lsm_tree/
compression.rs

1// Copyright (c) 2024-present, fjall-rs
2// This source code is licensed under both the Apache 2.0 and MIT License
3// (found in the LICENSE-* files in the repository)
4
5use crate::coding::{Decode, DecodeError, Encode, EncodeError};
6use byteorder::{ReadBytesExt, WriteBytesExt};
7use std::io::{Read, Write};
8
9/// Compression algorithm to use
10#[derive(Copy, Clone, Debug, Eq, PartialEq)]
11#[allow(clippy::module_name_repetitions)]
12pub enum CompressionType {
13    /// No compression
14    ///
15    /// Not recommended.
16    None,
17
18    /// LZ4 compression
19    ///
20    /// Recommended for use cases with a focus
21    /// on speed over compression ratio.
22    #[cfg(feature = "lz4")]
23    Lz4,
24}
25
26impl Encode for CompressionType {
27    fn encode_into<W: Write>(&self, writer: &mut W) -> Result<(), EncodeError> {
28        match self {
29            Self::None => {
30                writer.write_u8(0)?;
31            }
32
33            #[cfg(feature = "lz4")]
34            Self::Lz4 => {
35                writer.write_u8(1)?;
36            }
37        }
38
39        Ok(())
40    }
41}
42
43impl Decode for CompressionType {
44    fn decode_from<R: Read>(reader: &mut R) -> Result<Self, DecodeError> {
45        let tag = reader.read_u8()?;
46
47        match tag {
48            0 => Ok(Self::None),
49
50            #[cfg(feature = "lz4")]
51            1 => Ok(Self::Lz4),
52
53            tag => Err(DecodeError::InvalidTag(("CompressionType", tag))),
54        }
55    }
56}
57
58impl std::fmt::Display for CompressionType {
59    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
60        write!(
61            f,
62            "{}",
63            match self {
64                Self::None => "none",
65
66                #[cfg(feature = "lz4")]
67                Self::Lz4 => "lz4",
68            }
69        )
70    }
71}
72
73#[cfg(test)]
74mod tests {
75    use super::*;
76    use test_log::test;
77
78    #[test]
79    fn compression_serialize_none() {
80        let serialized = CompressionType::None.encode_into_vec();
81        assert_eq!(1, serialized.len());
82    }
83
84    #[cfg(feature = "lz4")]
85    mod lz4 {
86        use super::*;
87        use test_log::test;
88
89        #[test]
90        fn compression_serialize_none() {
91            let serialized = CompressionType::Lz4.encode_into_vec();
92            assert_eq!(1, serialized.len());
93        }
94    }
95}
lsm_tree/compression.rs

lsm_tree/
compression.rs
