File 1 of 1 : MulticallerWithSender.sol
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.4;
/**
* @title MulticallerWithSender
* @author vectorized.eth
* @notice Contract that allows for efficient aggregation of multiple calls
* in a single transaction, while "forwarding" the `msg.sender`.
*/
contract MulticallerWithSender {
// =============================================================
// ERRORS
// =============================================================
/**
* @dev The lengths of the input arrays are not the same.
*/
error ArrayLengthsMismatch();
/**
* @dev This function does not support reentrancy.
*/
error Reentrancy();
// =============================================================
// CONSTRUCTOR
// =============================================================
constructor() payable {
assembly {
// Throughout this code, we will abuse returndatasize
// in place of zero anywhere before a call to save a bit of gas.
// We will use storage slot zero to store the caller at
// bits [0..159] and reentrancy guard flag at bit 160.
sstore(returndatasize(), shl(160, 1))
}
}
// =============================================================
// AGGREGATION OPERATIONS
// =============================================================
/**
* @dev Returns the address that called `aggregateWithSender` on this contract.
* The value is always the zero address outside a transaction.
*/
receive() external payable {
assembly {
mstore(returndatasize(), and(sub(shl(160, 1), 1), sload(returndatasize())))
return(returndatasize(), 0x20)
}
}
/**
* @dev Aggregates multiple calls in a single transaction.
* This method will set `sender` to the `msg.sender` temporarily
* for the span of its execution.
* This method does not support reentrancy.
* @param targets An array of addresses to call.
* @param data An array of calldata to forward to the targets.
* @param values How much ETH to forward to each target.
* @return An array of the returndata from each call.
*/
function aggregateWithSender(
address[] calldata targets,
bytes[] calldata data,
uint256[] calldata values
) external payable returns (bytes[] memory) {
assembly {
if iszero(and(eq(targets.length, data.length), eq(data.length, values.length))) {
// Store the function selector of `ArrayLengthsMismatch()`.
mstore(returndatasize(), 0x3b800a46)
// Revert with (offset, size).
revert(0x1c, 0x04)
}
if iszero(and(sload(returndatasize()), shl(160, 1))) {
// Store the function selector of `Reentrancy()`.
mstore(returndatasize(), 0xab143c06)
// Revert with (offset, size).
revert(0x1c, 0x04)
}
mstore(returndatasize(), 0x20) // Store the memory offset of the `results`.
mstore(0x20, data.length) // Store `data.length` into `results`.
// Early return if no data.
if iszero(data.length) { return(returndatasize(), 0x40) }
// Set the sender slot temporarily for the span of this transaction.
sstore(returndatasize(), caller())
let results := 0x40
// Left shift by 5 is equivalent to multiplying by 0x20.
data.length := shl(5, data.length)
// Copy the offsets from calldata into memory.
calldatacopy(results, data.offset, data.length)
// Offset into `results`.
let resultsOffset := data.length
// Pointer to the end of `results`.
// Recycle `data.length` to avoid stack too deep.
data.length := add(results, data.length)
for {} 1 {} {
// The offset of the current bytes in the calldata.
let o := add(data.offset, mload(results))
let memPtr := add(resultsOffset, 0x40)
// Copy the current bytes from calldata to the memory.
calldatacopy(
memPtr,
add(o, 0x20), // The offset of the current bytes' bytes.
calldataload(o) // The length of the current bytes.
)
if iszero(
call(
gas(), // Remaining gas.
calldataload(targets.offset), // Address to call.
calldataload(values.offset), // ETH to send.
memPtr, // Start of input calldata in memory.
calldataload(o), // Size of input calldata.
0x00, // We will use returndatacopy instead.
0x00 // We will use returndatacopy instead.
)
) {
// Bubble up the revert if the call reverts.
returndatacopy(0x00, 0x00, returndatasize())
revert(0x00, returndatasize())
}
// Advance the `targets.offset`.
targets.offset := add(targets.offset, 0x20)
// Advance the `values.offset`.
values.offset := add(values.offset, 0x20)
// Append the current `resultsOffset` into `results`.
mstore(results, resultsOffset)
results := add(results, 0x20)
// Append the returndatasize, and the returndata.
mstore(memPtr, returndatasize())
returndatacopy(add(memPtr, 0x20), 0x00, returndatasize())
// Advance the `resultsOffset` by `returndatasize() + 0x20`,
// rounded up to the next multiple of 0x20.
resultsOffset := and(add(add(resultsOffset, returndatasize()), 0x3f), not(0x1f))
if iszero(lt(results, data.length)) { break }
}
// Restore the `sender` slot.
sstore(0, shl(160, 1))
// Direct return.
return(0x00, add(resultsOffset, 0x40))
}
}
}