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DataSource

alimentar::streaming

Trait DataSource 

Source 
pub trait DataSource: Send {
    // Required methods
    fn schema(&self) -> SchemaRef;
    fn next_batch(&mut self) -> Result<Option<RecordBatch>>;

    // Provided methods
    fn size_hint(&self) -> Option<usize> { ... }
    fn reset(&mut self) -> Result<()> { ... }
}
Expand description

A data source that can produce RecordBatches on demand.

Required Methods§

Source

fn schema(&self) -> SchemaRef

Returns the schema of the data.

Source

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

Returns the next batch of data, or None if exhausted.

§Errors

Returns an error if reading the next batch fails.

Provided Methods§

Source

fn size_hint(&self) -> Option<usize>

Returns an estimate of total rows, if known.

Source

fn reset(&mut self) -> Result<()>

Resets the source to the beginning, if supported.

§Errors

Returns an error if this data source does not support reset.

Implementors§