kosiew commented on code in PR #25765:
URL: https://github.com/apache/datafusion/pull/25765#discussion_r4282992988
##########
datafusion/physical-plan/src/memory.rs:
##########
@@ -159,6 +159,19 @@ pub trait LazyBatchGenerator: Send + Sync + fmt::Debug +
fmt::Display {
/// Returns a new instance with the state reset.
fn reset_state(&self) -> Arc<RwLock<dyn LazyBatchGenerator>>;
+
+ /// Encode this generator using the built-in generate-series wire format.
Review Comment:
Could we clarify the contract for this hook? Returning `Some(node)` means
the plan will be reconstructed as a built-in series generator, so its rows,
batch boundaries, and schema should match the original generator after reset.
It would also help to mention that `Err` stops serialization, while only
`Ok(None)` allows extension fallback.
##########
datafusion/proto/tests/cases/plans/lazy_memory.rs:
##########
@@ -0,0 +1,345 @@
+// 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::fmt;
+use std::sync::Arc;
+
+use arrow::array::{Int64Array, RecordBatch, TimestampNanosecondArray};
+use arrow::datatypes::{DataType, Field, Schema, TimeUnit};
+use datafusion_common::{Result, assert_contains, not_impl_err};
+use datafusion_execution::TaskContext;
+use datafusion_physical_plan::ExecutionPlan;
+use datafusion_physical_plan::common::collect;
+use datafusion_physical_plan::memory::{LazyBatchGenerator, LazyMemoryExec};
+use datafusion_proto::physical_plan::{
+ AsExecutionPlan, DefaultPhysicalExtensionCodec, PhysicalExtensionCodec,
+ PhysicalProtoConverterExtension,
+};
+use datafusion_proto::protobuf::{self, PhysicalPlanNode};
+use parking_lot::RwLock;
+use prost::Message;
+
+fn plan_node(node: protobuf::GenerateSeriesNode) -> PhysicalPlanNode {
+ PhysicalPlanNode {
+ physical_plan_type: Some(
+
protobuf::physical_plan_node::PhysicalPlanType::GenerateSeries(node),
+ ),
+ }
+}
+
+fn int_node() -> Result<protobuf::GenerateSeriesNode> {
+ let schema = Schema::new(vec![Field::new("v", DataType::Int64, false)]);
+ Ok(protobuf::GenerateSeriesNode {
+ schema: Some((&schema).try_into()?),
+ target_batch_size: 2,
+ args: Some(protobuf::generate_series_node::Args::Int64Args(
+ protobuf::GenerateSeriesArgsInt64 {
+ start: 3,
+ end: 1,
+ step: -1,
+ include_end: true,
+ name: protobuf::GenerateSeriesName::GsGenerateSeries as i32,
+ },
+ )),
+ })
+}
+
+/// Construct the legacy wire messages independently of the generator hooks,
+/// then check exact re-encoding and actual execution, including batch sizes.
+#[tokio::test]
+async fn lazy_memory_legacy_wire_roundtrip() -> Result<()> {
+ use protobuf::generate_series_node::Args;
+ for (name, include_end) in [
+ (protobuf::GenerateSeriesName::GsGenerateSeries, true),
+ (protobuf::GenerateSeriesName::GsRange, false),
+ ] {
+ let mut integer = int_node()?;
+ let Some(Args::Int64Args(args)) = integer.args.as_mut() else {
+ unreachable!()
+ };
+ args.name = name as i32;
+ args.include_end = include_end;
+ let mut empty = integer.clone();
+ empty.target_batch_size = 8192;
+ empty.args = Some(Args::ContainsNull(
+ protobuf::GenerateSeriesArgsContainsNull { name: name as i32 },
+ ));
+ let expected = if include_end {
+ vec![3, 2, 1]
+ } else {
+ vec![3, 2]
+ };
+ let mut cases = vec![(integer, expected.clone()), (empty, vec![])];
+ for tz in [None, Some("+08:00")] {
+ let schema = Schema::new(vec![Field::new(
+ "v",
+ DataType::Timestamp(TimeUnit::Nanosecond, tz.map(Into::into)),
+ false,
+ )]);
+ let step = Some(datafusion_proto_common::IntervalMonthDayNanoValue
{
+ months: 0,
+ days: 0,
+ nanos: -1,
+ });
+ let args = match tz {
+ Some(tz) =>
Args::TimestampArgs(protobuf::GenerateSeriesArgsTimestamp {
+ start: 3,
+ end: 1,
+ step,
+ include_end,
+ name: name as i32,
+ tz: Some(tz.to_string()),
+ }),
+ None => Args::DateArgs(protobuf::GenerateSeriesArgsDate {
+ start: 3,
+ end: 1,
+ step,
+ include_end,
+ name: name as i32,
+ }),
+ };
+ cases.push((
+ protobuf::GenerateSeriesNode {
+ schema: Some((&schema).try_into()?),
+ target_batch_size: 2,
+ args: Some(args),
+ },
+ expected.clone(),
+ ));
+ }
+ for (node, expected) in cases {
+ let legacy = plan_node(node);
+ let bytes = legacy.encode_to_vec();
+ let decoded = PhysicalPlanNode::decode(bytes.as_slice()).unwrap();
+ let ctx = Arc::new(TaskContext::default());
+ let plan = decoded
+ .try_into_physical_plan(&ctx, &DefaultPhysicalExtensionCodec
{})?;
+ let encoded = PhysicalPlanNode::try_from_physical_plan(
+ Arc::clone(&plan),
+ &DefaultPhysicalExtensionCodec {},
+ )?;
+ assert_eq!(encoded.encode_to_vec(), bytes);
+ // Repeated execute calls must still produce fresh independent
streams.
+ for _ in 0..2 {
+ let batches = collect(plan.execute(0,
Arc::clone(&ctx))?).await?;
+ let sizes: Vec<_> =
batches.iter().map(RecordBatch::num_rows).collect();
+ let expected_sizes: Vec<_> =
+ expected.chunks(2).map(<[i64]>::len).collect();
+ assert_eq!(sizes, expected_sizes);
+ let actual: Vec<i64> = batches
+ .iter()
+ .flat_map(|batch| {
+ let column = batch.column(0);
+ if let Some(array) =
column.as_any().downcast_ref::<Int64Array>()
+ {
+ array.values().to_vec()
+ } else {
+ column
+ .as_any()
+ .downcast_ref::<TimestampNanosecondArray>()
+ .unwrap()
+ .values()
+ .to_vec()
+ }
+ })
+ .collect();
+ assert_eq!(actual, expected);
+ }
+ }
+ }
+ Ok(())
+}
+
+#[derive(Debug, Clone)]
+struct HookGenerator(protobuf::GenerateSeriesNode);
+
+impl fmt::Display for HookGenerator {
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ write!(f, "HookGenerator")
+ }
+}
+
+impl LazyBatchGenerator for HookGenerator {
+ fn as_any(&self) -> &dyn Any {
+ self
+ }
+ fn generate_next_batch(&mut self) -> Result<Option<RecordBatch>> {
+ Ok(None)
+ }
+ fn reset_state(&self) -> Arc<RwLock<dyn LazyBatchGenerator>> {
+ Arc::new(RwLock::new(self.clone()))
+ }
+ fn try_to_proto(&self) -> Result<Option<protobuf::GenerateSeriesNode>> {
+ Ok(Some(self.0.clone()))
+ }
+}
+
+#[test]
+fn lazy_memory_dispatches_to_generator_hook() -> Result<()> {
Review Comment:
Could we optionally add a custom generator that delegates execution and
reset to a real series, then compare its rows, batch sizes, and schema before
and after serialization? The current `HookGenerator` returns no rows even
though its payload represents `[3, 2, 1]`, so this would help demonstrate the
execution contract for custom generators.
--
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]
