1use std::fmt;
  2
  3use poulpy_hal::{
  4    api::ZnFillUniform,
  5    layouts::{Backend, Data, DataMut, DataRef, FillUniform, Module, ReaderFrom, WriterTo, Zn, ZnxInfos, ZnxView, ZnxViewMut},
  6    source::Source,
  7};
  8
  9use crate::layouts::{Base2K, Degree, LWECiphertext, LWEInfos, TorusPrecision, compressed::Decompress};
 10
 11#[derive(PartialEq, Eq, Clone)]
 12pub struct LWECiphertextCompressed<D: Data> {
 13    pub(crate) data: Zn<D>,
 14    pub(crate) k: TorusPrecision,
 15    pub(crate) base2k: Base2K,
 16    pub(crate) seed: [u8; 32],
 17}
 18
 19impl<D: Data> LWEInfos for LWECiphertextCompressed<D> {
 20    fn base2k(&self) -> Base2K {
 21        self.base2k
 22    }
 23
 24    fn k(&self) -> TorusPrecision {
 25        self.k
 26    }
 27
 28    fn n(&self) -> Degree {
 29        Degree(self.data.n() as u32)
 30    }
 31
 32    fn size(&self) -> usize {
 33        self.data.size()
 34    }
 35}
 36
 37impl<D: DataRef> fmt::Debug for LWECiphertextCompressed<D> {
 38    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
 39        write!(f, "{self}")
 40    }
 41}
 42
 43impl<D: DataRef> fmt::Display for LWECiphertextCompressed<D> {
 44    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
 45        write!(
 46            f,
 47            "LWECiphertextCompressed: base2k={} k={} seed={:?}: {}",
 48            self.base2k(),
 49            self.k(),
 50            self.seed,
 51            self.data
 52        )
 53    }
 54}
 55
 56impl<D: DataMut> FillUniform for LWECiphertextCompressed<D> {
 57    fn fill_uniform(&mut self, log_bound: usize, source: &mut Source) {
 58        self.data.fill_uniform(log_bound, source);
 59    }
 60}
 61
 62impl LWECiphertextCompressed<Vec<u8>> {
 63    pub fn alloc<A>(infos: &A) -> Self
 64    where
 65        A: LWEInfos,
 66    {
 67        Self::alloc_with(infos.base2k(), infos.k())
 68    }
 69
 70    pub fn alloc_with(base2k: Base2K, k: TorusPrecision) -> Self {
 71        Self {
 72            data: Zn::alloc(1, 1, k.0.div_ceil(base2k.0) as usize),
 73            k,
 74            base2k,
 75            seed: [0u8; 32],
 76        }
 77    }
 78
 79    pub fn alloc_bytes<A>(infos: &A) -> usize
 80    where
 81        A: LWEInfos,
 82    {
 83        Self::alloc_bytes_with(infos.base2k(), infos.k())
 84    }
 85
 86    pub fn alloc_bytes_with(base2k: Base2K, k: TorusPrecision) -> usize {
 87        Zn::alloc_bytes(1, 1, k.0.div_ceil(base2k.0) as usize)
 88    }
 89}
 90
 91use byteorder::{LittleEndian, ReadBytesExt, WriteBytesExt};
 92
 93impl<D: DataMut> ReaderFrom for LWECiphertextCompressed<D> {
 94    fn read_from<R: std::io::Read>(&mut self, reader: &mut R) -> std::io::Result<()> {
 95        self.k = TorusPrecision(reader.read_u32::<LittleEndian>()?);
 96        self.base2k = Base2K(reader.read_u32::<LittleEndian>()?);
 97        reader.read_exact(&mut self.seed)?;
 98        self.data.read_from(reader)
 99    }
100}
101
102impl<D: DataRef> WriterTo for LWECiphertextCompressed<D> {
103    fn write_to<W: std::io::Write>(&self, writer: &mut W) -> std::io::Result<()> {
104        writer.write_u32::<LittleEndian>(self.k.into())?;
105        writer.write_u32::<LittleEndian>(self.base2k.into())?;
106        writer.write_all(&self.seed)?;
107        self.data.write_to(writer)
108    }
109}
110
111impl<D: DataMut, B: Backend, DR: DataRef> Decompress<B, LWECiphertextCompressed<DR>> for LWECiphertext<D>
112where
113    Module<B>: ZnFillUniform,
114{
115    fn decompress(&mut self, module: &Module<B>, other: &LWECiphertextCompressed<DR>) {
116        debug_assert_eq!(self.size(), other.size());
117        let mut source: Source = Source::new(other.seed);
118        module.zn_fill_uniform(
119            self.n().into(),
120            other.base2k().into(),
121            &mut self.data,
122            0,
123            &mut source,
124        );
125        (0..self.size()).for_each(|i| {
126            self.data.at_mut(0, i)[0] = other.data.at(0, i)[0];
127        });
128    }
129}