Should we use unchecked arithmetic in the sender amount calculations?

[PaulRBerg]

@smol-ninja's question here remained unanswered:

#813 (comment)

Some historical context: we used to use unchecked, but then Cantina (Zach and Rusty) recommended removing it during the 1st audit of the code base:

https://github.com/cantinasec/review-sablier/issues/3

But IIRC, we didn't have this if block at the time when Cantina's feedback was given:

v2-core/src/abstracts/SablierV2Lockup.sol

Lines 559 to 561 in 76e29fe

	if (streamedAmount >= amounts.deposited) {
	revert Errors.SablierV2Lockup_StreamSettled(streamId);
	}

As Shub pointed out, it should be completely safe to use unchecked arithmetic for calculating the sender amount.

WDYT @andreivladbrg?

[smol-ninja]

Bumping this up @andreivladbrg since Cantina audit is starting from Apr 15.

[PaulRBerg]

@andreivladbrg can we please get an answer from you here

[andreivladbrg]

Completely sorry. I have my notifications active and still got no mail for this...

If it happens in the future to not answer again, please ping me via Slack DM

But IIRC, we didn't have this if block at the time when Cantina's feedback was given:

yes, we didn't

it should be completely safe to use unchecked arithmetic for calculating the sender amount

agree, we can use safely use unchecked

[PaulRBerg]

No worries. @smol-ninja can you put together a PR for this, please.

[smol-ninja]

Sure!

[smol-ninja]

Resolved in:

• perf: use unchecked to calculate sender amount #892