Contract Name:
AaveEcosystemReserveV2
Contract Source Code:
// SPDX-License-Identifier: AGPL-3.0
pragma solidity ^0.8.0;
/**
* @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);
}
// SPDX-License-Identifier: GPL-3.0
pragma solidity ^0.8.10;
import {IERC20} from '@aave/core-v3/contracts/dependencies/openzeppelin/contracts/IERC20.sol';
import {IStreamable} from './interfaces/IStreamable.sol';
import {AdminControlledEcosystemReserve} from './AdminControlledEcosystemReserve.sol';
import {ReentrancyGuard} from './libs/ReentrancyGuard.sol';
import {SafeERC20} from './libs/SafeERC20.sol';
/**
* @title AaveEcosystemReserve v2
* @notice Stores ERC20 tokens of an ecosystem reserve, adding streaming capabilities.
* Modification of Sablier https://github.com/sablierhq/sablier/blob/develop/packages/protocol/contracts/Sablier.sol
* Original can be found also deployed on https://etherscan.io/address/0xCD18eAa163733Da39c232722cBC4E8940b1D8888
* Modifications:
* - Sablier "pulls" the funds from the creator of the stream at creation. In the Aave case, we already have the funds.
* - Anybody can create streams on Sablier. Here, only the funds admin (Aave governance via controller) can
* - Adapted codebase to Solidity 0.8.11, mainly removing SafeMath and CarefulMath to use native safe math
* - Same as with creation, on Sablier the `sender` and `recipient` can cancel a stream. Here, only fund admin and recipient
* @author BGD Labs
**/
contract AaveEcosystemReserveV2 is AdminControlledEcosystemReserve, ReentrancyGuard, IStreamable {
using SafeERC20 for IERC20;
/*** Storage Properties ***/
/**
* @notice Counter for new stream ids.
*/
uint256 private _nextStreamId;
/**
* @notice The stream objects identifiable by their unsigned integer ids.
*/
mapping(uint256 => Stream) private _streams;
/*** Modifiers ***/
/**
* @dev Throws if the caller is not the funds admin of the recipient of the stream.
*/
modifier onlyAdminOrRecipient(uint256 streamId) {
require(
msg.sender == _fundsAdmin || msg.sender == _streams[streamId].recipient,
'caller is not the funds admin or the recipient of the stream'
);
_;
}
/**
* @dev Throws if the provided id does not point to a valid stream.
*/
modifier streamExists(uint256 streamId) {
require(_streams[streamId].isEntity, 'stream does not exist');
_;
}
/*** Contract Logic Starts Here */
function initialize(address fundsAdmin) external initializer {
_nextStreamId = 100000;
_setFundsAdmin(fundsAdmin);
}
/*** View Functions ***/
/**
* @notice Returns the next available stream id
* @notice Returns the stream id.
*/
function getNextStreamId() external view returns (uint256) {
return _nextStreamId;
}
/**
* @notice Returns the stream with all its properties.
* @dev Throws if the id does not point to a valid stream.
* @param streamId The id of the stream to query.
* @notice Returns the stream object.
*/
function getStream(
uint256 streamId
)
external
view
streamExists(streamId)
returns (
address sender,
address recipient,
uint256 deposit,
address tokenAddress,
uint256 startTime,
uint256 stopTime,
uint256 remainingBalance,
uint256 ratePerSecond
)
{
sender = _streams[streamId].sender;
recipient = _streams[streamId].recipient;
deposit = _streams[streamId].deposit;
tokenAddress = _streams[streamId].tokenAddress;
startTime = _streams[streamId].startTime;
stopTime = _streams[streamId].stopTime;
remainingBalance = _streams[streamId].remainingBalance;
ratePerSecond = _streams[streamId].ratePerSecond;
}
/**
* @notice Returns either the delta in seconds between `block.timestamp` and `startTime` or
* between `stopTime` and `startTime, whichever is smaller. If `block.timestamp` is before
* `startTime`, it returns 0.
* @dev Throws if the id does not point to a valid stream.
* @param streamId The id of the stream for which to query the delta.
* @notice Returns the time delta in seconds.
*/
function deltaOf(uint256 streamId) public view streamExists(streamId) returns (uint256 delta) {
Stream memory stream = _streams[streamId];
if (block.timestamp <= stream.startTime) return 0;
if (block.timestamp < stream.stopTime) return block.timestamp - stream.startTime;
return stream.stopTime - stream.startTime;
}
struct BalanceOfLocalVars {
uint256 recipientBalance;
uint256 withdrawalAmount;
uint256 senderBalance;
}
/**
* @notice Returns the available funds for the given stream id and address.
* @dev Throws if the id does not point to a valid stream.
* @param streamId The id of the stream for which to query the balance.
* @param who The address for which to query the balance.
* @notice Returns the total funds allocated to `who` as uint256.
*/
function balanceOf(
uint256 streamId,
address who
) public view streamExists(streamId) returns (uint256 balance) {
Stream memory stream = _streams[streamId];
BalanceOfLocalVars memory vars;
uint256 delta = deltaOf(streamId);
vars.recipientBalance = delta * stream.ratePerSecond;
/*
* If the stream `balance` does not equal `deposit`, it means there have been withdrawals.
* We have to subtract the total amount withdrawn from the amount of money that has been
* streamed until now.
*/
if (stream.deposit > stream.remainingBalance) {
vars.withdrawalAmount = stream.deposit - stream.remainingBalance;
vars.recipientBalance = vars.recipientBalance - vars.withdrawalAmount;
}
if (who == stream.recipient) return vars.recipientBalance;
if (who == stream.sender) {
vars.senderBalance = stream.remainingBalance - vars.recipientBalance;
return vars.senderBalance;
}
return 0;
}
/*** Public Effects & Interactions Functions ***/
struct CreateStreamLocalVars {
uint256 duration;
uint256 ratePerSecond;
}
/**
* @notice Creates a new stream funded by this contracts itself and paid towards `recipient`.
* @dev Throws if the recipient is the zero address, the contract itself or the caller.
* Throws if the deposit is 0.
* Throws if the start time is before `block.timestamp`.
* Throws if the stop time is before the start time.
* Throws if the duration calculation has a math error.
* Throws if the deposit is smaller than the duration.
* Throws if the deposit is not a multiple of the duration.
* Throws if the rate calculation has a math error.
* Throws if the next stream id calculation has a math error.
* Throws if the contract is not allowed to transfer enough tokens.
* Throws if there is a token transfer failure.
* @param recipient The address towards which the money is streamed.
* @param deposit The amount of money to be streamed.
* @param tokenAddress The ERC20 token to use as streaming currency.
* @param startTime The unix timestamp for when the stream starts.
* @param stopTime The unix timestamp for when the stream stops.
* @notice Returns the uint256 id of the newly created stream.
*/
function createStream(
address recipient,
uint256 deposit,
address tokenAddress,
uint256 startTime,
uint256 stopTime
) external onlyFundsAdmin returns (uint256) {
require(recipient != address(0), 'stream to the zero address');
require(recipient != address(this), 'stream to the contract itself');
require(recipient != msg.sender, 'stream to the caller');
require(deposit > 0, 'deposit is zero');
require(startTime >= block.timestamp, 'start time before block.timestamp');
require(stopTime > startTime, 'stop time before the start time');
CreateStreamLocalVars memory vars;
vars.duration = stopTime - startTime;
/* Without this, the rate per second would be zero. */
require(deposit >= vars.duration, 'deposit smaller than time delta');
/* This condition avoids dealing with remainders */
require(deposit % vars.duration == 0, 'deposit not multiple of time delta');
vars.ratePerSecond = deposit / vars.duration;
/* Create and store the stream object. */
uint256 streamId = _nextStreamId;
_streams[streamId] = Stream({
remainingBalance: deposit,
deposit: deposit,
isEntity: true,
ratePerSecond: vars.ratePerSecond,
recipient: recipient,
sender: address(this),
startTime: startTime,
stopTime: stopTime,
tokenAddress: tokenAddress
});
/* Increment the next stream id. */
_nextStreamId++;
emit CreateStream(
streamId,
address(this),
recipient,
deposit,
tokenAddress,
startTime,
stopTime
);
return streamId;
}
/**
* @notice Withdraws from the contract to the recipient's account.
* @dev Throws if the id does not point to a valid stream.
* Throws if the caller is not the funds admin or the recipient of the stream.
* Throws if the amount exceeds the available balance.
* Throws if there is a token transfer failure.
* @param streamId The id of the stream to withdraw tokens from.
* @param amount The amount of tokens to withdraw.
*/
function withdrawFromStream(
uint256 streamId,
uint256 amount
) external nonReentrant streamExists(streamId) onlyAdminOrRecipient(streamId) returns (bool) {
require(amount > 0, 'amount is zero');
Stream memory stream = _streams[streamId];
uint256 balance = balanceOf(streamId, stream.recipient);
require(balance >= amount, 'amount exceeds the available balance');
_streams[streamId].remainingBalance = stream.remainingBalance - amount;
if (_streams[streamId].remainingBalance == 0) delete _streams[streamId];
IERC20(stream.tokenAddress).safeTransfer(stream.recipient, amount);
emit WithdrawFromStream(streamId, stream.recipient, amount);
return true;
}
/**
* @notice Cancels the stream and transfers the tokens back on a pro rata basis.
* @dev Throws if the id does not point to a valid stream.
* Throws if the caller is not the funds admin or the recipient of the stream.
* Throws if there is a token transfer failure.
* @param streamId The id of the stream to cancel.
* @notice Returns bool true=success, otherwise false.
*/
function cancelStream(
uint256 streamId
) external nonReentrant streamExists(streamId) onlyAdminOrRecipient(streamId) returns (bool) {
Stream memory stream = _streams[streamId];
uint256 senderBalance = balanceOf(streamId, stream.sender);
uint256 recipientBalance = balanceOf(streamId, stream.recipient);
delete _streams[streamId];
IERC20 token = IERC20(stream.tokenAddress);
if (recipientBalance > 0) token.safeTransfer(stream.recipient, recipientBalance);
emit CancelStream(streamId, stream.sender, stream.recipient, senderBalance, recipientBalance);
return true;
}
}
// SPDX-License-Identifier: GPL-3.0
pragma solidity ^0.8.10;
import {IERC20} from '@aave/core-v3/contracts/dependencies/openzeppelin/contracts/IERC20.sol';
import {IAdminControlledEcosystemReserve} from './interfaces/IAdminControlledEcosystemReserve.sol';
import {VersionedInitializable} from './libs/VersionedInitializable.sol';
import {SafeERC20} from './libs/SafeERC20.sol';
import {ReentrancyGuard} from './libs/ReentrancyGuard.sol';
import {Address} from './libs/Address.sol';
/**
* @title AdminControlledEcosystemReserve
* @notice Stores ERC20 tokens, and allows to dispose of them via approval or transfer dynamics
* Adapted to be an implementation of a transparent proxy
* @dev Done abstract to add an `initialize()` function on the child, with `initializer` modifier
* @author BGD Labs
**/
abstract contract AdminControlledEcosystemReserve is
VersionedInitializable,
IAdminControlledEcosystemReserve
{
using SafeERC20 for IERC20;
using Address for address payable;
address internal _fundsAdmin;
uint256 public constant REVISION = 1;
/// @inheritdoc IAdminControlledEcosystemReserve
address public constant ETH_MOCK_ADDRESS = 0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE;
modifier onlyFundsAdmin() {
require(msg.sender == _fundsAdmin, 'ONLY_BY_FUNDS_ADMIN');
_;
}
function getRevision() internal pure override returns (uint256) {
return REVISION;
}
/// @inheritdoc IAdminControlledEcosystemReserve
function getFundsAdmin() external view returns (address) {
return _fundsAdmin;
}
/// @inheritdoc IAdminControlledEcosystemReserve
function approve(IERC20 token, address recipient, uint256 amount) external onlyFundsAdmin {
token.safeApprove(recipient, amount);
}
/// @inheritdoc IAdminControlledEcosystemReserve
function transfer(IERC20 token, address recipient, uint256 amount) external onlyFundsAdmin {
require(recipient != address(0), 'INVALID_0X_RECIPIENT');
if (address(token) == ETH_MOCK_ADDRESS) {
payable(recipient).sendValue(amount);
} else {
token.safeTransfer(recipient, amount);
}
}
/// @dev needed in order to receive ETH from the Aave v1 ecosystem reserve
receive() external payable {}
function _setFundsAdmin(address admin) internal {
_fundsAdmin = admin;
emit NewFundsAdmin(admin);
}
}
// SPDX-License-Identifier: GPL-3.0
pragma solidity ^0.8.10;
import {IERC20} from '@aave/core-v3/contracts/dependencies/openzeppelin/contracts/IERC20.sol';
interface IAdminControlledEcosystemReserve {
/** @notice Emitted when the funds admin changes
* @param fundsAdmin The new funds admin
**/
event NewFundsAdmin(address indexed fundsAdmin);
/** @notice Returns the mock ETH reference address
* @return address The address
**/
function ETH_MOCK_ADDRESS() external pure returns (address);
/**
* @notice Return the funds admin, only entity to be able to interact with this contract (controller of reserve)
* @return address The address of the funds admin
**/
function getFundsAdmin() external view returns (address);
/**
* @dev Function for the funds admin to give ERC20 allowance to other parties
* @param token The address of the token to give allowance from
* @param recipient Allowance's recipient
* @param amount Allowance to approve
**/
function approve(IERC20 token, address recipient, uint256 amount) external;
/**
* @notice Function for the funds admin to transfer ERC20 tokens to other parties
* @param token The address of the token to transfer
* @param recipient Transfer's recipient
* @param amount Amount to transfer
**/
function transfer(IERC20 token, address recipient, uint256 amount) external;
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.10;
interface IStreamable {
struct Stream {
uint256 deposit;
uint256 ratePerSecond;
uint256 remainingBalance;
uint256 startTime;
uint256 stopTime;
address recipient;
address sender;
address tokenAddress;
bool isEntity;
}
event CreateStream(
uint256 indexed streamId,
address indexed sender,
address indexed recipient,
uint256 deposit,
address tokenAddress,
uint256 startTime,
uint256 stopTime
);
event WithdrawFromStream(uint256 indexed streamId, address indexed recipient, uint256 amount);
event CancelStream(
uint256 indexed streamId,
address indexed sender,
address indexed recipient,
uint256 senderBalance,
uint256 recipientBalance
);
function balanceOf(uint256 streamId, address who) external view returns (uint256 balance);
function getStream(
uint256 streamId
)
external
view
returns (
address sender,
address recipient,
uint256 deposit,
address token,
uint256 startTime,
uint256 stopTime,
uint256 remainingBalance,
uint256 ratePerSecond
);
function createStream(
address recipient,
uint256 deposit,
address tokenAddress,
uint256 startTime,
uint256 stopTime
) external returns (uint256 streamId);
function withdrawFromStream(uint256 streamId, uint256 funds) external returns (bool);
function cancelStream(uint256 streamId) external returns (bool);
function initialize(address fundsAdmin) external;
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (utils/Address.sol)
pragma solidity ^0.8.1;
/**
* @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
* ====
*
* [IMPORTANT]
* ====
* You shouldn't rely on `isContract` to protect against flash loan attacks!
*
* Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
* like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
* constructor.
* ====
*/
function isContract(address account) internal view returns (bool) {
// This method relies on extcodesize/address.code.length, which returns 0
// for contracts in construction, since the code is only stored at the end
// of the constructor execution.
return account.code.length > 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');
(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');
require(isContract(target), 'Address: call to non-contract');
(bool success, bytes memory returndata) = target.call{value: value}(data);
return verifyCallResult(success, returndata, errorMessage);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but performing a static call.
*
* _Available since v3.3._
*/
function functionStaticCall(
address target,
bytes memory data
) internal view returns (bytes memory) {
return functionStaticCall(target, data, 'Address: low-level static call failed');
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
* but performing a static call.
*
* _Available since v3.3._
*/
function functionStaticCall(
address target,
bytes memory data,
string memory errorMessage
) internal view returns (bytes memory) {
require(isContract(target), 'Address: static call to non-contract');
(bool success, bytes memory returndata) = target.staticcall(data);
return verifyCallResult(success, returndata, errorMessage);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but performing a delegate call.
*
* _Available since v3.4._
*/
function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
return functionDelegateCall(target, data, 'Address: low-level delegate call failed');
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
* but performing a delegate call.
*
* _Available since v3.4._
*/
function functionDelegateCall(
address target,
bytes memory data,
string memory errorMessage
) internal returns (bytes memory) {
require(isContract(target), 'Address: delegate call to non-contract');
(bool success, bytes memory returndata) = target.delegatecall(data);
return verifyCallResult(success, returndata, errorMessage);
}
/**
* @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the
* revert reason using the provided one.
*
* _Available since v4.3._
*/
function verifyCallResult(
bool success,
bytes memory returndata,
string memory errorMessage
) internal pure returns (bytes memory) {
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
assembly {
let returndata_size := mload(returndata)
revert(add(32, returndata), returndata_size)
}
} else {
revert(errorMessage);
}
}
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (security/ReentrancyGuard.sol)
pragma solidity ^0.8.0;
/**
* @dev Contract module that helps prevent reentrant calls to a function.
*
* Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
* available, which can be applied to functions to make sure there are no nested
* (reentrant) calls to them.
*
* Note that because there is a single `nonReentrant` guard, functions marked as
* `nonReentrant` may not call one another. This can be worked around by making
* those functions `private`, and then adding `external` `nonReentrant` entry
* points to them.
*
* TIP: If you would like to learn more about reentrancy and alternative ways
* to protect against it, check out our blog post
* https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
*/
abstract contract ReentrancyGuard {
// Booleans are more expensive than uint256 or any type that takes up a full
// word because each write operation emits an extra SLOAD to first read the
// slot's contents, replace the bits taken up by the boolean, and then write
// back. This is the compiler's defense against contract upgrades and
// pointer aliasing, and it cannot be disabled.
// The values being non-zero value makes deployment a bit more expensive,
// but in exchange the refund on every call to nonReentrant will be lower in
// amount. Since refunds are capped to a percentage of the total
// transaction's gas, it is best to keep them low in cases like this one, to
// increase the likelihood of the full refund coming into effect.
uint256 private constant _NOT_ENTERED = 1;
uint256 private constant _ENTERED = 2;
uint256 private _status;
constructor() {
_status = _NOT_ENTERED;
}
/**
* @dev Prevents a contract from calling itself, directly or indirectly.
* Calling a `nonReentrant` function from another `nonReentrant`
* function is not supported. It is possible to prevent this from happening
* by making the `nonReentrant` function external, and making it call a
* `private` function that does the actual work.
*/
modifier nonReentrant() {
// On the first call to nonReentrant, _notEntered will be true
require(_status != _ENTERED, 'ReentrancyGuard: reentrant call');
// Any calls to nonReentrant after this point will fail
_status = _ENTERED;
_;
// By storing the original value once again, a refund is triggered (see
// https://eips.ethereum.org/EIPS/eip-2200)
_status = _NOT_ENTERED;
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC20/utils/SafeERC20.sol)
pragma solidity ^0.8.0;
import {IERC20} from '@aave/core-v3/contracts/dependencies/openzeppelin/contracts/IERC20.sol';
import {Address} from './Address.sol';
/**
* @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 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'
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) + value;
_callOptionalReturn(
token,
abi.encodeWithSelector(token.approve.selector, spender, newAllowance)
);
}
function safeDecreaseAllowance(IERC20 token, address spender, uint256 value) internal {
unchecked {
uint256 oldAllowance = token.allowance(address(this), spender);
require(oldAllowance >= value, 'SafeERC20: decreased allowance below zero');
uint256 newAllowance = oldAllowance - value;
_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
require(abi.decode(returndata, (bool)), 'SafeERC20: ERC20 operation did not succeed');
}
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.10;
/**
* @title VersionedInitializable
*
* @dev Helper contract to support initializer functions. To use it, replace
* the constructor with a function that has the `initializer` modifier.
* WARNING: Unlike constructors, initializer functions must be manually
* invoked. This applies both to deploying an Initializable contract, as well
* as extending an Initializable contract via inheritance.
* WARNING: When used with inheritance, manual care must be taken to not invoke
* a parent initializer twice, or ensure that all initializers are idempotent,
* because this is not dealt with automatically as with constructors.
*
* @author Aave, inspired by the OpenZeppelin Initializable contract
*/
abstract contract VersionedInitializable {
/**
* @dev Indicates that the contract has been initialized.
*/
uint256 internal lastInitializedRevision = 0;
/**
* @dev Modifier to use in the initializer function of a contract.
*/
modifier initializer() {
uint256 revision = getRevision();
require(revision > lastInitializedRevision, 'Contract instance has already been initialized');
lastInitializedRevision = revision;
_;
}
/// @dev returns the revision number of the contract.
/// Needs to be defined in the inherited class as a constant.
function getRevision() internal pure virtual returns (uint256);
// Reserved storage space to allow for layout changes in the future.
uint256[50] private ______gap;
}