I'm looking into the event logs of makerdao's CDP operation, and I'm confused why there are several event logs for 1 cdp operation, like this tx: https://etherscan.io/tx/0x0fb6a8d8f10410c544b27b848319e67a422be883e4252fea639c89a444209685#eventlog, it contains 1 cdp operation: draw dai.
there is only 1 Draw event of 95 Dai:
while in event logs, there are several event logs(totally 6) with the Topic0:
(0x440f19ba00000000000000000000000000000000000000000000000000000000
):
why is this?
Note: signature of draw event is:
function draw(bytes32 cup, uint wad) public note {
here the log is made by the modifier note
, which is:
event LogNote(
bytes4 indexed sig,
address indexed guy,
bytes32 indexed foo,
bytes32 indexed bar,
uint wad,
bytes fax
) anonymous;
modifier note {
bytes32 foo;
bytes32 bar;
assembly {
foo := calldataload(4)
bar := calldataload(36)
}
LogNote(msg.sig, msg.sender, foo, bar, msg.value, msg.data);
_;
}
event LogNote
is anonymous
, so topic0 is msg.sig instead of the signature of the event. and msg.sig for func dai is: draw(bytes32,uint256)
, the keccak is: 0x440f19ba0