nautilus_persistence/python/wranglers/
trade.rsuse std::{collections::HashMap, io::Cursor, str::FromStr};
use datafusion::arrow::ipc::reader::StreamReader;
use nautilus_core::python::to_pyvalue_err;
use nautilus_model::{data::trade::TradeTick, identifiers::InstrumentId};
use nautilus_serialization::arrow::DecodeFromRecordBatch;
use pyo3::prelude::*;
#[pyclass]
pub struct TradeTickDataWrangler {
instrument_id: InstrumentId,
price_precision: u8,
size_precision: u8,
metadata: HashMap<String, String>,
}
#[pymethods]
impl TradeTickDataWrangler {
#[new]
fn py_new(instrument_id: &str, price_precision: u8, size_precision: u8) -> PyResult<Self> {
let instrument_id = InstrumentId::from_str(instrument_id).map_err(to_pyvalue_err)?;
let metadata = TradeTick::get_metadata(&instrument_id, price_precision, size_precision);
Ok(Self {
instrument_id,
price_precision,
size_precision,
metadata,
})
}
#[getter]
fn instrument_id(&self) -> String {
self.instrument_id.to_string()
}
#[getter]
const fn price_precision(&self) -> u8 {
self.price_precision
}
#[getter]
const fn size_precision(&self) -> u8 {
self.size_precision
}
fn process_record_batch_bytes(&self, data: &[u8]) -> PyResult<Vec<TradeTick>> {
let cursor = Cursor::new(data);
let reader = match StreamReader::try_new(cursor, None) {
Ok(reader) => reader,
Err(e) => return Err(to_pyvalue_err(e)),
};
let mut ticks = Vec::new();
for maybe_batch in reader {
let record_batch = match maybe_batch {
Ok(record_batch) => record_batch,
Err(e) => return Err(to_pyvalue_err(e)),
};
let batch_deltas =
TradeTick::decode_batch(&self.metadata, record_batch).map_err(to_pyvalue_err)?;
ticks.extend(batch_deltas);
}
Ok(ticks)
}
}