tds-driver 0.2.0

A TDS (Microsoft SQL Server) driver for 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
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112

use crate::{sql_read_bytes::SqlReadBytes, tds::Collation, ColumnData};

pub(crate) async fn decode<R>(
    src: &mut R,
    collation: Option<Collation>,
) -> crate::Result<ColumnData<'static>>
where
    R: SqlReadBytes + Unpin,
{
    let ptr_len = src.read_u8().await? as usize;

    if ptr_len == 0 {
        return Ok(ColumnData::String(None));
    }

    super::plp::read_bytes(src, ptr_len).await?;

    src.read_i32_le().await?; // days
    src.read_u32_le().await?; // second fractions

    let text_len = src.read_u32_le().await? as usize;
    let buf = super::plp::read_bytes(src, text_len).await?;

    let text = match collation {
        // TEXT
        Some(collation) => super::string::decode_varchar(buf, &collation)?,
        // NTEXT
        None => super::string::decode_nchar(&buf)?,
    };

    Ok(ColumnData::String(Some(text.into())))
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::sql_read_bytes::test_utils::IntoSqlReadBytes;
    use bytes::{BufMut, BytesMut};

    #[tokio::test]
    async fn decode_null_when_ptr_len_zero() {
        let mut buf = BytesMut::new();
        buf.put_u8(0);

        let data = decode(&mut buf.into_sql_read_bytes(), None).await.unwrap();
        assert_eq!(data, ColumnData::String(None));
    }

    #[tokio::test]
    async fn decode_ntext_reads_utf16_payload() {
        let mut buf = BytesMut::new();
        buf.put_u8(1); // ptr_len
        buf.put_u8(0xAA); // pointer byte (ignored)
        buf.put_i32_le(0); // days
        buf.put_u32_le(0); // second fractions
        buf.put_u32_le(4); // byte length of the UTF-16 text (2 chars)
        buf.put_u16_le('h' as u16);
        buf.put_u16_le('i' as u16);

        let data = decode(&mut buf.into_sql_read_bytes(), None).await.unwrap();
        assert_eq!(data, ColumnData::String(Some("hi".into())));
    }

    /// As nvarchar: the trailing byte used to be dropped.
    #[tokio::test]
    async fn decode_ntext_of_odd_length_is_an_error() {
        let mut buf = BytesMut::new();
        buf.put_u8(1);
        buf.put_u8(0xAA);
        buf.put_i32_le(0);
        buf.put_u32_le(0);
        buf.put_u32_le(3);
        buf.put_slice(&[b'h', 0, b'i']);

        let res = decode(&mut buf.into_sql_read_bytes(), None).await;
        assert!(matches!(res, Err(crate::Error::Protocol(_))), "{res:?}");
    }

    #[tokio::test]
    async fn decode_text_with_an_invalid_sequence_is_lossy() {
        let mut buf = BytesMut::new();
        buf.put_u8(1);
        buf.put_u8(0xAA);
        buf.put_i32_le(0);
        buf.put_u32_le(0);
        buf.put_u32_le(3);
        buf.put_slice(&[b'A', 0x82, 0x20]);

        let collation = crate::tds::Collation::new(0x0411, 0); // Japanese_CI_AS
        let data = decode(&mut buf.into_sql_read_bytes(), Some(collation))
            .await
            .unwrap();
        assert_eq!(data, ColumnData::String(Some("A\u{FFFD} ".into())));
    }

    #[tokio::test]
    async fn decode_text_uses_collation_encoding() {
        let mut buf = BytesMut::new();
        buf.put_u8(1); // ptr_len
        buf.put_u8(0xAA);
        buf.put_i32_le(0);
        buf.put_u32_le(0);
        buf.put_u32_le(2); // 2 raw bytes in codepage encoding
        buf.put_slice(b"hi");

        let collation = crate::tds::Collation::new(0x0409, 0); // WINDOWS_1252
        let data = decode(&mut buf.into_sql_read_bytes(), Some(collation))
            .await
            .unwrap();
        assert_eq!(data, ColumnData::String(Some("hi".into())));
    }
}