234ddb495d
* fix: mStable USD Sampler and Mixin fix * chore: adding mBTC (mStable) pool * fix linter
128 lines
4.2 KiB
Solidity
128 lines
4.2 KiB
Solidity
// SPDX-License-Identifier: Apache-2.0
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/*
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Copyright 2020 ZeroEx Intl.
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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pragma solidity ^0.6;
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pragma experimental ABIEncoderV2;
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import "./interfaces/IMStable.sol";
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import "./ApproximateBuys.sol";
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import "./SamplerUtils.sol";
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contract MStableSampler is
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SamplerUtils,
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ApproximateBuys
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{
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/// @dev Default gas limit for mStable calls.
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uint256 constant private DEFAULT_CALL_GAS = 800e3; // 800k
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/// @dev Sample sell quotes from the mStable contract
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/// @param router Address of the mStable contract
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/// @param takerToken Address of the taker token (what to sell).
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/// @param makerToken Address of the maker token (what to buy).
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/// @param takerTokenAmounts Taker token sell amount for each sample.
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/// @return makerTokenAmounts Maker amounts bought at each taker token
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/// amount.
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function sampleSellsFromMStable(
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address router,
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address takerToken,
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address makerToken,
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uint256[] memory takerTokenAmounts
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)
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public
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view
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returns (uint256[] memory makerTokenAmounts)
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{
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_assertValidPair(makerToken, takerToken);
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// Initialize array of maker token amounts.
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uint256 numSamples = takerTokenAmounts.length;
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makerTokenAmounts = new uint256[](numSamples);
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for (uint256 i = 0; i < numSamples; i++) {
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try
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IMStable(router).getSwapOutput
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{gas: DEFAULT_CALL_GAS}
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(takerToken, makerToken, takerTokenAmounts[i])
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returns (uint256 amount)
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{
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makerTokenAmounts[i] = amount;
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// Break early if there are 0 amounts
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if (makerTokenAmounts[i] == 0) {
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break;
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}
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} catch (bytes memory) {
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// Swallow failures, leaving all results as zero.
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break;
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}
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}
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}
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/// @dev Sample buy quotes from MStable contract
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/// @param router Address of the mStable contract
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/// @param takerToken Address of the taker token (what to sell).
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/// @param makerToken Address of the maker token (what to buy).
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/// @param makerTokenAmounts Maker token buy amount for each sample.
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/// @return takerTokenAmounts Taker amounts sold at each maker token
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/// amount.
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function sampleBuysFromMStable(
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address router,
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address takerToken,
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address makerToken,
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uint256[] memory makerTokenAmounts
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)
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public
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view
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returns (uint256[] memory takerTokenAmounts)
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{
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return _sampleApproximateBuys(
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ApproximateBuyQuoteOpts({
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makerTokenData: abi.encode(makerToken, router),
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takerTokenData: abi.encode(takerToken, router),
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getSellQuoteCallback: _sampleSellForApproximateBuyFromMStable
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}),
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makerTokenAmounts
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);
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}
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function _sampleSellForApproximateBuyFromMStable(
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bytes memory takerTokenData,
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bytes memory makerTokenData,
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uint256 sellAmount
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)
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private
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view
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returns (uint256 buyAmount)
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{
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(address takerToken, address router) =
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abi.decode(takerTokenData, (address, address));
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(address makerToken) =
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abi.decode(makerTokenData, (address));
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try
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this.sampleSellsFromMStable
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(router, takerToken, makerToken, _toSingleValueArray(sellAmount))
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returns (uint256[] memory amounts)
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{
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return amounts[0];
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} catch (bytes memory) {
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// Swallow failures, leaving all results as zero.
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return 0;
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}
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}
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}
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