It's not all that rare to do these operations, and requiring annotations
for it is a little painful.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
We don't preserve detailed asset information at the moment, so provide a
way to convert from a sat to an amount_asset struct.
We also need a way to convert from an 'amount_asset' to a 'value' for
elements, which for explicit (i.e. non-blinded) asssets is a 0x01 prefix
plus the big-endian encoded value.
Currently the only source for amount_asset is the value getter on a tx output,
and we don't hand it too far around (mainly ignoring it if it isn't the
chain's main currency). Eventually we could bubble them up to the wallet, use
them to select outputs or actually support assets in the channels.
Since we don't hand them around too widely I thought it was ok for them to be
pass-by-value rather than having to allocate them and pass them around by
reference. They're just 41 bytes currently so the overhead should be ok.
Signed-off-by: Christian Decker <@cdecker>
1. amount operations should force you to check validity, rather than
needing a separate call, so make amount_msat_to_u32 return bool,
and WARN_UNUSED_RESULT it.
2. Create a special parsing function for this; not only does this mean
we now only need that one amount call, but also 'check' will correctly
fail with invalid amounts (it only does the parsing step).
3. If we create a primitive which we immediately take(), we allocate it
off NULL to make it clear we expect its lifetime to end here.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
I tried to fundchannel 0.01btc, and of course it wanted 8 decimals exactly.
If I can't get this right, it's probably a bad idea.
I still don't allow whole number of btc though, since that's probably a mistake
and you're not supposed to put that much in c-lightning yet :)
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
They're generally used pass-by-copy (unusual for C structs, but
convenient they're basically u64) and all possibly problematic
operations return WARN_UNUSED_RESULT bool to make you handle the
over/underflow cases.
The new #include in json.h means we bolt11.c sees the amount.h definition
of MSAT_PER_BTC, so delete its local version.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
