Struct ListBatchIterator 

pub struct ListBatchIterator { /* private fields */ }

Iterator for scanning Redis lists in batches as Arrow RecordBatches.

This iterator fetches list keys matching a pattern and retrieves their elements, converting them to Arrow RecordBatches for use with Polars. Each element becomes a row in the output.

Example

use polars_redis::{ListBatchIterator, ListSchema, BatchConfig};

let schema = ListSchema::new().with_key(true).with_position(true);
let config = BatchConfig::new("queue:*").with_batch_size(1000);

let mut iterator = ListBatchIterator::new(url, schema, config)?;

while let Some(batch) = iterator.next_batch()? {
    println!("Got {} elements", batch.num_rows());
}

Output Schema

• _key (optional): The Redis key
• element: The list element value (Utf8)
• position (optional): The element’s position in the list (Int64)

Implementations

impl ListBatchIterator

pub fn new(url: &str, schema: ListSchema, config: BatchConfig) -> Result<Self>

Create a new ListBatchIterator.

pub fn next_batch(&mut self) -> Result<Option<RecordBatch>>

Get the next batch of data as a RecordBatch.

pub fn is_done(&self) -> bool

Check if iteration is complete.

pub fn rows_yielded(&self) -> usize

Get the number of rows (elements) yielded so far.