zero_mysql/
buffer.rs

1/// A set of reusable buffers for MySQL protocol communication
2///
3/// `Conn` uses a single `BufferSet` for all its operations.
4#[derive(Debug)]
5pub struct BufferSet {
6    /// Bytes are valid during Conn.
7    pub initial_handshake: Vec<u8>,
8
9    /// General-purpose read buffer
10    /// Bytes are valid during an operation.
11    pub read_buffer: Vec<u8>,
12
13    /// General-purpose write buffer
14    /// It always has at least 4 bytes which is reserved for the first packet header.
15    /// It is followed by payload bytes without considering 16MB split.
16    /// Layout: [4-byte header space][payload that is possibly larger than 16MB]
17    /// Bytes are valid during an operation.
18    pub write_buffer: Vec<u8>,
19
20    /// ColumnDefinition packets in one buffer
21    /// Bytes are valid during an operation.
22    pub column_definition_buffer: Vec<u8>,
23}
24
25impl BufferSet {
26    /// Create a new empty buffer set
27    pub fn new() -> Self {
28        Self {
29            initial_handshake: Vec::new(),
30            read_buffer: Vec::new(),
31            write_buffer: vec![0; 4],
32            column_definition_buffer: Vec::new(),
33        }
34    }
35
36    /// Create a new buffer set with the initial handshake packet
37    pub fn with_initial_handshake(initial_handshake: Vec<u8>) -> Self {
38        Self {
39            initial_handshake,
40            read_buffer: Vec::new(),
41            write_buffer: vec![0; 4],
42            column_definition_buffer: Vec::new(),
43        }
44    }
45
46    /// Clear the write buffer, reserve 4 bytes for the header, and return mutable access.
47    #[inline]
48    pub fn new_write_buffer(&mut self) -> &mut Vec<u8> {
49        self.write_buffer.clear();
50        self.write_buffer.extend_from_slice(&[0_u8; 4]);
51        &mut self.write_buffer
52    }
53
54    /// Get mutable access to the write buffer.
55    #[inline]
56    pub fn write_buffer_mut(&mut self) -> &mut Vec<u8> {
57        &mut self.write_buffer
58    }
59
60    /// Get the write buffer for reading.
61    #[inline]
62    pub fn write_buffer(&self) -> &[u8] {
63        &self.write_buffer
64    }
65
66    /// Get the payload length (total buffer length minus 4-byte header).
67    #[inline]
68    pub fn payload_len(&self) -> usize {
69        self.write_buffer.len().saturating_sub(4)
70    }
71}
72
73impl Default for BufferSet {
74    fn default() -> Self {
75        Self::new()
76    }
77}
zero_mysql/buffer.rs

zero_mysql/
buffer.rs
