Initial commit of FFI table provider code

Cargo.toml

@@ -26,6 +26,7 @@ members = [
     "datafusion/expr",
     "datafusion/expr-common",
     "datafusion/execution",
+    "datafusion/ffi",
     "datafusion/functions",
     "datafusion/functions-aggregate",
     "datafusion/functions-aggregate-common",
@@ -99,6 +100,7 @@ datafusion-common-runtime = { path = "datafusion/common-runtime", version = "42.
 datafusion-execution = { path = "datafusion/execution", version = "42.1.0" }
 datafusion-expr = { path = "datafusion/expr", version = "42.1.0" }
 datafusion-expr-common = { path = "datafusion/expr-common", version = "42.1.0" }
+datafusion-ffi = { path = "datafusion/ffi", version = "42.1.0" }
 datafusion-functions = { path = "datafusion/functions", version = "42.1.0" }
 datafusion-functions-aggregate = { path = "datafusion/functions-aggregate", version = "42.1.0" }
 datafusion-functions-aggregate-common = { path = "datafusion/functions-aggregate-common", version = "42.1.0" }

datafusion/ffi/Cargo.toml

@@ -0,0 +1,45 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# 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
+# "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.
+
+[package]
+name = "datafusion-ffi"
+description = "Foreign Function Interface implementation for DataFusion"
+readme = "README.md"
+version = { workspace = true }
+edition = { workspace = true }
+homepage = { workspace = true }
+repository = { workspace = true }
+license = { workspace = true }
+authors = { workspace = true }
+# Specify MSRV here as `cargo msrv` doesn't support workspace version
+rust-version = "1.76"
+
+[lints]
+workspace = true
+
+[lib]
+name = "datafusion_ffi"
+path = "src/lib.rs"
+
+[dependencies]
+arrow = { workspace = true, features = ["ffi"] }
+datafusion = { workspace = true, default-features = true }
+datafusion-proto = { workspace = true }
+futures = { workspace = true }
+async-trait = { workspace = true }
+tokio = { workspace = true }
+prost = { workspace = true }

datafusion/ffi/README.md

@@ -0,0 +1,28 @@
+<!---
+  Licensed to the Apache Software Foundation (ASF) under one
+  or more contributor license agreements.  See the NOTICE file
+  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
+  "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.
+-->
+
+# `datafusion-ffi`: Apache DataFusion Foreign Function Interface
+
+This crate contains code to allow interoperability of Apache [DataFusion]
+with functions from other languages using a stable interface.
+
+See [API Docs] for details and examples.
+
+[datafusion]: https://datafusion.apache.org
+[api docs]: http://docs.rs/datafusion-ffi/latest