datafusion_python/
udtf.rs

1// Licensed to the Apache Software Foundation (ASF) under one
2// or more contributor license agreements.  See the NOTICE file
3// distributed with this work for additional information
4// regarding copyright ownership.  The ASF licenses this file
5// to you under the Apache License, Version 2.0 (the
6// "License"); you may not use this file except in compliance
7// with the License.  You may obtain a copy of the License at
8//
9//   http://www.apache.org/licenses/LICENSE-2.0
10//
11// Unless required by applicable law or agreed to in writing,
12// software distributed under the License is distributed on an
13// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
14// KIND, either express or implied.  See the License for the
15// specific language governing permissions and limitations
16// under the License.
17
18use std::sync::Arc;
19
20use datafusion::catalog::{TableFunctionImpl, TableProvider};
21use datafusion::error::Result as DataFusionResult;
22use datafusion::logical_expr::Expr;
23use datafusion_ffi::udtf::{FFI_TableFunction, ForeignTableFunction};
24use pyo3::prelude::*;
25use pyo3::types::{PyCapsule, PyTuple};
26
27use crate::errors::{py_datafusion_err, to_datafusion_err};
28use crate::expr::PyExpr;
29use crate::table::PyTable;
30use crate::utils::validate_pycapsule;
31
32/// Represents a user defined table function
33#[pyclass(frozen, name = "TableFunction", module = "datafusion")]
34#[derive(Debug, Clone)]
35pub struct PyTableFunction {
36    pub(crate) name: String,
37    pub(crate) inner: PyTableFunctionInner,
38}
39
40// TODO: Implement pure python based user defined table functions
41#[derive(Debug, Clone)]
42pub(crate) enum PyTableFunctionInner {
43    PythonFunction(Arc<Py<PyAny>>),
44    FFIFunction(Arc<dyn TableFunctionImpl>),
45}
46
47#[pymethods]
48impl PyTableFunction {
49    #[new]
50    #[pyo3(signature=(name, func))]
51    pub fn new(name: &str, func: Bound<'_, PyAny>) -> PyResult<Self> {
52        let inner = if func.hasattr("__datafusion_table_function__")? {
53            let capsule = func.getattr("__datafusion_table_function__")?.call0()?;
54            let capsule = capsule.downcast::<PyCapsule>().map_err(py_datafusion_err)?;
55            validate_pycapsule(capsule, "datafusion_table_function")?;
56
57            let ffi_func = unsafe { capsule.reference::<FFI_TableFunction>() };
58            let foreign_func: ForeignTableFunction = ffi_func.to_owned().into();
59
60            PyTableFunctionInner::FFIFunction(Arc::new(foreign_func))
61        } else {
62            let py_obj = Arc::new(func.unbind());
63            PyTableFunctionInner::PythonFunction(py_obj)
64        };
65
66        Ok(Self {
67            name: name.to_string(),
68            inner,
69        })
70    }
71
72    #[pyo3(signature = (*args))]
73    pub fn __call__(&self, args: Vec<PyExpr>) -> PyResult<PyTable> {
74        let args: Vec<Expr> = args.iter().map(|e| e.expr.clone()).collect();
75        let table_provider = self.call(&args).map_err(py_datafusion_err)?;
76
77        Ok(PyTable::from(table_provider))
78    }
79
80    fn __repr__(&self) -> PyResult<String> {
81        Ok(format!("TableUDF({})", self.name))
82    }
83}
84
85#[allow(clippy::result_large_err)]
86fn call_python_table_function(
87    func: &Arc<Py<PyAny>>,
88    args: &[Expr],
89) -> DataFusionResult<Arc<dyn TableProvider>> {
90    let args = args
91        .iter()
92        .map(|arg| PyExpr::from(arg.clone()))
93        .collect::<Vec<_>>();
94
95    // move |args: &[ArrayRef]| -> Result<ArrayRef, DataFusionError> {
96    Python::attach(|py| {
97        let py_args = PyTuple::new(py, args)?;
98        let provider_obj = func.call1(py, py_args)?;
99        let provider = provider_obj.bind(py);
100
101        Ok::<Arc<dyn TableProvider>, PyErr>(PyTable::new(provider)?.table)
102    })
103    .map_err(to_datafusion_err)
104}
105
106impl TableFunctionImpl for PyTableFunction {
107    fn call(&self, args: &[Expr]) -> DataFusionResult<Arc<dyn TableProvider>> {
108        match &self.inner {
109            PyTableFunctionInner::FFIFunction(func) => func.call(args),
110            PyTableFunctionInner::PythonFunction(obj) => call_python_table_function(obj, args),
111        }
112    }
113}
datafusion_python/udtf.rs

datafusion_python/
udtf.rs
