ironwork_rt/sql/
mod.rs

1//! The SQL runtime: values at the database boundary, the host variables they come from and go to,
2//! and EXEC SQL statements run against the session (`run`, over the executor's `SqlHost`). It
3//! reaches storage only as a byte range and a host type, so any executor can call it.
4
5mod convert;
6mod database;
7mod host;
8mod postgres;
9mod replay;
10mod run;
11
12pub use convert::{ReadError, Written, read, write};
13pub use database::{Abandoned, Answer, Call, Database, OpenCursor, Outcome, Session};
14pub use postgres::{Postgres, Stream, Tls};
15pub use replay::{Recorder, Replay};
16pub use run::{Ran, SqlHost, run};
17
18use crate::vocab::SignClause;
19
20/// A value at the database boundary.
21#[derive(Clone, Debug, PartialEq)]
22pub enum Value {
23    Null,
24    Int(i64),
25    /// The unscaled value and its decimal places.
26    Decimal { value: i128, scale: u32 },
27    Double(f64),
28    Char(String),
29    Binary(Vec<u8>),
30}
31
32impl Value {
33    /// A decimal's text, `-1234.50` for -123450 at scale 2, as recordings and backends write it.
34    pub fn decimal_text(value: i128, scale: u32) -> String {
35        let s = scale as usize;
36        let digits = format!("{:0>width$}", value.unsigned_abs(), width = s + 1);
37        let (whole, places) = digits.split_at(digits.len() - s);
38        let sign = if value < 0 { "-" } else { "" };
39        if s == 0 { format!("{sign}{whole}") } else { format!("{sign}{whole}.{places}") }
40    }
41
42    /// A decimal from its text, its scale the count of digits after the point.
43    pub fn parse_decimal(text: &str) -> Option<Value> {
44        let (negative, digits) = match text.strip_prefix('-') {
45            Some(d) => (true, d),
46            None => (false, text.strip_prefix('+').unwrap_or(text)),
47        };
48        let (whole, places) = digits.split_once('.').unwrap_or((digits, ""));
49        if whole.is_empty() || !whole.bytes().chain(places.bytes()).all(|b| b.is_ascii_digit()) {
50            return None;
51        }
52        let magnitude: i128 = format!("{whole}{places}").parse().ok()?;
53        Some(Value::Decimal { value: if negative { -magnitude } else { magnitude }, scale: places.len() as u32 })
54    }
55}
56
57/// An SQLCODE and its SQLSTATE.
58#[derive(Clone, Copy, Debug, PartialEq, Eq)]
59pub struct SqlError {
60    pub code: i32,
61    pub state: &'static str,
62}
63
64pub const NOT_ASSIGNABLE: SqlError = SqlError { code: -303, state: "42806" };
65pub const OUT_OF_RANGE: SqlError = SqlError { code: -304, state: "22003" };
66pub const NULL_WITHOUT_INDICATOR: SqlError = SqlError { code: -305, state: "22002" };
67pub const BAD_LENGTH: SqlError = SqlError { code: -311, state: "22501" };
68pub const UNCONVERTIBLE: SqlError = SqlError { code: -330, state: "22021" };
69
70/// What a host variable holds, as Db2 reads its COBOL declaration.
71#[derive(Clone, Debug, PartialEq, Eq)]
72pub enum HostType {
73    SmallInt { signed: bool },
74    Integer { signed: bool },
75    BigInt { signed: bool },
76    Decimal { digits: u32, scale: u32, signed: bool },
77    Zoned { digits: u32, scale: u32, signed: bool, sign: Option<SignClause> },
78    Real,
79    Double,
80    Char(u32),
81    VarChar(u32),
82    /// A host structure: its members' layout items and types, in order.
83    Structure(Vec<(usize, HostType)>),
84}
85
86/// A statement's identity in a recording: 32-bit FNV-1a over its canonical text.
87pub fn fingerprint(text: &str) -> u32 {
88    text.bytes().fold(0x811c_9dc5, |h, b| (h ^ u32::from(b)).wrapping_mul(0x0100_0193))
89}
90
91#[cfg(test)]
92mod tests {
93    use super::*;
94
95    #[test]
96    fn the_fingerprint_of_nothing_is_the_fnv_offset() {
97        assert_eq!(fingerprint(""), 0x811c_9dc5);
98        assert_ne!(fingerprint("COMMIT"), fingerprint("ROLLBACK"));
99    }
100}
ironwork_rt/sql/mod.rs

ironwork_rt/sql/
mod.rs
