zero_postgres/conversion/
bytes.rs

1//! Byte type implementations (`&[u8]`, `Vec<u8>`).
2
3use crate::error::{Error, Result};
4use crate::protocol::types::{Oid, oid};
5
6use super::{FromWireValue, ToWireValue};
7
8impl<'a> FromWireValue<'a> for &'a [u8] {
9    fn from_text(oid: Oid, bytes: &'a [u8]) -> Result<Self> {
10        if oid != oid::BYTEA {
11            return Err(Error::Decode(format!("cannot decode oid {} as bytes", oid)));
12        }
13        // Text format for bytea is hex-encoded: \x followed by hex digits
14        // For simplicity, we just return the raw bytes (caller can decode if needed)
15        Ok(bytes)
16    }
17
18    fn from_binary(oid: Oid, bytes: &'a [u8]) -> Result<Self> {
19        if oid != oid::BYTEA {
20            return Err(Error::Decode(format!("cannot decode oid {} as bytes", oid)));
21        }
22        Ok(bytes)
23    }
24}
25
26impl FromWireValue<'_> for Vec<u8> {
27    fn from_text(oid: Oid, bytes: &[u8]) -> Result<Self> {
28        if oid != oid::BYTEA {
29            return Err(Error::Decode(format!(
30                "cannot decode oid {} as Vec<u8>",
31                oid
32            )));
33        }
34        // Text format for bytea is hex-encoded: \xDEADBEEF
35        if bytes.starts_with(b"\\x") {
36            decode_hex(&bytes[2..])
37        } else {
38            // Fallback: return raw bytes
39            Ok(bytes.to_vec())
40        }
41    }
42
43    fn from_binary(oid: Oid, bytes: &[u8]) -> Result<Self> {
44        if oid != oid::BYTEA {
45            return Err(Error::Decode(format!(
46                "cannot decode oid {} as Vec<u8>",
47                oid
48            )));
49        }
50        Ok(bytes.to_vec())
51    }
52}
53
54impl ToWireValue for [u8] {
55    fn natural_oid(&self) -> Oid {
56        oid::BYTEA
57    }
58
59    fn encode(&self, target_oid: Oid, buf: &mut Vec<u8>) -> Result<()> {
60        match target_oid {
61            oid::BYTEA => {
62                buf.extend_from_slice(&(self.len() as i32).to_be_bytes());
63                buf.extend_from_slice(self);
64                Ok(())
65            }
66            _ => Err(Error::type_mismatch(self.natural_oid(), target_oid)),
67        }
68    }
69}
70
71impl ToWireValue for Vec<u8> {
72    fn natural_oid(&self) -> Oid {
73        oid::BYTEA
74    }
75
76    fn encode(&self, target_oid: Oid, buf: &mut Vec<u8>) -> Result<()> {
77        self.as_slice().encode(target_oid, buf)
78    }
79}
80
81/// Decode hex string to bytes
82fn decode_hex(hex: &[u8]) -> Result<Vec<u8>> {
83    if !hex.len().is_multiple_of(2) {
84        return Err(Error::Decode("invalid hex length".into()));
85    }
86
87    let mut result = Vec::with_capacity(hex.len() >> 1);
88    for chunk in hex.chunks(2) {
89        let high = hex_digit(chunk[0])?;
90        let low = hex_digit(chunk[1])?;
91        result.push((high << 4) | low);
92    }
93    Ok(result)
94}
95
96fn hex_digit(b: u8) -> Result<u8> {
97    match b {
98        b'0'..=b'9' => Ok(b - b'0'),
99        b'a'..=b'f' => Ok(b - b'a' + 10),
100        b'A'..=b'F' => Ok(b - b'A' + 10),
101        _ => Err(Error::Decode(format!("invalid hex digit: {}", b as char))),
102    }
103}
104
105#[cfg(test)]
106mod tests {
107    use super::*;
108
109    #[test]
110    fn test_bytea_hex() {
111        assert_eq!(
112            Vec::<u8>::from_text(oid::BYTEA, b"\\xDEADBEEF").unwrap(),
113            vec![0xDE, 0xAD, 0xBE, 0xEF]
114        );
115    }
116}
zero_postgres/conversion/bytes.rs

zero_postgres/conversion/
bytes.rs
