cdrs-tokio 9.0.2

Async Cassandra DB driver written in Rust
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63

use cassandra_protocol::compression::Compression;
use cassandra_protocol::frame::frame_decoder::{
    FrameDecoder, LegacyFrameDecoder, Lz4FrameDecoder, UncompressedFrameDecoder,
};
use cassandra_protocol::frame::frame_encoder::{
    FrameEncoder, LegacyFrameEncoder, Lz4FrameEncoder, UncompressedFrameEncoder,
};
use cassandra_protocol::frame::Version;

/// A factory for frame encoder/decoder.
pub trait FrameEncodingFactory {
    /// Creates a new frame encoder based on given protocol settings.
    fn create_encoder(
        &self,
        version: Version,
        compression: Compression,
    ) -> Box<dyn FrameEncoder + Send + Sync>;

    /// Creates a new frame decoder based on given protocol settings.
    fn create_decoder(
        &self,
        version: Version,
        compression: Compression,
    ) -> Box<dyn FrameDecoder + Send + Sync>;
}

/// Frame encoding factor based on protocol settings.
#[derive(Copy, Clone, Debug, Default, Ord, PartialOrd, Eq, PartialEq, Hash)]
pub struct ProtocolFrameEncodingFactory;

impl FrameEncodingFactory for ProtocolFrameEncodingFactory {
    fn create_encoder(
        &self,
        version: Version,
        compression: Compression,
    ) -> Box<dyn FrameEncoder + Send + Sync> {
        if version >= Version::V5 {
            match compression {
                Compression::Lz4 => Box::<Lz4FrameEncoder>::default(),
                // >= v5 supports only lz4 => fall back to uncompressed
                _ => Box::<UncompressedFrameEncoder>::default(),
            }
        } else {
            Box::<LegacyFrameEncoder>::default()
        }
    }

    fn create_decoder(
        &self,
        version: Version,
        compression: Compression,
    ) -> Box<dyn FrameDecoder + Send + Sync> {
        if version >= Version::V5 {
            match compression {
                Compression::Lz4 => Box::<Lz4FrameDecoder>::default(),
                // >= v5 supports only lz4 => fall back to uncompressed
                _ => Box::<UncompressedFrameDecoder>::default(),
            }
        } else {
            Box::<LegacyFrameDecoder>::default()
        }
    }
}