src/expr/repartition.rs

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// distributed with this work for additional information
// regarding copyright ownership.  The ASF licenses this file
// to you under the Apache License, Version 2.0 (the
// "License"); you may not use this file except in compliance
// with the License.  You may obtain a copy of the License at
//
//   http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing,
// software distributed under the License is distributed on an
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// KIND, either express or implied.  See the License for the
// specific language governing permissions and limitations
// under the License.

use std::fmt::{self, Display, Formatter};

use datafusion::logical_expr::logical_plan::Repartition;
use datafusion::logical_expr::{Expr, Partitioning};
use pyo3::prelude::*;
use pyo3::IntoPyObjectExt;

use super::logical_node::LogicalNode;
use super::PyExpr;
use crate::errors::py_type_err;
use crate::sql::logical::PyLogicalPlan;

#[pyclass(frozen, name = "Repartition", module = "datafusion.expr", subclass)]
#[derive(Clone)]
pub struct PyRepartition {
    repartition: Repartition,
}

#[pyclass(frozen, name = "Partitioning", module = "datafusion.expr", subclass)]
#[derive(Clone)]
pub struct PyPartitioning {
    partitioning: Partitioning,
}

impl From<PyPartitioning> for Partitioning {
    fn from(partitioning: PyPartitioning) -> Self {
        partitioning.partitioning
    }
}

impl From<Partitioning> for PyPartitioning {
    fn from(partitioning: Partitioning) -> Self {
        PyPartitioning { partitioning }
    }
}

impl From<PyRepartition> for Repartition {
    fn from(repartition: PyRepartition) -> Self {
        repartition.repartition
    }
}

impl From<Repartition> for PyRepartition {
    fn from(repartition: Repartition) -> PyRepartition {
        PyRepartition { repartition }
    }
}

impl Display for PyRepartition {
    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
        write!(
            f,
            "Repartition
            input: {:?}
            partitioning_scheme: {:?}",
            &self.repartition.input, &self.repartition.partitioning_scheme,
        )
    }
}

#[pymethods]
impl PyRepartition {
    fn input(&self) -> PyResult<Vec<PyLogicalPlan>> {
        Ok(Self::inputs(self))
    }

    fn partitioning_scheme(&self) -> PyResult<PyPartitioning> {
        Ok(PyPartitioning {
            partitioning: self.repartition.partitioning_scheme.clone(),
        })
    }

    fn distribute_list(&self) -> PyResult<Vec<PyExpr>> {
        match &self.repartition.partitioning_scheme {
            Partitioning::DistributeBy(distribute_list) => Ok(distribute_list
                .iter()
                .map(|e| PyExpr::from(e.clone()))
                .collect()),
            _ => Err(py_type_err("unexpected repartition strategy")),
        }
    }

    fn distribute_columns(&self) -> PyResult<String> {
        match &self.repartition.partitioning_scheme {
            Partitioning::DistributeBy(distribute_list) => Ok(distribute_list
                .iter()
                .map(|e| match &e {
                    Expr::Column(column) => column.name.clone(),
                    _ => panic!("Encountered a type other than Expr::Column"),
                })
                .collect()),
            _ => Err(py_type_err("unexpected repartition strategy")),
        }
    }

    fn __repr__(&self) -> PyResult<String> {
        Ok(format!("Repartition({self})"))
    }

    fn __name__(&self) -> PyResult<String> {
        Ok("Repartition".to_string())
    }
}

impl LogicalNode for PyRepartition {
    fn inputs(&self) -> Vec<PyLogicalPlan> {
        vec![PyLogicalPlan::from((*self.repartition.input).clone())]
    }

    fn to_variant<'py>(&self, py: Python<'py>) -> PyResult<Bound<'py, PyAny>> {
        self.clone().into_bound_py_any(py)
    }
}