Balancer Finance V2

1// SPDX-License-Identifier: GPL-3.0-or-later
2// This program is free software: you can redistribute it and/or modify
3// it under the terms of the GNU General Public License as published by
4// the Free Software Foundation, either version 3 of the License, or
5// (at your option) any later version.
6​
7// This program is distributed in the hope that it will be useful,
8// but WITHOUT ANY WARRANTY; without even the implied warranty of
9// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
10// GNU General Public License for more details.
11​
12// You should have received a copy of the GNU General Public License
13// along with this program.  If not, see <http://www.gnu.org/licenses/>.
14​
15pragma solidity ^0.7.0;
16pragma experimental ABIEncoderV2;
17​
18import "@balancer-labs/v2-solidity-utils/contracts/misc/IWETH.sol";
19​
20import "./interfaces/IAuthorizer.sol";
21​
22import "./VaultAuthorization.sol";
23import "./FlashLoans.sol";
24import "./Swaps.sol";
25​
26/**
27 * @dev The `Vault` is Balancer V2's core contract. A single instance of it exists for the entire network, and it is the
28 * entity used to interact with Pools by Liquidity Providers who join and exit them, Traders who swap, and Asset
29 * Managers who withdraw and deposit tokens.
30 *
31 * The `Vault`'s source code is split among a number of sub-contracts, with the goal of improving readability and making
32 * understanding the system easier. Most sub-contracts have been marked as `abstract` to explicitly indicate that only
33 * the full `Vault` is meant to be deployed.
34 *
35 * Roughly speaking, these are the contents of each sub-contract:
36 *
37 *  - `AssetManagers`: Pool token Asset Manager registry, and Asset Manager interactions.
38 *  - `Fees`: set and compute protocol fees.
39 *  - `FlashLoans`: flash loan transfers and fees.
40 *  - `PoolBalances`: Pool joins and exits.
41 *  - `PoolRegistry`: Pool registration, ID management, and basic queries.
42 *  - `PoolTokens`: Pool token registration and registration, and balance queries.
43 *  - `Swaps`: Pool swaps.
44 *  - `UserBalance`: manage user balances (Internal Balance operations and external balance transfers)
45 *  - `VaultAuthorization`: access control, relayers and signature validation.
46 *
47 * Additionally, the different Pool specializations are handled by the `GeneralPoolsBalance`,
48 * `MinimalSwapInfoPoolsBalance` and `TwoTokenPoolsBalance` sub-contracts, which in turn make use of the
49 * `BalanceAllocation` library.
50 *
51 * The most important goal of the `Vault` is to make token swaps use as little gas as possible. This is reflected in a
52 * multitude of design decisions, from minor things like the format used to store Pool IDs, to major features such as
53 * the different Pool specialization settings.
54 *
55 * Finally, the large number of tasks carried out by the Vault means its bytecode is very large, close to exceeding
56 * the contract size limit imposed by EIP 170 (https://eips.ethereum.org/EIPS/eip-170). Manual tuning of the source code
57 * was required to improve code generation and bring the bytecode size below this limit. This includes extensive
58 * utilization of `internal` functions (particularly inside modifiers), usage of named return arguments, dedicated
59 * storage access methods, dynamic revert reason generation, and usage of inline assembly, to name a few.
60 */
61contract Vault is VaultAuthorization, FlashLoans, Swaps {
62    constructor(
63        IAuthorizer authorizer,
64        IWETH weth,
65        uint256 pauseWindowDuration,
66        uint256 bufferPeriodDuration
67    ) VaultAuthorization(authorizer) AssetHelpers(weth) TemporarilyPausable(pauseWindowDuration, bufferPeriodDuration) {
68        / solhint-disable-previous-line no-empty-blocks
69    }
70​
71    function setPaused(bool paused) external override nonReentrant authenticate {
72        _setPaused(paused);
73    }
74​
75    / solhint-disable-next-line func-name-mixedcase
76    function WETH() external view override returns (IWETH) {
77        return _WETH();
78    }
79}

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