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use nom::{IResult, le_u8, le_u16, le_u32, le_u64, Needed};
use nom::IResult::*;
#[inline]
fn le_u24(i: &[u8]) -> IResult<&[u8], u32> {
if i.len() < 3 {
Incomplete(Needed::Size(3))
} else {
let res = ((i[2] as u32) << 16) + ((i[1] as u32) << 8) + i[0] as u32;
Done(&i[3..], res)
}
}
#[inline]
pub fn lenenc_int(i: &[u8]) -> IResult<&[u8], (u8, u64)> {
let (i, len) = try_parse!(i, le_u8);
match len {
0xfc => map!(i, le_u16, |x| (3, u64::from(x))),
0xfd => map!(i, le_u24, |x| (4, u64::from(x))),
0xfe => map!(i, le_u64, |x| (9, x)),
x => Done(i, (1, x as u64)),
}
}
#[inline]
pub fn lenenc_bytes(i: &[u8]) -> IResult<&[u8], (u64, &[u8])> {
let (i, (cons, len)) = try_parse!(i, lenenc_int);
map!(i, take!(len), |x| (cons as u64 + len, x))
}
/// Description: https://dev.mysql.com/doc/internals/en/com-query-response.html#packet-Protocol::ColumnDefinition41
///
/// ```ignore
/// (
/// schema,
/// table,
/// org_table,
/// name,
/// org_name,
/// character_set,
/// column_length,
/// column_type,
/// flags,
/// decimals,
/// default_values,
/// )
/// }
/// ```
pub type ColumnDef<'a> = (&'a [u8], &'a[u8], &'a[u8], &'a[u8], &'a[u8], u16, u32, u8, u16, u8, Option<&'a[u8]>);
pub fn column_def<'a>(pld: &'a [u8]) -> IResult<&[u8], ColumnDef<'a>> {
chain! (pld,
// Skip catalog which is always "\x03def"
take!(4) ~
schema: call!(lenenc_bytes) ~
table: call!(lenenc_bytes) ~
org_table: call!(lenenc_bytes) ~
name: call!(lenenc_bytes) ~
org_name: call!(lenenc_bytes) ~
take!(1) ~
character_set: call!(le_u16) ~
column_length: call!(le_u32) ~
column_type: call!(le_u8) ~
flags: call!(le_u16) ~
decimals: call!(le_u8) ~
take!(2) ~
len: opt!(complete!(call!(lenenc_int))) ~
default_values: cond!(
len.is_some(),
take!(len.unwrap().1)
),
|| {
return (
schema.1,
table.1,
org_table.1,
name.1,
org_name.1,
character_set,
column_length,
column_type,
flags,
decimals,
default_values,
);
}
)
}
#[cfg(test)]
mod test {
use nom::IResult::Done;
use super::*;
#[test]
fn should_parse_column_definition() {
let payload1 = b"\x03def\x06schema\x05table\x09org_table\x04name\x08org_name\
\x0c\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00";
let payload2 = b"\x03def\x06schema\x05table\x09org_table\x04name\x08org_name\
\x0c\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x07default";
let out1 = column_def(&payload1[..]);
let out2 = column_def(&payload2[..]);
println!("{:?}", out1);
assert!(
out1 == Done(&[][..], (b"schema", b"table", b"org_table", b"name", b"org_name",
0, 0, 0, 0, 0, None))
);
assert!(
out2 == Done(&[][..], (b"schema", b"table", b"org_table", b"name", b"org_name",
0, 0, 0, 0, 0, Some(b"default")))
)
}
#[cfg(feature = "nightly")]
mod bench {
use test;
use super::super::*;
use Column;
static COLUMN_PAYLOAD: &'static [u8] = b"\x03def\x06schema\x05table\x09org_table\x04name\
\x08org_name\x0c\x00\x00\x00\x00\x00\x0F\x00\x00\
\x00\x00\x00\x00\x07default";
#[bench]
fn nom_column(bencher: &mut test::Bencher) {
bencher.iter(|| {
let out = column_def(&COLUMN_PAYLOAD[..]);
test::black_box(out);
});
}
#[bench]
fn new_column(bencher: &mut test::Bencher) {
bencher.iter(|| {
let pld = unsafe {
::std::vec::Vec::from_raw_parts(COLUMN_PAYLOAD.as_ptr() as *mut u8,
COLUMN_PAYLOAD.len(),
COLUMN_PAYLOAD.len())
};
let out = Column::from_payload(pld);
test::black_box(::std::mem::forget(out));
});
}
}
}