From d967d2e1670ad3943aed1061f6b42a375e34fc11 Mon Sep 17 00:00:00 2001
From: Dylan Chen <zilin@singularity-data.com>
Date: Mon, 22 Jul 2024 13:52:55 +0800
Subject: [PATCH] support dedicated runtime for file scan

---
 src/frontend/src/expr/table_function.rs | 69 ++++++++++++++-----------
 1 file changed, 39 insertions(+), 30 deletions(-)

diff --git a/src/frontend/src/expr/table_function.rs b/src/frontend/src/expr/table_function.rs
index f4dda8d8176be..0cfab3e102553 100644
--- a/src/frontend/src/expr/table_function.rs
+++ b/src/frontend/src/expr/table_function.rs
@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-use std::sync::Arc;
+use std::sync::{Arc, LazyLock};
 
 use itertools::Itertools;
 use risingwave_common::array::arrow::IcebergArrowConvert;
@@ -20,6 +20,7 @@ use risingwave_common::types::{DataType, ScalarImpl, StructType};
 use risingwave_connector::source::iceberg::create_parquet_stream_builder;
 pub use risingwave_pb::expr::table_function::PbType as TableFunctionType;
 use risingwave_pb::expr::PbTableFunction;
+use tokio::runtime::Runtime;
 
 use super::{infer_type, Expr, ExprImpl, ExprRewriter, RwResult};
 use crate::catalog::function_catalog::{FunctionCatalog, FunctionKind};
@@ -132,36 +133,44 @@ impl TableFunction {
                 .into());
             }
 
-            #[cfg(madsim)]
-            return Err(crate::error::ErrorCode::BindError(
-                "file_scan can't be used in the madsim mode".to_string(),
-            )
-            .into());
-
-            #[cfg(not(madsim))]
-            tokio::task::block_in_place(|| {
-                tokio::runtime::Handle::current().block_on(async {
-                    let parquet_stream_builder = create_parquet_stream_builder(
-                        eval_args[2].clone(),
-                        eval_args[3].clone(),
-                        eval_args[4].clone(),
-                        eval_args[5].clone(),
-                    )
-                    .await?;
-
-                    let mut rw_types = vec![];
-                    for field in parquet_stream_builder.schema().fields() {
-                        rw_types.push((
-                            field.name().to_string(),
-                            IcebergArrowConvert.type_from_field(field)?,
-                        ));
-                    }
+            if cfg!(madsim) {
+                return Err(crate::error::ErrorCode::BindError(
+                    "file_scan can't be used in the madsim mode".to_string(),
+                )
+                .into());
+            } else {
+                static RUNTIME: LazyLock<Runtime> = LazyLock::new(|| {
+                    tokio::runtime::Builder::new_multi_thread()
+                        .thread_name("rw-file-scan")
+                        .enable_all()
+                        .build()
+                        .expect("failed to build file-scan runtime")
+                });
+
+                tokio::task::block_in_place(|| {
+                    RUNTIME.block_on(async {
+                        let parquet_stream_builder = create_parquet_stream_builder(
+                            eval_args[2].clone(),
+                            eval_args[3].clone(),
+                            eval_args[4].clone(),
+                            eval_args[5].clone(),
+                        )
+                        .await?;
+
+                        let mut rw_types = vec![];
+                        for field in parquet_stream_builder.schema().fields() {
+                            rw_types.push((
+                                field.name().to_string(),
+                                IcebergArrowConvert.type_from_field(field)?,
+                            ));
+                        }
 
-                    Ok::<risingwave_common::types::DataType, anyhow::Error>(DataType::Struct(
-                        StructType::new(rw_types),
-                    ))
-                })
-            })?
+                        Ok::<risingwave_common::types::DataType, anyhow::Error>(DataType::Struct(
+                            StructType::new(rw_types),
+                        ))
+                    })
+                })?
+            }
         };
 
         Ok(TableFunction {