ETH Price: $2,311.13 (-1.97%)

Contract Diff Checker

Contract Name:
ChunkedDataStorage

Contract Source Code:

<i class='far fa-question-circle text-muted ms-2' data-bs-trigger='hover' data-bs-toggle='tooltip' data-bs-html='true' data-bs-title='Click on the check box to select individual contract to compare. Only 1 contract can be selected from each side.'></i>

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.4;
import './libraries/SSTORE2Map.sol';

import '@openzeppelin/contracts/utils/Strings.sol';
import '@openzeppelin/contracts/utils/Base64.sol';
import '@openzeppelin/contracts/access/Ownable.sol';
import '@abf-monorepo/protocol/contracts/libraries/BytesUtils.sol';

contract ChunkedDataStorage is Ownable {
  uint256 public constant MAX_UINT_16 = 0xFFFF;

  mapping(uint256 => uint256) public numLayerDataInChunk;

  uint256 public currentMaxChunksIndex = 0;

  constructor() {}

  function batchAddChunkedData(bytes[] calldata data) public onlyOwner {
    numLayerDataInChunk[currentMaxChunksIndex] = data.length;

    bytes memory chunkedLayerData = '';

    for (uint256 i = 0; i < data.length; ++i) {
      require(
        data[i].length <= MAX_UINT_16,
        'ChunkedDataStorage: data exceeds size of 0xFFFF'
      );
      chunkedLayerData = abi.encodePacked(
        chunkedLayerData,
        uint16(data[i].length),
        data[i]
      );
    }
    SSTORE2Map.write(bytes32(currentMaxChunksIndex), chunkedLayerData);
    currentMaxChunksIndex++;
  }

  function indexToData(uint256 index) public view returns (bytes memory) {
    uint256 currentChunkIndex = 0;
    uint256 currentIndex = 0;
    do {
      currentIndex += numLayerDataInChunk[currentChunkIndex];
      currentChunkIndex++;
      if (numLayerDataInChunk[currentChunkIndex] == 0) {
        break;
      }
    } while (currentIndex <= index);
    currentChunkIndex--;
    currentIndex -= numLayerDataInChunk[currentChunkIndex];
    uint256 localChunkIndex = index - currentIndex;
    bytes memory chunkedData = SSTORE2Map.read(bytes32(currentChunkIndex));
    uint256 localChunkIndexPointer = 0;
    for (uint256 i = 0; i < chunkedData.length; i += 0) {
      if (localChunkIndexPointer == localChunkIndex) {
        return
          BytesUtils.slice(
            chunkedData,
            i + 2,
            BytesUtils.toUint16(chunkedData, i)
          );
      }
      i += BytesUtils.toUint16(chunkedData, i) + 2;
      localChunkIndexPointer++;
    }

    return '';
  }
}

<i class='far fa-question-circle text-muted ms-2' data-bs-trigger='hover' data-bs-toggle='tooltip' data-bs-html='true' data-bs-title='Click on the check box to select individual contract to compare. Only 1 contract can be selected from each side.'></i>

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.4;

import './Create3.sol';

import './Bytecode.sol';

/**
  @title A write-once key-value storage for storing chunks of data with a lower write & read cost.
  @author Agustin Aguilar <aa@horizon.io>
  Readme: https://github.com/0xsequence/sstore2#readme
*/
library SSTORE2Map {
  error WriteError();

  //                                         keccak256(bytes('@0xSequence.SSTORE2Map.slot'))
  bytes32 private constant SLOT_KEY_PREFIX =
    0xd351a9253491dfef66f53115e9e3afda3b5fdef08a1de6937da91188ec553be5;

  function internalKey(bytes32 _key) internal pure returns (bytes32) {
    // Mutate the key so it doesn't collide
    // if the contract is also using CREATE3 for other things
    return keccak256(abi.encode(SLOT_KEY_PREFIX, _key));
  }

  /**
    @notice Stores `_data` and returns `pointer` as key for later retrieval
    @dev The pointer is a contract address with `_data` as code
    @param _data To be written
    @param _key unique string key for accessing the written data (can only be used once)
    @return pointer Pointer to the written `_data`
  */
  function write(string memory _key, bytes memory _data)
    internal
    returns (address pointer)
  {
    return write(keccak256(bytes(_key)), _data);
  }

  /**
    @notice Stores `_data` and returns `pointer` as key for later retrieval
    @dev The pointer is a contract address with `_data` as code
    @param _data to be written
    @param _key unique bytes32 key for accessing the written data (can only be used once)
    @return pointer Pointer to the written `_data`
  */
  function write(bytes32 _key, bytes memory _data)
    internal
    returns (address pointer)
  {
    // Append 00 to _data so contract can't be called
    // Build init code
    bytes memory code = Bytecode.creationCodeFor(
      abi.encodePacked(hex'00', _data)
    );

    // Deploy contract using create3
    pointer = Create3.create3(internalKey(_key), code);
  }

  /**
    @notice Reads the contents for a given `_key`, it maps to a contract code as data, skips the first byte
    @dev The function is intended for reading pointers first written by `write`
    @param _key string key that constains the data
    @return data read from contract associated with `_key`
  */
  function read(string memory _key) internal view returns (bytes memory) {
    return read(keccak256(bytes(_key)));
  }

  /**
    @notice Reads the contents for a given `_key`, it maps to a contract code as data, skips the first byte
    @dev The function is intended for reading pointers first written by `write`
    @param _key string key that constains the data
    @param _start number of bytes to skip
    @return data read from contract associated with `_key`
  */
  function read(string memory _key, uint256 _start)
    internal
    view
    returns (bytes memory)
  {
    return read(keccak256(bytes(_key)), _start);
  }

  /**
    @notice Reads the contents for a given `_key`, it maps to a contract code as data, skips the first byte
    @dev The function is intended for reading pointers first written by `write`
    @param _key string key that constains the data
    @param _start number of bytes to skip
    @param _end index before which to end extraction
    @return data read from contract associated with `_key`
  */
  function read(
    string memory _key,
    uint256 _start,
    uint256 _end
  ) internal view returns (bytes memory) {
    return read(keccak256(bytes(_key)), _start, _end);
  }

  /**
    @notice Reads the contents for a given `_key`, it maps to a contract code as data, skips the first byte
    @dev The function is intended for reading pointers first written by `write`
    @param _key bytes32 key that constains the data
    @return data read from contract associated with `_key`
  */
  function read(bytes32 _key) internal view returns (bytes memory) {
    return
      Bytecode.codeAt(
        Create3.addressOf(internalKey(_key)),
        1,
        type(uint256).max
      );
  }

  /**
    @notice Reads the contents for a given `_key`, it maps to a contract code as data, skips the first byte
    @dev The function is intended for reading pointers first written by `write`
    @param _key bytes32 key that constains the data
    @param _start number of bytes to skip
    @return data read from contract associated with `_key`
  */
  function read(bytes32 _key, uint256 _start)
    internal
    view
    returns (bytes memory)
  {
    return
      Bytecode.codeAt(
        Create3.addressOf(internalKey(_key)),
        _start + 1,
        type(uint256).max
      );
  }

  /**
    @notice Reads the contents for a given `_key`, it maps to a contract code as data, skips the first byte
    @dev The function is intended for reading pointers first written by `write`
    @param _key bytes32 key that constains the data
    @param _start number of bytes to skip
    @param _end index before which to end extraction
    @return data read from contract associated with `_key`
  */
  function read(
    bytes32 _key,
    uint256 _start,
    uint256 _end
  ) internal view returns (bytes memory) {
    return
      Bytecode.codeAt(
        Create3.addressOf(internalKey(_key)),
        _start + 1,
        _end + 1
      );
  }
}

<i class='far fa-question-circle text-muted ms-2' data-bs-trigger='hover' data-bs-toggle='tooltip' data-bs-html='true' data-bs-title='Click on the check box to select individual contract to compare. Only 1 contract can be selected from each side.'></i>

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (utils/Strings.sol)

pragma solidity ^0.8.0;

/**
 * @dev String operations.
 */
library Strings {
    bytes16 private constant _HEX_SYMBOLS = "0123456789abcdef";
    uint8 private constant _ADDRESS_LENGTH = 20;

    /**
     * @dev Converts a `uint256` to its ASCII `string` decimal representation.
     */
    function toString(uint256 value) internal pure returns (string memory) {
        // Inspired by OraclizeAPI's implementation - MIT licence
        // https://github.com/oraclize/ethereum-api/blob/b42146b063c7d6ee1358846c198246239e9360e8/oraclizeAPI_0.4.25.sol

        if (value == 0) {
            return "0";
        }
        uint256 temp = value;
        uint256 digits;
        while (temp != 0) {
            digits++;
            temp /= 10;
        }
        bytes memory buffer = new bytes(digits);
        while (value != 0) {
            digits -= 1;
            buffer[digits] = bytes1(uint8(48 + uint256(value % 10)));
            value /= 10;
        }
        return string(buffer);
    }

    /**
     * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.
     */
    function toHexString(uint256 value) internal pure returns (string memory) {
        if (value == 0) {
            return "0x00";
        }
        uint256 temp = value;
        uint256 length = 0;
        while (temp != 0) {
            length++;
            temp >>= 8;
        }
        return toHexString(value, length);
    }

    /**
     * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation with fixed length.
     */
    function toHexString(uint256 value, uint256 length) internal pure returns (string memory) {
        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_SYMBOLS[value & 0xf];
            value >>= 4;
        }
        require(value == 0, "Strings: hex length insufficient");
        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);
    }
}

<i class='far fa-question-circle text-muted ms-2' data-bs-trigger='hover' data-bs-toggle='tooltip' data-bs-html='true' data-bs-title='Click on the check box to select individual contract to compare. Only 1 contract can be selected from each side.'></i>

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (utils/Base64.sol)

pragma solidity ^0.8.0;

/**
 * @dev Provides a set of functions to operate with Base64 strings.
 *
 * _Available since v4.5._
 */
library Base64 {
    /**
     * @dev Base64 Encoding/Decoding Table
     */
    string internal constant _TABLE = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";

    /**
     * @dev Converts a `bytes` to its Bytes64 `string` representation.
     */
    function encode(bytes memory data) internal pure returns (string memory) {
        /**
         * Inspired by Brecht Devos (Brechtpd) implementation - MIT licence
         * https://github.com/Brechtpd/base64/blob/e78d9fd951e7b0977ddca77d92dc85183770daf4/base64.sol
         */
        if (data.length == 0) return "";

        // Loads the table into memory
        string memory table = _TABLE;

        // Encoding takes 3 bytes chunks of binary data from `bytes` data parameter
        // and split into 4 numbers of 6 bits.
        // The final Base64 length should be `bytes` data length multiplied by 4/3 rounded up
        // - `data.length + 2`  -> Round up
        // - `/ 3`              -> Number of 3-bytes chunks
        // - `4 *`              -> 4 characters for each chunk
        string memory result = new string(4 * ((data.length + 2) / 3));

        /// @solidity memory-safe-assembly
        assembly {
            // Prepare the lookup table (skip the first "length" byte)
            let tablePtr := add(table, 1)

            // Prepare result pointer, jump over length
            let resultPtr := add(result, 32)

            // Run over the input, 3 bytes at a time
            for {
                let dataPtr := data
                let endPtr := add(data, mload(data))
            } lt(dataPtr, endPtr) {

            } {
                // Advance 3 bytes
                dataPtr := add(dataPtr, 3)
                let input := mload(dataPtr)

                // To write each character, shift the 3 bytes (18 bits) chunk
                // 4 times in blocks of 6 bits for each character (18, 12, 6, 0)
                // and apply logical AND with 0x3F which is the number of
                // the previous character in the ASCII table prior to the Base64 Table
                // The result is then added to the table to get the character to write,
                // and finally write it in the result pointer but with a left shift
                // of 256 (1 byte) - 8 (1 ASCII char) = 248 bits

                mstore8(resultPtr, mload(add(tablePtr, and(shr(18, input), 0x3F))))
                resultPtr := add(resultPtr, 1) // Advance

                mstore8(resultPtr, mload(add(tablePtr, and(shr(12, input), 0x3F))))
                resultPtr := add(resultPtr, 1) // Advance

                mstore8(resultPtr, mload(add(tablePtr, and(shr(6, input), 0x3F))))
                resultPtr := add(resultPtr, 1) // Advance

                mstore8(resultPtr, mload(add(tablePtr, and(input, 0x3F))))
                resultPtr := add(resultPtr, 1) // Advance
            }

            // When data `bytes` is not exactly 3 bytes long
            // it is padded with `=` characters at the end
            switch mod(mload(data), 3)
            case 1 {
                mstore8(sub(resultPtr, 1), 0x3d)
                mstore8(sub(resultPtr, 2), 0x3d)
            }
            case 2 {
                mstore8(sub(resultPtr, 1), 0x3d)
            }
        }

        return result;
    }
}

<i class='far fa-question-circle text-muted ms-2' data-bs-trigger='hover' data-bs-toggle='tooltip' data-bs-html='true' data-bs-title='Click on the check box to select individual contract to compare. Only 1 contract can be selected from each side.'></i>

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (access/Ownable.sol)

pragma solidity ^0.8.0;

import "../utils/Context.sol";

/**
 * @dev Contract module which provides a basic access control mechanism, where
 * there is an account (an owner) that can be granted exclusive access to
 * specific functions.
 *
 * By default, the owner account will be the one that deploys the contract. This
 * can later be changed with {transferOwnership}.
 *
 * This module is used through inheritance. It will make available the modifier
 * `onlyOwner`, which can be applied to your functions to restrict their use to
 * the owner.
 */
abstract contract Ownable is Context {
    address private _owner;

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
    constructor() {
        _transferOwnership(_msgSender());
    }

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        _checkOwner();
        _;
    }

    /**
     * @dev Returns the address of the current owner.
     */
    function owner() public view virtual returns (address) {
        return _owner;
    }

    /**
     * @dev Throws if the sender is not the owner.
     */
    function _checkOwner() internal view virtual {
        require(owner() == _msgSender(), "Ownable: caller is not the owner");
    }

    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions anymore. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby removing any functionality that is only available to the owner.
     */
    function renounceOwnership() public virtual onlyOwner {
        _transferOwnership(address(0));
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Can only be called by the current owner.
     */
    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        _transferOwnership(newOwner);
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Internal function without access restriction.
     */
    function _transferOwnership(address newOwner) internal virtual {
        address oldOwner = _owner;
        _owner = newOwner;
        emit OwnershipTransferred(oldOwner, newOwner);
    }
}

<i class='far fa-question-circle text-muted ms-2' data-bs-trigger='hover' data-bs-toggle='tooltip' data-bs-html='true' data-bs-title='Click on the check box to select individual contract to compare. Only 1 contract can be selected from each side.'></i>

// SPDX-License-Identifier: MIT
/*
 * @title Solidity Bytes Arrays Utils
 * @author Gonçalo Sá <goncalo.sa@consensys.net>
 *
 * @dev Bytes tightly packed arrays utility library for ethereum contracts written in Solidity.
 *      The library lets you concatenate, slice and type cast bytes arrays both in memory and storage.
 */
pragma solidity ^0.8.4;

library BytesUtils {
    function concat(
        bytes memory _preBytes,
        bytes memory _postBytes
    )
        internal
        pure
        returns (bytes memory)
    {
        bytes memory tempBytes;

        assembly {
            // Get a location of some free memory and store it in tempBytes as
            // Solidity does for memory variables.
            tempBytes := mload(0x40)

            // Store the length of the first bytes array at the beginning of
            // the memory for tempBytes.
            let length := mload(_preBytes)
            mstore(tempBytes, length)

            // Maintain a memory counter for the current write location in the
            // temp bytes array by adding the 32 bytes for the array length to
            // the starting location.
            let mc := add(tempBytes, 0x20)
            // Stop copying when the memory counter reaches the length of the
            // first bytes array.
            let end := add(mc, length)

            for {
                // Initialize a copy counter to the start of the _preBytes data,
                // 32 bytes into its memory.
                let cc := add(_preBytes, 0x20)
            } lt(mc, end) {
                // Increase both counters by 32 bytes each iteration.
                mc := add(mc, 0x20)
                cc := add(cc, 0x20)
            } {
                // Write the _preBytes data into the tempBytes memory 32 bytes
                // at a time.
                mstore(mc, mload(cc))
            }

            // Add the length of _postBytes to the current length of tempBytes
            // and store it as the new length in the first 32 bytes of the
            // tempBytes memory.
            length := mload(_postBytes)
            mstore(tempBytes, add(length, mload(tempBytes)))

            // Move the memory counter back from a multiple of 0x20 to the
            // actual end of the _preBytes data.
            mc := end
            // Stop copying when the memory counter reaches the new combined
            // length of the arrays.
            end := add(mc, length)

            for {
                let cc := add(_postBytes, 0x20)
            } lt(mc, end) {
                mc := add(mc, 0x20)
                cc := add(cc, 0x20)
            } {
                mstore(mc, mload(cc))
            }

            // Update the free-memory pointer by padding our last write location
            // to 32 bytes: add 31 bytes to the end of tempBytes to move to the
            // next 32 byte block, then round down to the nearest multiple of
            // 32. If the sum of the length of the two arrays is zero then add
            // one before rounding down to leave a blank 32 bytes (the length block with 0).
            mstore(0x40, and(
              add(add(end, iszero(add(length, mload(_preBytes)))), 31),
              not(31) // Round down to the nearest 32 bytes.
            ))
        }

        return tempBytes;
    }

    function concatStorage(bytes storage _preBytes, bytes memory _postBytes) internal {
        assembly {
            // Read the first 32 bytes of _preBytes storage, which is the length
            // of the array. (We don't need to use the offset into the slot
            // because arrays use the entire slot.)
            let fslot := sload(_preBytes.slot)
            // Arrays of 31 bytes or less have an even value in their slot,
            // while longer arrays have an odd value. The actual length is
            // the slot divided by two for odd values, and the lowest order
            // byte divided by two for even values.
            // If the slot is even, bitwise and the slot with 255 and divide by
            // two to get the length. If the slot is odd, bitwise and the slot
            // with -1 and divide by two.
            let slength := div(and(fslot, sub(mul(0x100, iszero(and(fslot, 1))), 1)), 2)
            let mlength := mload(_postBytes)
            let newlength := add(slength, mlength)
            // slength can contain both the length and contents of the array
            // if length < 32 bytes so let's prepare for that
            // v. http://solidity.readthedocs.io/en/latest/miscellaneous.html#layout-of-state-variables-in-storage
            switch add(lt(slength, 32), lt(newlength, 32))
            case 2 {
                // Since the new array still fits in the slot, we just need to
                // update the contents of the slot.
                // uint256(bytes_storage) = uint256(bytes_storage) + uint256(bytes_memory) + new_length
                sstore(
                    _preBytes.slot,
                    // all the modifications to the slot are inside this
                    // next block
                    add(
                        // we can just add to the slot contents because the
                        // bytes we want to change are the LSBs
                        fslot,
                        add(
                            mul(
                                div(
                                    // load the bytes from memory
                                    mload(add(_postBytes, 0x20)),
                                    // zero all bytes to the right
                                    exp(0x100, sub(32, mlength))
                                ),
                                // and now shift left the number of bytes to
                                // leave space for the length in the slot
                                exp(0x100, sub(32, newlength))
                            ),
                            // increase length by the double of the memory
                            // bytes length
                            mul(mlength, 2)
                        )
                    )
                )
            }
            case 1 {
                // The stored value fits in the slot, but the combined value
                // will exceed it.
                // get the keccak hash to get the contents of the array
                mstore(0x0, _preBytes.slot)
                let sc := add(keccak256(0x0, 0x20), div(slength, 32))

                // save new length
                sstore(_preBytes.slot, add(mul(newlength, 2), 1))

                // The contents of the _postBytes array start 32 bytes into
                // the structure. Our first read should obtain the `submod`
                // bytes that can fit into the unused space in the last word
                // of the stored array. To get this, we read 32 bytes starting
                // from `submod`, so the data we read overlaps with the array
                // contents by `submod` bytes. Masking the lowest-order
                // `submod` bytes allows us to add that value directly to the
                // stored value.

                let submod := sub(32, slength)
                let mc := add(_postBytes, submod)
                let end := add(_postBytes, mlength)
                let mask := sub(exp(0x100, submod), 1)

                sstore(
                    sc,
                    add(
                        and(
                            fslot,
                            0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff00
                        ),
                        and(mload(mc), mask)
                    )
                )

                for {
                    mc := add(mc, 0x20)
                    sc := add(sc, 1)
                } lt(mc, end) {
                    sc := add(sc, 1)
                    mc := add(mc, 0x20)
                } {
                    sstore(sc, mload(mc))
                }

                mask := exp(0x100, sub(mc, end))

                sstore(sc, mul(div(mload(mc), mask), mask))
            }
            default {
                // get the keccak hash to get the contents of the array
                mstore(0x0, _preBytes.slot)
                // Start copying to the last used word of the stored array.
                let sc := add(keccak256(0x0, 0x20), div(slength, 32))

                // save new length
                sstore(_preBytes.slot, add(mul(newlength, 2), 1))

                // Copy over the first `submod` bytes of the new data as in
                // case 1 above.
                let slengthmod := mod(slength, 32)
                let mlengthmod := mod(mlength, 32)
                let submod := sub(32, slengthmod)
                let mc := add(_postBytes, submod)
                let end := add(_postBytes, mlength)
                let mask := sub(exp(0x100, submod), 1)

                sstore(sc, add(sload(sc), and(mload(mc), mask)))

                for {
                    sc := add(sc, 1)
                    mc := add(mc, 0x20)
                } lt(mc, end) {
                    sc := add(sc, 1)
                    mc := add(mc, 0x20)
                } {
                    sstore(sc, mload(mc))
                }

                mask := exp(0x100, sub(mc, end))

                sstore(sc, mul(div(mload(mc), mask), mask))
            }
        }
    }

    function slice(
        bytes memory _bytes,
        uint256 _start,
        uint256 _length
    )
        internal
        pure
        returns (bytes memory)
    {
        require(_length + 31 >= _length, "slice_overflow");
        require(_bytes.length >= _start + _length, "slice_outOfBounds");

        bytes memory tempBytes;

        assembly {
            switch iszero(_length)
            case 0 {
                // Get a location of some free memory and store it in tempBytes as
                // Solidity does for memory variables.
                tempBytes := mload(0x40)

                // The first word of the slice result is potentially a partial
                // word read from the original array. To read it, we calculate
                // the length of that partial word and start copying that many
                // bytes into the array. The first word we copy will start with
                // data we don't care about, but the last `lengthmod` bytes will
                // land at the beginning of the contents of the new array. When
                // we're done copying, we overwrite the full first word with
                // the actual length of the slice.
                let lengthmod := and(_length, 31)

                // The multiplication in the next line is necessary
                // because when slicing multiples of 32 bytes (lengthmod == 0)
                // the following copy loop was copying the origin's length
                // and then ending prematurely not copying everything it should.
                let mc := add(add(tempBytes, lengthmod), mul(0x20, iszero(lengthmod)))
                let end := add(mc, _length)

                for {
                    // The multiplication in the next line has the same exact purpose
                    // as the one above.
                    let cc := add(add(add(_bytes, lengthmod), mul(0x20, iszero(lengthmod))), _start)
                } lt(mc, end) {
                    mc := add(mc, 0x20)
                    cc := add(cc, 0x20)
                } {
                    mstore(mc, mload(cc))
                }

                mstore(tempBytes, _length)

                //update free-memory pointer
                //allocating the array padded to 32 bytes like the compiler does now
                mstore(0x40, and(add(mc, 31), not(31)))
            }
            //if we want a zero-length slice let's just return a zero-length array
            default {
                tempBytes := mload(0x40)
                //zero out the 32 bytes slice we are about to return
                //we need to do it because Solidity does not garbage collect
                mstore(tempBytes, 0)

                mstore(0x40, add(tempBytes, 0x20))
            }
        }

        return tempBytes;
    }

    function toAddress(bytes memory _bytes, uint256 _start) internal pure returns (address) {
        require(_bytes.length >= _start + 20, "toAddress_outOfBounds");
        address tempAddress;

        assembly {
            tempAddress := div(mload(add(add(_bytes, 0x20), _start)), 0x1000000000000000000000000)
        }

        return tempAddress;
    }

    function toUint8(bytes memory _bytes, uint256 _start) internal pure returns (uint8) {
        require(_bytes.length >= _start + 1 , "toUint8_outOfBounds");
        uint8 tempUint;

        assembly {
            tempUint := mload(add(add(_bytes, 0x1), _start))
        }

        return tempUint;
    }

    function toUint16(bytes memory _bytes, uint256 _start) internal pure returns (uint16) {
        require(_bytes.length >= _start + 2, "toUint16_outOfBounds");
        uint16 tempUint;

        assembly {
            tempUint := mload(add(add(_bytes, 0x2), _start))
        }

        return tempUint;
    }

    function toUint32(bytes memory _bytes, uint256 _start) internal pure returns (uint32) {
        require(_bytes.length >= _start + 4, "toUint32_outOfBounds");
        uint32 tempUint;

        assembly {
            tempUint := mload(add(add(_bytes, 0x4), _start))
        }

        return tempUint;
    }

    function toUint64(bytes memory _bytes, uint256 _start) internal pure returns (uint64) {
        require(_bytes.length >= _start + 8, "toUint64_outOfBounds");
        uint64 tempUint;

        assembly {
            tempUint := mload(add(add(_bytes, 0x8), _start))
        }

        return tempUint;
    }

    function toUint96(bytes memory _bytes, uint256 _start) internal pure returns (uint96) {
        require(_bytes.length >= _start + 12, "toUint96_outOfBounds");
        uint96 tempUint;

        assembly {
            tempUint := mload(add(add(_bytes, 0xc), _start))
        }

        return tempUint;
    }

    function toUint128(bytes memory _bytes, uint256 _start) internal pure returns (uint128) {
        require(_bytes.length >= _start + 16, "toUint128_outOfBounds");
        uint128 tempUint;

        assembly {
            tempUint := mload(add(add(_bytes, 0x10), _start))
        }

        return tempUint;
    }

    function toUint256(bytes memory _bytes, uint256 _start) internal pure returns (uint256) {
        require(_bytes.length >= _start + 32, "toUint256_outOfBounds");
        uint256 tempUint;

        assembly {
            tempUint := mload(add(add(_bytes, 0x20), _start))
        }

        return tempUint;
    }

    function toBytes32(bytes memory _bytes, uint256 _start) internal pure returns (bytes32) {
        require(_bytes.length >= _start + 32, "toBytes32_outOfBounds");
        bytes32 tempBytes32;

        assembly {
            tempBytes32 := mload(add(add(_bytes, 0x20), _start))
        }

        return tempBytes32;
    }

    function equal(bytes memory _preBytes, bytes memory _postBytes) internal pure returns (bool) {
        bool success = true;

        assembly {
            let length := mload(_preBytes)

            // if lengths don't match the arrays are not equal
            switch eq(length, mload(_postBytes))
            case 1 {
                // cb is a circuit breaker in the for loop since there's
                //  no said feature for inline assembly loops
                // cb = 1 - don't breaker
                // cb = 0 - break
                let cb := 1

                let mc := add(_preBytes, 0x20)
                let end := add(mc, length)

                for {
                    let cc := add(_postBytes, 0x20)
                // the next line is the loop condition:
                // while(uint256(mc < end) + cb == 2)
                } eq(add(lt(mc, end), cb), 2) {
                    mc := add(mc, 0x20)
                    cc := add(cc, 0x20)
                } {
                    // if any of these checks fails then arrays are not equal
                    if iszero(eq(mload(mc), mload(cc))) {
                        // unsuccess:
                        success := 0
                        cb := 0
                    }
                }
            }
            default {
                // unsuccess:
                success := 0
            }
        }

        return success;
    }

    function equalStorage(
        bytes storage _preBytes,
        bytes memory _postBytes
    )
        internal
        view
        returns (bool)
    {
        bool success = true;

        assembly {
            // we know _preBytes_offset is 0
            let fslot := sload(_preBytes.slot)
            // Decode the length of the stored array like in concatStorage().
            let slength := div(and(fslot, sub(mul(0x100, iszero(and(fslot, 1))), 1)), 2)
            let mlength := mload(_postBytes)

            // if lengths don't match the arrays are not equal
            switch eq(slength, mlength)
            case 1 {
                // slength can contain both the length and contents of the array
                // if length < 32 bytes so let's prepare for that
                // v. http://solidity.readthedocs.io/en/latest/miscellaneous.html#layout-of-state-variables-in-storage
                if iszero(iszero(slength)) {
                    switch lt(slength, 32)
                    case 1 {
                        // blank the last byte which is the length
                        fslot := mul(div(fslot, 0x100), 0x100)

                        if iszero(eq(fslot, mload(add(_postBytes, 0x20)))) {
                            // unsuccess:
                            success := 0
                        }
                    }
                    default {
                        // cb is a circuit breaker in the for loop since there's
                        //  no said feature for inline assembly loops
                        // cb = 1 - don't breaker
                        // cb = 0 - break
                        let cb := 1

                        // get the keccak hash to get the contents of the array
                        mstore(0x0, _preBytes.slot)
                        let sc := keccak256(0x0, 0x20)

                        let mc := add(_postBytes, 0x20)
                        let end := add(mc, mlength)

                        // the next line is the loop condition:
                        // while(uint256(mc < end) + cb == 2)
                        for {} eq(add(lt(mc, end), cb), 2) {
                            sc := add(sc, 1)
                            mc := add(mc, 0x20)
                        } {
                            if iszero(eq(sload(sc), mload(mc))) {
                                // unsuccess:
                                success := 0
                                cb := 0
                            }
                        }
                    }
                }
            }
            default {
                // unsuccess:
                success := 0
            }
        }

        return success;
    }
}

<i class='far fa-question-circle text-muted ms-2' data-bs-trigger='hover' data-bs-toggle='tooltip' data-bs-html='true' data-bs-title='Click on the check box to select individual contract to compare. Only 1 contract can be selected from each side.'></i>

//SPDX-License-Identifier: Unlicense
pragma solidity ^0.8.4;

/**
  @title A library for deploying contracts EIP-3171 style.
  @author Agustin Aguilar <aa@horizon.io>
*/
library Create3 {
  error ErrorCreatingProxy();
  error ErrorCreatingContract();
  error TargetAlreadyExists();

  /**
    @notice The bytecode for a contract that proxies the creation of another contract
    @dev If this code is deployed using CREATE2 it can be used to decouple `creationCode` from the child contract address
  0x67363d3d37363d34f03d5260086018f3:
      0x00  0x67  0x67XXXXXXXXXXXXXXXX  PUSH8 bytecode  0x363d3d37363d34f0
      0x01  0x3d  0x3d                  RETURNDATASIZE  0 0x363d3d37363d34f0
      0x02  0x52  0x52                  MSTORE
      0x03  0x60  0x6008                PUSH1 08        8
      0x04  0x60  0x6018                PUSH1 18        24 8
      0x05  0xf3  0xf3                  RETURN
  0x363d3d37363d34f0:
      0x00  0x36  0x36                  CALLDATASIZE    cds
      0x01  0x3d  0x3d                  RETURNDATASIZE  0 cds
      0x02  0x3d  0x3d                  RETURNDATASIZE  0 0 cds
      0x03  0x37  0x37                  CALLDATACOPY
      0x04  0x36  0x36                  CALLDATASIZE    cds
      0x05  0x3d  0x3d                  RETURNDATASIZE  0 cds
      0x06  0x34  0x34                  CALLVALUE       val 0 cds
      0x07  0xf0  0xf0                  CREATE          addr
  */

  bytes internal constant PROXY_CHILD_BYTECODE =
    hex'67_36_3d_3d_37_36_3d_34_f0_3d_52_60_08_60_18_f3';

  //                        KECCAK256_PROXY_CHILD_BYTECODE = keccak256(PROXY_CHILD_BYTECODE);
  bytes32 internal constant KECCAK256_PROXY_CHILD_BYTECODE =
    0x21c35dbe1b344a2488cf3321d6ce542f8e9f305544ff09e4993a62319a497c1f;

  /**
    @notice Returns the size of the code on a given address
    @param _addr Address that may or may not contain code
    @return size of the code on the given `_addr`
  */
  function codeSize(address _addr) internal view returns (uint256 size) {
    assembly {
      size := extcodesize(_addr)
    }
  }

  /**
    @notice Creates a new contract with given `_creationCode` and `_salt`
    @param _salt Salt of the contract creation, resulting address will be derivated from this value only
    @param _creationCode Creation code (constructor) of the contract to be deployed, this value doesn't affect the resulting address
    @return addr of the deployed contract, reverts on error
  */
  function create3(bytes32 _salt, bytes memory _creationCode)
    internal
    returns (address addr)
  {
    return create3(_salt, _creationCode, 0);
  }

  /**
    @notice Creates a new contract with given `_creationCode` and `_salt`
    @param _salt Salt of the contract creation, resulting address will be derivated from this value only
    @param _creationCode Creation code (constructor) of the contract to be deployed, this value doesn't affect the resulting address
    @param _value In WEI of ETH to be forwarded to child contract
    @return addr of the deployed contract, reverts on error
  */
  function create3(
    bytes32 _salt,
    bytes memory _creationCode,
    uint256 _value
  ) internal returns (address addr) {
    // Creation code
    bytes memory creationCode = PROXY_CHILD_BYTECODE;

    // Get target final address
    addr = addressOf(_salt);
    if (codeSize(addr) != 0) revert TargetAlreadyExists();

    // Create CREATE2 proxy
    address proxy;
    assembly {
      proxy := create2(0, add(creationCode, 32), mload(creationCode), _salt)
    }
    if (proxy == address(0)) revert ErrorCreatingProxy();

    // Call proxy with final init code
    (bool success, ) = proxy.call{value: _value}(_creationCode);
    if (!success || codeSize(addr) == 0) revert ErrorCreatingContract();
  }

  /**
    @notice Computes the resulting address of a contract deployed using address(this) and the given `_salt`
    @param _salt Salt of the contract creation, resulting address will be derivated from this value only
    @return addr of the deployed contract, reverts on error
    @dev The address creation formula is: keccak256(rlp([keccak256(0xff ++ address(this) ++ _salt ++ keccak256(childBytecode))[12:], 0x01]))
  */
  function addressOf(bytes32 _salt) internal view returns (address) {
    address proxy = address(
      uint160(
        uint256(
          keccak256(
            abi.encodePacked(
              hex'ff',
              address(this),
              _salt,
              KECCAK256_PROXY_CHILD_BYTECODE
            )
          )
        )
      )
    );

    return
      address(
        uint160(
          uint256(keccak256(abi.encodePacked(hex'd6_94', proxy, hex'01')))
        )
      );
  }
}

<i class='far fa-question-circle text-muted ms-2' data-bs-trigger='hover' data-bs-toggle='tooltip' data-bs-html='true' data-bs-title='Click on the check box to select individual contract to compare. Only 1 contract can be selected from each side.'></i>

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.4;

library Bytecode {
  error InvalidCodeAtRange(uint256 _size, uint256 _start, uint256 _end);

  /**
    @notice Generate a creation code that results on a contract with `_code` as bytecode
    @param _code The returning value of the resulting `creationCode`
    @return creationCode (constructor) for new contract
  */
  function creationCodeFor(bytes memory _code)
    internal
    pure
    returns (bytes memory)
  {
    /*
      0x00    0x63         0x63XXXXXX  PUSH4 _code.length  size
      0x01    0x80         0x80        DUP1                size size
      0x02    0x60         0x600e      PUSH1 14            14 size size
      0x03    0x60         0x6000      PUSH1 00            0 14 size size
      0x04    0x39         0x39        CODECOPY            size
      0x05    0x60         0x6000      PUSH1 00            0 size
      0x06    0xf3         0xf3        RETURN
      <CODE>
    */

    return
      abi.encodePacked(
        hex'63',
        uint32(_code.length),
        hex'80_60_0E_60_00_39_60_00_F3',
        _code
      );
  }

  /**
    @notice Returns the size of the code on a given address
    @param _addr Address that may or may not contain code
    @return size of the code on the given `_addr`
  */
  function codeSize(address _addr) internal view returns (uint256 size) {
    assembly {
      size := extcodesize(_addr)
    }
  }

  /**
    @notice Returns the code of a given address
    @dev It will fail if `_end < _start`
    @param _addr Address that may or may not contain code
    @param _start number of bytes of code to skip on read
    @param _end index before which to end extraction
    @return oCode read from `_addr` deployed bytecode
    Forked from: https://gist.github.com/KardanovIR/fe98661df9338c842b4a30306d507fbd
  */
  function codeAt(
    address _addr,
    uint256 _start,
    uint256 _end
  ) internal view returns (bytes memory oCode) {
    uint256 csize = codeSize(_addr);
    if (csize == 0) return bytes('');

    if (_start > csize) return bytes('');
    if (_end < _start) revert InvalidCodeAtRange(csize, _start, _end);

    unchecked {
      uint256 reqSize = _end - _start;
      uint256 maxSize = csize - _start;

      uint256 size = maxSize < reqSize ? maxSize : reqSize;

      assembly {
        // allocate output byte array - this could also be done without assembly
        // by using o_code = new bytes(size)
        oCode := mload(0x40)
        // new "memory end" including padding
        mstore(0x40, add(oCode, and(add(add(size, 0x20), 0x1f), not(0x1f))))
        // store length in memory
        mstore(oCode, size)
        // actually retrieve the code, this needs assembly
        extcodecopy(_addr, add(oCode, 0x20), _start, size)
      }
    }
  }
}

<i class='far fa-question-circle text-muted ms-2' data-bs-trigger='hover' data-bs-toggle='tooltip' data-bs-html='true' data-bs-title='Click on the check box to select individual contract to compare. Only 1 contract can be selected from each side.'></i>

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)

pragma solidity ^0.8.0;

/**
 * @dev Provides information about the current execution context, including the
 * sender of the transaction and its data. While these are generally available
 * via msg.sender and msg.data, they should not be accessed in such a direct
 * manner, since when dealing with meta-transactions the account sending and
 * paying for execution may not be the actual sender (as far as an application
 * is concerned).
 *
 * This contract is only required for intermediate, library-like contracts.
 */
abstract contract Context {
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes calldata) {
        return msg.data;
    }
}

Please enter a contract address above to load the contract details and source code.

Context size (optional):