use super::{ValueRef, Value};
use std::error::Error;
use std::fmt;
#[derive(Debug)]
pub enum FromSqlError {
InvalidType,
OutOfRange(i64),
Other(Box<Error + Send + Sync>),
}
impl fmt::Display for FromSqlError {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
match *self {
FromSqlError::InvalidType => write!(f, "Invalid type"),
FromSqlError::OutOfRange(i) => write!(f, "Value {} out of range", i),
FromSqlError::Other(ref err) => err.fmt(f),
}
}
}
impl Error for FromSqlError {
fn description(&self) -> &str {
match *self {
FromSqlError::InvalidType => "invalid type",
FromSqlError::OutOfRange(_) => "value out of range",
FromSqlError::Other(ref err) => err.description(),
}
}
#[cfg_attr(feature="clippy", allow(match_same_arms))]
fn cause(&self) -> Option<&Error> {
match *self {
FromSqlError::Other(ref err) => err.cause(),
FromSqlError::InvalidType |
FromSqlError::OutOfRange(_) => None,
}
}
}
pub type FromSqlResult<T> = Result<T, FromSqlError>;
pub trait FromSql: Sized {
fn column_result(value: ValueRef) -> FromSqlResult<Self>;
}
macro_rules! from_sql_integral(
($t:ident) => (
impl FromSql for $t {
fn column_result(value: ValueRef) -> FromSqlResult<Self> {
i64::column_result(value).and_then(|i| {
if i < $t::min_value() as i64 || i > $t::max_value() as i64 {
Err(FromSqlError::OutOfRange(i))
} else {
Ok(i as $t)
}
})
}
}
)
);
from_sql_integral!(i8);
from_sql_integral!(i16);
from_sql_integral!(i32);
from_sql_integral!(isize);
from_sql_integral!(u8);
from_sql_integral!(u16);
from_sql_integral!(u32);
impl FromSql for i64 {
fn column_result(value: ValueRef) -> FromSqlResult<Self> {
value.as_i64()
}
}
impl FromSql for f64 {
fn column_result(value: ValueRef) -> FromSqlResult<Self> {
match value {
ValueRef::Integer(i) => Ok(i as f64),
ValueRef::Real(f) => Ok(f),
_ => Err(FromSqlError::InvalidType),
}
}
}
impl FromSql for bool {
fn column_result(value: ValueRef) -> FromSqlResult<Self> {
i64::column_result(value).map(|i| match i {
0 => false,
_ => true,
})
}
}
impl FromSql for String {
fn column_result(value: ValueRef) -> FromSqlResult<Self> {
value.as_str().map(|s| s.to_string())
}
}
impl FromSql for Vec<u8> {
fn column_result(value: ValueRef) -> FromSqlResult<Self> {
value.as_blob().map(|b| b.to_vec())
}
}
impl<T: FromSql> FromSql for Option<T> {
fn column_result(value: ValueRef) -> FromSqlResult<Self> {
match value {
ValueRef::Null => Ok(None),
_ => FromSql::column_result(value).map(Some),
}
}
}
impl FromSql for Value {
fn column_result(value: ValueRef) -> FromSqlResult<Self> {
Ok(value.into())
}
}
#[cfg(test)]
mod test {
use {Connection, Error};
use super::FromSql;
fn checked_memory_handle() -> Connection {
Connection::open_in_memory().unwrap()
}
#[test]
fn test_integral_ranges() {
let db = checked_memory_handle();
fn check_ranges<T>(db: &Connection, out_of_range: &[i64], in_range: &[i64])
where T: Into<i64> + FromSql + ::std::fmt::Debug
{
for n in out_of_range {
let err = db.query_row("SELECT ?", &[n], |r| r.get_checked::<_, T>(0))
.unwrap()
.unwrap_err();
match err {
Error::IntegralValueOutOfRange(_, value) => assert_eq!(*n, value),
_ => panic!("unexpected error: {}", err),
}
}
for n in in_range {
assert_eq!(*n,
db.query_row("SELECT ?", &[n], |r| r.get::<_, T>(0)).unwrap().into());
}
}
check_ranges::<i8>(&db, &[-129, 128], &[-128, 0, 1, 127]);
check_ranges::<i16>(&db, &[-32769, 32768], &[-32768, -1, 0, 1, 32767]);
check_ranges::<i32>(&db,
&[-2147483649, 2147483648],
&[-2147483648, -1, 0, 1, 2147483647]);
check_ranges::<u8>(&db, &[-2, -1, 256], &[0, 1, 255]);
check_ranges::<u16>(&db, &[-2, -1, 65536], &[0, 1, 65535]);
check_ranges::<u32>(&db, &[-2, -1, 4294967296], &[0, 1, 4294967295]);
}
}