77 lines
1.8 KiB
Rust
77 lines
1.8 KiB
Rust
use crate::ctx::Context;
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use crate::dbs::Options;
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use crate::dbs::Transaction;
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use crate::err::Error;
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use crate::sql::comment::shouldbespace;
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use crate::sql::error::IResult;
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use crate::sql::number::Number;
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use crate::sql::value::{value, Value};
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use nom::bytes::complete::tag_no_case;
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use nom::combinator::opt;
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use nom::sequence::tuple;
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use serde::{Deserialize, Serialize};
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use std::fmt;
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#[derive(Clone, Debug, Default, Eq, PartialEq, PartialOrd, Serialize, Deserialize, Hash)]
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pub struct Limit(pub Value);
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impl Limit {
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pub(crate) async fn process(
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&self,
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ctx: &Context<'_>,
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opt: &Options,
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txn: &Transaction,
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doc: Option<&Value>,
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) -> Result<usize, Error> {
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match self.0.compute(ctx, opt, txn, doc).await {
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// This is a valid limiting number
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Ok(Value::Number(Number::Int(v))) if v >= 0 => Ok(v as usize),
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// An invalid value was specified
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Ok(v) => Err(Error::InvalidLimit {
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value: v.as_string(),
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}),
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// A different error occured
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Err(e) => Err(e),
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}
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}
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}
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impl fmt::Display for Limit {
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fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
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write!(f, "LIMIT {}", self.0)
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}
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}
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pub fn limit(i: &str) -> IResult<&str, Limit> {
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let (i, _) = tag_no_case("LIMIT")(i)?;
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let (i, _) = opt(tuple((shouldbespace, tag_no_case("BY"))))(i)?;
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let (i, _) = shouldbespace(i)?;
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let (i, v) = value(i)?;
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Ok((i, Limit(v)))
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}
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#[cfg(test)]
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mod tests {
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use super::*;
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#[test]
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fn limit_statement() {
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let sql = "LIMIT 100";
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let res = limit(sql);
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assert!(res.is_ok());
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let out = res.unwrap().1;
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assert_eq!(out, Limit(Value::from(100)));
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assert_eq!("LIMIT 100", format!("{}", out));
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}
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#[test]
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fn limit_statement_by() {
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let sql = "LIMIT BY 100";
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let res = limit(sql);
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assert!(res.is_ok());
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let out = res.unwrap().1;
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assert_eq!(out, Limit(Value::from(100)));
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assert_eq!("LIMIT 100", format!("{}", out));
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}
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}
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