Contract Name:
BuildrBuild
Contract Source Code:
// SPDX-License-Identifier: UNLICENSED
pragma solidity ^0.8.20;
import "../lib/solmate/src/tokens/ERC721.sol";
import "../lib/openzeppelin-contracts/contracts/utils/Strings.sol";
error FixTokenId();
error NotEOA();
error TransferFailed();
error NotTokenOwner();
error NotTheBuildr();
/// @title buildr contract
/// @author 2bb.dev
/// @notice this contract spawns buildrs
contract BuildrBuild is ERC721 {
using Strings for uint256;
enum Web3District {
Nomads,
ContentMaestros,
Founders,
Investors,
Devs
}
struct Outputs {
uint256 tokenId;
uint256 balance;
Web3District district;
uint256 order;
}
mapping(uint256 => uint256) private map;
mapping(uint256 => Web3District) private buildrDistrict;
mapping(uint256 => string) private buildrInfo;
mapping(uint256 => mapping(Web3District => uint256)) private buildrBalance;
Outputs[] public outputs;
string public baseURI;
uint256 private constant TOTAL_SUPPLY = 4024;
uint256 private constant INFRA_COST = 0.005 ether;
address private buildr;
event Received(
address indexed caller,
uint256 indexed amount,
string indexed message
);
event MapChange(
uint256 indexed mapToken1,
uint256 indexed mapToken2,
uint256 indexed token2
);
modifier onlyEOA() {
if (msg.sender != tx.origin) {
revert NotEOA();
}
_;
}
constructor(
string memory _name,
string memory _symbol,
string memory _baseURI
) ERC721(_name, _symbol) {
baseURI = _baseURI;
buildr = msg.sender;
}
receive() external payable {
emit Received(msg.sender, msg.value, "Kudos");
}
fallback() external payable {
emit Received(msg.sender, msg.value, "Fallback was called");
}
function mintBuildr(uint256 _tokenId) external payable onlyEOA {
if (msg.value < INFRA_COST) {
revert TransferFailed();
}
if (_tokenId > TOTAL_SUPPLY || _tokenId < 1) {
revert FixTokenId();
}
_mint(msg.sender, _tokenId);
}
/// @notice destination token is burned
/// _token1 -> _token2 => _token2 is burned afterwards
function mapChange(uint256 _token1, uint256 _token2) external {
if (
ownerOf(_token1) != ownerOf(_token2) ||
ownerOf(_token2) != msg.sender
) {
revert NotTokenOwner();
}
uint256 tmp_token1 = mapView(_token1);
uint256 tmp_token2 = mapView(_token2);
resetBuildrInfo(_token2);
_burn(_token2);
map[_token1] = tmp_token2;
map[_token2] = tmp_token1;
emit MapChange(map[_token1], map[_token2], _token2);
}
function fundBuildr(
uint256 _tokenId,
Web3District _district
) external payable {
if (_tokenId > TOTAL_SUPPLY || _tokenId < 1) {
revert FixTokenId();
}
buildrBalance[_tokenId][_district] += msg.value;
}
function withdrawETH() external {
uint256 balance = address(this).balance;
(bool transferTx /*memory data*/, ) = buildr.call{value: balance}("");
if (!transferTx) {
revert TransferFailed();
}
}
function editAllDetails_v2(
Web3District _district,
uint256 _tokenId,
string calldata _ipfsCID
) external {
if (ownerOf(_tokenId) != msg.sender) {
revert NotTokenOwner();
}
editDistrict(_district, _tokenId);
editBuildrDetail(_ipfsCID, _tokenId);
}
function editBuildrDistrict(
Web3District _district,
uint256 _tokenId
) external {
if (ownerOf(_tokenId) != msg.sender) {
revert NotTokenOwner();
}
editDistrict(_district, _tokenId);
}
function editBuildrInfo(
string calldata _ipfsCID,
uint256 _tokenId
) external {
if (ownerOf(_tokenId) != msg.sender) {
revert NotTokenOwner();
}
editBuildrDetail(_ipfsCID, _tokenId);
}
function changeBuildr(address _buildr) external {
if (msg.sender != buildr) {
revert NotTheBuildr();
}
buildr = _buildr;
}
function transferFrom(
address from,
address to,
uint256 id
) public override {
super.transferFrom(from, to, id);
resetBuildrInfo(id);
}
function tokenURI(
uint256 tokenId
) public view override returns (string memory) {
return string(abi.encodePacked(baseURI, tokenId.toString(), ".json"));
}
function getBuildrInfo(
uint256 _tokenId
) public view returns (string memory) {
if (_tokenId > TOTAL_SUPPLY || _tokenId < 1) {
revert FixTokenId();
}
return buildrInfo[_tokenId];
}
function getInfraCosts() public pure returns (uint256) {
return INFRA_COST;
}
function getTokenMap(uint256 _tokenId) public view returns (uint256) {
if (_tokenId > TOTAL_SUPPLY || _tokenId < 1) {
revert FixTokenId();
}
return mapView(_tokenId);
}
function getFullMap(
uint256 _start,
uint256 _limit
) public view returns (Outputs[] memory) {
if (_start < 1) {
revert FixTokenId();
}
Outputs[] memory mapOutput = new Outputs[](_limit);
for (uint256 i = 0; i < _limit; i++) {
uint256 id = _start + i;
if (id <= 4024) {
mapOutput[i].tokenId = id;
mapOutput[i].balance = getBuildrTotalBalance(id);
mapOutput[i].district = buildrDistrict[id];
mapOutput[i].order = mapView(id);
}
}
return mapOutput;
}
function getFullMap_v2(
uint256 _start,
uint256 _limit
) public view returns (Outputs[] memory) {
if (_start < 1) {
revert FixTokenId();
}
Outputs[] memory mapOutput = new Outputs[](_limit);
for (uint256 i = 0; i < _limit; i++) {
uint256 id = _start + i;
if (id <= 4024) {
mapOutput[i].district = buildrDistrict[id];
mapOutput[i].balance = getBuildrDistrictBalance(
_start + i,
buildrDistrict[id]
);
mapOutput[i].tokenId = id;
}
}
return mapOutput;
}
function getDistrictMap_v2(
Web3District _district,
uint256 _start,
uint256 _limit
) public view returns (Outputs[] memory) {
if (_start < 1) {
revert FixTokenId();
}
Outputs[] memory mapOutput = new Outputs[](_limit);
uint256 temp;
for (uint256 i = 0; i < _limit; i++) {
uint256 id = _start + i;
if (
(buildrDistrict[id] == _district) &&
(_ownerOf[id] != address(0))
) {
mapOutput[temp].tokenId = id;
mapOutput[temp].balance = getBuildrDistrictBalance(
id,
_district
);
mapOutput[temp].district = buildrDistrict[id];
temp++;
}
}
return mapOutput;
}
function getUnassignedBuildrs(
uint256 _start,
uint256 _limit
) public view returns (Outputs[] memory) {
if (_start < 1) {
revert FixTokenId();
}
Outputs[] memory mapOutput = new Outputs[](_limit);
uint256 temp;
for (uint256 i = 0; i < _limit; i++) {
uint256 id = _start + i;
if (
(buildrDistrict[id] == Web3District(0)) &&
(_ownerOf[id] == address(0) && (id <= 4024))
) {
mapOutput[temp].tokenId = id;
mapOutput[temp].balance = getBuildrTotalBalance(id);
temp++;
}
}
return mapOutput;
}
function getDistrict(uint256 _tokenId) public view returns (Web3District) {
if (_tokenId > TOTAL_SUPPLY || _tokenId < 1) {
revert FixTokenId();
}
return buildrDistrict[_tokenId];
}
function getBuildrDistrictBalance(
uint256 _tokenId,
Web3District _district
) public view returns (uint256) {
return buildrBalance[_tokenId][_district];
}
function getBuildrTotalBalance(
uint256 _tokenId
) public view returns (uint256) {
uint256 balance;
for (uint256 i = 0; i < 5; i++) {
Web3District district = Web3District(i);
balance += buildrBalance[_tokenId][district];
}
return balance;
}
function totalSupply() public pure returns (uint256) {
return TOTAL_SUPPLY;
}
function getBuildr() public view returns (address) {
return buildr;
}
function resetBuildrInfo(uint256 _tokenId) private {
delete buildrInfo[_tokenId];
buildrDistrict[_tokenId] = Web3District.Nomads;
}
function editDistrict(Web3District _district, uint256 _tokenId) private {
buildrDistrict[_tokenId] = _district;
}
function editBuildrDetail(
string calldata _ipfsCID,
uint256 _tokenId
) private {
buildrInfo[_tokenId] = _ipfsCID;
}
function mapView(uint256 _tokenId) private view returns (uint256) {
return map[_tokenId] == 0 ? _tokenId : map[_tokenId];
}
}
// SPDX-License-Identifier: AGPL-3.0-only
pragma solidity >=0.8.0;
/// @notice Modern, minimalist, and gas efficient ERC-721 implementation.
/// @author Solmate (https://github.com/transmissions11/solmate/blob/main/src/tokens/ERC721.sol)
abstract contract ERC721 {
/*//////////////////////////////////////////////////////////////
EVENTS
//////////////////////////////////////////////////////////////*/
event Transfer(address indexed from, address indexed to, uint256 indexed id);
event Approval(address indexed owner, address indexed spender, uint256 indexed id);
event ApprovalForAll(address indexed owner, address indexed operator, bool approved);
/*//////////////////////////////////////////////////////////////
METADATA STORAGE/LOGIC
//////////////////////////////////////////////////////////////*/
string public name;
string public symbol;
function tokenURI(uint256 id) public view virtual returns (string memory);
/*//////////////////////////////////////////////////////////////
ERC721 BALANCE/OWNER STORAGE
//////////////////////////////////////////////////////////////*/
mapping(uint256 => address) internal _ownerOf;
mapping(address => uint256) internal _balanceOf;
function ownerOf(uint256 id) public view virtual returns (address owner) {
require((owner = _ownerOf[id]) != address(0), "NOT_MINTED");
}
function balanceOf(address owner) public view virtual returns (uint256) {
require(owner != address(0), "ZERO_ADDRESS");
return _balanceOf[owner];
}
/*//////////////////////////////////////////////////////////////
ERC721 APPROVAL STORAGE
//////////////////////////////////////////////////////////////*/
mapping(uint256 => address) public getApproved;
mapping(address => mapping(address => bool)) public isApprovedForAll;
/*//////////////////////////////////////////////////////////////
CONSTRUCTOR
//////////////////////////////////////////////////////////////*/
constructor(string memory _name, string memory _symbol) {
name = _name;
symbol = _symbol;
}
/*//////////////////////////////////////////////////////////////
ERC721 LOGIC
//////////////////////////////////////////////////////////////*/
function approve(address spender, uint256 id) public virtual {
address owner = _ownerOf[id];
require(msg.sender == owner || isApprovedForAll[owner][msg.sender], "NOT_AUTHORIZED");
getApproved[id] = spender;
emit Approval(owner, spender, id);
}
function setApprovalForAll(address operator, bool approved) public virtual {
isApprovedForAll[msg.sender][operator] = approved;
emit ApprovalForAll(msg.sender, operator, approved);
}
function transferFrom(
address from,
address to,
uint256 id
) public virtual {
require(from == _ownerOf[id], "WRONG_FROM");
require(to != address(0), "INVALID_RECIPIENT");
require(
msg.sender == from || isApprovedForAll[from][msg.sender] || msg.sender == getApproved[id],
"NOT_AUTHORIZED"
);
// Underflow of the sender's balance is impossible because we check for
// ownership above and the recipient's balance can't realistically overflow.
unchecked {
_balanceOf[from]--;
_balanceOf[to]++;
}
_ownerOf[id] = to;
delete getApproved[id];
emit Transfer(from, to, id);
}
function safeTransferFrom(
address from,
address to,
uint256 id
) public virtual {
transferFrom(from, to, id);
require(
to.code.length == 0 ||
ERC721TokenReceiver(to).onERC721Received(msg.sender, from, id, "") ==
ERC721TokenReceiver.onERC721Received.selector,
"UNSAFE_RECIPIENT"
);
}
function safeTransferFrom(
address from,
address to,
uint256 id,
bytes calldata data
) public virtual {
transferFrom(from, to, id);
require(
to.code.length == 0 ||
ERC721TokenReceiver(to).onERC721Received(msg.sender, from, id, data) ==
ERC721TokenReceiver.onERC721Received.selector,
"UNSAFE_RECIPIENT"
);
}
/*//////////////////////////////////////////////////////////////
ERC165 LOGIC
//////////////////////////////////////////////////////////////*/
function supportsInterface(bytes4 interfaceId) public view virtual returns (bool) {
return
interfaceId == 0x01ffc9a7 || // ERC165 Interface ID for ERC165
interfaceId == 0x80ac58cd || // ERC165 Interface ID for ERC721
interfaceId == 0x5b5e139f; // ERC165 Interface ID for ERC721Metadata
}
/*//////////////////////////////////////////////////////////////
INTERNAL MINT/BURN LOGIC
//////////////////////////////////////////////////////////////*/
function _mint(address to, uint256 id) internal virtual {
require(to != address(0), "INVALID_RECIPIENT");
require(_ownerOf[id] == address(0), "ALREADY_MINTED");
// Counter overflow is incredibly unrealistic.
unchecked {
_balanceOf[to]++;
}
_ownerOf[id] = to;
emit Transfer(address(0), to, id);
}
function _burn(uint256 id) internal virtual {
address owner = _ownerOf[id];
require(owner != address(0), "NOT_MINTED");
// Ownership check above ensures no underflow.
unchecked {
_balanceOf[owner]--;
}
delete _ownerOf[id];
delete getApproved[id];
emit Transfer(owner, address(0), id);
}
/*//////////////////////////////////////////////////////////////
INTERNAL SAFE MINT LOGIC
//////////////////////////////////////////////////////////////*/
function _safeMint(address to, uint256 id) internal virtual {
_mint(to, id);
require(
to.code.length == 0 ||
ERC721TokenReceiver(to).onERC721Received(msg.sender, address(0), id, "") ==
ERC721TokenReceiver.onERC721Received.selector,
"UNSAFE_RECIPIENT"
);
}
function _safeMint(
address to,
uint256 id,
bytes memory data
) internal virtual {
_mint(to, id);
require(
to.code.length == 0 ||
ERC721TokenReceiver(to).onERC721Received(msg.sender, address(0), id, data) ==
ERC721TokenReceiver.onERC721Received.selector,
"UNSAFE_RECIPIENT"
);
}
}
/// @notice A generic interface for a contract which properly accepts ERC721 tokens.
/// @author Solmate (https://github.com/transmissions11/solmate/blob/main/src/tokens/ERC721.sol)
abstract contract ERC721TokenReceiver {
function onERC721Received(
address,
address,
uint256,
bytes calldata
) external virtual returns (bytes4) {
return ERC721TokenReceiver.onERC721Received.selector;
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.0) (utils/Strings.sol)
pragma solidity ^0.8.20;
import {Math} from "./math/Math.sol";
import {SignedMath} from "./math/SignedMath.sol";
/**
* @dev String operations.
*/
library Strings {
bytes16 private constant HEX_DIGITS = "0123456789abcdef";
uint8 private constant ADDRESS_LENGTH = 20;
/**
* @dev The `value` string doesn't fit in the specified `length`.
*/
error StringsInsufficientHexLength(uint256 value, uint256 length);
/**
* @dev Converts a `uint256` to its ASCII `string` decimal representation.
*/
function toString(uint256 value) internal pure returns (string memory) {
unchecked {
uint256 length = Math.log10(value) + 1;
string memory buffer = new string(length);
uint256 ptr;
/// @solidity memory-safe-assembly
assembly {
ptr := add(buffer, add(32, length))
}
while (true) {
ptr--;
/// @solidity memory-safe-assembly
assembly {
mstore8(ptr, byte(mod(value, 10), HEX_DIGITS))
}
value /= 10;
if (value == 0) break;
}
return buffer;
}
}
/**
* @dev Converts a `int256` to its ASCII `string` decimal representation.
*/
function toStringSigned(int256 value) internal pure returns (string memory) {
return string.concat(value < 0 ? "-" : "", toString(SignedMath.abs(value)));
}
/**
* @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.
*/
function toHexString(uint256 value) internal pure returns (string memory) {
unchecked {
return toHexString(value, Math.log256(value) + 1);
}
}
/**
* @dev Converts a `uint256` to its ASCII `string` hexadecimal representation with fixed length.
*/
function toHexString(uint256 value, uint256 length) internal pure returns (string memory) {
uint256 localValue = value;
bytes memory buffer = new bytes(2 * length + 2);
buffer[0] = "0";
buffer[1] = "x";
for (uint256 i = 2 * length + 1; i > 1; --i) {
buffer[i] = HEX_DIGITS[localValue & 0xf];
localValue >>= 4;
}
if (localValue != 0) {
revert StringsInsufficientHexLength(value, length);
}
return string(buffer);
}
/**
* @dev Converts an `address` with fixed length of 20 bytes to its not checksummed ASCII `string` hexadecimal
* representation.
*/
function toHexString(address addr) internal pure returns (string memory) {
return toHexString(uint256(uint160(addr)), ADDRESS_LENGTH);
}
/**
* @dev Returns true if the two strings are equal.
*/
function equal(string memory a, string memory b) internal pure returns (bool) {
return bytes(a).length == bytes(b).length && keccak256(bytes(a)) == keccak256(bytes(b));
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.0) (utils/math/Math.sol)
pragma solidity ^0.8.20;
/**
* @dev Standard math utilities missing in the Solidity language.
*/
library Math {
/**
* @dev Muldiv operation overflow.
*/
error MathOverflowedMulDiv();
enum Rounding {
Floor, // Toward negative infinity
Ceil, // Toward positive infinity
Trunc, // Toward zero
Expand // Away from zero
}
/**
* @dev Returns the addition of two unsigned integers, with an overflow flag.
*/
function tryAdd(uint256 a, uint256 b) internal pure returns (bool, uint256) {
unchecked {
uint256 c = a + b;
if (c < a) return (false, 0);
return (true, c);
}
}
/**
* @dev Returns the subtraction of two unsigned integers, with an overflow flag.
*/
function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {
unchecked {
if (b > a) return (false, 0);
return (true, a - b);
}
}
/**
* @dev Returns the multiplication of two unsigned integers, with an overflow flag.
*/
function tryMul(uint256 a, uint256 b) internal pure returns (bool, uint256) {
unchecked {
// Gas optimization: this is cheaper than requiring 'a' not being zero, but the
// benefit is lost if 'b' is also tested.
// See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
if (a == 0) return (true, 0);
uint256 c = a * b;
if (c / a != b) return (false, 0);
return (true, c);
}
}
/**
* @dev Returns the division of two unsigned integers, with a division by zero flag.
*/
function tryDiv(uint256 a, uint256 b) internal pure returns (bool, uint256) {
unchecked {
if (b == 0) return (false, 0);
return (true, a / b);
}
}
/**
* @dev Returns the remainder of dividing two unsigned integers, with a division by zero flag.
*/
function tryMod(uint256 a, uint256 b) internal pure returns (bool, uint256) {
unchecked {
if (b == 0) return (false, 0);
return (true, a % b);
}
}
/**
* @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 towards infinity instead
* of rounding towards zero.
*/
function ceilDiv(uint256 a, uint256 b) internal pure returns (uint256) {
if (b == 0) {
// Guarantee the same behavior as in a regular Solidity division.
return a / b;
}
// (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 = x * y; // Least significant 256 bits of the product
uint256 prod1; // Most significant 256 bits of the product
assembly {
let mm := mulmod(x, y, not(0))
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.
if (denominator <= prod1) {
revert MathOverflowedMulDiv();
}
///////////////////////////////////////////////
// 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.
uint256 twos = denominator & (0 - denominator);
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 (unsignedRoundsUp(rounding) && 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
* towards zero.
*
* 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 + (unsignedRoundsUp(rounding) && result * result < a ? 1 : 0);
}
}
/**
* @dev Return the log in base 2 of a positive value rounded towards zero.
* 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 + (unsignedRoundsUp(rounding) && 1 << result < value ? 1 : 0);
}
}
/**
* @dev Return the log in base 10 of a positive value rounded towards zero.
* 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 + (unsignedRoundsUp(rounding) && 10 ** result < value ? 1 : 0);
}
}
/**
* @dev Return the log in base 256 of a positive value rounded towards zero.
* 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 + (unsignedRoundsUp(rounding) && 1 << (result << 3) < value ? 1 : 0);
}
}
/**
* @dev Returns whether a provided rounding mode is considered rounding up for unsigned integers.
*/
function unsignedRoundsUp(Rounding rounding) internal pure returns (bool) {
return uint8(rounding) % 2 == 1;
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.0) (utils/math/SignedMath.sol)
pragma solidity ^0.8.20;
/**
* @dev Standard signed math utilities missing in the Solidity language.
*/
library SignedMath {
/**
* @dev Returns the largest of two signed numbers.
*/
function max(int256 a, int256 b) internal pure returns (int256) {
return a > b ? a : b;
}
/**
* @dev Returns the smallest of two signed numbers.
*/
function min(int256 a, int256 b) internal pure returns (int256) {
return a < b ? a : b;
}
/**
* @dev Returns the average of two signed numbers without overflow.
* The result is rounded towards zero.
*/
function average(int256 a, int256 b) internal pure returns (int256) {
// Formula from the book "Hacker's Delight"
int256 x = (a & b) + ((a ^ b) >> 1);
return x + (int256(uint256(x) >> 255) & (a ^ b));
}
/**
* @dev Returns the absolute unsigned value of a signed value.
*/
function abs(int256 n) internal pure returns (uint256) {
unchecked {
// must be unchecked in order to support `n = type(int256).min`
return uint256(n >= 0 ? n : -n);
}
}
}