Simplify function interface

evadb/functions/My_SimpleUDF.py

@@ -0,0 +1,2 @@
+def My_SimpleUDF(cls, x:int)->int:
+    return x + 5

evadb/functions/simple_udf.py

@@ -0,0 +1,104 @@
+# coding=utf-8
+# Copyright 2018-2023 EvaDB
+#
+# Licensed 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 "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+import numpy as np
+import pandas as pd
+import importlib
+import pickle
+from pathlib import Path
+import typing
+
+from evadb.catalog.catalog_type import NdArrayType
+from evadb.functions.abstract.abstract_function import AbstractFunction
+from evadb.functions.decorators.decorators import forward, setup
+from evadb.functions.decorators.io_descriptors.data_types import PandasDataframe
+from evadb.configuration.constants import EvaDB_ROOT_DIR
+
+class SimpleUDF(AbstractFunction):
+    @setup(cacheable=False, function_type="SimpleUDF", batchable=False)
+    def setup(self):
+        in_labels = []
+        in_types = []
+        for label in self.types:
+            if label == "return": continue
+            in_labels.append(label)
+            in_types.append(self.convert_python_types(self.types[label]))
+        out_types = [self.convert_python_types(self.types['return'])]
+
+        self.forward.tags["input"] = [PandasDataframe(
+            columns=in_labels,
+            column_types=in_types,
+            column_shapes=[(1) * len(in_labels)]
+        )]
+
+        self.forward.tags["output"] = [PandasDataframe(
+            columns=["output"],
+            column_types=out_types,
+            column_shapes=[(1) * len(out_types)],
+        )]
+
+    @property
+    def name(self) -> str:
+        return "SimpleUDF"
+
+    @forward(None, None)
+    def forward(self, df: pd.DataFrame) -> pd.DataFrame:
+        def _forward(row: pd.Series) -> np.ndarray:
+            temp = self.udf
+            return temp(row)
+
+        ret = pd.DataFrame()
+        ret["output"] = df.apply(_forward, axis=1)
+        return ret
+
+    def set_udf(self, classname:str, filepath: str):
+        if f"{EvaDB_ROOT_DIR}/simple_udfs/" in filepath:
+            f = open(f"{EvaDB_ROOT_DIR}/simple_udfs/Func_SimpleUDF", 'rb')
+            self.udf = pickle.load(f)
+        else:
+            try:
+                abs_path = Path(filepath).resolve()
+                spec = importlib.util.spec_from_file_location(abs_path.stem, abs_path)
+                module = importlib.util.module_from_spec(spec)
+                spec.loader.exec_module(module)
+            except ImportError as e:
+                # ImportError in the case when we are able to find the file but not able to load the module
+                err_msg = f"ImportError : Couldn't load function from {filepath} : {str(e)}. Not able to load the code provided in the file {abs_path}. Please ensure that the file contains the implementation code for the function."
+                raise ImportError(err_msg)
+            except FileNotFoundError as e:
+                # FileNotFoundError in the case when we are not able to find the file at all at the path.
+                err_msg = f"FileNotFoundError : Couldn't load function from {filepath} : {str(e)}. This might be because the function implementation file does not exist. Please ensure the file exists at {abs_path}"
+                raise FileNotFoundError(err_msg)
+            except Exception as e:
+                # Default exception, we don't know what exactly went wrong so we just output the error message
+                err_msg = f"Couldn't load function from {filepath} : {str(e)}."
+                raise RuntimeError(err_msg)
+
+            # Try to load the specified class by name
+            if classname and hasattr(module, classname):
+                self.udf = getattr(module, classname)
+
+        self.types = typing.get_type_hints(self.udf)
+
+    def convert_python_types(self, type):
+        if type == bool:
+            return NdArrayType.BOOL
+        elif type == int:
+            return NdArrayType.INT32
+        elif type == float:
+            return NdArrayType.FLOAT32
+        elif type == str:
+            return NdArrayType.STR
+        else:
+            return NdArrayType.ANYTYPE

evadb/interfaces/relational/db.py

@@ -16,8 +16,9 @@
 import multiprocessing
 
 import pandas
+import pickle
 
-from evadb.configuration.constants import EvaDB_DATABASE_DIR
+from evadb.configuration.constants import EvaDB_DATABASE_DIR, EvaDB_ROOT_DIR
 from evadb.database import EvaDBDatabase, init_evadb_instance
 from evadb.expression.tuple_value_expression import TupleValueExpression
 from evadb.functions.function_bootstrap_queries import init_builtin_functions
@@ -413,6 +414,30 @@ def create_function(
             function_name, if_not_exists, impl_path, type, **kwargs
         )
         return EvaDBQuery(self._evadb, stmt)
+
+    def create_simple_function(
+        self,
+        function_name: str,
+        function: callable,
+        if_not_exists: bool = True,
+    ) -> "EvaDBQuery":
+        """
+        Create a function in the database by passing in a function instance.
+
+        Args:
+            function_name (str): Name of the function to be created.
+            if_not_exists (bool): If True, do not raise an error if the function already exist. If False, raise an error.
+            function (callable): The function instance
+
+        Returns:
+            EvaDBQuery: The EvaDBQuery object representing the function created.
+        """
+        impl_path = f"{EvaDB_ROOT_DIR}/simple_udfs/{function_name}"
+        f = open(impl_path, 'ab')
+        pickle.dump(function, f)
+        f.close()
+
+        return self.create_function(function_name, if_not_exists, impl_path)
 
     def create_table(
         self, table_name: str, if_not_exists: bool = True, columns: str = None, **kwargs

evadb/utils/generic_utils.py

@@ -28,6 +28,7 @@
 
 from evadb.configuration.constants import EvaDB_INSTALLATION_DIR
 from evadb.utils.logging_manager import logger
+from evadb.configuration.constants import EvaDB_ROOT_DIR
 
 
 def validate_kwargs(
@@ -79,6 +80,14 @@ def load_function_class_from_file(filepath, classname=None):
         FileNotFoundError: If the file cannot be found.
         RuntimeError: Any othe type of runtime error.
     """
+    simple_udf_filepath = None
+    simple_udf_classname = None
+    if classname and "_SimpleUDF" in classname:
+        simple_udf_classname = classname
+        classname = "SimpleUDF"
+        simple_udf_filepath = filepath
+        filepath = f"{EvaDB_ROOT_DIR}/evadb/functions/simple_udf.py"
+
     try:
         abs_path = Path(filepath).resolve()
         spec = importlib.util.spec_from_file_location(abs_path.stem, abs_path)
@@ -99,6 +108,10 @@ def load_function_class_from_file(filepath, classname=None):
 
     # Try to load the specified class by name
     if classname and hasattr(module, classname):
+        if classname == "SimpleUDF":
+            cls = getattr(module, classname)
+            cls.set_udf(cls, simple_udf_classname, simple_udf_filepath)
+            return cls
         return getattr(module, classname)
 
     # If class name not specified, check if there is only one class in the file

test/integration_tests/long/test_simple_function.py

@@ -0,0 +1,73 @@
+# coding=utf-8
+# Copyright 2018-2023 EvaDB
+#
+# Licensed 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 "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+import unittest
+from test.util import suffix_pytest_xdist_worker_id_to_dir
+
+import pytest
+import pandas as pd
+
+from evadb.configuration.constants import EvaDB_DATABASE_DIR, EvaDB_ROOT_DIR
+from evadb.interfaces.relational.db import connect
+from evadb.server.command_handler import execute_query_fetch_all
+
+def Func_SimpleUDF(cls, x:int)->int:
+    return x + 10
+
+@pytest.mark.notparallel
+class SimpleFunctionTests(unittest.TestCase):
+    def setUp(self):
+        self.db_dir = suffix_pytest_xdist_worker_id_to_dir(EvaDB_DATABASE_DIR)
+        self.conn = connect(self.db_dir)
+        self.evadb = self.conn._evadb
+        self.evadb.catalog().reset()
+
+    def tearDown(self):
+        execute_query_fetch_all(self.evadb, "DROP TABLE IF EXISTS test_table;")
+        execute_query_fetch_all(self.evadb, "DROP FUNCTION IF EXISTS My_SimpleUDF;")
+        execute_query_fetch_all(self.evadb, "DROP FUNCTION IF EXISTS Func_SimpleUDF;")
+
+    def test_from_file(self):
+        cursor = self.conn.cursor()
+
+        execute_query_fetch_all(self.evadb, "CREATE TABLE IF NOT EXISTS test_table (val INTEGER);")
+        cursor.insert("test_table", "(val)", "(1)").df()
+
+        cursor.create_function(
+            "My_SimpleUDF",
+            True,
+            f"{EvaDB_ROOT_DIR}/evadb/functions/My_SimpleUDF.py",
+        ).df()
+
+        result = cursor.query("SELECT My_SimpleUDF(val) FROM test_table;").df()
+        expected = pd.DataFrame({'output': [6]})
+
+        self.assertTrue(expected.equals(result)) 
+
+    def test_from_function(self):
+        cursor = self.conn.cursor()
+
+        execute_query_fetch_all(self.evadb, "CREATE TABLE IF NOT EXISTS test_table (val INTEGER);")
+        cursor.insert("test_table", "(val)", "(1)").df()
+
+        cursor.create_simple_function(
+            "Func_SimpleUDF",
+            Func_SimpleUDF,
+            True,
+        ).df()
+
+        result = cursor.query("SELECT Func_SimpleUDF(val) FROM test_table;").df()
+        expected = pd.DataFrame({'output': [11]})
+
+        self.assertTrue(expected.equals(result))