rust-postgres/tokio-postgres/src/rows.rs
2018-12-08 17:39:20 -08:00

90 lines
2.0 KiB
Rust

use fallible_iterator::FallibleIterator;
use postgres_protocol::message::backend::DataRowBody;
use std::io;
use std::ops::Range;
use rows::sealed::Sealed;
use stmt::Column;
mod sealed {
use stmt::Column;
pub trait Sealed {
fn __idx(&self, stmt: &[Column]) -> Option<usize>;
}
}
/// A trait implemented by types that can index into columns of a row.
///
/// This cannot be implemented outside of this crate.
pub trait RowIndex: Sealed {}
impl Sealed for usize {
#[inline]
fn __idx(&self, stmt: &[Column]) -> Option<usize> {
if *self >= stmt.len() {
None
} else {
Some(*self)
}
}
}
impl RowIndex for usize {}
impl Sealed for str {
#[inline]
fn __idx(&self, stmt: &[Column]) -> Option<usize> {
if let Some(idx) = stmt.iter().position(|d| d.name() == self) {
return Some(idx);
};
// FIXME ASCII-only case insensitivity isn't really the right thing to
// do. Postgres itself uses a dubious wrapper around tolower and JDBC
// uses the US locale.
stmt.iter()
.position(|d| d.name().eq_ignore_ascii_case(self))
}
}
impl RowIndex for str {}
impl<'a, T> Sealed for &'a T
where
T: ?Sized + Sealed,
{
#[inline]
fn __idx(&self, columns: &[Column]) -> Option<usize> {
T::__idx(*self, columns)
}
}
impl<'a, T> RowIndex for &'a T where T: ?Sized + Sealed {}
#[doc(hidden)]
pub struct RowData {
body: DataRowBody,
ranges: Vec<Option<Range<usize>>>,
}
impl RowData {
pub fn new(body: DataRowBody) -> io::Result<RowData> {
let ranges = body.ranges().collect()?;
Ok(RowData {
body: body,
ranges: ranges,
})
}
pub fn len(&self) -> usize {
self.ranges.len()
}
pub fn get(&self, index: usize) -> Option<&[u8]> {
match &self.ranges[index] {
&Some(ref range) => Some(&self.body.buffer()[range.clone()]),
&None => None,
}
}
}