Struct TableFunctionOutputIter

pub struct TableFunctionOutputIter<'a> {
    stream: BoxStream<'a, Result<DataChunk>>,
    chunk: Option<DataChunk>,
    index: usize,
}

A wrapper over the output of table function that allows iteration by rows.

If the table function returns multiple columns, the output will be struct values.

Note that to get datum reference for efficiency, this iterator doesn’t follow the standard Stream API. Instead, it provides a peek method to get the next row without consuming it, and a next method to consume the next row.

let mut iter = TableFunctionOutputIter::new(
    futures_util::stream::iter([
        DataChunk::from_pretty(
            "i I
             0 0
             1 1",
        ),
        DataChunk::from_pretty(
            "i I
             2 2
             3 3",
        ),
    ])
    .map(Ok)
    .boxed(),
)
.await.unwrap();

for i in 0..4 {
    let (index, value) = iter.peek().unwrap();
    assert_eq!(index, i);
    assert_eq!(value.unwrap(), Some((i as i64).into()));
    iter.next().await.unwrap();
}
assert!(iter.peek().is_none());

Fields

stream: BoxStream<'a, Result<DataChunk>>

chunk: Option<DataChunk>

index: usize

Implementations

impl<'a> TableFunctionOutputIter<'a>

pub async fn new( stream: BoxStream<'a, Result<DataChunk>>, ) -> Result<TableFunctionOutputIter<'a>>

pub fn peek(&'a self) -> Option<(usize, Result<DatumRef<'a>>)>

Gets the current row.

pub async fn next(&mut self) -> Result<()>

Moves to the next row.

This method is cancellation safe.

async fn pop_from_stream(&mut self) -> Result<()>

Gets the next chunk from stream.