Trait Record

Source

pub trait Record:
    Send
    + Sized
    + 'static {
    // Required methods
    fn schema() -> SchemaRef;
    fn to_record_batch(&self) -> RecordBatch;

    // Provided method
    fn event_time(&self) -> Option<i64> { ... }
}

Expand description

Trait for types that can be streamed through a Source.

Implementations must provide:

Conversion to/from Arrow RecordBatch
Schema definition
Optional event time extraction

§Example

use laminar_core::streaming::Record;
use arrow::array::RecordBatch;
use arrow::datatypes::{Schema, SchemaRef, Field, DataType};

#[derive(Clone)]
struct TradeEvent {
    symbol: String,
    price: f64,
    timestamp: i64,
}

impl Record for TradeEvent {
    fn schema() -> SchemaRef {
        Arc::new(Schema::new(vec![
            Field::new("symbol", DataType::Utf8, false),
            Field::new("price", DataType::Float64, false),
            Field::new("timestamp", DataType::Int64, false),
        ]))
    }

    fn to_record_batch(&self) -> RecordBatch {
        // Convert to RecordBatch...
    }

    fn event_time(&self) -> Option<i64> {
        Some(self.timestamp)
    }
}