514 lines
14 KiB
Rust
514 lines
14 KiB
Rust
/* OpenTally: Open-source election vote counting
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* Copyright © 2021 Lee Yingtong Li (RunasSudo)
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*
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* This program is free software: you can redistribute it and/or modify
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* it under the terms of the GNU Affero General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU Affero General Public License for more details.
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*
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* You should have received a copy of the GNU Affero General Public License
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* along with this program. If not, see <https://www.gnu.org/licenses/>.
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*/
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use super::{Assign, Number};
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use ibig::{IBig, ops::Abs};
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use num_traits::{Num, One, Signed, Zero};
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use std::cell::{Cell, UnsafeCell};
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use std::cmp::{Ord, Ordering, PartialEq, PartialOrd};
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use std::ops;
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use std::fmt;
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thread_local! {
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static DPS: Cell<usize> = Cell::new(5);
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static FACTOR: UnsafeCell<IBig> = UnsafeCell::new(IBig::from(10).pow(10));
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static FACTOR_CMP: UnsafeCell<IBig> = UnsafeCell::new(IBig::from(10).pow(5) / IBig::from(2));
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}
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pub fn get_dps() -> usize {
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return DPS.with(|dps_cell| dps_cell.get());
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}
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fn get_factor<'a>() -> &'a IBig {
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FACTOR.with(|factor_cell| {
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let factor_ptr = factor_cell.get();
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// SAFETY: Safe if requirements of GuardedFixed::set_dps met
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let factor_ref = unsafe { &*factor_ptr };
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return factor_ref;
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})
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}
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fn get_factor_cmp<'a>() -> &'a IBig {
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FACTOR_CMP.with(|factor_cmp_cell| {
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let factor_cmp_ptr = factor_cmp_cell.get();
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// SAFETY: Safe if requirements of Fixed::set_dps met
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let factor_cmp_ref = unsafe { &*factor_cmp_ptr };
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return factor_cmp_ref;
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})
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}
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/// Guarded fixed-point number
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#[derive(Clone, Debug, Eq)]
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pub struct GuardedFixed(IBig);
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impl GuardedFixed {
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/// Set the number of decimal places to compute results to
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///
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/// SAFETY: This must be called before, and never after, any operations on [GuardedFixed].
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pub fn set_dps(dps: usize) {
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DPS.with(|dps_cell| {
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dps_cell.set(dps);
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});
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FACTOR.with(|factor_cell| {
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let factor = IBig::from(10).pow(dps * 2);
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let factor_ptr = factor_cell.get();
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// SAFETY: Safe if requirements above met
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unsafe {
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*factor_ptr = factor;
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}
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});
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FACTOR_CMP.with(|factor_cmp_cell| {
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let factor_cmp = IBig::from(10).pow(dps) / IBig::from(2);
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let factor_cmp_ptr = factor_cmp_cell.get();
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// SAFETY: Safe if requirements above met
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unsafe {
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*factor_cmp_ptr = factor_cmp;
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}
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});
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}
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}
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impl Number for GuardedFixed {
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fn new() -> Self { Self(IBig::zero()) }
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fn describe() -> String { format!("--numbers gfixed --decimals {}", get_dps()) }
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fn pow_assign(&mut self, exponent: i32) {
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if exponent < 0 {
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todo!();
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}
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self.0 = self.0.pow(exponent as usize) * get_factor() / get_factor().pow(exponent as usize);
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}
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fn floor_mut(&mut self, dps: usize) {
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// Only do something if truncating
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if dps < get_dps() * 2 {
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let factor = IBig::from(10).pow(get_dps() * 2 - dps);
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self.0 /= &factor;
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self.0 *= factor;
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}
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}
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fn ceil_mut(&mut self, dps: usize) {
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// Only do something if truncating
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if dps < get_dps() * 2 {
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self.0 -= IBig::one();
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let factor = IBig::from(10).pow(get_dps() * 2 - dps);
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self.0 /= &factor;
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self.0 += IBig::one();
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self.0 *= factor;
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}
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}
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fn round_mut(&mut self, dps: usize) {
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// Only do something if truncating
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if dps < get_dps() * 2 {
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let mut factor = IBig::from(10).pow(get_dps() * 2 - dps);
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factor /= IBig::from(2);
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self.0 += factor;
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self.floor_mut(dps);
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}
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}
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fn parse(s: &str) -> Self {
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// Parse decimal
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if s.contains('.') {
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let (whole, decimal) = s.split_once('.').unwrap();
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let whole = match IBig::from_str_radix(whole, 10) {
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Ok(value) => value,
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Err(_) => panic!("Syntax Error"),
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} * get_factor();
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let decimal = match IBig::from_str_radix(decimal, 10) {
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Ok(value) => value,
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Err(_) => panic!("Syntax Error"),
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} * get_factor() / IBig::from(10).pow(decimal.len());
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if whole.is_negative() {
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return Self(whole - decimal);
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} else {
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return Self(whole + decimal);
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}
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}
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// Parse integer
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if let Ok(value) = Self::from_str_radix(s, 10) {
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return value;
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} else {
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panic!("Syntax Error");
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}
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}
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}
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#[test]
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fn rounding() {
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GuardedFixed::set_dps(5);
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let mut x = GuardedFixed::parse("55.550"); x.floor_mut(2); assert_eq!(x, GuardedFixed::parse("55.55"));
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let mut x = GuardedFixed::parse("55.552"); x.floor_mut(2); assert_eq!(x, GuardedFixed::parse("55.55"));
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let mut x = GuardedFixed::parse("55.555"); x.floor_mut(2); assert_eq!(x, GuardedFixed::parse("55.55"));
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let mut x = GuardedFixed::parse("55.557"); x.floor_mut(2); assert_eq!(x, GuardedFixed::parse("55.55"));
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let mut x = GuardedFixed::parse("55.550"); x.ceil_mut(2); assert_eq!(x, GuardedFixed::parse("55.55"));
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let mut x = GuardedFixed::parse("55.552"); x.ceil_mut(2); assert_eq!(x, GuardedFixed::parse("55.56"));
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let mut x = GuardedFixed::parse("55.555"); x.ceil_mut(2); assert_eq!(x, GuardedFixed::parse("55.56"));
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let mut x = GuardedFixed::parse("55.557"); x.ceil_mut(2); assert_eq!(x, GuardedFixed::parse("55.56"));
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let mut x = GuardedFixed::parse("55.550"); x.round_mut(2); assert_eq!(x, GuardedFixed::parse("55.55"));
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let mut x = GuardedFixed::parse("55.552"); x.round_mut(2); assert_eq!(x, GuardedFixed::parse("55.55"));
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let mut x = GuardedFixed::parse("55.555"); x.round_mut(2); assert_eq!(x, GuardedFixed::parse("55.56"));
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let mut x = GuardedFixed::parse("55.557"); x.round_mut(2); assert_eq!(x, GuardedFixed::parse("55.56"));
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}
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impl Num for GuardedFixed {
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type FromStrRadixErr = ibig::error::ParseError;
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fn from_str_radix(str: &str, radix: u32) -> Result<Self, Self::FromStrRadixErr> {
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match IBig::from_str_radix(str, radix) {
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Ok(value) => Ok(Self(value * get_factor())),
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Err(err) => Err(err)
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}
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}
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}
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impl PartialEq for GuardedFixed {
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fn eq(&self, other: &Self) -> bool {
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if &(&self.0 - &other.0).abs() < get_factor_cmp() {
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return true;
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} else {
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return false;
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}
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}
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}
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impl PartialOrd for GuardedFixed {
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fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
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return Some(self.cmp(other));
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}
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}
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impl Ord for GuardedFixed {
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fn cmp(&self, other: &Self) -> Ordering {
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if self.eq(other) {
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return Ordering::Equal;
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} else {
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return self.0.cmp(&other.0);
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}
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}
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}
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impl Assign for GuardedFixed {
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fn assign(&mut self, src: Self) { self.0 = src.0 }
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}
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impl Assign<&Self> for GuardedFixed {
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fn assign(&mut self, src: &Self) { self.0 = src.0.clone() }
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}
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#[test]
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fn assign() {
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GuardedFixed::set_dps(2);
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let a = GuardedFixed::parse("123.45");
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let b = GuardedFixed::parse("678.90");
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let mut x = a.clone(); x.assign(b.clone()); assert_eq!(x, b);
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let mut x = a.clone(); x.assign(&b); assert_eq!(x, b);
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}
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impl From<usize> for GuardedFixed {
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fn from(n: usize) -> Self { Self(IBig::from(n) * get_factor()) }
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}
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impl fmt::Display for GuardedFixed {
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fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
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let dps = match f.precision() {
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Some(precision) => if precision < get_dps() * 2 { precision } else { get_dps() * 2 },
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None => get_dps(),
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};
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let mut result;
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if dps == get_dps() * 2 {
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result = self.0.clone().abs().to_string();
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} else {
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// Rounding required
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let factor = IBig::from(10).pow(get_dps() * 2 - dps - 1);
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let mut rounded = (&self.0 / factor).abs() + IBig::from(5); // Add 5 to force round-to-nearest
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rounded /= IBig::from(10); // Remove rounding digit
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result = rounded.to_string();
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}
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//let should_add_minus = (self.0 < IBig::zero()) && result != "0";
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let should_add_minus = self.0 < IBig::zero();
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// Add leading 0s
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result = format!("{0:0>1$}", result, dps + 1);
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// Add the decimal point
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if dps > 0 {
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result.insert(result.len() - dps, '.');
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}
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// Add the sign
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if should_add_minus {
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result.insert(0, '-');
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}
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return f.write_str(&result);
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}
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}
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#[test]
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fn display_debug() {
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GuardedFixed::set_dps(2);
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let x = GuardedFixed::parse("123.4"); assert_eq!(format!("{}", x), "123.40");
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let x = GuardedFixed::parse("123.4"); assert_eq!(format!("{:?}", x), "GuardedFixed(1234000)");
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}
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impl One for GuardedFixed {
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fn one() -> Self { Self(get_factor().clone()) }
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}
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impl Zero for GuardedFixed {
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fn zero() -> Self { Self::new() }
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fn is_zero(&self) -> bool { self.0.is_zero() }
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}
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impl ops::Neg for GuardedFixed {
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type Output = Self;
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fn neg(self) -> Self::Output { Self(-self.0) }
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}
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impl ops::Add for GuardedFixed {
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type Output = Self;
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fn add(self, rhs: Self) -> Self::Output { Self(self.0 + rhs.0) }
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}
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impl ops::Sub for GuardedFixed {
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type Output = Self;
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fn sub(self, rhs: Self) -> Self::Output { Self(self.0 - rhs.0) }
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}
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impl ops::Mul for GuardedFixed {
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type Output = Self;
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fn mul(self, rhs: Self) -> Self::Output { Self(self.0 * rhs.0 / get_factor())}
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}
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impl ops::Div for GuardedFixed {
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type Output = Self;
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fn div(self, rhs: Self) -> Self::Output { Self(self.0 * get_factor() / rhs.0) }
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}
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impl ops::Rem for GuardedFixed {
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type Output = Self;
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fn rem(self, rhs: Self) -> Self::Output { Self(self.0 % rhs.0) }
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}
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#[test]
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fn arith_owned_owned() {
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GuardedFixed::set_dps(2);
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let a = GuardedFixed::parse("123.45");
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let b = GuardedFixed::parse("678.90");
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assert_eq!(a.clone() + b.clone(), GuardedFixed::parse("802.35"));
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assert_eq!(a.clone() - b.clone(), GuardedFixed::parse("-555.45"));
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assert_eq!(a.clone() * b.clone(), GuardedFixed::parse("83810.205")); // Must compare to 3 d.p.s as doesn't meet FACTOR_CMP
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assert_eq!(a.clone() / b.clone(), GuardedFixed::parse("0.18")); // Meets FACTOR_CMP so compare only 2 d.p.s
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assert_eq!(b.clone() % a.clone(), GuardedFixed::parse("61.65"));
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}
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impl ops::Add<&Self> for GuardedFixed {
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type Output = Self;
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fn add(self, rhs: &Self) -> Self::Output { Self(self.0 + &rhs.0) }
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}
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impl ops::Sub<&Self> for GuardedFixed {
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type Output = Self;
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fn sub(self, rhs: &Self) -> Self::Output { Self(self.0 - &rhs.0) }
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}
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impl ops::Mul<&Self> for GuardedFixed {
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type Output = Self;
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fn mul(self, rhs: &Self) -> Self::Output { Self(self.0 * &rhs.0 / get_factor()) }
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}
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impl ops::Div<&Self> for GuardedFixed {
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type Output = Self;
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fn div(self, rhs: &Self) -> Self::Output { Self(self.0 * get_factor() / &rhs.0) }
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}
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impl ops::Rem<&Self> for GuardedFixed {
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type Output = Self;
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fn rem(self, rhs: &Self) -> Self::Output { Self(self.0 % &rhs.0) }
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}
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#[test]
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fn arith_owned_ref() {
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GuardedFixed::set_dps(2);
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let a = GuardedFixed::parse("123.45");
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let b = GuardedFixed::parse("678.90");
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assert_eq!(a.clone() + &b, GuardedFixed::parse("802.35"));
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assert_eq!(a.clone() - &b, GuardedFixed::parse("-555.45"));
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assert_eq!(a.clone() * &b, GuardedFixed::parse("83810.205"));
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assert_eq!(a.clone() / &b, GuardedFixed::parse("0.18"));
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assert_eq!(b.clone() % &a, GuardedFixed::parse("61.65"));
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}
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impl ops::AddAssign for GuardedFixed {
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fn add_assign(&mut self, rhs: Self) { self.0 += rhs.0; }
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}
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impl ops::SubAssign for GuardedFixed {
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fn sub_assign(&mut self, rhs: Self) { self.0 -= rhs.0; }
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}
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impl ops::MulAssign for GuardedFixed {
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fn mul_assign(&mut self, rhs: Self) {
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self.0 *= rhs.0;
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self.0 /= get_factor();
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}
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}
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impl ops::DivAssign for GuardedFixed {
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fn div_assign(&mut self, rhs: Self) {
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self.0 *= get_factor();
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self.0 /= rhs.0;
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}
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}
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impl ops::RemAssign for GuardedFixed {
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fn rem_assign(&mut self, rhs: Self) { self.0 %= rhs.0; }
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}
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#[test]
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fn arithassign_owned() {
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GuardedFixed::set_dps(2);
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let a = GuardedFixed::parse("123.45");
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let b = GuardedFixed::parse("678.90");
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let mut x = a.clone(); x += b.clone(); assert_eq!(x, GuardedFixed::parse("802.35"));
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let mut x = a.clone(); x -= b.clone(); assert_eq!(x, GuardedFixed::parse("-555.45"));
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let mut x = a.clone(); x *= b.clone(); assert_eq!(x, GuardedFixed::parse("83810.205"));
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let mut x = a.clone(); x /= b.clone(); assert_eq!(x, GuardedFixed::parse("0.18"));
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let mut x = b.clone(); x %= a.clone(); assert_eq!(x, GuardedFixed::parse("61.65"));
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}
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impl ops::AddAssign<&Self> for GuardedFixed {
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fn add_assign(&mut self, rhs: &Self) { self.0 += &rhs.0; }
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}
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impl ops::SubAssign<&Self> for GuardedFixed {
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fn sub_assign(&mut self, rhs: &Self) { self.0 -= &rhs.0; }
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}
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impl ops::MulAssign<&Self> for GuardedFixed {
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fn mul_assign(&mut self, rhs: &Self) {
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self.0 *= &rhs.0;
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self.0 /= get_factor();
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}
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}
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impl ops::DivAssign<&Self> for GuardedFixed {
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fn div_assign(&mut self, rhs: &Self) {
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self.0 *= get_factor();
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self.0 /= &rhs.0;
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}
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}
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impl ops::RemAssign<&Self> for GuardedFixed {
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fn rem_assign(&mut self, rhs: &Self) { self.0 %= &rhs.0; }
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}
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#[test]
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fn arithassign_ref() {
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GuardedFixed::set_dps(2);
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let a = GuardedFixed::parse("123.45");
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let b = GuardedFixed::parse("678.90");
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let mut x = a.clone(); x += &b; assert_eq!(x, GuardedFixed::parse("802.35"));
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let mut x = a.clone(); x -= &b; assert_eq!(x, GuardedFixed::parse("-555.45"));
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let mut x = a.clone(); x *= &b; assert_eq!(x, GuardedFixed::parse("83810.205"));
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let mut x = a.clone(); x /= &b; assert_eq!(x, GuardedFixed::parse("0.18"));
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let mut x = b.clone(); x %= &a; assert_eq!(x, GuardedFixed::parse("61.65"));
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}
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impl ops::Neg for &GuardedFixed {
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type Output = GuardedFixed;
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fn neg(self) -> Self::Output { GuardedFixed(-&self.0) }
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}
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impl ops::Add<Self> for &GuardedFixed {
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type Output = GuardedFixed;
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fn add(self, rhs: Self) -> Self::Output { GuardedFixed(&self.0 + &rhs.0) }
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}
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impl ops::Sub<Self> for &GuardedFixed {
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type Output = GuardedFixed;
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fn sub(self, rhs: Self) -> Self::Output { GuardedFixed(&self.0 - &rhs.0) }
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}
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impl ops::Mul<Self> for &GuardedFixed {
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type Output = GuardedFixed;
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fn mul(self, rhs: Self) -> Self::Output { GuardedFixed(&self.0 * &rhs.0 / get_factor()) }
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}
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impl ops::Div<Self> for &GuardedFixed {
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type Output = GuardedFixed;
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fn div(self, rhs: Self) -> Self::Output { GuardedFixed(&self.0 * get_factor() / &rhs.0) }
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}
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|
|
impl ops::Rem<Self> for &GuardedFixed {
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|
type Output = GuardedFixed;
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|
fn rem(self, rhs: Self) -> Self::Output { GuardedFixed(&self.0 % &rhs.0) }
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|
}
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|
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#[test]
|
|
fn arith_ref_ref() {
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|
GuardedFixed::set_dps(2);
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|
let a = GuardedFixed::parse("123.45");
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|
let b = GuardedFixed::parse("678.90");
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|
|
|
assert_eq!(&a + &b, GuardedFixed::parse("802.35"));
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|
assert_eq!(&a - &b, GuardedFixed::parse("-555.45"));
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|
assert_eq!(&a * &b, GuardedFixed::parse("83810.205"));
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|
assert_eq!(&a / &b, GuardedFixed::parse("0.18"));
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|
assert_eq!(&b % &a, GuardedFixed::parse("61.65"));
|
|
}
|
|
|
|
/*
|
|
impl ops::Add<&&Rational> for &Rational {
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|
|
|
}
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|
|
|
impl ops::Sub<&&Rational> for &Rational {
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|
|
|
}
|
|
|
|
impl ops::Mul<&&Rational> for &Rational {
|
|
|
|
}
|
|
|
|
impl ops::Div<&&Rational> for &Rational {
|
|
|
|
}
|
|
|
|
impl ops::Rem<&&Rational> for &Rational {
|
|
|
|
}
|
|
*/
|