lb_rs/model/
wire.rs

1use serde::Serialize;
2use serde::de::DeserializeOwned;
3
4/// Header used by both client and server to negotiate body encoding.
5pub const WIRE_FORMAT_HEADER: &str = "X-Lockbook-Wire-Format";
6
7#[derive(Debug, Clone, Copy, PartialEq, Eq)]
8pub enum WireFormat {
9    Json,
10    Bincode,
11}
12
13impl WireFormat {
14    pub const CLIENT_DEFAULT: Self = WireFormat::Bincode;
15
16    pub fn as_str(self) -> &'static str {
17        match self {
18            WireFormat::Json => "json",
19            WireFormat::Bincode => "bincode",
20        }
21    }
22
23    pub fn from_header(value: Option<&str>) -> Self {
24        match value.map(|v| v.trim()) {
25            Some(v) if v.eq_ignore_ascii_case("bincode") => WireFormat::Bincode,
26            _ => WireFormat::Json,
27        }
28    }
29
30    pub fn serialize<T: Serialize + ?Sized>(self, value: &T) -> Result<Vec<u8>, WireError> {
31        match self {
32            WireFormat::Json => {
33                serde_json::to_vec(value).map_err(|e| WireError::Serialize(e.to_string()))
34            }
35            WireFormat::Bincode => {
36                bincode::serialize(value).map_err(|e| WireError::Serialize(e.to_string()))
37            }
38        }
39    }
40
41    pub fn deserialize<T: DeserializeOwned>(self, bytes: &[u8]) -> Result<T, WireError> {
42        match self {
43            WireFormat::Json => {
44                serde_json::from_slice(bytes).map_err(|e| WireError::Deserialize(e.to_string()))
45            }
46            WireFormat::Bincode => {
47                bincode::deserialize(bytes).map_err(|e| WireError::Deserialize(e.to_string()))
48            }
49        }
50    }
51}
52
53#[derive(Debug)]
54pub enum WireError {
55    Serialize(String),
56    Deserialize(String),
57}
58
59impl std::fmt::Display for WireError {
60    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
61        match self {
62            WireError::Serialize(e) => write!(f, "serialize: {e}"),
63            WireError::Deserialize(e) => write!(f, "deserialize: {e}"),
64        }
65    }
66}
67
68impl std::error::Error for WireError {}
69
70#[cfg(test)]
71mod tests {
72    use super::*;
73
74    #[test]
75    fn from_header_handles_common_inputs() {
76        assert_eq!(WireFormat::from_header(None), WireFormat::Json);
77        assert_eq!(WireFormat::from_header(Some("")), WireFormat::Json);
78        assert_eq!(WireFormat::from_header(Some("json")), WireFormat::Json);
79        assert_eq!(WireFormat::from_header(Some("bincode")), WireFormat::Bincode);
80        assert_eq!(WireFormat::from_header(Some("BINCODE")), WireFormat::Bincode);
81        assert_eq!(WireFormat::from_header(Some(" bincode ")), WireFormat::Bincode);
82        // Unknown values fall back to JSON.
83        assert_eq!(WireFormat::from_header(Some("msgpack")), WireFormat::Json);
84    }
85
86    #[test]
87    fn roundtrip_byte_heavy_payload() {
88        #[derive(serde::Serialize, serde::Deserialize, Debug, PartialEq, Eq)]
89        struct Doc {
90            #[serde(with = "serde_bytes")]
91            bytes: Vec<u8>,
92        }
93
94        let doc = Doc { bytes: vec![0u8, 1, 2, 200, 255] };
95
96        for fmt in [WireFormat::Json, WireFormat::Bincode] {
97            let encoded = fmt.serialize(&doc).unwrap();
98            let decoded: Doc = fmt.deserialize(&encoded).unwrap();
99            assert_eq!(doc, decoded, "{fmt:?} roundtrip mismatch");
100        }
101    }
102
103    #[test]
104    fn bincode_is_more_compact_for_bytes_than_json() {
105        #[derive(serde::Serialize, serde::Deserialize)]
106        struct Doc {
107            #[serde(with = "serde_bytes")]
108            bytes: Vec<u8>,
109        }
110
111        let doc = Doc { bytes: (0u8..=255).collect() };
112        let json_len = WireFormat::Json.serialize(&doc).unwrap().len();
113        let bincode_len = WireFormat::Bincode.serialize(&doc).unwrap().len();
114        assert!(
115            bincode_len * 3 < json_len,
116            "bincode={bincode_len} json={json_len} — bincode should be much smaller"
117        );
118    }
119}
lb_rs/model/wire.rs

lb_rs/model/
wire.rs
