < oldWeight) {

_totalWeight = bsub(_totalWeight, bsub(oldWeight, denorm));

}

_records[token].denorm = denorm;

// Adjust the balance record and actual token balance

uint oldBalance = _records[token].balance;

_records[token].balance = balance;

if (balance > oldBalance) {

_pullUnderlying(token, msg.sender, bsub(balance, oldBalance));

} else if (balance < oldBalance) {

// In this case liquidity is being withdrawn, so charge EXIT_FEE

uint tokenBalanceWithdrawn = bsub(oldBalance, balance);

uint tokenExitFee = bmul(tokenBalanceWithdrawn, EXIT_FEE);

_pushUnderlying(token, msg.sender, bsub(tokenBalanceWithdrawn, tokenExitFee));

_pushUnderlying(token, _factory, tokenExitFee);

}

function unbind(address token)

external

_logs_

_lock_

{

require(msg.sender == _controller, "ERR_NOT_CONTROLLER");

require(msg.sender == _controller);

require(_records[token].bound, "ERR_NOT_BOUND");

require(_records[token].bound);

require(!_finalized, "ERR_IS_FINALIZED");

require(!_finalized);

uint tokenBalance = _records[token].balance;

uint tokenExitFee = bmul(tokenBalance, EXIT_FEE);

_totalWeight = bsub(_totalWeight, _records[token].denorm);

// Swap the token-to-unbind with the last token,

// then delete the last token

uint index = _records[token].index;

uint last = _tokens.length - 1;

_tokens[index] = _tokens[last];

_records[_tokens[index]].index = index;

_tokens.pop();

_records[token] = Record({

bound: false,

index: 0,

denorm: 0,

balance: 0

});

_pushUnderlying(token, msg.sender, bsub(tokenBalance, tokenExitFee));

_pushUnderlying(token, _factory, tokenExitFee);

}

// Absorb any tokens that have been sent to this contract into the pool

function gulp(address token)

external

_logs_

_lock_

{

require(_records[token].bound, "ERR_NOT_BOUND");

require(_records[token].bound);

_records[token].balance = IERC20(token).balanceOf(address(this));

uint erc20Balance = IERC20(token).balanceOf(address(this));

uint reserves = totalReserves[token];

// `_records[token].balance` should be equaled to `bsub(erc20Balance, reserves)` unless there are extra

// tokens transferred to this pool without calling `joinxxx`.

require(_records[token].balance <= bsub(erc20Balance, reserves));

_records[token].balance = bsub(erc20Balance, reserves);

}

function seize(address token, uint amount)

external

_logs_

_lock_

{

require(msg.sender == _controller);

require(!_records[token].bound);

uint bal = IERC20(token).balanceOf(address(this));

require(amount <= bal);

_pushUnderlying(token, msg.sender, amount);

}

function getSpotPrice(address tokenIn, address tokenOut)

external view

_viewlock_

returns (uint spotPrice)

{

require(_records[tokenIn].bound, "ERR_NOT_BOUND");

require(_records[tokenOut].bound, "ERR_NOT_BOUND");

Record storage inRecord = _records[tokenIn];

Record storage outRecord = _records[tokenOut];

return calcSpotPrice(inRecord.balance, inRecord.denorm, outRecord.balance, outRecord.denorm, _swapFee);

}

function getSpotPriceSansFee(address tokenIn, address tokenOut)

external view

_viewlock_

returns (uint spotPrice)

{

require(_records[tokenIn].bound, "ERR_NOT_BOUND");

require(_records[tokenOut].bound, "ERR_NOT_BOUND");

Record storage inRecord = _records[tokenIn];

Record storage outRecord = _records[tokenOut];

return calcSpotPrice(inRecord.balance, inRecord.denorm, outRecord.balance, outRecord.denorm, 0);

}

function joinPool(uint poolAmountOut, uint[] calldata maxAmountsIn)

external

_logs_

_lock_

{

require(_finalized, "ERR_NOT_FINALIZED");

uint poolTotal = totalSupply();

uint ratio = bdiv(poolAmountOut, poolTotal);

require(ratio != 0, "ERR_MATH_APPROX");

for (uint i = 0; i < _tokens.length; i++) {

address t = _tokens[i];

uint bal = _records[t].balance;

uint tokenAmountIn = bmul(ratio, bal);

require(tokenAmountIn != 0, "ERR_MATH_APPROX");

require(tokenAmountIn <= maxAmountsIn[i], "ERR_LIMIT_IN");

_records[t].balance = badd(_records[t].balance, tokenAmountIn);

emit LOG_JOIN(msg.sender, t, tokenAmountIn);

emit LOG_JOIN(msg.sender, t, tokenAmountIn, 0);

_pullUnderlying(t, msg.sender, tokenAmountIn);

}

_mintPoolShare(poolAmountOut);

_pushPoolShare(msg.sender, poolAmountOut);

}

function exitPool(uint poolAmountIn, uint[] calldata minAmountsOut)

external

_logs_

_lock_

{

require(_finalized, "ERR_NOT_FINALIZED");

uint poolTotal = totalSupply();

uint exitFee = bmul(poolAmountIn, EXIT_FEE);

uint pAiAfterExitFee = bsub(poolAmountIn, exitFee);

uint ratio = bdiv(pAiAfterExitFee, poolTotal);

require(ratio != 0, "ERR_MATH_APPROX");

_pullPoolShare(msg.sender, poolAmountIn);

_pushPoolShare(_factory, exitFee);

_burnPoolShare(pAiAfterExitFee);

for (uint i = 0; i < _tokens.length; i++) {

address t = _tokens[i];

uint bal = _records[t].balance;

uint tokenAmountOut = bmul(ratio, bal);

require(tokenAmountOut != 0, "ERR_MATH_APPROX");

require(tokenAmountOut >= minAmountsOut[i], "ERR_LIMIT_OUT");

_records[t].balance = bsub(_records[t].balance, tokenAmountOut);

emit LOG_EXIT(msg.sender, t, tokenAmountOut);

emit LOG_EXIT(msg.sender, t, tokenAmountOut, 0);

_pushUnderlying(t, msg.sender, tokenAmountOut);

}

function swapExactAmountIn(

address tokenIn,

uint tokenAmountIn,

address tokenOut,

uint minAmountOut,

uint maxPrice

)

external

_logs_

_lock_

returns (uint tokenAmountOut, uint spotPriceAfter)

{

require(_records[tokenIn].bound, "ERR_NOT_BOUND");

require(_records[tokenOut].bound, "ERR_NOT_BOUND");

require(_publicSwap, "ERR_SWAP_NOT_PUBLIC");

Record storage inRecord = _records[address(tokenIn)];

Record storage outRecord = _records[address(tokenOut)];

require(tokenAmountIn <= bmul(inRecord.balance, MAX_IN_RATIO), "ERR_MAX_IN_RATIO");

uint spotPriceBefore = calcSpotPrice(

inRecord.balance,

inRecord.denorm,

outRecord.balance,

outRecord.denorm,

_swapFee

);

require(spotPriceBefore <= maxPrice, "ERR_BAD_LIMIT_PRICE");

tokenAmountOut = calcOutGivenIn(

uint tokenInFee;

inRecord.balance,

(tokenAmountOut, tokenInFee) = calcOutGivenIn(

inRecord.denorm,

inRecord.balance,

outRecord.balance,

inRecord.denorm,

outRecord.denorm,

outRecord.balance,

tokenAmountIn,

outRecord.denorm,

_swapFee

tokenAmountIn,

);

_swapFee

);

require(tokenAmountOut >= minAmountOut, "ERR_LIMIT_OUT");

inRecord.balance = badd(inRecord.balance, tokenAmountIn);

uint reserves = calcReservesFromFee(tokenInFee, _reservesRatio);

// Subtract `reserves`.

inRecord.balance = bsub(badd(inRecord.balance, tokenAmountIn), reserves);

outRecord.balance = bsub(outRecord.balance, tokenAmountOut);

spotPriceAfter = calcSpotPrice(

inRecord.balance,

inRecord.denorm,

outRecord.balance,

outRecord.denorm,

_swapFee

);

require(spotPriceAfter >= spotPriceBefore, "ERR_MATH_APPROX");

require(spotPriceAfter <= maxPrice, "ERR_LIMIT_PRICE");

require(spotPriceBefore <= bdiv(tokenAmountIn, tokenAmountOut), "ERR_MATH_APPROX");

emit LOG_SWAP(msg.sender, tokenIn, tokenOut, tokenAmountIn, tokenAmountOut);

emit LOG_SWAP(msg.sender, tokenIn, tokenOut, tokenAmountIn, tokenAmountOut, reserves);

totalReserves[address(tokenIn)] = badd(totalReserves[address(tokenIn)], reserves);

emit LOG_ADD_RESERVES(address(tokenIn), reserves);

_pullUnderlying(tokenIn, msg.sender, tokenAmountIn);

_pushUnderlying(tokenOut, msg.sender, tokenAmountOut);

return (tokenAmountOut, spotPriceAfter);

}

function swapExactAmountOut(

address tokenIn,

uint maxAmountIn,

address tokenOut,

uint tokenAmountOut,

uint maxPrice

)

external

_logs_

_lock_

returns (uint tokenAmountIn, uint spotPriceAfter)

{

require(_records[tokenIn].bound, "ERR_NOT_BOUND");

require(_records[tokenOut].bound, "ERR_NOT_BOUND");

require(_publicSwap, "ERR_SWAP_NOT_PUBLIC");

Record storage inRecord = _records[address(tokenIn)];

Record storage outRecord = _records[address(tokenOut)];

require(tokenAmountOut <= bmul(outRecord.balance, MAX_OUT_RATIO), "ERR_MAX_OUT_RATIO");

uint spotPriceBefore = calcSpotPrice(

inRecord.balance,

inRecord.denorm,

outRecord.balance,

outRecord.denorm,

_swapFee

);

require(spotPriceBefore <= maxPrice, "ERR_BAD_LIMIT_PRICE");

tokenAmountIn = calcInGivenOut(

uint tokenInFee;

inRecord.balance,

(tokenAmountIn, tokenInFee) = calcInGivenOut(

inRecord.denorm,

inRecord.balance,

outRecord.balance,

inRecord.denorm,

outRecord.denorm,

outRecord.balance,

tokenAmountOut,

outRecord.denorm,

_swapFee

tokenAmountOut,

);

_swapFee

);

require(tokenAmountIn <= maxAmountIn, "ERR_LIMIT_IN");

inRecord.balance = badd(inRecord.balance, tokenAmountIn);

uint reserves = calcReservesFromFee(

tokenInFee,

_reservesRatio

);

// Subtract `reserves` which is reserved for admin.

inRecord.balance = bsub(badd(inRecord.balance, tokenAmountIn), reserves);

outRecord.balance = bsub(outRecord.balance, tokenAmountOut);

spotPriceAfter = calcSpotPrice(

inRecord.balance,

inRecord.denorm,

outRecord.balance,

outRecord.denorm,

_swapFee

);

require(spotPriceAfter >= spotPriceBefore, "ERR_MATH_APPROX");

require(spotPriceAfter <= maxPrice, "ERR_LIMIT_PRICE");

require(spotPriceBefore <= bdiv(tokenAmountIn, tokenAmountOut), "ERR_MATH_APPROX");

emit LOG_SWAP(msg.sender, tokenIn, tokenOut, tokenAmountIn, tokenAmountOut);

emit LOG_SWAP(msg.sender, tokenIn, tokenOut, tokenAmountIn, tokenAmountOut, reserves);

totalReserves[address(tokenIn)] = badd(totalReserves[address(tokenIn)], reserves);

emit LOG_ADD_RESERVES(address(tokenIn), reserves);

_pullUnderlying(tokenIn, msg.sender, tokenAmountIn);

_pushUnderlying(tokenOut, msg.sender, tokenAmountOut);

return (tokenAmountIn, spotPriceAfter);

}

function joinswapExternAmountIn(address tokenIn, uint tokenAmountIn, uint minPoolAmountOut)

external

_logs_

_lock_

returns (uint poolAmountOut)

{

require(_finalized, "ERR_NOT_FINALIZED");

require(_records[tokenIn].bound, "ERR_NOT_BOUND");

require(tokenAmountIn <= bmul(_records[tokenIn].balance, MAX_IN_RATIO), "ERR_MAX_IN_RATIO");

Record storage inRecord = _records[tokenIn];

poolAmountOut = calcPoolOutGivenSingleIn(

uint reserves;

(poolAmountOut, reserves) = calcPoolOutGivenSingleIn(

inRecord.balance,

inRecord.denorm,

_totalSupply,

_totalWeight,

tokenAmountIn,

_swapFee

_swapFee,

_reservesRatio

);

require(poolAmountOut >= minPoolAmountOut, "ERR_LIMIT_OUT");

inRecord.balance = badd(inRecord.balance, tokenAmountIn);

inRecord.balance = bsub(badd(inRecord.balance, tokenAmountIn), reserves);

emit LOG_JOIN(msg.sender, tokenIn, tokenAmountIn);

emit LOG_JOIN(msg.sender, tokenIn, tokenAmountIn, reserves);

totalReserves[address(tokenIn)] = badd(totalReserves[address(tokenIn)], reserves);

emit LOG_ADD_RESERVES(address(tokenIn), reserves);

_mintPoolShare(poolAmountOut);

_pushPoolShare(msg.sender, poolAmountOut);

_pullUnderlying(tokenIn, msg.sender, tokenAmountIn);

return poolAmountOut;

}

function joinswapPoolAmountOut(address tokenIn, uint poolAmountOut, uint maxAmountIn)

external

_logs_

_lock_

returns (uint tokenAmountIn)

{

require(_finalized, "ERR_NOT_FINALIZED");

require(_records[tokenIn].bound, "ERR_NOT_BOUND");

Record storage inRecord = _records[tokenIn];

tokenAmountIn = calcSingleInGivenPoolOut(

inRecord.balance,

inRecord.denorm,

_totalSupply,

_totalWeight,

poolAmountOut,

_swapFee

);

require(tokenAmountIn != 0, "ERR_MATH_APPROX");

require(tokenAmountIn <= maxAmountIn, "ERR_LIMIT_IN");

require(tokenAmountIn <= bmul(_records[tokenIn].balance, MAX_IN_RATIO), "ERR_MAX_IN_RATIO");

inRecord.balance = badd(inRecord.balance, tokenAmountIn);

uint tokenAmountInZeroFee = calcSingleInGivenPoolOut(

inRecord.balance,

inRecord.denorm,

_totalSupply,

_totalWeight,

poolAmountOut,

);

uint reserves = calcReserves(

tokenAmountIn,

tokenAmountInZeroFee,

_reservesRatio

);

emit LOG_JOIN(msg.sender, tokenIn, tokenAmountIn);

inRecord.balance = bsub(badd(inRecord.balance, tokenAmountIn), reserves);

emit LOG_JOIN(msg.sender, tokenIn, tokenAmountIn, reserves);

totalReserves[address(tokenIn)] = badd(totalReserves[address(tokenIn)], reserves);

emit LOG_ADD_RESERVES(address(tokenIn), reserves);

_mintPoolShare(poolAmountOut);

_pushPoolShare(msg.sender, poolAmountOut);

_pullUnderlying(tokenIn, msg.sender, tokenAmountIn);

return tokenAmountIn;

}

function exitswapPoolAmountIn(address tokenOut, uint poolAmountIn, uint minAmountOut)

external

_logs_

_lock_

returns (uint tokenAmountOut)

{

require(_finalized, "ERR_NOT_FINALIZED");

require(_records[tokenOut].bound, "ERR_NOT_BOUND");

Record storage outRecord = _records[tokenOut];

tokenAmountOut = calcSingleOutGivenPoolIn(

outRecord.balance,

outRecord.denorm,

_totalSupply,

_totalWeight,

poolAmountIn,

_swapFee

);

require(tokenAmountOut >= minAmountOut, "ERR_LIMIT_OUT");

require(tokenAmountOut <= bmul(_records[tokenOut].balance, MAX_OUT_RATIO), "ERR_MAX_OUT_RATIO");

outRecord.balance = bsub(outRecord.balance, tokenAmountOut);

uint tokenAmountOutZeroFee = calcSingleOutGivenPoolIn(

outRecord.balance,

outRecord.denorm,

_totalSupply,

_totalWeight,

poolAmountIn,

);

uint reserves = calcReserves(

tokenAmountOutZeroFee,

tokenAmountOut,

_reservesRatio

);

outRecord.balance = bsub(bsub(outRecord.balance, tokenAmountOut), reserves);

uint exitFee = bmul(poolAmountIn, EXIT_FEE);

emit LOG_EXIT(msg.sender, tokenOut, tokenAmountOut);

emit LOG_EXIT(msg.sender, tokenOut, tokenAmountOut, reserves);

totalReserves[address(tokenOut)] = badd(totalReserves[address(tokenOut)], reserves);

emit LOG_ADD_RESERVES(address(tokenOut), reserves);

_pullPoolShare(msg.sender, poolAmountIn);

_burnPoolShare(bsub(poolAmountIn, exitFee));

_pushPoolShare(_factory, exitFee);

_pushUnderlying(tokenOut, msg.sender, tokenAmountOut);

return tokenAmountOut;

}

function exitswapExternAmountOut(address tokenOut, uint tokenAmountOut, uint maxPoolAmountIn)

external

_logs_

_lock_

returns (uint poolAmountIn)

{

require(_finalized, "ERR_NOT_FINALIZED");

require(_records[tokenOut].bound, "ERR_NOT_BOUND");

require(tokenAmountOut <= bmul(_records[tokenOut].balance, MAX_OUT_RATIO), "ERR_MAX_OUT_RATIO");

Record storage outRecord = _records[tokenOut];

poolAmountIn = calcPoolInGivenSingleOut(

uint reserves;

(poolAmountIn, reserves) = calcPoolInGivenSingleOut(

outRecord.balance,

outRecord.denorm,

_totalSupply,

_totalWeight,

tokenAmountOut,

_swapFee

);

require(poolAmountIn != 0, "ERR_MATH_APPROX");

require(poolAmountIn <= maxPoolAmountIn, "ERR_LIMIT_IN");

outRecord.balance = bsub(outRecord.balance, tokenAmountOut);

uint exitFee = bmul(poolAmountIn, EXIT_FEE);

emit LOG_EXIT(msg.sender, tokenOut, tokenAmountOut);

_pullPoolShare(msg.sender, poolAmountIn);

_burnPoolShare(bsub(poolAmountIn, exitFee));

_pushPoolShare(_factory, exitFee);

_pushUnderlying(tokenOut, msg.sender, tokenAmountOut);

return poolAmountIn;

}

// ==

// 'Underlying' token-manipulation functions make external calls but are NOT locked

// You must `_lock_` or otherwise ensure reentry-safety

function _pullUnderlying(address erc20, address from, uint amount)

internal

{

bool xfer = IERC20(erc20).transferFrom(from, address(this), amount);

require(xfer, "ERR_ERC20_FALSE");

}

function _pushUnderlying(address erc20, address to, uint amount)

internal

{

bool xfer = IERC20(erc20).transfer(to, amount);

require(xfer, "ERR_ERC20_FALSE");

}

function _pullPoolShare(address from, uint amount)

internal

{

_pull(from, amount);

}

function _pushPoolShare(address to, uint amount)

internal

{

_push(to, amount);

}

function _mintPoolShare(uint amount)

internal

{

_mint(amount);

}

function _burnPoolShare(uint amount)

internal

{

_burn(amount);

}

已保存差異

原始文本

開啟檔案

// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

pragma solidity 0.5.12;

import "./BToken.sol";
import "./BMath.sol";

contract BPool is BBronze, BToken, BMath {

struct Record {
        bool bound;   // is token bound to pool
        uint index;   // private
        uint denorm;  // denormalized weight
        uint balance;
    }

event LOG_SWAP(
        address indexed caller,
        address indexed tokenIn,
        address indexed tokenOut,
        uint256         tokenAmountIn,
        uint256         tokenAmountOut
    );

event LOG_JOIN(
        address indexed caller,
        address indexed tokenIn,
        uint256         tokenAmountIn
    );

event LOG_EXIT(
        address indexed caller,
        address indexed tokenOut,
        uint256         tokenAmountOut
    );

event LOG_CALL(
        bytes4  indexed sig,
        address indexed caller,
        bytes           data
    ) anonymous;

modifier _logs_() {
        emit LOG_CALL(msg.sig, msg.sender, msg.data);
        _;
    }

modifier _lock_() {
        require(!_mutex, "ERR_REENTRY");
        _mutex = true;
        _;
        _mutex = false;
    }

modifier _viewlock_() {
        require(!_mutex, "ERR_REENTRY");
        _;
    }

bool private _mutex;

address private _factory;    // BFactory address to push token exitFee to
    address private _controller; // has CONTROL role
    bool private _publicSwap; // true if PUBLIC can call SWAP functions

// `setSwapFee` and `finalize` require CONTROL
    // `finalize` sets `PUBLIC can SWAP`, `PUBLIC can JOIN`
    uint private _swapFee;
    bool private _finalized;

address[] private _tokens;
    mapping(address=>Record) private  _records;
    uint private _totalWeight;

constructor() public {
        _controller = msg.sender;
        _factory = msg.sender;
        _swapFee = MIN_FEE;
        _publicSwap = false;
        _finalized = false;
    }

function isPublicSwap()
        external view
        returns (bool)
    {
        return _publicSwap;
    }

function isFinalized()
        external view
        returns (bool)
    {
        return _finalized;
    }

function isBound(address t)
        external view
        returns (bool)
    {
        return _records[t].bound;
    }

function getNumTokens()
        external view
        returns (uint) 
    {
        return _tokens.length;
    }

function getCurrentTokens()
        external view _viewlock_
        returns (address[] memory tokens)
    {
        return _tokens;
    }

function getFinalTokens()
        external view
        _viewlock_
        returns (address[] memory tokens)
    {
        require(_finalized, "ERR_NOT_FINALIZED");
        return _tokens;
    }

function getDenormalizedWeight(address token)
        external view
        _viewlock_
        returns (uint)
    {

require(_records[token].bound, "ERR_NOT_BOUND");
        return _records[token].denorm;
    }

function getTotalDenormalizedWeight()
        external view
        _viewlock_
        returns (uint)
    {
        return _totalWeight;
    }

function getNormalizedWeight(address token)
        external view
        _viewlock_
        returns (uint)
    {

require(_records[token].bound, "ERR_NOT_BOUND");
        uint denorm = _records[token].denorm;
        return bdiv(denorm, _totalWeight);
    }

function getBalance(address token)
        external view
        _viewlock_
        returns (uint)
    {

require(_records[token].bound, "ERR_NOT_BOUND");
        return _records[token].balance;
    }

function getSwapFee()
        external view
        _viewlock_
        returns (uint)
    {
        return _swapFee;
    }

function getController()
        external view
        _viewlock_
        returns (address)
    {
        return _controller;
    }

function setSwapFee(uint swapFee)
        external
        _logs_
        _lock_
    { 
        require(!_finalized, "ERR_IS_FINALIZED");
        require(msg.sender == _controller, "ERR_NOT_CONTROLLER");
        require(swapFee >= MIN_FEE, "ERR_MIN_FEE");
        require(swapFee <= MAX_FEE, "ERR_MAX_FEE");
        _swapFee = swapFee;
    }

function setController(address manager)
        external
        _logs_
        _lock_
    {
        require(msg.sender == _controller, "ERR_NOT_CONTROLLER");
        _controller = manager;
    }

function setPublicSwap(bool public_)
        external
        _logs_
        _lock_
    {
        require(!_finalized, "ERR_IS_FINALIZED");
        require(msg.sender == _controller, "ERR_NOT_CONTROLLER");
        _publicSwap = public_;
    }

function finalize()
        external
        _logs_
        _lock_
    {
        require(msg.sender == _controller, "ERR_NOT_CONTROLLER");
        require(!_finalized, "ERR_IS_FINALIZED");
        require(_tokens.length >= MIN_BOUND_TOKENS, "ERR_MIN_TOKENS");

_finalized = true;
        _publicSwap = true;

_mintPoolShare(INIT_POOL_SUPPLY);
        _pushPoolShare(msg.sender, INIT_POOL_SUPPLY);
    }

function bind(address token, uint balance, uint denorm)
        external
        _logs_
        // _lock_  Bind does not lock because it jumps to `rebind`, which does
    {
        require(msg.sender == _controller, "ERR_NOT_CONTROLLER");
        require(!_records[token].bound, "ERR_IS_BOUND");
        require(!_finalized, "ERR_IS_FINALIZED");

require(_tokens.length < MAX_BOUND_TOKENS, "ERR_MAX_TOKENS");

_records[token] = Record({
            bound: true,
            index: _tokens.length,
            denorm: 0,    // balance and denorm will be validated
            balance: 0   // and set by `rebind`
        });
        _tokens.push(token);
        rebind(token, balance, denorm);
    }

function rebind(address token, uint balance, uint denorm)
        public
        _logs_
        _lock_
    {

require(msg.sender == _controller, "ERR_NOT_CONTROLLER");
        require(_records[token].bound, "ERR_NOT_BOUND");
        require(!_finalized, "ERR_IS_FINALIZED");

require(denorm >= MIN_WEIGHT, "ERR_MIN_WEIGHT");
        require(denorm <= MAX_WEIGHT, "ERR_MAX_WEIGHT");
        require(balance >= MIN_BALANCE, "ERR_MIN_BALANCE");

// Adjust the denorm and totalWeight
        uint oldWeight = _records[token].denorm;
        if (denorm > oldWeight) {
            _totalWeight = badd(_totalWeight, bsub(denorm, oldWeight));
            require(_totalWeight <= MAX_TOTAL_WEIGHT, "ERR_MAX_TOTAL_WEIGHT");
        } else if (denorm < oldWeight) {
            _totalWeight = bsub(_totalWeight, bsub(oldWeight, denorm));
        }        
        _records[token].denorm = denorm;

// Adjust the balance record and actual token balance
        uint oldBalance = _records[token].balance;
        _records[token].balance = balance;
        if (balance > oldBalance) {
            _pullUnderlying(token, msg.sender, bsub(balance, oldBalance));
        } else if (balance < oldBalance) {
            // In this case liquidity is being withdrawn, so charge EXIT_FEE
            uint tokenBalanceWithdrawn = bsub(oldBalance, balance);
            uint tokenExitFee = bmul(tokenBalanceWithdrawn, EXIT_FEE);
            _pushUnderlying(token, msg.sender, bsub(tokenBalanceWithdrawn, tokenExitFee));
            _pushUnderlying(token, _factory, tokenExitFee);
        }
    }

function unbind(address token)
        external
        _logs_
        _lock_
    {

require(msg.sender == _controller, "ERR_NOT_CONTROLLER");
        require(_records[token].bound, "ERR_NOT_BOUND");
        require(!_finalized, "ERR_IS_FINALIZED");

uint tokenBalance = _records[token].balance;
        uint tokenExitFee = bmul(tokenBalance, EXIT_FEE);

_totalWeight = bsub(_totalWeight, _records[token].denorm);

// Swap the token-to-unbind with the last token,
        // then delete the last token
        uint index = _records[token].index;
        uint last = _tokens.length - 1;
        _tokens[index] = _tokens[last];
        _records[_tokens[index]].index = index;
        _tokens.pop();
        _records[token] = Record({
            bound: false,
            index: 0,
            denorm: 0,
            balance: 0
        });

_pushUnderlying(token, msg.sender, bsub(tokenBalance, tokenExitFee));
        _pushUnderlying(token, _factory, tokenExitFee);
    }

// Absorb any tokens that have been sent to this contract into the pool
    function gulp(address token)
        external
        _logs_
        _lock_
    {
        require(_records[token].bound, "ERR_NOT_BOUND");
        _records[token].balance = IERC20(token).balanceOf(address(this));
    }

function getSpotPrice(address tokenIn, address tokenOut)
        external view
        _viewlock_
        returns (uint spotPrice)
    {
        require(_records[tokenIn].bound, "ERR_NOT_BOUND");
        require(_records[tokenOut].bound, "ERR_NOT_BOUND");
        Record storage inRecord = _records[tokenIn];
        Record storage outRecord = _records[tokenOut];
        return calcSpotPrice(inRecord.balance, inRecord.denorm, outRecord.balance, outRecord.denorm, _swapFee);
    }

function getSpotPriceSansFee(address tokenIn, address tokenOut)
        external view
        _viewlock_
        returns (uint spotPrice)
    {
        require(_records[tokenIn].bound, "ERR_NOT_BOUND");
        require(_records[tokenOut].bound, "ERR_NOT_BOUND");
        Record storage inRecord = _records[tokenIn];
        Record storage outRecord = _records[tokenOut];
        return calcSpotPrice(inRecord.balance, inRecord.denorm, outRecord.balance, outRecord.denorm, 0);
    }

function joinPool(uint poolAmountOut, uint[] calldata maxAmountsIn)
        external
        _logs_
        _lock_
    {
        require(_finalized, "ERR_NOT_FINALIZED");

uint poolTotal = totalSupply();
        uint ratio = bdiv(poolAmountOut, poolTotal);
        require(ratio != 0, "ERR_MATH_APPROX");

for (uint i = 0; i < _tokens.length; i++) {
            address t = _tokens[i];
            uint bal = _records[t].balance;
            uint tokenAmountIn = bmul(ratio, bal);
            require(tokenAmountIn != 0, "ERR_MATH_APPROX");
            require(tokenAmountIn <= maxAmountsIn[i], "ERR_LIMIT_IN");
            _records[t].balance = badd(_records[t].balance, tokenAmountIn);
            emit LOG_JOIN(msg.sender, t, tokenAmountIn);
            _pullUnderlying(t, msg.sender, tokenAmountIn);
        }
        _mintPoolShare(poolAmountOut);
        _pushPoolShare(msg.sender, poolAmountOut);
    }

function exitPool(uint poolAmountIn, uint[] calldata minAmountsOut)
        external
        _logs_
        _lock_
    {
        require(_finalized, "ERR_NOT_FINALIZED");

uint poolTotal = totalSupply();
        uint exitFee = bmul(poolAmountIn, EXIT_FEE);
        uint pAiAfterExitFee = bsub(poolAmountIn, exitFee);
        uint ratio = bdiv(pAiAfterExitFee, poolTotal);
        require(ratio != 0, "ERR_MATH_APPROX");

_pullPoolShare(msg.sender, poolAmountIn);
        _pushPoolShare(_factory, exitFee);
        _burnPoolShare(pAiAfterExitFee);

for (uint i = 0; i < _tokens.length; i++) {
            address t = _tokens[i];
            uint bal = _records[t].balance;
            uint tokenAmountOut = bmul(ratio, bal);
            require(tokenAmountOut != 0, "ERR_MATH_APPROX");
            require(tokenAmountOut >= minAmountsOut[i], "ERR_LIMIT_OUT");
            _records[t].balance = bsub(_records[t].balance, tokenAmountOut);
            emit LOG_EXIT(msg.sender, t, tokenAmountOut);
            _pushUnderlying(t, msg.sender, tokenAmountOut);
        }

}

function swapExactAmountIn(
        address tokenIn,
        uint tokenAmountIn,
        address tokenOut,
        uint minAmountOut,
        uint maxPrice
    )
        external
        _logs_
        _lock_
        returns (uint tokenAmountOut, uint spotPriceAfter)
    {

require(_records[tokenIn].bound, "ERR_NOT_BOUND");
        require(_records[tokenOut].bound, "ERR_NOT_BOUND");
        require(_publicSwap, "ERR_SWAP_NOT_PUBLIC");

Record storage inRecord = _records[address(tokenIn)];
        Record storage outRecord = _records[address(tokenOut)];

require(tokenAmountIn <= bmul(inRecord.balance, MAX_IN_RATIO), "ERR_MAX_IN_RATIO");

uint spotPriceBefore = calcSpotPrice(
                                    inRecord.balance,
                                    inRecord.denorm,
                                    outRecord.balance,
                                    outRecord.denorm,
                                    _swapFee
                                );
        require(spotPriceBefore <= maxPrice, "ERR_BAD_LIMIT_PRICE");

tokenAmountOut = calcOutGivenIn(
                            inRecord.balance,
                            inRecord.denorm,
                            outRecord.balance,
                            outRecord.denorm,
                            tokenAmountIn,
                            _swapFee
                        );
        require(tokenAmountOut >= minAmountOut, "ERR_LIMIT_OUT");

inRecord.balance = badd(inRecord.balance, tokenAmountIn);
        outRecord.balance = bsub(outRecord.balance, tokenAmountOut);

spotPriceAfter = calcSpotPrice(
                                inRecord.balance,
                                inRecord.denorm,
                                outRecord.balance,
                                outRecord.denorm,
                                _swapFee
                            );
        require(spotPriceAfter >= spotPriceBefore, "ERR_MATH_APPROX");     
        require(spotPriceAfter <= maxPrice, "ERR_LIMIT_PRICE");
        require(spotPriceBefore <= bdiv(tokenAmountIn, tokenAmountOut), "ERR_MATH_APPROX");

emit LOG_SWAP(msg.sender, tokenIn, tokenOut, tokenAmountIn, tokenAmountOut);

_pullUnderlying(tokenIn, msg.sender, tokenAmountIn);
        _pushUnderlying(tokenOut, msg.sender, tokenAmountOut);

return (tokenAmountOut, spotPriceAfter);
    }

function swapExactAmountOut(
        address tokenIn,
        uint maxAmountIn,
        address tokenOut,
        uint tokenAmountOut,
        uint maxPrice
    )
        external
        _logs_
        _lock_ 
        returns (uint tokenAmountIn, uint spotPriceAfter)
    {
        require(_records[tokenIn].bound, "ERR_NOT_BOUND");
        require(_records[tokenOut].bound, "ERR_NOT_BOUND");
        require(_publicSwap, "ERR_SWAP_NOT_PUBLIC");

Record storage inRecord = _records[address(tokenIn)];
        Record storage outRecord = _records[address(tokenOut)];

require(tokenAmountOut <= bmul(outRecord.balance, MAX_OUT_RATIO), "ERR_MAX_OUT_RATIO");

tokenAmountIn = calcInGivenOut(
                            inRecord.balance,
                            inRecord.denorm,
                            outRecord.balance,
                            outRecord.denorm,
                            tokenAmountOut,
                            _swapFee
                        );
        require(tokenAmountIn <= maxAmountIn, "ERR_LIMIT_IN");

inRecord.balance = badd(inRecord.balance, tokenAmountIn);
        outRecord.balance = bsub(outRecord.balance, tokenAmountOut);

spotPriceAfter = calcSpotPrice(
                                inRecord.balance,
                                inRecord.denorm,
                                outRecord.balance,
                                outRecord.denorm,
                                _swapFee
                            );
        require(spotPriceAfter >= spotPriceBefore, "ERR_MATH_APPROX");
        require(spotPriceAfter <= maxPrice, "ERR_LIMIT_PRICE");
        require(spotPriceBefore <= bdiv(tokenAmountIn, tokenAmountOut), "ERR_MATH_APPROX");

emit LOG_SWAP(msg.sender, tokenIn, tokenOut, tokenAmountIn, tokenAmountOut);

_pullUnderlying(tokenIn, msg.sender, tokenAmountIn);
        _pushUnderlying(tokenOut, msg.sender, tokenAmountOut);

return (tokenAmountIn, spotPriceAfter);
    }

function joinswapExternAmountIn(address tokenIn, uint tokenAmountIn, uint minPoolAmountOut)
        external
        _logs_
        _lock_
        returns (uint poolAmountOut)

{        
        require(_finalized, "ERR_NOT_FINALIZED");
        require(_records[tokenIn].bound, "ERR_NOT_BOUND");
        require(tokenAmountIn <= bmul(_records[tokenIn].balance, MAX_IN_RATIO), "ERR_MAX_IN_RATIO");

Record storage inRecord = _records[tokenIn];

poolAmountOut = calcPoolOutGivenSingleIn(
                            inRecord.balance,
                            inRecord.denorm,
                            _totalSupply,
                            _totalWeight,
                            tokenAmountIn,
                            _swapFee
                        );

require(poolAmountOut >= minPoolAmountOut, "ERR_LIMIT_OUT");

inRecord.balance = badd(inRecord.balance, tokenAmountIn);

emit LOG_JOIN(msg.sender, tokenIn, tokenAmountIn);

_mintPoolShare(poolAmountOut);
        _pushPoolShare(msg.sender, poolAmountOut);
        _pullUnderlying(tokenIn, msg.sender, tokenAmountIn);

return poolAmountOut;
    }

function joinswapPoolAmountOut(address tokenIn, uint poolAmountOut, uint maxAmountIn)
        external
        _logs_
        _lock_
        returns (uint tokenAmountIn)
    {
        require(_finalized, "ERR_NOT_FINALIZED");
        require(_records[tokenIn].bound, "ERR_NOT_BOUND");

Record storage inRecord = _records[tokenIn];

tokenAmountIn = calcSingleInGivenPoolOut(
                            inRecord.balance,
                            inRecord.denorm,
                            _totalSupply,
                            _totalWeight,
                            poolAmountOut,
                            _swapFee
                        );

require(tokenAmountIn != 0, "ERR_MATH_APPROX");
        require(tokenAmountIn <= maxAmountIn, "ERR_LIMIT_IN");
        
        require(tokenAmountIn <= bmul(_records[tokenIn].balance, MAX_IN_RATIO), "ERR_MAX_IN_RATIO");

inRecord.balance = badd(inRecord.balance, tokenAmountIn);

emit LOG_JOIN(msg.sender, tokenIn, tokenAmountIn);

_mintPoolShare(poolAmountOut);
        _pushPoolShare(msg.sender, poolAmountOut);
        _pullUnderlying(tokenIn, msg.sender, tokenAmountIn);

return tokenAmountIn;
    }

function exitswapPoolAmountIn(address tokenOut, uint poolAmountIn, uint minAmountOut)
        external
        _logs_
        _lock_
        returns (uint tokenAmountOut)
    {
        require(_finalized, "ERR_NOT_FINALIZED");
        require(_records[tokenOut].bound, "ERR_NOT_BOUND");

Record storage outRecord = _records[tokenOut];

tokenAmountOut = calcSingleOutGivenPoolIn(
                            outRecord.balance,
                            outRecord.denorm,
                            _totalSupply,
                            _totalWeight,
                            poolAmountIn,
                            _swapFee
                        );

require(tokenAmountOut >= minAmountOut, "ERR_LIMIT_OUT");
        
        require(tokenAmountOut <= bmul(_records[tokenOut].balance, MAX_OUT_RATIO), "ERR_MAX_OUT_RATIO");

outRecord.balance = bsub(outRecord.balance, tokenAmountOut);

uint exitFee = bmul(poolAmountIn, EXIT_FEE);

emit LOG_EXIT(msg.sender, tokenOut, tokenAmountOut);

_pullPoolShare(msg.sender, poolAmountIn);
        _burnPoolShare(bsub(poolAmountIn, exitFee));
        _pushPoolShare(_factory, exitFee);
        _pushUnderlying(tokenOut, msg.sender, tokenAmountOut);

return tokenAmountOut;
    }

function exitswapExternAmountOut(address tokenOut, uint tokenAmountOut, uint maxPoolAmountIn)
        external
        _logs_
        _lock_
        returns (uint poolAmountIn)
    {
        require(_finalized, "ERR_NOT_FINALIZED");
        require(_records[tokenOut].bound, "ERR_NOT_BOUND");
        require(tokenAmountOut <= bmul(_records[tokenOut].balance, MAX_OUT_RATIO), "ERR_MAX_OUT_RATIO");

Record storage outRecord = _records[tokenOut];

poolAmountIn = calcPoolInGivenSingleOut(
                            outRecord.balance,
                            outRecord.denorm,
                            _totalSupply,
                            _totalWeight,
                            tokenAmountOut,
                            _swapFee
                        );

require(poolAmountIn != 0, "ERR_MATH_APPROX");
        require(poolAmountIn <= maxPoolAmountIn, "ERR_LIMIT_IN");

outRecord.balance = bsub(outRecord.balance, tokenAmountOut);

uint exitFee = bmul(poolAmountIn, EXIT_FEE);

emit LOG_EXIT(msg.sender, tokenOut, tokenAmountOut);

return poolAmountIn;
    }

// ==
    // 'Underlying' token-manipulation functions make external calls but are NOT locked
    // You must `_lock_` or otherwise ensure reentry-safety

function _pullUnderlying(address erc20, address from, uint amount)
        internal
    {
        bool xfer = IERC20(erc20).transferFrom(from, address(this), amount);
        require(xfer, "ERR_ERC20_FALSE");
    }

function _pushUnderlying(address erc20, address to, uint amount)
        internal
    {
        bool xfer = IERC20(erc20).transfer(to, amount);
        require(xfer, "ERR_ERC20_FALSE");
    }

function _pullPoolShare(address from, uint amount)
        internal
    {
        _pull(from, amount);
    }

function _pushPoolShare(address to, uint amount)
        internal
    {
        _push(to, amount);
    }

function _mintPoolShare(uint amount)
        internal
    {
        _mint(amount);
    }

function _burnPoolShare(uint amount)
        internal
    {
        _burn(amount);
    }

}

更改後文本

開啟檔案

// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

pragma solidity 0.5.12;

import "./BToken.sol";
import "./BMath.sol";

contract BPool is BBronze, BToken, BMath {

struct Record {
        bool bound;   // is token bound to pool
        uint index;   // private
        uint denorm;  // denormalized weight
        uint balance;
    }

event LOG_SWAP(
        address indexed caller,
        address indexed tokenIn,
        address indexed tokenOut,
        uint256         tokenAmountIn,
        uint256         tokenAmountOut,
        uint256         reservesAmount
    );

event LOG_JOIN(
        address indexed caller,
        address indexed tokenIn,
        uint256         tokenAmountIn,
        uint256         reservesAmount
    );

event LOG_EXIT(
        address indexed caller,
        address indexed tokenOut,
        uint256         tokenAmountOut,
        uint256         reservesAmount
    );

event LOG_DRAIN_RESERVES(
        address indexed caller,
        address indexed tokenOut,
        uint256         tokenAmountOut
    );

event LOG_ADD_RESERVES(
        address indexed token,
        uint256         reservesAmount
    );

event LOG_CALL(
        bytes4  indexed sig,
        address indexed caller,
        bytes           data
    ) anonymous;

modifier _logs_() {
        emit LOG_CALL(msg.sig, msg.sender, msg.data);
        _;
    }

modifier _lock_() {
        require(!_mutex);
        _mutex = true;
        _;
        _mutex = false;
    }

modifier _viewlock_() {
        require(!_mutex);
        _;
    }

bool private _mutex;

address private _factory;    // BFactory address to push token exitFee to
    address private _controller; // has CONTROL role
    bool private _publicSwap; // true if PUBLIC can call SWAP functions

// `setSwapFee` and `finalize` require CONTROL
    // `finalize` sets `PUBLIC can SWAP`, `PUBLIC can JOIN`
    uint private _swapFee;
    uint private _reservesRatio;
    bool private _finalized;

address[] private _tokens;
    mapping(address=>Record) private  _records;
    mapping(address=>uint) public totalReserves;

uint private _totalWeight;

constructor() public {
        _controller = msg.sender;
        _factory = msg.sender;
        _swapFee = MIN_FEE;
        _reservesRatio = DEFAULT_RESERVES_RATIO;
        _publicSwap = false;
        _finalized = false;
    }

function isPublicSwap()
        external view
        returns (bool)
    {
        return _publicSwap;
    }

function isFinalized()
        external view
        returns (bool)
    {
        return _finalized;
    }

function isBound(address t)
        external view
        returns (bool)
    {
        return _records[t].bound;
    }

function getNumTokens()
        external view
        returns (uint)
    {
        return _tokens.length;
    }

function getCurrentTokens()
        external view _viewlock_
        returns (address[] memory tokens)
    {
        return _tokens;
    }

function getFinalTokens()
        external view
        _viewlock_
        returns (address[] memory tokens)
    {
        require(_finalized);
        return _tokens;
    }

function getDenormalizedWeight(address token)
        external view
        _viewlock_
        returns (uint)
    {

require(_records[token].bound);
        return _records[token].denorm;
    }

function getTotalDenormalizedWeight()
        external view
        _viewlock_
        returns (uint)
    {
        return _totalWeight;
    }

function getNormalizedWeight(address token)
        external view
        _viewlock_
        returns (uint)
    {

require(_records[token].bound);
        uint denorm = _records[token].denorm;
        return bdiv(denorm, _totalWeight);
    }

function getBalance(address token)
        external view
        _viewlock_
        returns (uint)
    {

require(_records[token].bound);
        return _records[token].balance;
    }

function getSwapFee()
        external view
        _viewlock_
        returns (uint)
    {
        return _swapFee;
    }

function getReservesRatio()
        external view
        _viewlock_
        returns (uint)
    {
        return _reservesRatio;
    }

function getController()
        external view
        _viewlock_
        returns (address)
    {
        return _controller;
    }

function setSwapFee(uint swapFee)
        external
        _logs_
        _lock_
    {
        require(!_finalized);
        require(msg.sender == _controller);
        require(swapFee >= MIN_FEE);
        require(swapFee <= MAX_FEE);
        _swapFee = swapFee;
    }

function setReservesRatio(uint reservesRatio)
        external
        _logs_
        _lock_
    {
        require(!_finalized);
        require(msg.sender == _controller);
        require(reservesRatio <= BONE);
        require(reservesRatio >= DEFAULT_RESERVES_RATIO);
        _reservesRatio = reservesRatio;
    }

function setController(address manager)
        external
        _logs_
        _lock_
    {
        require(msg.sender == _controller);
        _controller = manager;
    }

function setPublicSwap(bool public_)
        external
        _logs_
        _lock_
    {
        require(!_finalized);
        require(msg.sender == _controller);
        _publicSwap = public_;
    }

function finalize()
        external
        _logs_
        _lock_
    {
        require(msg.sender == _controller);
        require(!_finalized);
        require(_tokens.length >= MIN_BOUND_TOKENS);

_finalized = true;
        _publicSwap = true;

_mintPoolShare(INIT_POOL_SUPPLY);
        _pushPoolShare(msg.sender, INIT_POOL_SUPPLY);
    }

function bind(address token, uint balance, uint denorm)
        external
        _logs_
        // _lock_  Bind does not lock because it jumps to `rebind`, which does
    {
        require(msg.sender == _controller);
        require(!_records[token].bound);
        require(!_finalized);

require(_tokens.length < MAX_BOUND_TOKENS);

function rebind(address token, uint balance, uint denorm)
        public
        _logs_
        _lock_
    {

require(msg.sender == _controller);
        require(_records[token].bound);
        require(!_finalized);

require(denorm >= MIN_WEIGHT);
        require(denorm <= MAX_WEIGHT);
        require(balance >= MIN_BALANCE);

// Adjust the denorm and totalWeight
        uint oldWeight = _records[token].denorm;
        if (denorm > oldWeight) {
            _totalWeight = badd(_totalWeight, bsub(denorm, oldWeight));
            require(_totalWeight <= MAX_TOTAL_WEIGHT);
        } else if (denorm < oldWeight) {
            _totalWeight = bsub(_totalWeight, bsub(oldWeight, denorm));
        }
        _records[token].denorm = denorm;

function unbind(address token)
        external
        _logs_
        _lock_
    {

require(msg.sender == _controller);
        require(_records[token].bound);
        require(!_finalized);

uint tokenBalance = _records[token].balance;
        uint tokenExitFee = bmul(tokenBalance, EXIT_FEE);

_totalWeight = bsub(_totalWeight, _records[token].denorm);

_pushUnderlying(token, msg.sender, bsub(tokenBalance, tokenExitFee));
        _pushUnderlying(token, _factory, tokenExitFee);
    }

// Absorb any tokens that have been sent to this contract into the pool
    function gulp(address token)
        external
        _logs_
        _lock_
    {
        require(_records[token].bound);
        uint erc20Balance = IERC20(token).balanceOf(address(this));
        uint reserves = totalReserves[token];
        // `_records[token].balance` should be equaled to `bsub(erc20Balance, reserves)` unless there are extra
        // tokens transferred to this pool without calling `joinxxx`.
        require(_records[token].balance <= bsub(erc20Balance, reserves));
        _records[token].balance = bsub(erc20Balance, reserves);
    }

function seize(address token, uint amount)
        external
        _logs_
        _lock_
    {
        require(msg.sender == _controller);
        require(!_records[token].bound);

uint bal = IERC20(token).balanceOf(address(this));
        require(amount <= bal);

_pushUnderlying(token, msg.sender, amount);
    }

function joinPool(uint poolAmountOut, uint[] calldata maxAmountsIn)
        external
        _logs_
        _lock_
    {
        require(_finalized, "ERR_NOT_FINALIZED");

uint poolTotal = totalSupply();
        uint ratio = bdiv(poolAmountOut, poolTotal);
        require(ratio != 0, "ERR_MATH_APPROX");

for (uint i = 0; i < _tokens.length; i++) {
            address t = _tokens[i];
            uint bal = _records[t].balance;
            uint tokenAmountIn = bmul(ratio, bal);
            require(tokenAmountIn != 0, "ERR_MATH_APPROX");
            require(tokenAmountIn <= maxAmountsIn[i], "ERR_LIMIT_IN");
            _records[t].balance = badd(_records[t].balance, tokenAmountIn);
            emit LOG_JOIN(msg.sender, t, tokenAmountIn, 0);
            _pullUnderlying(t, msg.sender, tokenAmountIn);
        }
        _mintPoolShare(poolAmountOut);
        _pushPoolShare(msg.sender, poolAmountOut);
    }

function exitPool(uint poolAmountIn, uint[] calldata minAmountsOut)
        external
        _logs_
        _lock_
    {
        require(_finalized, "ERR_NOT_FINALIZED");

_pullPoolShare(msg.sender, poolAmountIn);
        _pushPoolShare(_factory, exitFee);
        _burnPoolShare(pAiAfterExitFee);

for (uint i = 0; i < _tokens.length; i++) {
            address t = _tokens[i];
            uint bal = _records[t].balance;
            uint tokenAmountOut = bmul(ratio, bal);
            require(tokenAmountOut != 0, "ERR_MATH_APPROX");
            require(tokenAmountOut >= minAmountsOut[i], "ERR_LIMIT_OUT");
            _records[t].balance = bsub(_records[t].balance, tokenAmountOut);
            emit LOG_EXIT(msg.sender, t, tokenAmountOut, 0);
            _pushUnderlying(t, msg.sender, tokenAmountOut);
        }

}

require(_records[tokenIn].bound, "ERR_NOT_BOUND");
        require(_records[tokenOut].bound, "ERR_NOT_BOUND");
        require(_publicSwap, "ERR_SWAP_NOT_PUBLIC");

Record storage inRecord = _records[address(tokenIn)];
        Record storage outRecord = _records[address(tokenOut)];

require(tokenAmountIn <= bmul(inRecord.balance, MAX_IN_RATIO), "ERR_MAX_IN_RATIO");

uint tokenInFee;
        (tokenAmountOut, tokenInFee) = calcOutGivenIn(
                                            inRecord.balance,
                                            inRecord.denorm,
                                            outRecord.balance,
                                            outRecord.denorm,
                                            tokenAmountIn,
                                            _swapFee
                                        );
        require(tokenAmountOut >= minAmountOut, "ERR_LIMIT_OUT");

uint reserves = calcReservesFromFee(tokenInFee, _reservesRatio);

// Subtract `reserves`.
        inRecord.balance = bsub(badd(inRecord.balance, tokenAmountIn), reserves);
        outRecord.balance = bsub(outRecord.balance, tokenAmountOut);

spotPriceAfter = calcSpotPrice(
                                inRecord.balance,
                                inRecord.denorm,
                                outRecord.balance,
                                outRecord.denorm,
                                _swapFee
                            );
        require(spotPriceAfter >= spotPriceBefore, "ERR_MATH_APPROX");
        require(spotPriceAfter <= maxPrice, "ERR_LIMIT_PRICE");
        require(spotPriceBefore <= bdiv(tokenAmountIn, tokenAmountOut), "ERR_MATH_APPROX");

emit LOG_SWAP(msg.sender, tokenIn, tokenOut, tokenAmountIn, tokenAmountOut, reserves);

totalReserves[address(tokenIn)] = badd(totalReserves[address(tokenIn)], reserves);
        emit LOG_ADD_RESERVES(address(tokenIn), reserves);

_pullUnderlying(tokenIn, msg.sender, tokenAmountIn);
        _pushUnderlying(tokenOut, msg.sender, tokenAmountOut);

return (tokenAmountOut, spotPriceAfter);
    }

function swapExactAmountOut(
        address tokenIn,
        uint maxAmountIn,
        address tokenOut,
        uint tokenAmountOut,
        uint maxPrice
    )
        external
        _logs_
        _lock_
        returns (uint tokenAmountIn, uint spotPriceAfter)
    {
        require(_records[tokenIn].bound, "ERR_NOT_BOUND");
        require(_records[tokenOut].bound, "ERR_NOT_BOUND");
        require(_publicSwap, "ERR_SWAP_NOT_PUBLIC");

Record storage inRecord = _records[address(tokenIn)];
        Record storage outRecord = _records[address(tokenOut)];

require(tokenAmountOut <= bmul(outRecord.balance, MAX_OUT_RATIO), "ERR_MAX_OUT_RATIO");

uint tokenInFee;
        (tokenAmountIn, tokenInFee) = calcInGivenOut(
                                            inRecord.balance,
                                            inRecord.denorm,
                                            outRecord.balance,
                                            outRecord.denorm,
                                            tokenAmountOut,
                                            _swapFee
                                        );
        require(tokenAmountIn <= maxAmountIn, "ERR_LIMIT_IN");

uint reserves = calcReservesFromFee(
            tokenInFee,
            _reservesRatio
        );

// Subtract `reserves` which is reserved for admin.
        inRecord.balance = bsub(badd(inRecord.balance, tokenAmountIn), reserves);
        outRecord.balance = bsub(outRecord.balance, tokenAmountOut);

spotPriceAfter = calcSpotPrice(
                                inRecord.balance,
                                inRecord.denorm,
                                outRecord.balance,
                                outRecord.denorm,
                                _swapFee
                            );
        require(spotPriceAfter >= spotPriceBefore, "ERR_MATH_APPROX");
        require(spotPriceAfter <= maxPrice, "ERR_LIMIT_PRICE");
        require(spotPriceBefore <= bdiv(tokenAmountIn, tokenAmountOut), "ERR_MATH_APPROX");

emit LOG_SWAP(msg.sender, tokenIn, tokenOut, tokenAmountIn, tokenAmountOut, reserves);

totalReserves[address(tokenIn)] = badd(totalReserves[address(tokenIn)], reserves);
        emit LOG_ADD_RESERVES(address(tokenIn), reserves);

_pullUnderlying(tokenIn, msg.sender, tokenAmountIn);
        _pushUnderlying(tokenOut, msg.sender, tokenAmountOut);

return (tokenAmountIn, spotPriceAfter);
    }

function joinswapExternAmountIn(address tokenIn, uint tokenAmountIn, uint minPoolAmountOut)
        external
        _logs_
        _lock_
        returns (uint poolAmountOut)

{
        require(_finalized, "ERR_NOT_FINALIZED");
        require(_records[tokenIn].bound, "ERR_NOT_BOUND");
        require(tokenAmountIn <= bmul(_records[tokenIn].balance, MAX_IN_RATIO), "ERR_MAX_IN_RATIO");

Record storage inRecord = _records[tokenIn];

uint reserves;
        (poolAmountOut, reserves) = calcPoolOutGivenSingleIn(
                            inRecord.balance,
                            inRecord.denorm,
                            _totalSupply,
                            _totalWeight,
                            tokenAmountIn,
                            _swapFee,
                            _reservesRatio
                        );

require(poolAmountOut >= minPoolAmountOut, "ERR_LIMIT_OUT");

inRecord.balance = bsub(badd(inRecord.balance, tokenAmountIn), reserves);

emit LOG_JOIN(msg.sender, tokenIn, tokenAmountIn, reserves);

totalReserves[address(tokenIn)] = badd(totalReserves[address(tokenIn)], reserves);
        emit LOG_ADD_RESERVES(address(tokenIn), reserves);

_mintPoolShare(poolAmountOut);
        _pushPoolShare(msg.sender, poolAmountOut);
        _pullUnderlying(tokenIn, msg.sender, tokenAmountIn);

return poolAmountOut;
    }

Record storage inRecord = _records[tokenIn];

require(tokenAmountIn != 0, "ERR_MATH_APPROX");
        require(tokenAmountIn <= maxAmountIn, "ERR_LIMIT_IN");

require(tokenAmountIn <= bmul(_records[tokenIn].balance, MAX_IN_RATIO), "ERR_MAX_IN_RATIO");

uint tokenAmountInZeroFee = calcSingleInGivenPoolOut(
            inRecord.balance,
            inRecord.denorm,
            _totalSupply,
            _totalWeight,
            poolAmountOut,
            0
        );
        uint reserves = calcReserves(
            tokenAmountIn,
            tokenAmountInZeroFee,
            _reservesRatio
        );

inRecord.balance = bsub(badd(inRecord.balance, tokenAmountIn), reserves);

emit LOG_JOIN(msg.sender, tokenIn, tokenAmountIn, reserves);

totalReserves[address(tokenIn)] = badd(totalReserves[address(tokenIn)], reserves);
        emit LOG_ADD_RESERVES(address(tokenIn), reserves);

_mintPoolShare(poolAmountOut);
        _pushPoolShare(msg.sender, poolAmountOut);
        _pullUnderlying(tokenIn, msg.sender, tokenAmountIn);

return tokenAmountIn;
    }

Record storage outRecord = _records[tokenOut];

require(tokenAmountOut >= minAmountOut, "ERR_LIMIT_OUT");

require(tokenAmountOut <= bmul(_records[tokenOut].balance, MAX_OUT_RATIO), "ERR_MAX_OUT_RATIO");

uint tokenAmountOutZeroFee = calcSingleOutGivenPoolIn(
            outRecord.balance,
            outRecord.denorm,
            _totalSupply,
            _totalWeight,
            poolAmountIn,
            0
        );
        uint reserves = calcReserves(
            tokenAmountOutZeroFee,
            tokenAmountOut,
            _reservesRatio
        );

outRecord.balance = bsub(bsub(outRecord.balance, tokenAmountOut), reserves);

uint exitFee = bmul(poolAmountIn, EXIT_FEE);

emit LOG_EXIT(msg.sender, tokenOut, tokenAmountOut, reserves);

totalReserves[address(tokenOut)] = badd(totalReserves[address(tokenOut)], reserves);
        emit LOG_ADD_RESERVES(address(tokenOut), reserves);

return tokenAmountOut;
    }

Record storage outRecord = _records[tokenOut];

uint reserves;
        (poolAmountIn, reserves) = calcPoolInGivenSingleOut(
                            outRecord.balance,
                            outRecord.denorm,
                            _totalSupply,
                            _totalWeight,
                            tokenAmountOut,
                            _swapFee,
                            _reservesRatio
                        );

require(poolAmountIn != 0, "ERR_MATH_APPROX");
        require(poolAmountIn <= maxPoolAmountIn, "ERR_LIMIT_IN");

outRecord.balance = bsub(bsub(outRecord.balance, tokenAmountOut), reserves);

uint exitFee = bmul(poolAmountIn, EXIT_FEE);

emit LOG_EXIT(msg.sender, tokenOut, tokenAmountOut, reserves);

totalReserves[address(tokenOut)] = badd(totalReserves[address(tokenOut)], reserves);
        emit LOG_ADD_RESERVES(address(tokenOut), reserves);

return poolAmountIn;
    }

function drainTotalReserves(address reservesAddress)
        external
        _logs_
        _lock_
    {
        require(msg.sender == _factory);

for (uint i = 0; i < _tokens.length; i++) {
            address t = _tokens[i];
            uint tokenAmountOut = totalReserves[t];
            totalReserves[t] = 0;
            emit LOG_DRAIN_RESERVES(reservesAddress, t, tokenAmountOut);
            _pushUnderlying(t, reservesAddress, tokenAmountOut);
        }
    }

// ==
    // 'Underlying' token-manipulation functions make external calls but are NOT locked
    // You must `_lock_` or otherwise ensure reentry-safety

function _pushUnderlying(address erc20, address to, uint amount)
        internal
    {
        bool xfer = IERC20(erc20).transfer(to, amount);
        require(xfer, "ERR_ERC20_FALSE");
    }

function _pullPoolShare(address from, uint amount)
        internal
    {
        _pull(from, amount);
    }

function _pushPoolShare(address to, uint amount)
        internal
    {
        _push(to, amount);
    }

function _mintPoolShare(uint amount)
        internal
    {
        _mint(amount);
    }

function _burnPoolShare(uint amount)
        internal
    {
        _burn(amount);
    }

}