ERC-20
Overview
Max Total Supply
5,515,458,429,875,070,800 ERC-20:
Holders
37
Market
Onchain Market Cap
$0.00
Circulating Supply Market Cap
-
Other Info
Token Contract (WITH 0 Decimals)
Balance
69,000,000,000,000,000 ERC-20:Value
$0.00Loading...
Loading
Loading...
Loading
Loading...
Loading
# | Exchange | Pair | Price | 24H Volume | % Volume |
---|
Minimal Proxy Contract for 0x4abd5d3af06ce5356a455eb5ecdc1f07aa9c083a
Contract Name:
CrowdFinancingV1
Compiler Version
v0.8.17+commit.8df45f5f
Optimization Enabled:
Yes with 200 runs
Other Settings:
default evmVersion
Contract Source Code (Solidity)
/** *Submitted for verification at Etherscan.io on 2023-04-20 */ // SPDX-License-Identifier: MIT pragma solidity 0.8.17; // OpenZeppelin Contracts (last updated v4.6.0) (token/ERC20/IERC20.sol) /** * @dev Interface of the ERC20 standard as defined in the EIP. */ interface IERC20 { /** * @dev Emitted when `value` tokens are moved from one account (`from`) to * another (`to`). * * Note that `value` may be zero. */ event Transfer(address indexed from, address indexed to, uint256 value); /** * @dev Emitted when the allowance of a `spender` for an `owner` is set by * a call to {approve}. `value` is the new allowance. */ event Approval(address indexed owner, address indexed spender, uint256 value); /** * @dev 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 `to`. * * Returns a boolean value indicating whether the operation succeeded. * * Emits a {Transfer} event. */ function transfer(address to, 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 `from` to `to` 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 from, address to, uint256 amount) external returns (bool); } // OpenZeppelin Contracts (last updated v4.8.0) (token/ERC20/utils/SafeERC20.sol) // OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/IERC20Permit.sol) /** * @dev Interface of the ERC20 Permit extension allowing approvals to be made via signatures, as defined in * https://eips.ethereum.org/EIPS/eip-2612[EIP-2612]. * * Adds the {permit} method, which can be used to change an account's ERC20 allowance (see {IERC20-allowance}) by * presenting a message signed by the account. By not relying on {IERC20-approve}, the token holder account doesn't * need to send a transaction, and thus is not required to hold Ether at all. */ interface IERC20Permit { /** * @dev Sets `value` as the allowance of `spender` over ``owner``'s tokens, * given ``owner``'s signed approval. * * IMPORTANT: The same issues {IERC20-approve} has related to transaction * ordering also apply here. * * Emits an {Approval} event. * * Requirements: * * - `spender` cannot be the zero address. * - `deadline` must be a timestamp in the future. * - `v`, `r` and `s` must be a valid `secp256k1` signature from `owner` * over the EIP712-formatted function arguments. * - the signature must use ``owner``'s current nonce (see {nonces}). * * For more information on the signature format, see the * https://eips.ethereum.org/EIPS/eip-2612#specification[relevant EIP * section]. */ function permit( address owner, address spender, uint256 value, uint256 deadline, uint8 v, bytes32 r, bytes32 s ) external; /** * @dev Returns the current nonce for `owner`. This value must be * included whenever a signature is generated for {permit}. * * Every successful call to {permit} increases ``owner``'s nonce by one. This * prevents a signature from being used multiple times. */ function nonces(address owner) external view returns (uint256); /** * @dev Returns the domain separator used in the encoding of the signature for {permit}, as defined by {EIP712}. */ // solhint-disable-next-line func-name-mixedcase function DOMAIN_SEPARATOR() external view returns (bytes32); } // OpenZeppelin Contracts (last updated v4.8.0) (utils/Address.sol) /** * @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 * * Furthermore, `isContract` will also return true if the target contract within * the same transaction is already scheduled for destruction by `SELFDESTRUCT`, * which only has an effect at the end of a transaction. * ==== * * [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://consensys.net/diligence/blog/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 functionCallWithValue(target, data, 0, "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"); (bool success, bytes memory returndata) = target.call{value: value}(data); return verifyCallResultFromTarget(target, 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) { (bool success, bytes memory returndata) = target.staticcall(data); return verifyCallResultFromTarget(target, 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) { (bool success, bytes memory returndata) = target.delegatecall(data); return verifyCallResultFromTarget(target, success, returndata, errorMessage); } /** * @dev Tool to verify that a low level call to smart-contract was successful, and revert (either by bubbling * the revert reason or using the provided one) in case of unsuccessful call or if target was not a contract. * * _Available since v4.8._ */ function verifyCallResultFromTarget( address target, bool success, bytes memory returndata, string memory errorMessage ) internal view returns (bytes memory) { if (success) { if (returndata.length == 0) { // only check isContract if the call was successful and the return data is empty // otherwise we already know that it was a contract require(isContract(target), "Address: call to non-contract"); } return returndata; } else { _revert(returndata, errorMessage); } } /** * @dev Tool to verify that a low level call was successful, and revert if it wasn't, either by bubbling the * revert reason or 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 { _revert(returndata, errorMessage); } } function _revert(bytes memory returndata, string memory errorMessage) private pure { // 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 /// @solidity memory-safe-assembly assembly { let returndata_size := mload(returndata) revert(add(32, returndata), returndata_size) } } else { revert(errorMessage); } } } /** * @title SafeERC20 * @dev Wrappers around ERC20 operations that throw on failure (when the token * contract returns false). Tokens that return no value (and instead revert or * throw on failure) are also supported, non-reverting calls are assumed to be * successful. * To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract, * which allows you to call the safe operations as `token.safeTransfer(...)`, etc. */ library SafeERC20 { using Address for address; /** * @dev Transfer `value` amount of `token` from the calling contract to `to`. If `token` returns no value, * non-reverting calls are assumed to be successful. */ function safeTransfer(IERC20 token, address to, uint256 value) internal { _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value)); } /** * @dev Transfer `value` amount of `token` from `from` to `to`, spending the approval given by `from` to the * calling contract. If `token` returns no value, non-reverting calls are assumed to be successful. */ 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)); } /** * @dev Increase the calling contract's allowance toward `spender` by `value`. If `token` returns no value, * non-reverting calls are assumed to be successful. */ function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal { uint256 oldAllowance = token.allowance(address(this), spender); _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, oldAllowance + value)); } /** * @dev Decrease the calling contract's allowance toward `spender` by `value`. If `token` returns no value, * non-reverting calls are assumed to be successful. */ 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"); _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, oldAllowance - value)); } } /** * @dev Set the calling contract's allowance toward `spender` to `value`. If `token` returns no value, * non-reverting calls are assumed to be successful. Compatible with tokens that require the approval to be set to * 0 before setting it to a non-zero value. */ function forceApprove(IERC20 token, address spender, uint256 value) internal { bytes memory approvalCall = abi.encodeWithSelector(token.approve.selector, spender, value); if (!_callOptionalReturnBool(token, approvalCall)) { _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, 0)); _callOptionalReturn(token, approvalCall); } } /** * @dev Use a ERC-2612 signature to set the `owner` approval toward `spender` on `token`. * Revert on invalid signature. */ function safePermit( IERC20Permit token, address owner, address spender, uint256 value, uint256 deadline, uint8 v, bytes32 r, bytes32 s ) internal { uint256 nonceBefore = token.nonces(owner); token.permit(owner, spender, value, deadline, v, r, s); uint256 nonceAfter = token.nonces(owner); require(nonceAfter == nonceBefore + 1, "SafeERC20: permit did not succeed"); } /** * @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"); require(returndata.length == 0 || abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed"); } /** * @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). * * This is a variant of {_callOptionalReturn} that silents catches all reverts and returns a bool instead. */ function _callOptionalReturnBool(IERC20 token, bytes memory data) private returns (bool) { // 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 cannot use {Address-functionCall} here since this should return false // and not revert is the subcall reverts. (bool success, bytes memory returndata) = address(token).call(data); return success && (returndata.length == 0 || abi.decode(returndata, (bool))) && Address.isContract(address(token)); } } // OpenZeppelin Contracts (last updated v4.8.0) (utils/math/Math.sol) /** * @dev Standard math utilities missing in the Solidity language. */ library Math { enum Rounding { Down, // Toward negative infinity Up, // Toward infinity Zero // Toward zero } /** * @dev Returns the largest of two numbers. */ function max(uint256 a, uint256 b) internal pure returns (uint256) { return a > b ? a : b; } /** * @dev Returns the smallest of two numbers. */ function min(uint256 a, uint256 b) internal pure returns (uint256) { return a < b ? a : b; } /** * @dev Returns the average of two numbers. The result is rounded towards * zero. */ function average(uint256 a, uint256 b) internal pure returns (uint256) { // (a + b) / 2 can overflow. return (a & b) + (a ^ b) / 2; } /** * @dev Returns the ceiling of the division of two numbers. * * This differs from standard division with `/` in that it rounds up instead * of rounding down. */ function ceilDiv(uint256 a, uint256 b) internal pure returns (uint256) { // (a + b - 1) / b can overflow on addition, so we distribute. return a == 0 ? 0 : (a - 1) / b + 1; } /** * @notice Calculates floor(x * y / denominator) with full precision. Throws if result overflows a uint256 or denominator == 0 * @dev Original credit to Remco Bloemen under MIT license (https://xn--2-umb.com/21/muldiv) * with further edits by Uniswap Labs also under MIT license. */ function mulDiv(uint256 x, uint256 y, uint256 denominator) internal pure returns (uint256 result) { unchecked { // 512-bit multiply [prod1 prod0] = x * y. Compute the product mod 2^256 and mod 2^256 - 1, then use // use the Chinese Remainder Theorem to reconstruct the 512 bit result. The result is stored in two 256 // variables such that product = prod1 * 2^256 + prod0. uint256 prod0; // Least significant 256 bits of the product uint256 prod1; // Most significant 256 bits of the product assembly { let mm := mulmod(x, y, not(0)) prod0 := mul(x, y) prod1 := sub(sub(mm, prod0), lt(mm, prod0)) } // Handle non-overflow cases, 256 by 256 division. if (prod1 == 0) { // Solidity will revert if denominator == 0, unlike the div opcode on its own. // The surrounding unchecked block does not change this fact. // See https://docs.soliditylang.org/en/latest/control-structures.html#checked-or-unchecked-arithmetic. return prod0 / denominator; } // Make sure the result is less than 2^256. Also prevents denominator == 0. require(denominator > prod1, "Math: mulDiv overflow"); /////////////////////////////////////////////// // 512 by 256 division. /////////////////////////////////////////////// // Make division exact by subtracting the remainder from [prod1 prod0]. uint256 remainder; assembly { // Compute remainder using mulmod. remainder := mulmod(x, y, denominator) // Subtract 256 bit number from 512 bit number. prod1 := sub(prod1, gt(remainder, prod0)) prod0 := sub(prod0, remainder) } // Factor powers of two out of denominator and compute largest power of two divisor of denominator. Always >= 1. // See https://cs.stackexchange.com/q/138556/92363. // Does not overflow because the denominator cannot be zero at this stage in the function. uint256 twos = denominator & (~denominator + 1); assembly { // Divide denominator by twos. denominator := div(denominator, twos) // Divide [prod1 prod0] by twos. prod0 := div(prod0, twos) // Flip twos such that it is 2^256 / twos. If twos is zero, then it becomes one. twos := add(div(sub(0, twos), twos), 1) } // Shift in bits from prod1 into prod0. prod0 |= prod1 * twos; // Invert denominator mod 2^256. Now that denominator is an odd number, it has an inverse modulo 2^256 such // that denominator * inv = 1 mod 2^256. Compute the inverse by starting with a seed that is correct for // four bits. That is, denominator * inv = 1 mod 2^4. uint256 inverse = (3 * denominator) ^ 2; // Use the Newton-Raphson iteration to improve the precision. Thanks to Hensel's lifting lemma, this also works // in modular arithmetic, doubling the correct bits in each step. inverse *= 2 - denominator * inverse; // inverse mod 2^8 inverse *= 2 - denominator * inverse; // inverse mod 2^16 inverse *= 2 - denominator * inverse; // inverse mod 2^32 inverse *= 2 - denominator * inverse; // inverse mod 2^64 inverse *= 2 - denominator * inverse; // inverse mod 2^128 inverse *= 2 - denominator * inverse; // inverse mod 2^256 // Because the division is now exact we can divide by multiplying with the modular inverse of denominator. // This will give us the correct result modulo 2^256. Since the preconditions guarantee that the outcome is // less than 2^256, this is the final result. We don't need to compute the high bits of the result and prod1 // is no longer required. result = prod0 * inverse; return result; } } /** * @notice Calculates x * y / denominator with full precision, following the selected rounding direction. */ function mulDiv(uint256 x, uint256 y, uint256 denominator, Rounding rounding) internal pure returns (uint256) { uint256 result = mulDiv(x, y, denominator); if (rounding == Rounding.Up && mulmod(x, y, denominator) > 0) { result += 1; } return result; } /** * @dev Returns the square root of a number. If the number is not a perfect square, the value is rounded down. * * Inspired by Henry S. Warren, Jr.'s "Hacker's Delight" (Chapter 11). */ function sqrt(uint256 a) internal pure returns (uint256) { if (a == 0) { return 0; } // For our first guess, we get the biggest power of 2 which is smaller than the square root of the target. // // We know that the "msb" (most significant bit) of our target number `a` is a power of 2 such that we have // `msb(a) <= a < 2*msb(a)`. This value can be written `msb(a)=2**k` with `k=log2(a)`. // // This can be rewritten `2**log2(a) <= a < 2**(log2(a) + 1)` // → `sqrt(2**k) <= sqrt(a) < sqrt(2**(k+1))` // → `2**(k/2) <= sqrt(a) < 2**((k+1)/2) <= 2**(k/2 + 1)` // // Consequently, `2**(log2(a) / 2)` is a good first approximation of `sqrt(a)` with at least 1 correct bit. uint256 result = 1 << (log2(a) >> 1); // At this point `result` is an estimation with one bit of precision. We know the true value is a uint128, // since it is the square root of a uint256. Newton's method converges quadratically (precision doubles at // every iteration). We thus need at most 7 iteration to turn our partial result with one bit of precision // into the expected uint128 result. unchecked { result = (result + a / result) >> 1; result = (result + a / result) >> 1; result = (result + a / result) >> 1; result = (result + a / result) >> 1; result = (result + a / result) >> 1; result = (result + a / result) >> 1; result = (result + a / result) >> 1; return min(result, a / result); } } /** * @notice Calculates sqrt(a), following the selected rounding direction. */ function sqrt(uint256 a, Rounding rounding) internal pure returns (uint256) { unchecked { uint256 result = sqrt(a); return result + (rounding == Rounding.Up && result * result < a ? 1 : 0); } } /** * @dev Return the log in base 2, rounded down, of a positive value. * Returns 0 if given 0. */ function log2(uint256 value) internal pure returns (uint256) { uint256 result = 0; unchecked { if (value >> 128 > 0) { value >>= 128; result += 128; } if (value >> 64 > 0) { value >>= 64; result += 64; } if (value >> 32 > 0) { value >>= 32; result += 32; } if (value >> 16 > 0) { value >>= 16; result += 16; } if (value >> 8 > 0) { value >>= 8; result += 8; } if (value >> 4 > 0) { value >>= 4; result += 4; } if (value >> 2 > 0) { value >>= 2; result += 2; } if (value >> 1 > 0) { result += 1; } } return result; } /** * @dev Return the log in base 2, following the selected rounding direction, of a positive value. * Returns 0 if given 0. */ function log2(uint256 value, Rounding rounding) internal pure returns (uint256) { unchecked { uint256 result = log2(value); return result + (rounding == Rounding.Up && 1 << result < value ? 1 : 0); } } /** * @dev Return the log in base 10, rounded down, of a positive value. * Returns 0 if given 0. */ function log10(uint256 value) internal pure returns (uint256) { uint256 result = 0; unchecked { if (value >= 10 ** 64) { value /= 10 ** 64; result += 64; } if (value >= 10 ** 32) { value /= 10 ** 32; result += 32; } if (value >= 10 ** 16) { value /= 10 ** 16; result += 16; } if (value >= 10 ** 8) { value /= 10 ** 8; result += 8; } if (value >= 10 ** 4) { value /= 10 ** 4; result += 4; } if (value >= 10 ** 2) { value /= 10 ** 2; result += 2; } if (value >= 10 ** 1) { result += 1; } } return result; } /** * @dev Return the log in base 10, following the selected rounding direction, of a positive value. * Returns 0 if given 0. */ function log10(uint256 value, Rounding rounding) internal pure returns (uint256) { unchecked { uint256 result = log10(value); return result + (rounding == Rounding.Up && 10 ** result < value ? 1 : 0); } } /** * @dev Return the log in base 256, rounded down, of a positive value. * Returns 0 if given 0. * * Adding one to the result gives the number of pairs of hex symbols needed to represent `value` as a hex string. */ function log256(uint256 value) internal pure returns (uint256) { uint256 result = 0; unchecked { if (value >> 128 > 0) { value >>= 128; result += 16; } if (value >> 64 > 0) { value >>= 64; result += 8; } if (value >> 32 > 0) { value >>= 32; result += 4; } if (value >> 16 > 0) { value >>= 16; result += 2; } if (value >> 8 > 0) { result += 1; } } return result; } /** * @dev Return the log in base 256, following the selected rounding direction, of a positive value. * Returns 0 if given 0. */ function log256(uint256 value, Rounding rounding) internal pure returns (uint256) { unchecked { uint256 result = log256(value); return result + (rounding == Rounding.Up && 1 << (result << 3) < value ? 1 : 0); } } } // OpenZeppelin Contracts (last updated v4.8.0) (proxy/utils/Initializable.sol) // OpenZeppelin Contracts (last updated v4.8.0) (utils/Address.sol) /** * @dev Collection of functions related to the address type */ library AddressUpgradeable { /** * @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 * * Furthermore, `isContract` will also return true if the target contract within * the same transaction is already scheduled for destruction by `SELFDESTRUCT`, * which only has an effect at the end of a transaction. * ==== * * [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://consensys.net/diligence/blog/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 functionCallWithValue(target, data, 0, "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"); (bool success, bytes memory returndata) = target.call{value: value}(data); return verifyCallResultFromTarget(target, 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) { (bool success, bytes memory returndata) = target.staticcall(data); return verifyCallResultFromTarget(target, success, returndata, errorMessage); } /** * @dev Tool to verify that a low level call to smart-contract was successful, and revert (either by bubbling * the revert reason or using the provided one) in case of unsuccessful call or if target was not a contract. * * _Available since v4.8._ */ function verifyCallResultFromTarget( address target, bool success, bytes memory returndata, string memory errorMessage ) internal view returns (bytes memory) { if (success) { if (returndata.length == 0) { // only check isContract if the call was successful and the return data is empty // otherwise we already know that it was a contract require(isContract(target), "Address: call to non-contract"); } return returndata; } else { _revert(returndata, errorMessage); } } /** * @dev Tool to verify that a low level call was successful, and revert if it wasn't, either by bubbling the * revert reason or 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 { _revert(returndata, errorMessage); } } function _revert(bytes memory returndata, string memory errorMessage) private pure { // 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 /// @solidity memory-safe-assembly assembly { let returndata_size := mload(returndata) revert(add(32, returndata), returndata_size) } } else { revert(errorMessage); } } } /** * @dev This is a base contract to aid in writing upgradeable contracts, or any kind of contract that will be deployed * behind a proxy. Since proxied contracts do not make use of a constructor, it's common to move constructor logic to an * external initializer function, usually called `initialize`. It then becomes necessary to protect this initializer * function so it can only be called once. The {initializer} modifier provided by this contract will have this effect. * * The initialization functions use a version number. Once a version number is used, it is consumed and cannot be * reused. This mechanism prevents re-execution of each "step" but allows the creation of new initialization steps in * case an upgrade adds a module that needs to be initialized. * * For example: * * [.hljs-theme-light.nopadding] * ```solidity * contract MyToken is ERC20Upgradeable { * function initialize() initializer public { * __ERC20_init("MyToken", "MTK"); * } * } * * contract MyTokenV2 is MyToken, ERC20PermitUpgradeable { * function initializeV2() reinitializer(2) public { * __ERC20Permit_init("MyToken"); * } * } * ``` * * TIP: To avoid leaving the proxy in an uninitialized state, the initializer function should be called as early as * possible by providing the encoded function call as the `_data` argument to {ERC1967Proxy-constructor}. * * CAUTION: When used with inheritance, manual care must be taken to not invoke a parent initializer twice, or to ensure * that all initializers are idempotent. This is not verified automatically as constructors are by Solidity. * * [CAUTION] * ==== * Avoid leaving a contract uninitialized. * * An uninitialized contract can be taken over by an attacker. This applies to both a proxy and its implementation * contract, which may impact the proxy. To prevent the implementation contract from being used, you should invoke * the {_disableInitializers} function in the constructor to automatically lock it when it is deployed: * * [.hljs-theme-light.nopadding] * ``` * /// @custom:oz-upgrades-unsafe-allow constructor * constructor() { * _disableInitializers(); * } * ``` * ==== */ abstract contract Initializable { /** * @dev Indicates that the contract has been initialized. * @custom:oz-retyped-from bool */ uint8 private _initialized; /** * @dev Indicates that the contract is in the process of being initialized. */ bool private _initializing; /** * @dev Triggered when the contract has been initialized or reinitialized. */ event Initialized(uint8 version); /** * @dev A modifier that defines a protected initializer function that can be invoked at most once. In its scope, * `onlyInitializing` functions can be used to initialize parent contracts. * * Similar to `reinitializer(1)`, except that functions marked with `initializer` can be nested in the context of a * constructor. * * Emits an {Initialized} event. */ modifier initializer() { bool isTopLevelCall = !_initializing; require( (isTopLevelCall && _initialized < 1) || (!AddressUpgradeable.isContract(address(this)) && _initialized == 1), "Initializable: contract is already initialized" ); _initialized = 1; if (isTopLevelCall) { _initializing = true; } _; if (isTopLevelCall) { _initializing = false; emit Initialized(1); } } /** * @dev A modifier that defines a protected reinitializer function that can be invoked at most once, and only if the * contract hasn't been initialized to a greater version before. In its scope, `onlyInitializing` functions can be * used to initialize parent contracts. * * A reinitializer may be used after the original initialization step. This is essential to configure modules that * are added through upgrades and that require initialization. * * When `version` is 1, this modifier is similar to `initializer`, except that functions marked with `reinitializer` * cannot be nested. If one is invoked in the context of another, execution will revert. * * Note that versions can jump in increments greater than 1; this implies that if multiple reinitializers coexist in * a contract, executing them in the right order is up to the developer or operator. * * WARNING: setting the version to 255 will prevent any future reinitialization. * * Emits an {Initialized} event. */ modifier reinitializer(uint8 version) { require(!_initializing && _initialized < version, "Initializable: contract is already initialized"); _initialized = version; _initializing = true; _; _initializing = false; emit Initialized(version); } /** * @dev Modifier to protect an initialization function so that it can only be invoked by functions with the * {initializer} and {reinitializer} modifiers, directly or indirectly. */ modifier onlyInitializing() { require(_initializing, "Initializable: contract is not initializing"); _; } /** * @dev Locks the contract, preventing any future reinitialization. This cannot be part of an initializer call. * Calling this in the constructor of a contract will prevent that contract from being initialized or reinitialized * to any version. It is recommended to use this to lock implementation contracts that are designed to be called * through proxies. * * Emits an {Initialized} event the first time it is successfully executed. */ function _disableInitializers() internal virtual { require(!_initializing, "Initializable: contract is initializing"); if (_initialized != type(uint8).max) { _initialized = type(uint8).max; emit Initialized(type(uint8).max); } } /** * @dev Returns the highest version that has been initialized. See {reinitializer}. */ function _getInitializedVersion() internal view returns (uint8) { return _initialized; } /** * @dev Returns `true` if the contract is currently initializing. See {onlyInitializing}. */ function _isInitializing() internal view returns (bool) { return _initializing; } } // OpenZeppelin Contracts (last updated v4.8.0) (security/ReentrancyGuard.sol) /** * @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 ReentrancyGuardUpgradeable is Initializable { // 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; function __ReentrancyGuard_init() internal onlyInitializing { __ReentrancyGuard_init_unchained(); } function __ReentrancyGuard_init_unchained() internal onlyInitializing { _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() { _nonReentrantBefore(); _; _nonReentrantAfter(); } function _nonReentrantBefore() private { // On the first call to nonReentrant, _status will be _NOT_ENTERED require(_status != _ENTERED, "ReentrancyGuard: reentrant call"); // Any calls to nonReentrant after this point will fail _status = _ENTERED; } function _nonReentrantAfter() private { // By storing the original value once again, a refund is triggered (see // https://eips.ethereum.org/EIPS/eip-2200) _status = _NOT_ENTERED; } /** * @dev Returns true if the reentrancy guard is currently set to "entered", which indicates there is a * `nonReentrant` function in the call stack. */ function _reentrancyGuardEntered() internal view returns (bool) { return _status == _ENTERED; } /** * @dev This empty reserved space is put in place to allow future versions to add new * variables without shifting down storage in the inheritance chain. * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps */ uint256[49] private __gap; } /** * * Each instance of a Crowdfinancing Contract represents a single campaign with a goal * of raising funds for a specific purpose. The contract is deployed by the creator through * the CrowdFinancingV1Factory contract. The creator specifies the recipient address, the * token to use for payments, the minimum and maximum funding goals, the minimum and maximum * contribution amounts, and the start and end times. * * The campaign is deemed successful if the minimum funding goal is met by the end time, or the * maximum funding goal is met before the end time. * * If the campaign is successful funds can be transferred to the recipient address. If the * campaign is not successful the funds can be withdrawn by the contributors. * * @title Crowd Financing with Optional Yield * @author Fabric Inc. * */ contract CrowdFinancingV1 is Initializable, ReentrancyGuardUpgradeable, IERC20 { /// @dev Guard to gate ERC20 specific functions modifier erc20Only() { require(_erc20, "erc20 only fn called"); _; } /// @dev Guard to gate ETH specific functions modifier ethOnly() { require(!_erc20, "ETH only fn called"); _; } /// @dev Guard to ensure yields are allowed modifier yieldGuard(uint256 amount) { require(_state == State.FUNDED, "Cannot accept payment"); require(amount > 0, "Amount is 0"); _; } /// @dev Guard to ensure contributions are allowed modifier contributionGuard(uint256 amount) { require(isContributionAllowed(), "Contributions are not allowed"); uint256 total = _contributions[msg.sender] + amount; require(total >= _minContribution, "Contribution amount is too low"); require(total <= _maxContribution, "Contribution amount is too high"); require(_contributionTotal + amount <= _goalMax, "Contribution amount exceeds max goal"); _; } /// @dev If transfer doesn't occur within the TRANSFER_WINDOW, the campaign can be unlocked /// and put into a failed state for withdraws. This is to prevent a campaign from being /// locked forever if the recipient addresses are compromised. uint256 private constant TRANSFER_WINDOW = 90 days; /// @dev Max campaign duration: 90 Days uint256 private constant MAX_DURATION_SECONDS = 90 days; /// @dev Min campaign duration: 30 minutes uint256 private constant MIN_DURATION_SECONDS = 30 minutes; /// @dev Allow a campaign to be deployed where the start time is up to one minute in the past uint256 private constant PAST_START_TOLERANCE_SECONDS = 60; /// @dev Maximum fee basis points (12.5%) uint16 private constant MAX_FEE_BIPS = 1250; /// @dev Maximum basis points uint16 private constant MAX_BIPS = 10_000; /// @dev Emitted when an account contributes funds to the contract event Contribution(address indexed account, uint256 numTokens); /// @dev Emitted when an account withdraws their initial contribution or yield balance event Withdraw(address indexed account, uint256 numTokens); /// @dev Emitted when the funds are transferred to the recipient and when /// fees are transferred to the fee collector, if specified event TransferContributions(address indexed account, uint256 numTokens); /// @dev Emitted when the campaign is marked as failed event Fail(); /// @dev Emitted when yieldEth or yieldERC20 are called event Payout(address indexed account, uint256 numTokens); /// @dev A state enum to track the current state of the campaign enum State { FUNDING, FAILED, FUNDED } /// @dev The current state of the contract State private _state; /// @dev The address of the recipient in the event of a successful campaign address private _recipientAddress; /// @dev The token used for funding (optional) IERC20 private _token; /// @dev The minimum funding goal to meet for a successful campaign uint256 private _goalMin; /// @dev The maximum funding goal. If this goal is met, funds can be transferred early uint256 private _goalMax; /// @dev The minimum tokens an account can contribute uint256 private _minContribution; /// @dev The maximum tokens an account can contribute uint256 private _maxContribution; /// @dev The start timestamp for the campaign uint256 private _startTimestamp; /// @dev The end timestamp for the campaign uint256 private _endTimestamp; /// @dev The total amount contributed by all accounts uint256 private _contributionTotal; /// @dev The total amount withdrawn by all accounts uint256 private _withdrawTotal; /// @dev The mapping from account to balance (contributions or transfers) mapping(address => uint256) private _contributions; /// @dev The mapping from account to withdraws mapping(address => uint256) private _withdraws; /// @dev ERC20 allowances mapping(address => mapping(address => uint256)) private _allowances; // Fee related items /// @dev The optional address of the fee recipient address private _feeRecipient; /// @dev The transfer fee in basis points, sent to the fee recipient upon transfer uint16 private _feeTransferBips; /// @dev The yield fee in basis points, used to dilute the cap table upon transfer uint16 private _feeYieldBips; /// @dev Track the number of tokens sent via yield calls uint256 private _yieldTotal; /// @dev Flag indicating the contract works with ERC20 tokens rather than ETH bool private _erc20; /// @dev This contract is intended for use with proxies, so we prevent direct /// initialization. This contract will fail to function properly without a proxy constructor() { _disableInitializers(); } /** * @dev Initialize acts as the constructor, as this contract is intended to work with proxy contracts. * * @param recipient the address of the recipient, where funds are transferred when conditions are met * @param minGoal the minimum funding goal for the financing round * @param maxGoal the maximum funding goal for the financing round * @param minContribution the minimum initial contribution an account can make * @param maxContribution the maximum contribution an account can make * @param startTimestamp the UNIX time in seconds denoting when contributions can start * @param endTimestamp the UNIX time in seconds denoting when contributions are no longer allowed * @param erc20TokenAddr the address of the ERC20 token used for funding, or the 0 address for native token (ETH) * @param feeRecipientAddr the address of the fee recipient, or the 0 address if no fees are collected * @param feeTransferBips the transfer fee in basis points, collected during the transfer call * @param feeYieldBips the yield fee in basis points. Dilutes the cap table for the fee recipient. */ function initialize( address recipient, uint256 minGoal, uint256 maxGoal, uint256 minContribution, uint256 maxContribution, uint256 startTimestamp, uint256 endTimestamp, address erc20TokenAddr, address feeRecipientAddr, uint16 feeTransferBips, uint16 feeYieldBips ) external initializer { require(recipient != address(0), "Invalid recipient address"); require(startTimestamp + PAST_START_TOLERANCE_SECONDS >= block.timestamp, "Invalid start time"); require(startTimestamp + MIN_DURATION_SECONDS <= endTimestamp, "Invalid time range"); require( endTimestamp > block.timestamp && (endTimestamp - startTimestamp) < MAX_DURATION_SECONDS, "Invalid end time" ); require(minGoal > 0, "Min goal must be > 0"); require(minGoal <= maxGoal, "Min goal must be <= Max goal"); require(minContribution > 0, "Min contribution must be > 0"); require(minContribution <= maxContribution, "Min contribution must be <= Max contribution"); require( minContribution < (maxGoal - minGoal) || minContribution == 1, "Min contribution must be < (maxGoal - minGoal) or 1" ); require(feeTransferBips <= MAX_FEE_BIPS, "Transfer fee too high"); require(feeYieldBips <= MAX_FEE_BIPS, "Yield fee too high"); if (feeRecipientAddr != address(0)) { require(feeTransferBips > 0 || feeYieldBips > 0, "Fees required when fee recipient is present"); } else { require(feeTransferBips == 0 && feeYieldBips == 0, "Fees must be 0 when there is no fee recipient"); } _recipientAddress = recipient; _goalMin = minGoal; _goalMax = maxGoal; _minContribution = minContribution; _maxContribution = maxContribution; _startTimestamp = startTimestamp; _endTimestamp = endTimestamp; _token = IERC20(erc20TokenAddr); _erc20 = erc20TokenAddr != address(0); _feeRecipient = feeRecipientAddr; _feeTransferBips = feeTransferBips; _feeYieldBips = feeYieldBips; _contributionTotal = 0; _withdrawTotal = 0; _state = State.FUNDING; __ReentrancyGuard_init(); } /////////////////////////////////////////// // Contributions /////////////////////////////////////////// /** * @notice Contribute ERC20 tokens into the contract * * #### Events * - Emits a {Contribution} event * - Emits a {Transfer} event (ERC20) * * #### Requirements * - `amount` must be within range of min and max contribution for account * - `amount` must not cause max goal to be exceeded * - `amount` must be approved for transfer by the caller * - contributions must be allowed * - the contract must be configured to work with ERC20 tokens * * @param amount the amount of ERC20 tokens to contribute * */ function contributeERC20(uint256 amount) external erc20Only nonReentrant { _addContribution(msg.sender, _transferSafe(msg.sender, amount)); } /** * @notice Contribute ETH into the contract * * #### Events * - Emits a {Contribution} event * - Emits a {Transfer} event (ERC20) * * #### Requirements * - `msg.value` must be within range of min and max contribution for account * - `msg.value` must not cause max goal to be exceeded * - contributions must be allowed * - the contract must be configured to work with ETH */ function contributeEth() external payable ethOnly { _addContribution(msg.sender, msg.value); } /** * @dev Add a contribution to the account and update totals * * @param account the account to add the contribution to * @param amount the amount of the contribution */ function _addContribution(address account, uint256 amount) private contributionGuard(amount) { _contributions[account] += amount; _contributionTotal += amount; emit Contribution(account, amount); emit Transfer(address(0), account, amount); } /** * @return true if contributions are allowed */ function isContributionAllowed() public view returns (bool) { return _state == State.FUNDING && !isGoalMaxMet() && isStarted() && !isEnded(); } /////////////////////////////////////////// // Transfer /////////////////////////////////////////// /** * @return true if the goal was met and funds can be transferred */ function isTransferAllowed() public view returns (bool) { return ((isEnded() && isGoalMinMet()) || isGoalMaxMet()) && _state == State.FUNDING; } /** * @notice Transfer funds to the recipient and change the state * * #### Events * Emits a {TransferContributions} event if the target was met and funds transferred */ function transferBalanceToRecipient() external { require(isTransferAllowed(), "Transfer not allowed"); _state = State.FUNDED; uint256 feeAmount = _calculateTransferFee(); uint256 transferAmount = _contributionTotal - feeAmount; // This can mutate _contributionTotal, so that withdraws don't over withdraw _allocateYieldFee(); // If any transfer fee is present, pay that out to the fee recipient if (feeAmount > 0) { emit TransferContributions(_feeRecipient, feeAmount); if (_erc20) { SafeERC20.safeTransfer(_token, _feeRecipient, feeAmount); } else { (bool sent,) = payable(_feeRecipient).call{value: feeAmount}(""); require(sent, "Failed to transfer Ether"); } } emit TransferContributions(_recipientAddress, transferAmount); if (_erc20) { SafeERC20.safeTransfer(_token, _recipientAddress, transferAmount); } else { (bool sent,) = payable(_recipientAddress).call{value: transferAmount}(""); require(sent, "Failed to transfer Ether"); } } /** * @dev Dilutes supply by allocating tokens to the fee collector, allowing for * withdraws of yield */ function _allocateYieldFee() private returns (uint256) { if (_feeYieldBips == 0) { return 0; } uint256 feeAllocation = ((_contributionTotal * _feeYieldBips) / (MAX_BIPS - _feeYieldBips)); _contributions[_feeRecipient] += feeAllocation; _contributionTotal += feeAllocation; return feeAllocation; } /** * @dev Calculates a fee to transfer to the fee collector */ function _calculateTransferFee() private view returns (uint256) { if (_feeTransferBips == 0) { return 0; } return (_contributionTotal * _feeTransferBips) / (MAX_BIPS); } /** * @return true if the minimum goal was met */ function isGoalMinMet() public view returns (bool) { return _contributionTotal >= _goalMin; } /** * @return true if the maximum goal was met */ function isGoalMaxMet() public view returns (bool) { return _contributionTotal >= _goalMax; } /////////////////////////////////////////// // Unlocking Funds After Failed Transfer /////////////////////////////////////////// /** * @notice In the event that a transfer fails due to recipient contract behavior, the campaign * can be unlocked (marked as failed) to allow contributors to withdraw their funds. This can only * occur if the state of the campaign is FUNDING and the transfer window * has expired. Note: Recipient should invoke transferBalanceToRecipient immediately upon success * to prevent this function from being callable. This is a safety mechanism to prevent * permanent loss of funds. * * #### Events * - Emits {Fail} event */ function unlockFailedFunds() external { require(isUnlockAllowed(), "Funds cannot be unlocked"); _state = State.FAILED; emit Fail(); } /////////////////////////////////////////// // Phase 3: Yield / Refunds / Withdraws /////////////////////////////////////////// /** * @notice Yield ERC20 tokens to all campaign token holders in proportion to their token balance * * #### Requirements * - `amount` must be greater than 0 * - `amount` must be approved for transfer for the contract * * #### Events * - Emits {Payout} event with amount = `amount` * * @param amount the amount of tokens to payout */ function yieldERC20(uint256 amount) external erc20Only yieldGuard(amount) nonReentrant { _trackYield(msg.sender, _transferSafe(msg.sender, amount)); } /** * @notice Yield ETH to all token holders in proportion to their balance * * #### Requirements * - `msg.value` must be greater than 0 * * #### Events * - Emits {Payout} event with amount = `msg.value` */ function yieldEth() external payable ethOnly yieldGuard(msg.value) nonReentrant { _trackYield(msg.sender, msg.value); } /** * @dev Emit a Payout event and increase yield total */ function _trackYield(address from, uint256 amount) private { emit Payout(from, amount); _yieldTotal += amount; } /** * @return The total amount of tokens/wei paid back by the recipient */ function yieldTotal() public view returns (uint256) { return _yieldTotal; } /** * @param account the address of a contributor or token holder * * @return The total tokens withdrawn for a given account */ function withdrawsOf(address account) public view returns (uint256) { return _withdraws[account]; } /** * @return true if the contract allows withdraws */ function isWithdrawAllowed() public view returns (bool) { return state() == State.FUNDED || state() == State.FAILED || (isEnded() && !isGoalMinMet()); } /** * @return The total amount of tokens paid back to a given contributor */ function _payoutsMadeTo(address account) private view returns (uint256) { if (_contributionTotal == 0) { return 0; } return (_contributions[account] * yieldTotal()) / _contributionTotal; } /** * @param account the address of a token holder * * @return The withdrawable amount of tokens for a given account, attributable to yield */ function yieldBalanceOf(address account) public view returns (uint256) { return _payoutsMadeTo(account) - withdrawsOf(account); } /** * @param account the address of a contributor * * @return The total amount of tokens earned by the given account through yield */ function yieldTotalOf(address account) public view returns (uint256) { uint256 _payout = _payoutsMadeTo(account); if (_payout <= _contributions[account]) { return 0; } return _payout - _contributions[account]; } /** * @notice Withdraw all available funds to the caller if withdraws are allowed and * the caller has a contribution balance (campaign failed), or a yield balance (campaign succeeded) * * #### Events * - Emits a {Withdraw} event with amount = the amount withdrawn * - Emits a {Transfer} event representing a token burn if the campaign failed */ function withdraw() external { require(isWithdrawAllowed(), "Withdraw not allowed"); // Set the state to failed if (_state == State.FUNDING) { _state = State.FAILED; emit Fail(); } address account = msg.sender; if (_state == State.FUNDED) { _withdrawYieldBalance(account); } else { _withdrawContribution(account); } } /** * @dev Withdraw the initial contribution for the given account */ function _withdrawContribution(address account) private { uint256 amount = _contributions[account]; require(amount > 0, "No balance"); _contributions[account] = 0; _contributionTotal -= amount; emit Withdraw(account, amount); emit Transfer(account, address(0), amount); if (_erc20) { SafeERC20.safeTransfer(_token, account, amount); } else { (bool sent,) = payable(account).call{value: amount}(""); require(sent, "Failed to transfer Ether"); } } /** * @dev Withdraw the available yield balance for the given account */ function _withdrawYieldBalance(address account) private { uint256 amount = yieldBalanceOf(account); require(amount > 0, "No balance"); _withdraws[account] += amount; _withdrawTotal += amount; emit Withdraw(account, amount); if (_erc20) { SafeERC20.safeTransfer(_token, account, amount); } else { (bool sent,) = payable(account).call{value: amount}(""); require(sent, "Failed to transfer Ether"); } } /////////////////////////////////////////// // Utility Functions /////////////////////////////////////////// /** * @dev Token transfer function which leverages allowance. Additionally, it accounts * for tokens which take fees on transfer. Fetch the balance of this contract * before and after transfer, to determine the real amount of tokens transferred. * * @notice this contract is not compatible with tokens that rebase * * @return The amount of tokens transferred after fees */ function _transferSafe(address account, uint256 amount) private returns (uint256) { uint256 allowed = _token.allowance(msg.sender, address(this)); require(amount <= allowed, "Amount exceeds token allowance"); uint256 priorBalance = _token.balanceOf(address(this)); SafeERC20.safeTransferFrom(_token, account, address(this), amount); uint256 postBalance = _token.balanceOf(address(this)); return postBalance - priorBalance; } /////////////////////////////////////////// // IERC20 Implementation /////////////////////////////////////////// /** * @inheritdoc IERC20 * @dev Contributions mint tokens and increase the total supply */ function totalSupply() external view returns (uint256) { return _contributionTotal; } /// @inheritdoc IERC20 function balanceOf(address account) external view returns (uint256) { return _contributions[account]; } /// @inheritdoc IERC20 function transfer(address to, uint256 amount) external returns (bool) { _transfer(msg.sender, to, amount); return true; } /** * See ERC20._transfer * @dev The primary difference here is that we also need to adjust withdraws * to prevent over-withdrawal of yield/contribution */ function _transfer(address from, address to, uint256 amount) internal virtual { require(from != address(0), "ERC20: transfer from the zero address"); require(to != address(0), "ERC20: transfer to the zero address"); uint256 fromBalance = _contributions[from]; require(fromBalance >= amount, "ERC20: transfer amount exceeds balance"); unchecked { _contributions[from] = fromBalance - amount; // Overflow not possible: the sum of all balances is capped by totalSupply, and the sum is preserved by // decrementing then incrementing. _contributions[to] += amount; } // Transfer partial withdraws to balance payouts if (_state == State.FUNDED) { uint256 fromWithdraws = _withdraws[from]; uint256 withdrawAmount = (amount * fromWithdraws) / fromBalance; unchecked { _withdraws[from] = fromWithdraws - withdrawAmount; _withdraws[to] += withdrawAmount; } } emit Transfer(from, to, amount); } /// @inheritdoc IERC20 function allowance(address owner, address spender) public view returns (uint256) { return _allowances[owner][spender]; } /// @inheritdoc IERC20 function approve(address spender, uint256 amount) external returns (bool) { _approve(msg.sender, spender, amount); return true; } /// See ERC20._spendAllowance function _spendAllowance(address owner, address spender, uint256 amount) internal virtual { uint256 currentAllowance = allowance(owner, spender); if (currentAllowance != type(uint256).max) { require(currentAllowance >= amount, "ERC20: insufficient allowance"); unchecked { _approve(owner, spender, currentAllowance - amount); } } } /// See ERC20._approve function _approve(address owner, address spender, uint256 amount) internal virtual { require(owner != address(0), "ERC20: approve from the zero address"); require(spender != address(0), "ERC20: approve to the zero address"); _allowances[owner][spender] = amount; emit Approval(owner, spender, amount); } /// @inheritdoc IERC20 function transferFrom(address from, address to, uint256 amount) external returns (bool) { address spender = msg.sender; _spendAllowance(from, spender, amount); _transfer(from, to, amount); return true; } /// See ERC20.increaseAllowance function increaseAllowance(address spender, uint256 addedValue) external virtual returns (bool) { address owner = msg.sender; _approve(owner, spender, allowance(owner, spender) + addedValue); return true; } /// See ERC20.decreaseAllowance function decreaseAllowance(address spender, uint256 subtractedValue) external virtual returns (bool) { address owner = msg.sender; uint256 currentAllowance = allowance(owner, spender); require(currentAllowance >= subtractedValue, "ERC20: decreased allowance below zero"); unchecked { _approve(owner, spender, currentAllowance - subtractedValue); } return true; } /////////////////////////////////////////// // Public/External Views /////////////////////////////////////////// /** * @dev The values can be 0, indicating the account is not allowed to contribute. * This method is helpful for preflight checks to ensure the amount is within the range. * * @return min The minimum contribution for the account * @return max The maximum contribution for the account */ function contributionRangeFor(address account) external view returns (uint256 min, uint256 max) { uint256 balance = _contributions[account]; if (balance >= _maxContribution || isGoalMaxMet()) { return (0, 0); } int256 minContribution = int256(_minContribution) - int256(balance); if (minContribution <= 0) { minContribution = 1; } uint256 remainingGoal = _goalMax - _contributionTotal; // If the remaining goal is less than the minimum contribution, then the account cannot contribute // This can lead to a gap between the supply and max goal, but existing contributors can top it off if // they are anxious to transfer early if (remainingGoal < uint256(minContribution)) { return (0, 0); } return (uint256(minContribution), Math.min(_maxContribution - balance, remainingGoal)); } /** * @return The current state of the campaign */ function state() public view returns (State) { return _state; } /** * @return The minimum allowed contribution of ERC20 tokens or WEI */ function minAllowedContribution() external view returns (uint256) { return _minContribution; } /** * @return The maximum allowed contribution of ERC20 tokens or WEI */ function maxAllowedContribution() external view returns (uint256) { return _maxContribution; } /** * @return The unix timestamp in seconds when the time window for contribution starts */ function startsAt() external view returns (uint256) { return _startTimestamp; } /** * @return true if the time window for contribution has started */ function isStarted() public view returns (bool) { return block.timestamp >= _startTimestamp; } /** * @return The unix timestamp in seconds when the contribution window ends */ function endsAt() external view returns (uint256) { return _endTimestamp; } /** * @return true if the time window for contribution has closed */ function isEnded() public view returns (bool) { return block.timestamp >= _endTimestamp; } /** * @return The address of the recipient */ function recipientAddress() external view returns (address) { return _recipientAddress; } /** * @return true if the contract is ETH denominated */ function isEthDenominated() public view returns (bool) { return !_erc20; } /** * @return The address of the ERC20 Token, or 0x0 if ETH */ function erc20Address() external view returns (address) { return address(_token); } /** * @return The minimum goal amount as ERC20 tokens or WEI */ function goalMin() external view returns (uint256) { return _goalMin; } /** * @return The maximum goal amount as ERC20 tokens or WEI */ function goalMax() external view returns (uint256) { return _goalMax; } /** * @return The transfer fee as basis points */ function transferFeeBips() external view returns (uint16) { return _feeTransferBips; } /** * @return The yield fee as basis points */ function yieldFeeBips() external view returns (uint16) { return _feeYieldBips; } /** * @return The address where the fees are transferred to, or 0x0 if no fees are collected */ function feeRecipientAddress() external view returns (address) { return _feeRecipient; } /** * @return true if the funds are unlockable, which means the campaign succeeded, but transfer * failed to occur within the transfer window */ function isUnlockAllowed() public view returns (bool) { return _state == State.FUNDING && block.timestamp >= _endTimestamp + TRANSFER_WINDOW; } }
[{"inputs":[],"stateMutability":"nonpayable","type":"constructor"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"owner","type":"address"},{"indexed":true,"internalType":"address","name":"spender","type":"address"},{"indexed":false,"internalType":"uint256","name":"value","type":"uint256"}],"name":"Approval","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"account","type":"address"},{"indexed":false,"internalType":"uint256","name":"numTokens","type":"uint256"}],"name":"Contribution","type":"event"},{"anonymous":false,"inputs":[],"name":"Fail","type":"event"},{"anonymous":false,"inputs":[{"indexed":false,"internalType":"uint8","name":"version","type":"uint8"}],"name":"Initialized","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"account","type":"address"},{"indexed":false,"internalType":"uint256","name":"numTokens","type":"uint256"}],"name":"Payout","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"from","type":"address"},{"indexed":true,"internalType":"address","name":"to","type":"address"},{"indexed":false,"internalType":"uint256","name":"value","type":"uint256"}],"name":"Transfer","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"account","type":"address"},{"indexed":false,"internalType":"uint256","name":"numTokens","type":"uint256"}],"name":"TransferContributions","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"account","type":"address"},{"indexed":false,"internalType":"uint256","name":"numTokens","type":"uint256"}],"name":"Withdraw","type":"event"},{"inputs":[{"internalType":"address","name":"owner","type":"address"},{"internalType":"address","name":"spender","type":"address"}],"name":"allowance","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"spender","type":"address"},{"internalType":"uint256","name":"amount","type":"uint256"}],"name":"approve","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"account","type":"address"}],"name":"balanceOf","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"uint256","name":"amount","type":"uint256"}],"name":"contributeERC20","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[],"name":"contributeEth","outputs":[],"stateMutability":"payable","type":"function"},{"inputs":[{"internalType":"address","name":"account","type":"address"}],"name":"contributionRangeFor","outputs":[{"internalType":"uint256","name":"min","type":"uint256"},{"internalType":"uint256","name":"max","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"spender","type":"address"},{"internalType":"uint256","name":"subtractedValue","type":"uint256"}],"name":"decreaseAllowance","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[],"name":"endsAt","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"erc20Address","outputs":[{"internalType":"address","name":"","type":"address"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"feeRecipientAddress","outputs":[{"internalType":"address","name":"","type":"address"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"goalMax","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"goalMin","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"spender","type":"address"},{"internalType":"uint256","name":"addedValue","type":"uint256"}],"name":"increaseAllowance","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"recipient","type":"address"},{"internalType":"uint256","name":"minGoal","type":"uint256"},{"internalType":"uint256","name":"maxGoal","type":"uint256"},{"internalType":"uint256","name":"minContribution","type":"uint256"},{"internalType":"uint256","name":"maxContribution","type":"uint256"},{"internalType":"uint256","name":"startTimestamp","type":"uint256"},{"internalType":"uint256","name":"endTimestamp","type":"uint256"},{"internalType":"address","name":"erc20TokenAddr","type":"address"},{"internalType":"address","name":"feeRecipientAddr","type":"address"},{"internalType":"uint16","name":"feeTransferBips","type":"uint16"},{"internalType":"uint16","name":"feeYieldBips","type":"uint16"}],"name":"initialize","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[],"name":"isContributionAllowed","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"isEnded","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"isEthDenominated","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"isGoalMaxMet","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"isGoalMinMet","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"isStarted","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"isTransferAllowed","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"isUnlockAllowed","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"isWithdrawAllowed","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"maxAllowedContribution","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"minAllowedContribution","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"recipientAddress","outputs":[{"internalType":"address","name":"","type":"address"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"startsAt","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"state","outputs":[{"internalType":"enum CrowdFinancingV1.State","name":"","type":"uint8"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"totalSupply","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"to","type":"address"},{"internalType":"uint256","name":"amount","type":"uint256"}],"name":"transfer","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[],"name":"transferBalanceToRecipient","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[],"name":"transferFeeBips","outputs":[{"internalType":"uint16","name":"","type":"uint16"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"from","type":"address"},{"internalType":"address","name":"to","type":"address"},{"internalType":"uint256","name":"amount","type":"uint256"}],"name":"transferFrom","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[],"name":"unlockFailedFunds","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[],"name":"withdraw","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"account","type":"address"}],"name":"withdrawsOf","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"account","type":"address"}],"name":"yieldBalanceOf","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"uint256","name":"amount","type":"uint256"}],"name":"yieldERC20","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[],"name":"yieldEth","outputs":[],"stateMutability":"payable","type":"function"},{"inputs":[],"name":"yieldFeeBips","outputs":[{"internalType":"uint16","name":"","type":"uint16"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"yieldTotal","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"account","type":"address"}],"name":"yieldTotalOf","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"}]
Loading...
Loading
Loading...
Loading
[ Download: CSV Export ]
[ Download: CSV Export ]
A token is a representation of an on-chain or off-chain asset. The token page shows information such as price, total supply, holders, transfers and social links. Learn more about this page in our Knowledge Base.