1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
use crate::float::Ordf32;
use core::ops::{Add, Sub};
/// Fee rate
#[derive(Debug, Copy, Clone, PartialEq, Eq, PartialOrd, Ord)]
// Internally stored as satoshi/weight unit
pub struct FeeRate(Ordf32);
impl FeeRate {
/// A feerate of zero
pub const ZERO: Self = Self(Ordf32(0.0));
/// The default minimum relay fee that bitcoin core uses (1 sat per vbyte). The feerate your transaction has must
/// be at least this to be forwarded by most nodes on the network.
pub const DEFAULT_MIN_RELAY: Self = Self(Ordf32(0.25));
/// The defualt incremental relay fee that bitcoin core uses (1 sat per vbyte). You must pay
/// this fee over the fee of the transaction(s) you are replacing by through the replace-by-fee
/// mechanism. This feerate is applied to the transaction that is replacing the old
/// transactions.
pub const DEFUALT_RBF_INCREMENTAL_RELAY: Self = Self(Ordf32(0.25));
/// Create a new instance checking the value provided
///
/// ## Panics
///
/// Panics if the value is not [normal](https://doc.rust-lang.org/std/primitive.f32.html#method.is_normal) (except if it's a positive zero) or negative.
fn new_checked(value: f32) -> Self {
assert!(value.is_normal() || value == 0.0);
assert!(value.is_sign_positive());
Self(Ordf32(value))
}
/// Create a new instance of [`FeeRate`] given a float fee rate in btc/kvbytes
///
/// ## Panics
///
/// Panics if the value is not [normal](https://doc.rust-lang.org/std/primitive.f32.html#method.is_normal) (except if it's a positive zero) or negative.
pub fn from_btc_per_kvb(btc_per_kvb: f32) -> Self {
Self::new_checked(btc_per_kvb * 1e5 / 4.0)
}
/// Create a new instance of [`FeeRate`] given a float fee rate in satoshi/vbyte
///
/// ## Panics
///
/// Panics if the value is not [normal](https://doc.rust-lang.org/std/primitive.f32.html#method.is_normal) (except if it's a positive zero) or negative.
pub fn from_sat_per_vb(sat_per_vb: f32) -> Self {
Self::new_checked(sat_per_vb / 4.0)
}
/// Create a new [`FeeRate`] with the default min relay fee value
#[deprecated(note = "use the DEFAULT_MIN_RELAY constant instead")]
pub const fn default_min_relay_fee() -> Self {
Self(Ordf32(0.25))
}
/// Calculate fee rate from `fee` and weight units (`wu`).
pub fn from_wu(fee: u64, wu: usize) -> Self {
Self::from_sat_per_wu(fee as f32 / wu as f32)
}
/// Calculate feerate from `satoshi/wu`.
pub fn from_sat_per_wu(sats_per_wu: f32) -> Self {
Self::new_checked(sats_per_wu)
}
/// Calculate fee rate from `fee` and `vbytes`.
pub fn from_vb(fee: u64, vbytes: usize) -> Self {
let rate = fee as f32 / vbytes as f32;
Self::from_sat_per_vb(rate)
}
/// Return the value as satoshi/vbyte.
pub fn as_sat_vb(&self) -> f32 {
self.0 .0 * 4.0
}
/// Return the value as satoshi/wu.
pub fn spwu(&self) -> f32 {
self.0 .0
}
/// The fee that the transaction with weight `tx_weight` should pay in order to satisfy the fee rate given by `self`,
/// where the fee rate is applied to the rounded-up vbytes obtained from `tx_weight`.
pub fn implied_fee(&self, tx_weight: u64) -> u64 {
((tx_weight as f32 / 4.0).ceil() * self.as_sat_vb()).ceil() as u64
}
/// Same as [implied_fee](Self::implied_fee) except the fee rate given by `self` is applied to `tx_weight` directly.
pub fn implied_fee_wu(&self, tx_weight: u64) -> u64 {
(tx_weight as f32 * self.spwu()).ceil() as u64
}
}
impl Add<FeeRate> for FeeRate {
type Output = Self;
fn add(self, rhs: FeeRate) -> Self::Output {
Self(Ordf32(self.0 .0 + rhs.0 .0))
}
}
impl Sub<FeeRate> for FeeRate {
type Output = Self;
fn sub(self, rhs: FeeRate) -> Self::Output {
Self(Ordf32(self.0 .0 - rhs.0 .0))
}
}