_test_catalog_provider.py

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from __future__ import annotations

import pyarrow as pa

from datafusion import SessionContext, Table
from datafusion_ffi_example import MyCatalogProvider

from datafusion.context import PyCatalogProvider, PySchemaProvider


def test_catalog_provider():
    ctx = SessionContext()

    my_catalog_name = "my_catalog"
    expected_schema_name = "my_schema"
    expected_table_name = "my_table"
    expected_table_columns = ["units", "price"]

    catalog_provider = MyCatalogProvider()
    ctx.register_catalog_provider(my_catalog_name, catalog_provider)
    my_catalog = ctx.catalog(my_catalog_name)

    my_catalog_schemas = my_catalog.names()
    assert expected_schema_name in my_catalog_schemas
    my_database = my_catalog.database(expected_schema_name)
    assert expected_table_name in my_database.names()
    my_table = my_database.table(expected_table_name)
    assert expected_table_columns == my_table.schema.names

    result = ctx.table(
        f"{my_catalog_name}.{expected_schema_name}.{expected_table_name}"
    ).collect()
    assert len(result) == 2

    col0_result = [r.column(0) for r in result]
    col1_result = [r.column(1) for r in result]
    expected_col0 = [
        pa.array([10, 20, 30], type=pa.int32()),
        pa.array([5, 7], type=pa.int32()),
    ]
    expected_col1 = [
        pa.array([1, 2, 5], type=pa.float64()),
        pa.array([1.5, 2.5], type=pa.float64()),
    ]
    assert col0_result == expected_col0
    assert col1_result == expected_col1


class MyPyCatalogProvider(PyCatalogProvider):
    my_schemas = ['my_schema']

    def schema_names(self) -> list[str]:
        return self.my_schemas

    def schema(self, name: str) -> PySchemaProvider:
        return MyPySchemaProvider()


class MyPySchemaProvider(PySchemaProvider):
    my_tables = ['table1', 'table2', 'table3']

    def table_names(self) -> list[str]:
        return self.my_tables

    def table_exist(self, table_name: str) -> bool:
        return table_name in self.my_tables

    def table(self, table_name: str) -> Table:
        raise RuntimeError(f"Can not get table: {table_name}")

    def register_table(self, table: Table) -> None:
        raise RuntimeError(f"Can not register {table} as table")

    def deregister_table(self, table_name: str) -> None:
        raise RuntimeError(f"Can not deregister table: {table_name}")


def test_python_catalog_provider():
    ctx = SessionContext()

    my_catalog_name = "my_py_catalog"
    expected_schema_name = "my_schema"
    my_py_catalog_provider = MyPyCatalogProvider()
    ctx.register_catalog_provider(my_catalog_name, my_py_catalog_provider)
    my_py_catalog = ctx.catalog(my_catalog_name)
    assert MyPyCatalogProvider.my_schemas == my_py_catalog.names()

    my_database = my_py_catalog.database(expected_schema_name)
    assert set(MyPySchemaProvider.my_tables) == my_database.names()

    # asserting a non-compliant provider fails at the python level as expected
    try:
        ctx.register_catalog_provider(my_catalog_name, "non_compliant_provider")
    except TypeError:
        # expect a TypeError because we can not register a str as a catalog provider
        pass


if __name__ == "__main__":
    test_python_catalog_provider()