Remove unnecessary StageExec proto serde overhead (#163)

* Remove unnecessary StageExec proto serde overhead

* Add doc comments for protobuf parsing code

Author: gabotechs

Cargo.lock

@@ -30,6 +30,7 @@ dashmap = "6.1.0"
 prost = "0.13.5"
 rand = "0.8.5"
 object_store = "0.12.3"
+bytes = "1.10.1"
 
 # integration_tests deps
 insta = { version = "1.43.1", features = ["filters"], optional = true }

Cargo.toml

@@ -282,7 +282,6 @@ impl DistributedPhysicalOptimizerRule {
             distributed.data = Arc::new(CoalescePartitionsExec::new(distributed.data));
         }
 
-        let inputs = inputs.into_iter().map(Arc::new).collect();
         let mut stage = StageExec::new(query_id, *num, distributed.data, inputs, n_tasks);
         *num += 1;
 

src/distributed_physical_optimizer_rule.rs

@@ -8,5 +8,6 @@ mod stage;
 pub use network_coalesce::{NetworkCoalesceExec, NetworkCoalesceReady};
 pub use network_shuffle::{NetworkShuffleExec, NetworkShuffleReadyExec};
 pub use partition_isolator::PartitionIsolatorExec;
+pub(crate) use stage::InputStage;
 pub use stage::display_plan_graphviz;
 pub use stage::{DistributedTaskContext, ExecutionTask, StageExec};

src/execution_plans/mod.rs

@@ -6,7 +6,7 @@ use crate::distributed_physical_optimizer_rule::{NetworkBoundary, limit_tasks_er
 use crate::execution_plans::{DistributedTaskContext, StageExec};
 use crate::flight_service::DoGet;
 use crate::metrics::proto::MetricsSetProto;
-use crate::protobuf::{DistributedCodec, StageKey, proto_from_stage};
+use crate::protobuf::{DistributedCodec, StageKey, proto_from_input_stage};
 use crate::protobuf::{map_flight_to_datafusion_error, map_status_to_datafusion_error};
 use arrow_flight::Ticket;
 use arrow_flight::decode::FlightRecordBatchStream;
@@ -235,12 +235,11 @@ impl ExecutionPlan for NetworkCoalesceExec {
         // the `NetworkCoalesceExec` node can only be executed in the context of a `StageExec`
         let stage = StageExec::from_ctx(&context)?;
 
-        // of our child stages find the one that matches the one we are supposed to be
-        // reading from
-        let child_stage = stage.child_stage(self_ready.stage_num)?;
+        // of our input stages find the one that we are supposed to be reading from
+        let input_stage = stage.input_stage(self_ready.stage_num)?;
 
         let codec = DistributedCodec::new_combined_with_user(context.session_config());
-        let child_stage_proto = proto_from_stage(child_stage, &codec).map_err(|e| {
+        let input_stage_proto = proto_from_input_stage(input_stage, &codec).map_err(|e| {
             internal_datafusion_err!("NetworkCoalesceExec: failed to convert stage to proto: {e}")
         })?;
 
@@ -251,7 +250,7 @@ impl ExecutionPlan for NetworkCoalesceExec {
         }
 
         let partitions_per_task =
-            self.properties().partitioning.partition_count() / child_stage.tasks.len();
+            self.properties().partitioning.partition_count() / input_stage.tasks().len();
 
         let target_task = partition / partitions_per_task;
         let target_partition = partition % partitions_per_task;
@@ -261,11 +260,11 @@ impl ExecutionPlan for NetworkCoalesceExec {
             Extensions::default(),
             Ticket {
                 ticket: DoGet {
-                    stage_proto: Some(child_stage_proto.clone()),
+                    stage_proto: input_stage_proto,
                     target_partition: target_partition as u64,
                     stage_key: Some(StageKey {
                         query_id: stage.query_id.to_string(),
-                        stage_id: child_stage.num as u64,
+                        stage_id: input_stage.num() as u64,
                         task_number: target_task as u64,
                     }),
                     target_task_index: target_task as u64,
@@ -275,7 +274,7 @@ impl ExecutionPlan for NetworkCoalesceExec {
             },
         );
 
-        let Some(task) = child_stage.tasks.get(target_task) else {
+        let Some(task) = input_stage.tasks().get(target_task) else {
             return internal_err!("ProgrammingError: Task {target_task} not found");
         };
 

src/execution_plans/network_coalesce.rs

@@ -6,7 +6,7 @@ use crate::distributed_physical_optimizer_rule::NetworkBoundary;
 use crate::execution_plans::{DistributedTaskContext, StageExec};
 use crate::flight_service::DoGet;
 use crate::metrics::proto::MetricsSetProto;
-use crate::protobuf::{DistributedCodec, StageKey, proto_from_stage};
+use crate::protobuf::{DistributedCodec, StageKey, proto_from_input_stage};
 use crate::protobuf::{map_flight_to_datafusion_error, map_status_to_datafusion_error};
 use arrow_flight::Ticket;
 use arrow_flight::decode::FlightRecordBatchStream;
@@ -293,34 +293,34 @@ impl ExecutionPlan for NetworkShuffleExec {
 
         // of our child stages find the one that matches the one we are supposed to be
         // reading from
-        let child_stage = stage.child_stage(self_ready.stage_num)?;
+        let input_stage = stage.input_stage(self_ready.stage_num)?;
 
         let codec = DistributedCodec::new_combined_with_user(context.session_config());
-        let child_stage_proto = proto_from_stage(child_stage, &codec).map_err(|e| {
+        let input_stage_proto = proto_from_input_stage(input_stage, &codec).map_err(|e| {
             internal_datafusion_err!("NetworkShuffleExec: failed to convert stage to proto: {e}")
         })?;
 
-        let child_stage_tasks = child_stage.tasks.clone();
-        let child_stage_num = child_stage.num as u64;
+        let input_stage_tasks = input_stage.tasks().to_vec();
+        let input_stage_num = input_stage.num() as u64;
         let query_id = stage.query_id.to_string();
 
         let context_headers = ContextGrpcMetadata::headers_from_ctx(&context);
         let task_context = DistributedTaskContext::from_ctx(&context);
         let off = self_ready.properties.partitioning.partition_count() * task_context.task_index;
 
-        let stream = child_stage_tasks.into_iter().enumerate().map(|(i, task)| {
+        let stream = input_stage_tasks.into_iter().enumerate().map(|(i, task)| {
             let channel_resolver = Arc::clone(&channel_resolver);
 
             let ticket = Request::from_parts(
                 MetadataMap::from_headers(context_headers.clone()),
                 Extensions::default(),
                 Ticket {
                     ticket: DoGet {
-                        stage_proto: Some(child_stage_proto.clone()),
+                        stage_proto: input_stage_proto.clone(),
                         target_partition: (off + partition) as u64,
                         stage_key: Some(StageKey {
                             query_id: query_id.clone(),
-                            stage_id: child_stage_num,
+                            stage_id: input_stage_num,
                             task_number: i as u64,
                         }),
                         target_task_index: i as u64,