rbdc_mysql/protocol/statement/
row.rs

1use bytes::{Buf, Bytes};
2
3use crate::io::MySqlBufExt;
4use crate::protocol::text::ColumnType;
5use crate::protocol::Row;
6use crate::result_set::MySqlColumn;
7use rbdc::io::{BufExt, Decode};
8use rbdc::{err_protocol, Error};
9
10// https://dev.mysql.com/doc/internals/en/binary-protocol-resultset-row.html#packet-ProtocolBinary::ResultsetRow
11// https://dev.mysql.com/doc/internals/en/binary-protocol-value.html
12
13#[derive(Debug)]
14pub struct BinaryRow(pub Row);
15
16impl<'de> Decode<'de, &'de [MySqlColumn]> for BinaryRow {
17    fn decode_with(mut buf: Bytes, columns: &'de [MySqlColumn]) -> Result<Self, Error> {
18        let header = buf.get_u8();
19        if header != 0 {
20            return Err(err_protocol!(
21                "exepcted 0x00 (ROW) but found 0x{:02x}",
22                header
23            ));
24        }
25
26        let storage = buf.clone();
27        let offset = buf.len();
28
29        let null_bitmap_len = (columns.len() + 9) / 8;
30        if buf.len() < null_bitmap_len {
31            return Err(err_protocol!(
32                "binary row: null-bitmap length {} exceeds remaining {} bytes",
33                null_bitmap_len,
34                buf.len()
35            ));
36        }
37        let null_bitmap = buf.get_bytes(null_bitmap_len);
38
39        let mut values = Vec::with_capacity(columns.len());
40
41        for (column_idx, column) in columns.iter().enumerate() {
42            // NOTE: the column index starts at the 3rd bit
43            let column_null_idx = column_idx + 2;
44            let is_null =
45                null_bitmap[column_null_idx / 8] & (1 << (column_null_idx % 8) as u8) != 0;
46
47            if is_null {
48                values.push(None);
49                continue;
50            }
51
52            // NOTE: MySQL will never generate NULL types for non-NULL values
53            let type_info = &column.type_info;
54
55            let size: usize = match type_info.r#type {
56                ColumnType::String
57                | ColumnType::VarChar
58                | ColumnType::VarString
59                | ColumnType::Enum
60                | ColumnType::Set
61                | ColumnType::LongBlob
62                | ColumnType::MediumBlob
63                | ColumnType::Blob
64                | ColumnType::TinyBlob
65                | ColumnType::Geometry
66                | ColumnType::Bit
67                | ColumnType::Decimal
68                | ColumnType::Json
69                | ColumnType::NewDecimal => buf.get_uint_lenenc() as usize,
70
71                ColumnType::LongLong => 8,
72                ColumnType::Long | ColumnType::Int24 => 4,
73                ColumnType::Short | ColumnType::Year => 2,
74                ColumnType::Tiny => 1,
75                ColumnType::Float => 4,
76                ColumnType::Double => 8,
77
78                ColumnType::Time
79                | ColumnType::Timestamp
80                | ColumnType::Date
81                | ColumnType::Datetime => {
82                    // The size of this type is important for decoding
83                    if buf.is_empty() { return Err(err_protocol!("binary row: expected temporal length byte, found empty buffer")); }
84                    buf[0] as usize + 1
85                }
86
87                // NOTE: MySQL will never generate NULL types for non-NULL values
88                ColumnType::Null => unreachable!(),
89            };
90
91            if size > buf.len() {
92                return Err(err_protocol!(
93                    "binary row column length {} exceeds remaining {} bytes",
94                    size,
95                    buf.len()
96                ));
97            }
98
99            let offset = offset - buf.len();
100
101            values.push(Some(offset..(offset + size)));
102
103            buf.advance(size);
104        }
105        Ok(BinaryRow(Row::from((values, storage.to_vec()))))
106    }
107}
rbdc_mysql/protocol/statement/row.rs

rbdc_mysql/protocol/statement/
row.rs
