MulticallUpgradeable.sol

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.4) (utils/Multicall.sol)

pragma solidity ^0.8.0;

import "./AddressUpgradeable.sol";
import "./ContextUpgradeable.sol";
import {Initializable} from "../proxy/utils/Initializable.sol";

/**
 * @dev Provides a function to batch together multiple calls in a single external call.
 *
 * Consider any assumption about calldata validation performed by the sender may be violated if it's not especially
 * careful about sending transactions invoking {multicall}. For example, a relay address that filters function
 * selectors won't filter calls nested within a {multicall} operation.
 *
 * NOTE: Since 5.0.1 and 4.9.4, this contract identifies non-canonical contexts (i.e. `msg.sender` is not {_msgSender}).
 * If a non-canonical context is identified, the following self `delegatecall` appends the last bytes of `msg.data`
 * to the subcall. This makes it safe to use with {ERC2771Context}. Contexts that don't affect the resolution of
 * {_msgSender} are not propagated to subcalls.
 *
 * _Available since v4.1._
 */
abstract contract MulticallUpgradeable is Initializable, ContextUpgradeable {
    function __Multicall_init() internal onlyInitializing {
    }

    function __Multicall_init_unchained() internal onlyInitializing {
    }
    /**
     * @dev Receives and executes a batch of function calls on this contract.
     * @custom:oz-upgrades-unsafe-allow-reachable delegatecall
     */
    function multicall(bytes[] calldata data) external virtual returns (bytes[] memory results) {
        bytes memory context = msg.sender == _msgSender()
            ? new bytes(0)
            : msg.data[msg.data.length - _contextSuffixLength():];

        results = new bytes[](data.length);
        for (uint256 i = 0; i < data.length; i++) {
            results[i] = AddressUpgradeable.functionDelegateCall(address(this), bytes.concat(data[i], context));
        }
        return results;
    }

    /**
     * @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[50] private __gap;
}