use reifydb_core::value::column::{Column, columns::Columns, data::ColumnData};
use reifydb_type::value::r#type::Type;
use crate::function::{Function, FunctionCapability, FunctionContext, FunctionInfo, error::FunctionError};
pub struct Lcm {
info: FunctionInfo,
}
impl Default for Lcm {
fn default() -> Self {
Self::new()
}
}
impl Lcm {
pub fn new() -> Self {
Self {
info: FunctionInfo::new("math::lcm"),
}
}
}
fn numeric_to_i64(data: &ColumnData, i: usize) -> Option<i64> {
match data {
ColumnData::Int1(c) => c.get(i).map(|&v| v as i64),
ColumnData::Int2(c) => c.get(i).map(|&v| v as i64),
ColumnData::Int4(c) => c.get(i).map(|&v| v as i64),
ColumnData::Int8(c) => c.get(i).copied(),
ColumnData::Int16(c) => c.get(i).map(|&v| v as i64),
ColumnData::Uint1(c) => c.get(i).map(|&v| v as i64),
ColumnData::Uint2(c) => c.get(i).map(|&v| v as i64),
ColumnData::Uint4(c) => c.get(i).map(|&v| v as i64),
ColumnData::Uint8(c) => c.get(i).map(|&v| v as i64),
_ => None,
}
}
fn compute_gcd(mut a: i64, mut b: i64) -> i64 {
a = a.abs();
b = b.abs();
while b != 0 {
let t = b;
b = a % b;
a = t;
}
a
}
fn compute_lcm(a: i64, b: i64) -> i64 {
if a == 0 || b == 0 {
return 0;
}
(a.abs() / compute_gcd(a, b)) * b.abs()
}
impl Function for Lcm {
fn info(&self) -> &FunctionInfo {
&self.info
}
fn capabilities(&self) -> &[FunctionCapability] {
&[FunctionCapability::Scalar]
}
fn return_type(&self, _input_types: &[Type]) -> Type {
Type::Int8
}
fn execute(&self, ctx: &FunctionContext, args: &Columns) -> Result<Columns, FunctionError> {
if args.len() != 2 {
return Err(FunctionError::ArityMismatch {
function: ctx.fragment.clone(),
expected: 2,
actual: args.len(),
});
}
let a_col = &args[0];
let b_col = &args[1];
let (a_data, a_bitvec) = a_col.data().unwrap_option();
let (b_data, b_bitvec) = b_col.data().unwrap_option();
let row_count = a_data.len();
let expected_types = vec![
Type::Int1,
Type::Int2,
Type::Int4,
Type::Int8,
Type::Uint1,
Type::Uint2,
Type::Uint4,
Type::Uint8,
];
if !a_data.get_type().is_number() {
return Err(FunctionError::InvalidArgumentType {
function: ctx.fragment.clone(),
argument_index: 0,
expected: expected_types,
actual: a_data.get_type(),
});
}
if !b_data.get_type().is_number() {
return Err(FunctionError::InvalidArgumentType {
function: ctx.fragment.clone(),
argument_index: 1,
expected: expected_types,
actual: b_data.get_type(),
});
}
let mut result = Vec::with_capacity(row_count);
let mut res_bitvec = Vec::with_capacity(row_count);
for i in 0..row_count {
match (numeric_to_i64(a_data, i), numeric_to_i64(b_data, i)) {
(Some(a), Some(b)) => {
result.push(compute_lcm(a, b));
res_bitvec.push(true);
}
_ => {
result.push(0);
res_bitvec.push(false);
}
}
}
let result_data = ColumnData::int8_with_bitvec(result, res_bitvec);
let combined_bitvec = match (a_bitvec, b_bitvec) {
(Some(a), Some(b)) => Some(a.and(b)),
(Some(a), None) => Some(a.clone()),
(None, Some(b)) => Some(b.clone()),
(None, None) => None,
};
let final_data = if let Some(bv) = combined_bitvec {
ColumnData::Option {
inner: Box::new(result_data),
bitvec: bv,
}
} else {
result_data
};
Ok(Columns::new(vec![Column::new(ctx.fragment.clone(), final_data)]))
}
}