brk_vecs 0.0.85

A KISS index/value store
Documentation 
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use std::{fs, io, path::Path};

use serde_derive::{Deserialize, Serialize};

use crate::{Error, Result};

#[derive(Default, Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Serialize, Deserialize)]
pub enum Format {
    Compressed,
    #[default]
    Raw,
}

impl Format {
    pub fn write(&self, path: &Path) -> Result<(), io::Error> {
        fs::write(path, self.as_bytes())
    }

    pub fn is_raw(&self) -> bool {
        *self == Self::Raw
    }

    pub fn is_compressed(&self) -> bool {
        *self == Self::Compressed
    }

    fn as_bytes(&self) -> Vec<u8> {
        if self.is_compressed() {
            vec![1]
        } else {
            vec![0]
        }
    }

    fn from_bytes(bytes: &[u8]) -> Self {
        if bytes.len() != 1 {
            panic!();
        }
        if bytes[0] == 1 {
            Self::Compressed
        } else if bytes[0] == 0 {
            Self::Raw
        } else {
            panic!()
        }
    }

    pub fn validate(&self, path: &Path) -> Result<()> {
        if let Ok(prev_compressed) = Format::try_from(path)
            && prev_compressed != *self
        {
            return Err(Error::DifferentCompressionMode);
        }

        Ok(())
    }
}

impl TryFrom<&Path> for Format {
    type Error = Error;
    fn try_from(value: &Path) -> Result<Self, Self::Error> {
        Ok(Self::from_bytes(&fs::read(value)?))
    }
}