clickhouse/compression/
mod.rs

1#[cfg(feature = "lz4")]
2pub(crate) mod lz4;
3#[cfg(feature = "zstd")]
4pub(crate) mod zstd;
5
6#[derive(Debug, Clone, Copy, PartialEq, Eq)]
7#[non_exhaustive]
8pub enum Compression {
9    /// Disables any compression.
10    /// Used by default if no compression feature is enabled.
11    None,
12    /// Uses `LZ4` codec to (de)compress.
13    /// Used by default if the `lz4` feature is enabled.
14    #[cfg(feature = "lz4")]
15    Lz4,
16    /// Uses `LZ4HC` codec to compress and `LZ4` to decompress.
17    /// High compression levels are useful in networks with low bandwidth.
18    /// Affects only `INSERT`s, because others are compressed by the server.
19    /// Possible levels: `[1, 12]`. Recommended level range: `[4, 9]`.
20    ///
21    /// Deprecated: `lz4_flex` doesn't support HC mode yet: [lz4_flex#165].
22    ///
23    /// [lz4_flex#165]: https://github.com/PSeitz/lz4_flex/issues/165
24    #[cfg(feature = "lz4")]
25    #[deprecated(note = "use `Compression::Lz4` instead")]
26    Lz4Hc(i32),
27    /// Uses `ZSTD` codec to (de)compress.
28    /// Used by default if the `zstd` feature is enabled and `lz4` is not.
29    /// The `i32` parameter specifies the compression level.
30    /// Use [`Compression::zstd()`] for the default level.
31    ///
32    /// **Note:** Extremely high compression levels (e.g. above 19) are very
33    /// CPU-intensive and likely unsuitable for real-time networked
34    /// applications. They can also block the async executor for a
35    /// significant amount of time. Prefer moderate levels for online usage.
36    #[cfg(feature = "zstd")]
37    Zstd(i32),
38}
39
40impl Default for Compression {
41    #[cfg(all(not(feature = "test-util"), feature = "lz4"))]
42    #[inline]
43    fn default() -> Self {
44        Compression::Lz4
45    }
46
47    #[cfg(all(not(feature = "test-util"), not(feature = "lz4"), feature = "zstd"))]
48    #[inline]
49    fn default() -> Self {
50        Compression::zstd()
51    }
52
53    #[cfg(any(feature = "test-util", not(any(feature = "lz4", feature = "zstd"))))]
54    #[inline]
55    fn default() -> Self {
56        Compression::None
57    }
58}
59
60impl Compression {
61    /// Creates a `Zstd` compression with the default level.
62    #[cfg(feature = "zstd")]
63    pub fn zstd() -> Self {
64        Compression::Zstd(::zstd::DEFAULT_COMPRESSION_LEVEL)
65    }
66
67    pub(crate) fn is_enabled(&self) -> bool {
68        *self != Compression::None
69    }
70}
clickhouse/compression/mod.rs

clickhouse/compression/
mod.rs
