use schemars::JsonSchema;
use serde::{de, ser, Deserialize, Deserializer, Serialize};
use std::fmt::{self, Write};
use std::ops;
use std::str::FromStr;
use crate::errors::StdError;
use super::Fraction;
use super::Uint128;
#[derive(Copy, Clone, Default, Debug, PartialEq, Eq, PartialOrd, Ord, JsonSchema)]
pub struct Decimal(#[schemars(with = "String")] u128);
const DECIMAL_FRACTIONAL: u128 = 1_000_000_000_000_000_000;
const DECIMAL_FRACTIONAL_SQUARED: u128 = 1_000_000_000_000_000_000_000_000_000_000_000_000;
impl Decimal {
pub const MAX: Decimal = Decimal(u128::MAX);
pub const fn one() -> Decimal {
Decimal(DECIMAL_FRACTIONAL)
}
pub const fn zero() -> Decimal {
Decimal(0)
}
pub fn percent(x: u64) -> Decimal {
Decimal((x as u128) * 10_000_000_000_000_000)
}
pub fn permille(x: u64) -> Decimal {
Decimal((x as u128) * 1_000_000_000_000_000)
}
pub fn from_ratio<A: Into<u128>, B: Into<u128>>(numerator: A, denominator: B) -> Decimal {
let numerator: u128 = numerator.into();
let denominator: u128 = denominator.into();
if denominator == 0 {
panic!("Denominator must not be zero");
}
Decimal(numerator * DECIMAL_FRACTIONAL / denominator)
}
pub fn is_zero(&self) -> bool {
self.0 == 0
}
}
impl Fraction<u128> for Decimal {
#[inline]
fn numerator(&self) -> u128 {
self.0
}
#[inline]
fn denominator(&self) -> u128 {
DECIMAL_FRACTIONAL
}
fn inv(&self) -> Option<Decimal> {
if self.is_zero() {
None
} else {
Some(Decimal(DECIMAL_FRACTIONAL_SQUARED / self.0))
}
}
}
impl FromStr for Decimal {
type Err = StdError;
fn from_str(input: &str) -> Result<Self, Self::Err> {
let mut parts_iter = input.split('.');
let whole_part = parts_iter.next().unwrap();
let whole = whole_part
.parse::<u128>()
.map_err(|_| StdError::generic_err("Error parsing whole"))?;
let mut atomics = whole
.checked_mul(DECIMAL_FRACTIONAL)
.ok_or_else(|| StdError::generic_err("Value too big"))?;
if let Some(fractional_part) = parts_iter.next() {
let fractional = fractional_part
.parse::<u128>()
.map_err(|_| StdError::generic_err("Error parsing fractional"))?;
let exp = (18usize.checked_sub(fractional_part.len())).ok_or_else(|| {
StdError::generic_err("Cannot parse more than 18 fractional digits")
})?;
debug_assert!(exp <= 18);
let fractional_factor = 10u128.pow(exp as u32);
atomics = atomics
.checked_add(fractional * fractional_factor)
.ok_or_else(|| StdError::generic_err("Value too big"))?;
}
if parts_iter.next().is_some() {
return Err(StdError::generic_err("Unexpected number of dots"));
}
Ok(Decimal(atomics))
}
}
impl fmt::Display for Decimal {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
let whole = (self.0) / DECIMAL_FRACTIONAL;
let fractional = (self.0) % DECIMAL_FRACTIONAL;
if fractional == 0 {
write!(f, "{}", whole)
} else {
let fractional_string = format!("{:018}", fractional);
f.write_str(&whole.to_string())?;
f.write_char('.')?;
f.write_str(fractional_string.trim_end_matches('0'))?;
Ok(())
}
}
}
impl ops::Add for Decimal {
type Output = Self;
fn add(self, other: Self) -> Self {
Decimal(self.0 + other.0)
}
}
impl ops::Mul<Decimal> for Uint128 {
type Output = Self;
#[allow(clippy::suspicious_arithmetic_impl)]
fn mul(self, rhs: Decimal) -> Self::Output {
if self.is_zero() || rhs.is_zero() {
return Uint128::zero();
}
self.multiply_ratio(rhs.0, DECIMAL_FRACTIONAL)
}
}
impl ops::Mul<Uint128> for Decimal {
type Output = Uint128;
fn mul(self, rhs: Uint128) -> Self::Output {
rhs * self
}
}
impl Serialize for Decimal {
fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
where
S: ser::Serializer,
{
serializer.serialize_str(&self.to_string())
}
}
impl<'de> Deserialize<'de> for Decimal {
fn deserialize<D>(deserializer: D) -> Result<Decimal, D::Error>
where
D: Deserializer<'de>,
{
deserializer.deserialize_str(DecimalVisitor)
}
}
struct DecimalVisitor;
impl<'de> de::Visitor<'de> for DecimalVisitor {
type Value = Decimal;
fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
formatter.write_str("string-encoded decimal")
}
fn visit_str<E>(self, v: &str) -> Result<Self::Value, E>
where
E: de::Error,
{
match Decimal::from_str(v) {
Ok(d) => Ok(d),
Err(e) => Err(E::custom(format!("Error parsing decimal '{}': {}", v, e))),
}
}
}
#[cfg(test)]
mod tests {
use super::*;
use crate::errors::StdError;
use crate::{from_slice, to_vec};
#[test]
fn decimal_one() {
let value = Decimal::one();
assert_eq!(value.0, DECIMAL_FRACTIONAL);
}
#[test]
fn decimal_zero() {
let value = Decimal::zero();
assert_eq!(value.0, 0);
}
#[test]
fn decimal_percent() {
let value = Decimal::percent(50);
assert_eq!(value.0, DECIMAL_FRACTIONAL / 2);
}
#[test]
fn decimal_permille() {
let value = Decimal::permille(125);
assert_eq!(value.0, DECIMAL_FRACTIONAL / 8);
}
#[test]
fn decimal_from_ratio_works() {
assert_eq!(Decimal::from_ratio(1u128, 1u128), Decimal::one());
assert_eq!(Decimal::from_ratio(53u128, 53u128), Decimal::one());
assert_eq!(Decimal::from_ratio(125u128, 125u128), Decimal::one());
assert_eq!(Decimal::from_ratio(3u128, 2u128), Decimal::percent(150));
assert_eq!(Decimal::from_ratio(150u128, 100u128), Decimal::percent(150));
assert_eq!(Decimal::from_ratio(333u128, 222u128), Decimal::percent(150));
assert_eq!(Decimal::from_ratio(1u64, 8u64), Decimal::permille(125));
assert_eq!(Decimal::from_ratio(125u64, 1000u64), Decimal::permille(125));
assert_eq!(
Decimal::from_ratio(1u64, 3u64),
Decimal(333_333_333_333_333_333)
);
assert_eq!(
Decimal::from_ratio(2u64, 3u64),
Decimal(666_666_666_666_666_666)
);
}
#[test]
#[should_panic(expected = "Denominator must not be zero")]
fn decimal_from_ratio_panics_for_zero_denominator() {
Decimal::from_ratio(1u128, 0u128);
}
#[test]
fn decimal_implements_fraction() {
let fraction = Decimal::from_str("1234.567").unwrap();
assert_eq!(fraction.numerator(), 1_234_567_000_000_000_000_000);
assert_eq!(fraction.denominator(), 1_000_000_000_000_000_000);
}
#[test]
fn decimal_from_str_works() {
assert_eq!(Decimal::from_str("0").unwrap(), Decimal::percent(0));
assert_eq!(Decimal::from_str("1").unwrap(), Decimal::percent(100));
assert_eq!(Decimal::from_str("5").unwrap(), Decimal::percent(500));
assert_eq!(Decimal::from_str("42").unwrap(), Decimal::percent(4200));
assert_eq!(Decimal::from_str("000").unwrap(), Decimal::percent(0));
assert_eq!(Decimal::from_str("001").unwrap(), Decimal::percent(100));
assert_eq!(Decimal::from_str("005").unwrap(), Decimal::percent(500));
assert_eq!(Decimal::from_str("0042").unwrap(), Decimal::percent(4200));
assert_eq!(Decimal::from_str("1.0").unwrap(), Decimal::percent(100));
assert_eq!(Decimal::from_str("1.5").unwrap(), Decimal::percent(150));
assert_eq!(Decimal::from_str("0.5").unwrap(), Decimal::percent(50));
assert_eq!(Decimal::from_str("0.123").unwrap(), Decimal::permille(123));
assert_eq!(Decimal::from_str("40.00").unwrap(), Decimal::percent(4000));
assert_eq!(Decimal::from_str("04.00").unwrap(), Decimal::percent(400));
assert_eq!(Decimal::from_str("00.40").unwrap(), Decimal::percent(40));
assert_eq!(Decimal::from_str("00.04").unwrap(), Decimal::percent(4));
assert_eq!(
Decimal::from_str("7.123456789012345678").unwrap(),
Decimal(7123456789012345678)
);
assert_eq!(
Decimal::from_str("7.999999999999999999").unwrap(),
Decimal(7999999999999999999)
);
assert_eq!(
Decimal::from_str("340282366920938463463.374607431768211455").unwrap(),
Decimal::MAX
);
}
#[test]
fn decimal_from_str_errors_for_broken_whole_part() {
match Decimal::from_str("").unwrap_err() {
StdError::GenericErr { msg, .. } => assert_eq!(msg, "Error parsing whole"),
e => panic!("Unexpected error: {:?}", e),
}
match Decimal::from_str(" ").unwrap_err() {
StdError::GenericErr { msg, .. } => assert_eq!(msg, "Error parsing whole"),
e => panic!("Unexpected error: {:?}", e),
}
match Decimal::from_str("-1").unwrap_err() {
StdError::GenericErr { msg, .. } => assert_eq!(msg, "Error parsing whole"),
e => panic!("Unexpected error: {:?}", e),
}
}
#[test]
fn decimal_from_str_errors_for_broken_fractinal_part() {
match Decimal::from_str("1.").unwrap_err() {
StdError::GenericErr { msg, .. } => assert_eq!(msg, "Error parsing fractional"),
e => panic!("Unexpected error: {:?}", e),
}
match Decimal::from_str("1. ").unwrap_err() {
StdError::GenericErr { msg, .. } => assert_eq!(msg, "Error parsing fractional"),
e => panic!("Unexpected error: {:?}", e),
}
match Decimal::from_str("1.e").unwrap_err() {
StdError::GenericErr { msg, .. } => assert_eq!(msg, "Error parsing fractional"),
e => panic!("Unexpected error: {:?}", e),
}
match Decimal::from_str("1.2e3").unwrap_err() {
StdError::GenericErr { msg, .. } => assert_eq!(msg, "Error parsing fractional"),
e => panic!("Unexpected error: {:?}", e),
}
}
#[test]
fn decimal_from_str_errors_for_more_than_18_fractional_digits() {
match Decimal::from_str("7.1234567890123456789").unwrap_err() {
StdError::GenericErr { msg, .. } => {
assert_eq!(msg, "Cannot parse more than 18 fractional digits")
}
e => panic!("Unexpected error: {:?}", e),
}
match Decimal::from_str("7.1230000000000000000").unwrap_err() {
StdError::GenericErr { msg, .. } => {
assert_eq!(msg, "Cannot parse more than 18 fractional digits")
}
e => panic!("Unexpected error: {:?}", e),
}
}
#[test]
fn decimal_from_str_errors_for_invalid_number_of_dots() {
match Decimal::from_str("1.2.3").unwrap_err() {
StdError::GenericErr { msg, .. } => assert_eq!(msg, "Unexpected number of dots"),
e => panic!("Unexpected error: {:?}", e),
}
match Decimal::from_str("1.2.3.4").unwrap_err() {
StdError::GenericErr { msg, .. } => assert_eq!(msg, "Unexpected number of dots"),
e => panic!("Unexpected error: {:?}", e),
}
}
#[test]
fn decimal_from_str_errors_for_more_than_max_value() {
match Decimal::from_str("340282366920938463464").unwrap_err() {
StdError::GenericErr { msg, .. } => assert_eq!(msg, "Value too big"),
e => panic!("Unexpected error: {:?}", e),
}
match Decimal::from_str("340282366920938463464.0").unwrap_err() {
StdError::GenericErr { msg, .. } => assert_eq!(msg, "Value too big"),
e => panic!("Unexpected error: {:?}", e),
}
match Decimal::from_str("340282366920938463463.374607431768211456").unwrap_err() {
StdError::GenericErr { msg, .. } => assert_eq!(msg, "Value too big"),
e => panic!("Unexpected error: {:?}", e),
}
}
#[test]
fn decimal_is_zero_works() {
assert_eq!(Decimal::zero().is_zero(), true);
assert_eq!(Decimal::percent(0).is_zero(), true);
assert_eq!(Decimal::permille(0).is_zero(), true);
assert_eq!(Decimal::one().is_zero(), false);
assert_eq!(Decimal::percent(123).is_zero(), false);
assert_eq!(Decimal::permille(1234).is_zero(), false);
}
#[test]
fn decimal_inv_works() {
assert_eq!(Decimal::zero().inv(), None);
assert_eq!(Decimal::one().inv(), Some(Decimal::one()));
assert_eq!(
Decimal::from_str("2").unwrap().inv(),
Some(Decimal::from_str("0.5").unwrap())
);
assert_eq!(
Decimal::from_str("20").unwrap().inv(),
Some(Decimal::from_str("0.05").unwrap())
);
assert_eq!(
Decimal::from_str("200").unwrap().inv(),
Some(Decimal::from_str("0.005").unwrap())
);
assert_eq!(
Decimal::from_str("2000").unwrap().inv(),
Some(Decimal::from_str("0.0005").unwrap())
);
assert_eq!(
Decimal::from_str("3").unwrap().inv(),
Some(Decimal::from_str("0.333333333333333333").unwrap())
);
assert_eq!(
Decimal::from_str("6").unwrap().inv(),
Some(Decimal::from_str("0.166666666666666666").unwrap())
);
assert_eq!(
Decimal::from_str("0.5").unwrap().inv(),
Some(Decimal::from_str("2").unwrap())
);
assert_eq!(
Decimal::from_str("0.05").unwrap().inv(),
Some(Decimal::from_str("20").unwrap())
);
assert_eq!(
Decimal::from_str("0.005").unwrap().inv(),
Some(Decimal::from_str("200").unwrap())
);
assert_eq!(
Decimal::from_str("0.0005").unwrap().inv(),
Some(Decimal::from_str("2000").unwrap())
);
}
#[test]
fn decimal_add() {
let value = Decimal::one() + Decimal::percent(50);
assert_eq!(value.0, DECIMAL_FRACTIONAL * 3 / 2);
}
#[test]
fn uint128_decimal_multiply() {
let left = Uint128(300);
let right = Decimal::one() + Decimal::percent(50);
assert_eq!(left * right, Uint128(450));
let left = Uint128(300);
let right = Decimal::zero();
assert_eq!(left * right, Uint128(0));
let left = Uint128(0);
let right = Decimal::one() + Decimal::percent(50);
assert_eq!(left * right, Uint128(0));
}
#[test]
fn decimal_uint128_multiply() {
let left = Decimal::one() + Decimal::percent(50);
let right = Uint128(300);
assert_eq!(left * right, Uint128(450));
let left = Decimal::zero();
let right = Uint128(300);
assert_eq!(left * right, Uint128(0));
let left = Decimal::one() + Decimal::percent(50);
let right = Uint128(0);
assert_eq!(left * right, Uint128(0));
}
#[test]
fn decimal_to_string() {
assert_eq!(Decimal::zero().to_string(), "0");
assert_eq!(Decimal::one().to_string(), "1");
assert_eq!(Decimal::percent(500).to_string(), "5");
assert_eq!(Decimal::percent(125).to_string(), "1.25");
assert_eq!(Decimal::percent(42638).to_string(), "426.38");
assert_eq!(Decimal::percent(1).to_string(), "0.01");
assert_eq!(Decimal::permille(987).to_string(), "0.987");
assert_eq!(Decimal(1).to_string(), "0.000000000000000001");
assert_eq!(Decimal(10).to_string(), "0.00000000000000001");
assert_eq!(Decimal(100).to_string(), "0.0000000000000001");
assert_eq!(Decimal(1000).to_string(), "0.000000000000001");
assert_eq!(Decimal(10000).to_string(), "0.00000000000001");
assert_eq!(Decimal(100000).to_string(), "0.0000000000001");
assert_eq!(Decimal(1000000).to_string(), "0.000000000001");
assert_eq!(Decimal(10000000).to_string(), "0.00000000001");
assert_eq!(Decimal(100000000).to_string(), "0.0000000001");
assert_eq!(Decimal(1000000000).to_string(), "0.000000001");
assert_eq!(Decimal(10000000000).to_string(), "0.00000001");
assert_eq!(Decimal(100000000000).to_string(), "0.0000001");
assert_eq!(Decimal(10000000000000).to_string(), "0.00001");
assert_eq!(Decimal(100000000000000).to_string(), "0.0001");
assert_eq!(Decimal(1000000000000000).to_string(), "0.001");
assert_eq!(Decimal(10000000000000000).to_string(), "0.01");
assert_eq!(Decimal(100000000000000000).to_string(), "0.1");
}
#[test]
fn decimal_serialize() {
assert_eq!(to_vec(&Decimal::zero()).unwrap(), br#""0""#);
assert_eq!(to_vec(&Decimal::one()).unwrap(), br#""1""#);
assert_eq!(to_vec(&Decimal::percent(8)).unwrap(), br#""0.08""#);
assert_eq!(to_vec(&Decimal::percent(87)).unwrap(), br#""0.87""#);
assert_eq!(to_vec(&Decimal::percent(876)).unwrap(), br#""8.76""#);
assert_eq!(to_vec(&Decimal::percent(8765)).unwrap(), br#""87.65""#);
}
#[test]
fn decimal_deserialize() {
assert_eq!(from_slice::<Decimal>(br#""0""#).unwrap(), Decimal::zero());
assert_eq!(from_slice::<Decimal>(br#""1""#).unwrap(), Decimal::one());
assert_eq!(from_slice::<Decimal>(br#""000""#).unwrap(), Decimal::zero());
assert_eq!(from_slice::<Decimal>(br#""001""#).unwrap(), Decimal::one());
assert_eq!(
from_slice::<Decimal>(br#""0.08""#).unwrap(),
Decimal::percent(8)
);
assert_eq!(
from_slice::<Decimal>(br#""0.87""#).unwrap(),
Decimal::percent(87)
);
assert_eq!(
from_slice::<Decimal>(br#""8.76""#).unwrap(),
Decimal::percent(876)
);
assert_eq!(
from_slice::<Decimal>(br#""87.65""#).unwrap(),
Decimal::percent(8765)
);
}
}