lindera-dictionary 3.0.7

use std::fs::File;
use std::io::{Read, Write};
use std::ops::Deref;
use std::path::Path;

#[cfg(feature = "mmap")]
use memmap2::Mmap;

use anyhow::anyhow;
use encoding_rs::Encoding;
use serde::{Deserialize, Serialize};

use crate::LinderaResult;
use crate::error::LinderaErrorKind;

use rkyv::{Archive, Deserialize as RkyvDeserialize, Serialize as RkyvSerialize};

/// Write data directly to the writer.
pub fn write_data<W: Write>(buffer: &[u8], writer: &mut W) -> LinderaResult<()> {
    writer.write_all(buffer).map_err(|err| {
        LinderaErrorKind::Io
            .with_error(err)
            .add_context("Failed to write data to output")
    })?;
    Ok(())
}

pub fn read_file(filename: &Path) -> LinderaResult<Vec<u8>> {
    let mut input_read = File::open(filename).map_err(|err| {
        LinderaErrorKind::Io
            .with_error(err)
            .add_context(format!("Failed to open file: {}", filename.display()))
    })?;
    let mut buffer = Vec::new();
    input_read.read_to_end(&mut buffer).map_err(|err| {
        LinderaErrorKind::Io.with_error(err).add_context(format!(
            "Failed to read file contents: {}",
            filename.display()
        ))
    })?;
    Ok(buffer)
}

#[cfg(feature = "mmap")]
pub fn mmap_file(filename: &Path) -> LinderaResult<Mmap> {
    let file = File::open(filename).map_err(|err| {
        LinderaErrorKind::Io.with_error(err).add_context(format!(
            "Failed to open file for memory mapping: {}",
            filename.display()
        ))
    })?;
    let mmap = unsafe { Mmap::map(&file) }.map_err(|err| {
        LinderaErrorKind::Io
            .with_error(err)
            .add_context(format!("Failed to memory map file: {}", filename.display()))
    })?;
    Ok(mmap)
}

pub fn read_file_with_encoding(filepath: &Path, encoding_name: &str) -> LinderaResult<String> {
    let encoding = Encoding::for_label_no_replacement(encoding_name.as_bytes());
    let encoding = encoding.ok_or_else(|| {
        LinderaErrorKind::Decode.with_error(anyhow!("Invalid encoding: {encoding_name}"))
    })?;

    let buffer = read_file(filepath)?;
    Ok(encoding.decode(&buffer).0.into_owned())
}

use std::sync::Arc;

#[derive(Clone)]
pub enum Data {
    Static(&'static [u8]),
    Vec(Vec<u8>),
    #[cfg(feature = "mmap")]
    Map(Arc<Mmap>),
}

impl Archive for Data {
    type Archived = rkyv::vec::ArchivedVec<u8>;
    type Resolver = rkyv::vec::VecResolver;

    fn resolve(&self, resolver: Self::Resolver, out: rkyv::Place<Self::Archived>) {
        rkyv::vec::ArchivedVec::resolve_from_slice(self.deref(), resolver, out);
    }
}

impl<S> RkyvSerialize<S> for Data
where
    S: rkyv::rancor::Fallible + rkyv::ser::Writer + rkyv::ser::Allocator + ?Sized,
{
    fn serialize(&self, serializer: &mut S) -> Result<Self::Resolver, S::Error> {
        rkyv::vec::ArchivedVec::serialize_from_slice(self.deref(), serializer)
    }
}

impl<D: rkyv::rancor::Fallible + ?Sized> RkyvDeserialize<Data, D> for rkyv::vec::ArchivedVec<u8> {
    fn deserialize(&self, _deserializer: &mut D) -> Result<Data, D::Error> {
        let mut vec = Vec::with_capacity(self.len());
        vec.extend_from_slice(self.as_slice());
        Ok(Data::Vec(vec))
    }
}

impl Deref for Data {
    type Target = [u8];
    fn deref(&self) -> &Self::Target {
        match self {
            Data::Static(s) => s,
            Data::Vec(v) => v,
            #[cfg(feature = "mmap")]
            Data::Map(m) => m,
        }
    }
}

impl From<&'static [u8]> for Data {
    fn from(s: &'static [u8]) -> Self {
        Self::Static(s)
    }
}

impl<T: Deref<Target = [u8]>> From<&'static T> for Data {
    fn from(t: &'static T) -> Self {
        Self::Static(t)
    }
}

impl From<Vec<u8>> for Data {
    fn from(v: Vec<u8>) -> Self {
        Self::Vec(v)
    }
}

#[cfg(feature = "mmap")]
impl From<Mmap> for Data {
    fn from(m: Mmap) -> Self {
        Self::Map(Arc::new(m))
    }
}

impl Serialize for Data {
    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
    where
        S: serde::Serializer,
    {
        serializer.serialize_bytes(self.deref())
    }
}

impl<'de> Deserialize<'de> for Data {
    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
    where
        D: serde::Deserializer<'de>,
    {
        let v = <Vec<u8> as serde::Deserialize>::deserialize(deserializer)?;
        Ok(Data::Vec(v))
    }
}