Description:
Proxy contract enabling upgradeable smart contract patterns. Delegates calls to an implementation contract.
Blockchain: Ethereum
Source Code: View Code On The Blockchain
Solidity Source Code:
{{
"language": "Solidity",
"sources": {
"src/smart_contract.sol": {
"content": "// SPDX-License-Identifier: MIT
pragma solidity ^0.8.24;
// Import narzędzi bezpieczeństwa z OpenZeppelin
import "@openzeppelin/contracts/utils/Address.sol";
import "@openzeppelin/contracts/security/ReentrancyGuard.sol";
contract DawidR is ReentrancyGuard {
using Address for address;
// Przechowuje salda użytkowników
mapping(address => uint256) public balances;
// Zdarzenia (eventy) do śledzenia operacji
event Deposited(address indexed user, uint256 amount);
event Withdrawn(address indexed user, uint256 amount);
// Użytkownik wpłaca ETH do kontraktu
function deposit() public payable {
require(msg.value > 0, "Deposit amount must be greater than zero");
balances[msg.sender] += msg.value;
// Emitujemy zdarzenie dla logów
emit Deposited(msg.sender, msg.value);
}
// Użytkownik wypłaca ETH z kontraktu
// Zabezpieczone przed atakami reentrancy
function withdraw(uint256 amount) public nonReentrant {
// Sprawdź, czy użytkownik ma wystarczające saldo
require(balances[msg.sender] >= amount, "Insufficient balance");
// Aktualizuj saldo przed wysyłką!!
balances[msg.sender] -= amount;
// Wysyłka ETH do użytkownika
(bool sent, ) = msg.sender.call{value: amount}("");
// Zabezpieczenie przed nieudaną wypłatą
require(sent, "Transfer failed");
// Emitujemy zdarzenie dla logów
emit Withdrawn(msg.sender, amount);
}
// przyjmuje ETH wysłane bez wywołania funkcji deposit()
receive() external payable {
balances[msg.sender] += msg.value;
emit Deposited(msg.sender, msg.value);
}
}"
},
"@openzeppelin/contracts/security/ReentrancyGuard.sol": {
"content": "// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (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() {
_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;
}
}
"
},
"@openzeppelin/contracts/utils/Address.sol": {
"content": "// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.4.0) (utils/Address.sol)
pragma solidity ^0.8.20;
import {Errors} from "./Errors.sol";
/**
* @dev Collection of functions related to the address type
*/
library Address {
/**
* @dev There's no code at `target` (it is not a contract).
*/
error AddressEmptyCode(address target);
/**
* @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/v0.8.20/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
*/
function sendValue(address payable recipient, uint256 amount) internal {
if (address(this).balance < amount) {
revert Errors.InsufficientBalance(address(this).balance, amount);
}
(bool success, bytes memory returndata) = recipient.call{value: amount}("");
if (!success) {
_revert(returndata);
}
}
/**
* @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 or custom error, it is bubbled
* up by this function (like regular Solidity function calls). However, if
* the call reverted with no returned reason, this function reverts with a
* {Errors.FailedCall} error.
*
* 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.
*/
function functionCall(address target, bytes memory data) internal returns (bytes memory) {
return functionCallWithValue(target, data, 0);
}
/**
* @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`.
*/
function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {
if (address(this).balance < value) {
revert Errors.InsufficientBalance(address(this).balance, value);
}
(bool success, bytes memory returndata) = target.call{value: value}(data);
return verifyCallResultFromTarget(target, success, returndata);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but performing a static call.
*/
function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
(bool success, bytes memory returndata) = target.staticcall(data);
return verifyCallResultFromTarget(target, success, returndata);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but performing a delegate call.
*/
function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
(bool success, bytes memory returndata) = target.delegatecall(data);
return verifyCallResultFromTarget(target, success, returndata);
}
/**
* @dev Tool to verify that a low level call to smart-contract was successful, and reverts if the target
* was not a contract or bubbling up the revert reason (falling back to {Errors.FailedCall}) in case
* of an unsuccessful call.
*/
function verifyCallResultFromTarget(
address target,
bool success,
bytes memory returndata
) internal view returns (bytes memory) {
if (!success) {
_revert(returndata);
} else {
// only check if target is a contract if the call was successful and the return data is empty
// otherwise we already know that it was a contract
if (returndata.length == 0 && target.code.length == 0) {
revert AddressEmptyCode(target);
}
return returndata;
}
}
/**
* @dev Tool to verify that a low level call was successful, and reverts if it wasn't, either by bubbling the
* revert reason or with a default {Errors.FailedCall} error.
*/
function verifyCallResult(bool success, bytes memory returndata) internal pure returns (bytes memory) {
if (!success) {
_revert(returndata);
} else {
return returndata;
}
}
/**
* @dev Reverts with returndata if present. Otherwise reverts with {Errors.FailedCall}.
*/
function _revert(bytes memory returndata) 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
assembly ("memory-safe") {
revert(add(returndata, 0x20), mload(returndata))
}
} else {
revert Errors.FailedCall();
}
}
}
"
},
"@openzeppelin/contracts/utils/Errors.sol": {
"content": "// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.1.0) (utils/Errors.sol)
pragma solidity ^0.8.20;
/**
* @dev Collection of common custom errors used in multiple contracts
*
* IMPORTANT: Backwards compatibility is not guaranteed in future versions of the library.
* It is recommended to avoid relying on the error API for critical functionality.
*
* _Available since v5.1._
*/
library Errors {
/**
* @dev The ETH balance of the account is not enough to perform the operation.
*/
error InsufficientBalance(uint256 balance, uint256 needed);
/**
* @dev A call to an address target failed. The target may have reverted.
*/
error FailedCall();
/**
* @dev The deployment failed.
*/
error FailedDeployment();
/**
* @dev A necessary precompile is missing.
*/
error MissingPrecompile(address);
}
"
}
},
"settings": {
"optimizer": {
"enabled": false,
"runs": 200
},
"outputSelection": {
"*": {
"*": [
"evm.bytecode",
"evm.deployedBytecode",
"devdoc",
"userdoc",
"metadata",
"abi"
]
}
},
"remappings": []
}
}}
Submitted on: 2025-10-29 14:34:13
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