core-lightning/bitcoin/feerate.c
niftynei b2170cf3f4 feerate: add a 'common_weight' calculation for a tx
The bits of a transaction that are paid by the opener!
2020-09-09 19:54:20 +09:30

51 lines
1.1 KiB
C

#include <bitcoin/feerate.h>
#include <bitcoin/varint.h>
#include <limits.h>
#include <stdlib.h>
u32 feerate_from_style(u32 feerate, enum feerate_style style)
{
switch (style) {
case FEERATE_PER_KSIPA:
return feerate;
case FEERATE_PER_KBYTE:
/* Everyone uses satoshi per kbyte, but we use satoshi per ksipa
* (don't round down to zero though)! */
return (feerate + 3) / 4;
}
abort();
}
u32 feerate_to_style(u32 feerate_perkw, enum feerate_style style)
{
switch (style) {
case FEERATE_PER_KSIPA:
return feerate_perkw;
case FEERATE_PER_KBYTE:
if ((u64)feerate_perkw * 4 > UINT_MAX)
return UINT_MAX;
return feerate_perkw * 4;
}
abort();
}
const char *feerate_style_name(enum feerate_style style)
{
switch (style) {
case FEERATE_PER_KBYTE:
return "perkb";
case FEERATE_PER_KSIPA:
return "perkw";
}
abort();
}
size_t common_weight(size_t num_inputs, size_t num_outputs)
{
/*(nVersion + num inputs + num outputs + locktime) * 4
* + SegWit marker + SegWit flag */
return (4 + varint_size(num_inputs) +
varint_size(num_outputs) + 4) * 4
+ 1 + 1;
}