rust-postgres/postgres-shared/src/lib.rs
2016-12-22 15:30:03 -05:00

124 lines
2.8 KiB
Rust

#![allow(unknown_lints)] // for clippy
extern crate hex;
extern crate fallible_iterator;
extern crate phf;
extern crate postgres_protocol;
use fallible_iterator::{FallibleIterator, FromFallibleIterator};
use std::ascii::AsciiExt;
use std::ops::Range;
use types::Type;
pub mod error;
pub mod params;
pub mod types;
pub struct RowData {
buf: Vec<u8>,
indices: Vec<Option<Range<usize>>>,
}
impl<'a> FromFallibleIterator<Option<&'a [u8]>> for RowData {
fn from_fallible_iterator<I>(mut it: I) -> Result<RowData, I::Error>
where I: FallibleIterator<Item = Option<&'a [u8]>>
{
let mut row = RowData {
buf: vec![],
indices: Vec::with_capacity(it.size_hint().0),
};
while let Some(cell) = try!(it.next()) {
let index = match cell {
Some(cell) => {
let base = row.buf.len();
row.buf.extend_from_slice(cell);
Some(base..row.buf.len())
}
None => None,
};
row.indices.push(index);
}
Ok(row)
}
}
impl RowData {
pub fn len(&self) -> usize {
self.indices.len()
}
pub fn get(&self, index: usize) -> Option<&[u8]> {
match &self.indices[index] {
&Some(ref range) => Some(&self.buf[range.clone()]),
&None => None,
}
}
}
pub struct Column {
name: String,
type_: Type,
}
impl Column {
#[doc(hidden)]
pub fn new(name: String, type_: Type) -> Column {
Column {
name: name,
type_: type_,
}
}
pub fn name(&self) -> &str {
&self.name
}
pub fn type_(&self) -> &Type {
&self.type_
}
}
/// A trait implemented by types that can index into columns of a row.
pub trait RowIndex {
/// Returns the index of the appropriate column, or `None` if no such
/// column exists.
fn idx(&self, stmt: &[Column]) -> Option<usize>;
}
impl RowIndex for usize {
#[inline]
fn idx(&self, stmt: &[Column]) -> Option<usize> {
if *self >= stmt.len() {
None
} else {
Some(*self)
}
}
}
impl<'a> RowIndex 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<'a, T> RowIndex for &'a T
where T: RowIndex
{
#[inline]
fn idx(&self, columns: &[Column]) -> Option<usize> {
T::idx(*self, columns)
}
}