Feature/add srd selection

[yancyribbens]

I have renamed and moved the random function to it's own module. This feature is similar to SRD in core. Also, I've added effective_value which is used for the sum calculation instead of value. Lastly I did some minor refactoring so that the unit sizes used in the test match core.

[murchandamus]

BTW, I added this repository to my watch list, so if you ask something here, I should also see.

[Tibo-lg]

I'm ok with using a struct though I'm not sure if it gives you more than a trait.

[yancyribbens]

@Tibo-lg I think the only downside to using a Trait instead of a struct is the increased compile time. A monomorphised type has to be constructed at compile time, although the run-time should be the same, so either is probably fine.

[yancyribbens]

I believe this PR is ready to merge. Any objections @Tibo-lg ?

[murchandamus]

If you are going with integers for the feerate, you could consider using ṩ/kvB as the base unit, since it allows you to be more precise than just full satoshi increments. That way you can create transactions with feerates at 1.103 ṩ/vB, instead of needing to pay 2 ṩ/vB if 1 ṩ/vB is insufficient for the priority you want to imbue the transaction with.

[murchandamus]

I was also about to ask about how you avoid dust outputs, but then I saw the last commit. 👍

[yancyribbens]

If you are going with integers for the feerate, you could consider using ṩ/kvB as the base unit

Thanks, that's a good point. Wouldn't it be better to use a float for rate?

Otherwise, here would be:

let kv_bytes = weight / 4 /1024;
which means we lose a lot of precision with int division OR kvbytes is a float. It doesn't work to have kvbytes be a float and feerate as an int then.

[murchandamus]

We don’t use “kibivirtualbytes”, but “kilovirtualbytes“:

1 MvB = 1000 kvB = 1 000 000 vB

We never use floats for consensus relevant calculations in Bitcoin Core to avoid any sort of rounding issues. YMMV.

[yancyribbens]

How about something like this: d1d38b1

/// Takes as input the fee_rate in $ per Kilovirtualbytes
/// and a size in Kilovirtualbytes and returns the fee amount.
///
/// * fee_rate: $ per kilovirtualbytes $KvB
/// * size: kilovirtualbytes KvB
/// * fee: $

[yancyribbens]

I just noticed this PR rust-bitcoin/rust-bitcoin#1627. Maybe it would be better to build off FeeRate as defined by Rust Bitcoin.

[Tibo-lg]

SGTM

[murchandamus]

How about something like this: d1d38b1

/// Takes as input the fee_rate in $ per Kilovirtualbytes
/// and a size in Kilovirtualbytes and returns the fee amount.
///
/// * fee_rate: $ per kilovirtualbytes $KvB
/// * size: kilovirtualbytes KvB
/// * fee: $

It’s not a dollar symbol but an “s” with a dot above and below: ṩ (u+1e69). The symbol for kilo is “k”, not “K”, the latter is the symbol for Kelvin, so it’s kvB, and that makes the feerate ṩ/kvB (which without the slash would be a multiplication rather than a division).

[murchandamus]

Hey, this keeps popping up in my notifications but doesn’t seem to be ready for review. I’ll stop following notifications here for the time being. Please feel free to ping me here again when this PR is ready for review.

[yancyribbens]

Hey, this keeps popping up in my notifications but doesn’t seem to be ready for review. I’ll stop following notifications here for the time being. Please feel free to ping me here again when this PR is ready for review.

Sorry for all the noise. I think it's about ready now, however there seems to be some unrelated failure with the nightly toolchain I'm trying to figure out. Anyway, I think at this point I'll just close this PR and open a fresh one once I figure out what's going on with CI.

[yancyribbens]

@xekyo a new PR is now open here #23 - cheers.