use crate::{error::Error, sql_read_bytes::SqlReadBytes, tds::Collation, ColumnData};
pub(crate) async fn decode<R>(
src: &mut R,
collation: Option<Collation>,
) -> crate::Result<ColumnData<'static>>
where
R: SqlReadBytes + Unpin,
{
let ptr_len = src.read_u8().await? as usize;
if ptr_len == 0 {
return Ok(ColumnData::String(None));
}
for _ in 0..ptr_len {
src.read_u8().await?;
}
src.read_i32_le().await?; src.read_u32_le().await?;
let text = match collation {
Some(collation) => {
let encoder = collation.encoding()?;
let text_len = src.read_u32_le().await? as usize;
let mut buf = Vec::with_capacity(text_len);
for _ in 0..text_len {
buf.push(src.read_u8().await?);
}
encoder
.decode_without_bom_handling_and_without_replacement(buf.as_ref())
.ok_or_else(|| Error::Encoding("invalid sequence".into()))?
.to_string()
}
None => {
let text_len = src.read_u32_le().await? as usize / 2;
let mut buf = Vec::with_capacity(text_len);
for _ in 0..text_len {
buf.push(src.read_u16_le().await?);
}
String::from_utf16(&buf[..])?
}
};
Ok(ColumnData::String(Some(text.into())))
}