timsaucer commented on code in PR #19223: URL: https://github.com/apache/datafusion/pull/19223#discussion_r2601465878
########## datafusion/ffi/src/session/mod.rs: ########## @@ -0,0 +1,614 @@ +// 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. + +use std::any::Any; +use std::collections::HashMap; +use std::ffi::c_void; +use std::sync::Arc; + +use abi_stable::std_types::{RHashMap, RResult, RStr, RString, RVec}; +use abi_stable::StableAbi; +use arrow_schema::ffi::FFI_ArrowSchema; +use arrow_schema::SchemaRef; +use async_ffi::{FfiFuture, FutureExt}; +use async_trait::async_trait; +use datafusion_common::config::{ConfigOptions, TableOptions}; +use datafusion_common::{DFSchema, DataFusionError}; +use datafusion_execution::config::SessionConfig; +use datafusion_execution::runtime_env::RuntimeEnv; +use datafusion_execution::TaskContext; +use datafusion_expr::execution_props::ExecutionProps; +use datafusion_expr::{ + AggregateUDF, AggregateUDFImpl, Expr, LogicalPlan, ScalarUDF, ScalarUDFImpl, + WindowUDF, WindowUDFImpl, +}; +use datafusion_physical_expr::PhysicalExpr; +use datafusion_physical_plan::ExecutionPlan; +use datafusion_proto::bytes::{logical_plan_from_bytes, logical_plan_to_bytes}; +use datafusion_proto::logical_plan::from_proto::parse_expr; +use datafusion_proto::logical_plan::to_proto::serialize_expr; +use datafusion_proto::logical_plan::{ + DefaultLogicalExtensionCodec, LogicalExtensionCodec, +}; +use datafusion_proto::protobuf::LogicalExprNode; +use datafusion_session::Session; +use prost::Message; +use tokio::runtime::Handle; + +use crate::arrow_wrappers::WrappedSchema; +use crate::execution::{FFI_TaskContext, FFI_TaskContextProvider}; +use crate::execution_plan::FFI_ExecutionPlan; +use crate::physical_expr::FFI_PhysicalExpr; +use crate::proto::logical_extension_codec::FFI_LogicalExtensionCodec; +use crate::session::config::FFI_SessionConfig; +use crate::udaf::FFI_AggregateUDF; +use crate::udf::FFI_ScalarUDF; +use crate::udwf::FFI_WindowUDF; +use crate::util::FFIResult; +use crate::{df_result, rresult, rresult_return}; + +pub mod config; + +/// A stable struct for sharing [`Session`] across FFI boundaries. +#[repr(C)] +#[derive(Debug, StableAbi)] +#[allow(non_camel_case_types)] +pub struct FFI_Session { + pub session_id: unsafe extern "C" fn(&Self) -> RStr, + + pub config: unsafe extern "C" fn(&Self) -> FFI_SessionConfig, + + pub create_physical_plan: + unsafe extern "C" fn( + &Self, + logical_plan_serialized: RVec<u8>, + ) -> FfiFuture<FFIResult<FFI_ExecutionPlan>>, + + pub create_physical_expr: unsafe extern "C" fn( + &Self, + expr_serialized: RVec<u8>, + schema: WrappedSchema, + ) -> FFIResult<FFI_PhysicalExpr>, + + pub scalar_functions: unsafe extern "C" fn(&Self) -> RHashMap<RString, FFI_ScalarUDF>, + + pub aggregate_functions: + unsafe extern "C" fn(&Self) -> RHashMap<RString, FFI_AggregateUDF>, + + pub window_functions: unsafe extern "C" fn(&Self) -> RHashMap<RString, FFI_WindowUDF>, + + // TODO: Expand scope of FFI to include runtime environment + // pub runtime_env: unsafe extern "C" fn(&Self) -> FFI_RuntimeEnv, + + // pub execution_props: unsafe extern "C" fn(&Self) -> FFI_ExecutionProps, + pub table_options: unsafe extern "C" fn(&Self) -> RHashMap<RString, RString>, + + pub default_table_options: unsafe extern "C" fn(&Self) -> RHashMap<RString, RString>, + + pub task_ctx: unsafe extern "C" fn(&Self) -> FFI_TaskContext, + + pub logical_codec: FFI_LogicalExtensionCodec, + + /// Used to create a clone on the provider of the registry. This should + /// only need to be called by the receiver of the plan. + pub clone: unsafe extern "C" fn(plan: &Self) -> Self, + + /// Release the memory of the private data when it is no longer being used. + pub release: unsafe extern "C" fn(arg: &mut Self), + + /// Return the major DataFusion version number of this registry. + pub version: unsafe extern "C" fn() -> u64, + + /// Internal data. This is only to be accessed by the provider of the plan. + /// A [`ForeignSession`] should never attempt to access this data. + pub private_data: *mut c_void, + + /// Utility to identify when FFI objects are accessed locally through + /// the foreign interface. + pub library_marker_id: extern "C" fn() -> usize, +} + +unsafe impl Send for FFI_Session {} +unsafe impl Sync for FFI_Session {} + +struct SessionPrivateData<'a> { + session: &'a (dyn Session + Send + Sync), + runtime: Option<Handle>, +} Review Comment: This structure is different than all of the rest in this crate. We are carrying around borrowed data to the session. The reason for this is that `TableProvider::scan` passes `&dyn Session`. I need to think more about this. It is possible we need this to be `'static` instead, but that also would not work with how we intend to use it in the FFI Table Providers that need to implement the `TableProvider` trait. I am not 100% confident that we can guarantee the lifetime safety of this structure. Maybe we need a piece of dummy data just so we can carry a lifetime on `FFI_Session`? -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
