perf: Don't maintain order when maintain_order=False in new streaming sinks

crates/polars-io/src/csv/write/options.rs

@@ -10,7 +10,6 @@ pub struct CsvWriterOptions {
     pub include_bom: bool,
     pub include_header: bool,
     pub batch_size: NonZeroUsize,
-    pub maintain_order: bool,
     pub serialize_options: SerializeOptions,
 }
 
@@ -20,7 +19,6 @@ impl Default for CsvWriterOptions {
             include_bom: false,
             include_header: true,
             batch_size: NonZeroUsize::new(1024).unwrap(),
-            maintain_order: false,
             serialize_options: SerializeOptions::default(),
         }
     }

crates/polars-io/src/ipc/write.rs

@@ -14,8 +14,6 @@ use crate::shared::schema_to_arrow_checked;
 pub struct IpcWriterOptions {
     /// Data page compression
     pub compression: Option<IpcCompression>,
-    /// maintain the order the data was processed
-    pub maintain_order: bool,
 }
 
 impl IpcWriterOptions {

crates/polars-io/src/json/mod.rs

@@ -82,10 +82,7 @@ use crate::prelude::*;
 
 #[derive(Copy, Clone, Debug, PartialEq, Eq, Default, Hash)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
-pub struct JsonWriterOptions {
-    /// maintain the order the data was processed
-    pub maintain_order: bool,
-}
+pub struct JsonWriterOptions {}
 
 /// The format to use to write the DataFrame to JSON: `Json` (a JSON array)
 /// or `JsonLines` (each row output on a separate line).

crates/polars-io/src/parquet/write/options.rs

@@ -17,8 +17,6 @@ pub struct ParquetWriteOptions {
     pub row_group_size: Option<usize>,
     /// if `None` will be 1024^2 bytes
     pub data_page_size: Option<usize>,
-    /// maintain the order the data was processed
-    pub maintain_order: bool,
 }
 
 /// The compression strategy to use for writing Parquet files.

crates/polars-pipe/src/executors/sinks/output/csv.rs

@@ -45,7 +45,7 @@ impl CsvSink {
         let io_thread_handle = Arc::new(Some(init_writer_thread(
             receiver,
             writer,
-            options.maintain_order,
+            true,
             morsels_per_sink,
         )));
 

crates/polars-pipe/src/executors/sinks/output/ipc.rs

@@ -32,7 +32,7 @@ impl IpcSink {
         let io_thread_handle = Arc::new(Some(init_writer_thread(
             receiver,
             writer,
-            options.maintain_order,
+            true,
             morsels_per_sink,
         )));
 

crates/polars-pipe/src/executors/sinks/output/json.rs

@@ -24,7 +24,7 @@ impl JsonSink {
     #[allow(clippy::new_ret_no_self)]
     pub fn new(
         path: &Path,
-        options: JsonWriterOptions,
+        _options: JsonWriterOptions,
         _schema: &Schema,
         cloud_options: Option<&CloudOptions>,
     ) -> PolarsResult<FilesSink> {
@@ -38,7 +38,7 @@ impl JsonSink {
         let io_thread_handle = Arc::new(Some(init_writer_thread(
             receiver,
             writer,
-            options.maintain_order,
+            true,
             morsels_per_sink,
         )));
 

crates/polars-plan/src/dsl/options.rs

@@ -304,11 +304,23 @@ pub enum SyncOnCloseType {
 }
 
 /// Options that apply to all sinks.
-#[derive(Clone, PartialEq, Eq, Debug, Default, Hash)]
+#[derive(Clone, PartialEq, Eq, Debug, Hash)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 pub struct SinkOptions {
     /// Call sync when closing the file.
     pub sync_on_close: SyncOnCloseType,
+
+    /// The output file needs to maintain order of the data that comes in.
+    pub maintain_order: bool,
+}
+
+impl Default for SinkOptions {
+    fn default() -> Self {
+        Self {
+            sync_on_close: Default::default(),
+            maintain_order: true,
+        }
+    }
 }
 
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]

crates/polars-python/src/dataframe/io.rs

@@ -443,7 +443,6 @@ impl PyDataFrame {
                     statistics: statistics.0,
                     row_group_size,
                     data_page_size,
-                    maintain_order: true,
                 };
                 write_partitioned_dataset(
                     &mut self.df,

crates/polars-python/src/lazyframe/general.rs

@@ -704,7 +704,7 @@ impl PyLazyFrame {
     #[cfg(all(feature = "streaming", feature = "parquet"))]
     #[pyo3(signature = (
         target, compression, compression_level, statistics, row_group_size, data_page_size,
-        maintain_order, cloud_options, credential_provider, retries, sink_options
+        cloud_options, credential_provider, retries, sink_options
     ))]
     fn sink_parquet(
         &self,
@@ -715,7 +715,6 @@ impl PyLazyFrame {
         statistics: Wrap<StatisticsOptions>,
         row_group_size: Option<usize>,
         data_page_size: Option<usize>,
-        maintain_order: bool,
         cloud_options: Option<Vec<(String, String)>>,
         credential_provider: Option<PyObject>,
         retries: usize,
@@ -728,7 +727,6 @@ impl PyLazyFrame {
             statistics: statistics.0,
             row_group_size,
             data_page_size,
-            maintain_order,
         };
 
         let cloud_options = {
@@ -766,21 +764,19 @@ impl PyLazyFrame {
     }
 
     #[cfg(all(feature = "streaming", feature = "ipc"))]
-    #[pyo3(signature = (target, compression, maintain_order, cloud_options, credential_provider, retries, sink_options))]
+    #[pyo3(signature = (target, compression, cloud_options, credential_provider, retries, sink_options))]
     fn sink_ipc(
         &self,
         py: Python,
         target: SinkTarget,
         compression: Option<Wrap<IpcCompression>>,
-        maintain_order: bool,
         cloud_options: Option<Vec<(String, String)>>,
         credential_provider: Option<PyObject>,
         retries: usize,
         sink_options: Wrap<SinkOptions>,
     ) -> PyResult<()> {
         let options = IpcWriterOptions {
             compression: compression.map(|c| c.0),
-            maintain_order,
         };
 
         #[cfg(feature = "cloud")]
@@ -822,7 +818,7 @@ impl PyLazyFrame {
     #[pyo3(signature = (
         target, include_bom, include_header, separator, line_terminator, quote_char, batch_size,
         datetime_format, date_format, time_format, float_scientific, float_precision, null_value,
-        quote_style, maintain_order, cloud_options, credential_provider, retries, sink_options
+        quote_style, cloud_options, credential_provider, retries, sink_options
     ))]
     fn sink_csv(
         &self,
@@ -841,7 +837,6 @@ impl PyLazyFrame {
         float_precision: Option<usize>,
         null_value: Option<String>,
         quote_style: Option<Wrap<QuoteStyle>>,
-        maintain_order: bool,
         cloud_options: Option<Vec<(String, String)>>,
         credential_provider: Option<PyObject>,
         retries: usize,
@@ -866,7 +861,6 @@ impl PyLazyFrame {
         let options = CsvWriterOptions {
             include_bom,
             include_header,
-            maintain_order,
             batch_size,
             serialize_options,
         };
@@ -908,18 +902,17 @@ impl PyLazyFrame {
 
     #[allow(clippy::too_many_arguments)]
     #[cfg(all(feature = "streaming", feature = "json"))]
-    #[pyo3(signature = (target, maintain_order, cloud_options, credential_provider, retries, sink_options))]
+    #[pyo3(signature = (target, cloud_options, credential_provider, retries, sink_options))]
     fn sink_json(
         &self,
         py: Python,
         target: SinkTarget,
-        maintain_order: bool,
         cloud_options: Option<Vec<(String, String)>>,
         credential_provider: Option<PyObject>,
         retries: usize,
         sink_options: Wrap<SinkOptions>,
     ) -> PyResult<()> {
-        let options = JsonWriterOptions { maintain_order };
+        let options = JsonWriterOptions {};
 
         let cloud_options = {
             let cloud_options = parse_cloud_options(

crates/polars-python/src/lazyframe/sink.rs

@@ -74,16 +74,25 @@ impl<'py> FromPyObject<'py> for Wrap<SinkOptions> {
     fn extract_bound(ob: &Bound<'py, PyAny>) -> PyResult<Self> {
         let parsed = ob.extract::<pyo3::Bound<'_, PyDict>>()?;
 
-        if parsed.len() != 1 {
+        if parsed.len() != 2 {
             return Err(PyValueError::new_err(
-                "`sink_options` must be a dictionary with the exactly 1 field.",
+                "`sink_options` must be a dictionary with the exactly 2 field.",
             ));
         }
 
         let sync_on_close = PyDictMethods::get_item(&parsed, "sync_on_close")?
             .ok_or_else(|| PyValueError::new_err("`sink_options` must be `sync_on_close` field"))?;
         let sync_on_close = sync_on_close.extract::<Wrap<SyncOnCloseType>>()?.0;
 
-        Ok(Wrap(SinkOptions { sync_on_close }))
+        let maintain_order =
+            PyDictMethods::get_item(&parsed, "maintain_order")?.ok_or_else(|| {
+                PyValueError::new_err("`sink_options` must be `maintain_order` field")
+            })?;
+        let maintain_order = maintain_order.extract::<bool>()?;
+
+        Ok(Wrap(SinkOptions {
+            sync_on_close,
+            maintain_order,
+        }))
     }
 }

crates/polars-stream/src/async_primitives/linearizer.rs

@@ -59,6 +59,31 @@ impl<T: Ord> Linearizer<T> {
         (slf, inserters)
     }
 
+    pub fn new_with_maintain_order(
+        num_inserters: usize,
+        buffer_size: usize,
+        maintain_order: bool,
+    ) -> (Self, Vec<Inserter<T>>) {
+        if maintain_order {
+            return Self::new(num_inserters, buffer_size);
+        }
+
+        let (sender, receiver) = channel(buffer_size * num_inserters);
+        let receivers = vec![receiver];
+        let inserters = (0..num_inserters)
+            .map(|_| Inserter {
+                sender: sender.clone(),
+            })
+            .collect();
+
+        let slf = Self {
+            receivers,
+            poll_state: PollState::PollAll,
+            heap: BinaryHeap::with_capacity(1),
+        };
+        (slf, inserters)
+    }
+
     /// Fetch the next ordered item produced by senders.
     ///
     /// This may wait for at each sender to have sent at least one value before the [`Linearizer`]

crates/polars-stream/src/nodes/io_sinks/csv.rs

@@ -47,6 +47,9 @@ impl SinkNode for CsvSinkNode {
     fn is_sink_input_parallel(&self) -> bool {
         true
     }
+    fn do_maintain_order(&self) -> bool {
+        self.sink_options.maintain_order
+    }
 
     fn spawn_sink(
         &mut self,
@@ -74,8 +77,11 @@ impl SinkNode for CsvSinkNode {
         // .. -> Encode task
         let rxs = recv_port.parallel();
         // Encode tasks -> IO task
-        let (mut lin_rx, lin_txs) =
-            Linearizer::<Linearized>::new(num_pipelines, DEFAULT_SINK_LINEARIZER_BUFFER_SIZE);
+        let (mut lin_rx, lin_txs) = Linearizer::<Linearized>::new_with_maintain_order(
+            num_pipelines,
+            DEFAULT_SINK_LINEARIZER_BUFFER_SIZE,
+            self.sink_options.maintain_order,
+        );
 
         // 16MB
         const DEFAULT_ALLOCATION_SIZE: usize = 1 << 24;

crates/polars-stream/src/nodes/io_sinks/ipc.rs

@@ -70,6 +70,9 @@ impl SinkNode for IpcSinkNode {
     fn is_sink_input_parallel(&self) -> bool {
         false
     }
+    fn do_maintain_order(&self) -> bool {
+        self.sink_options.maintain_order
+    }
 
     fn spawn_sink(
         &mut self,

crates/polars-stream/src/nodes/io_sinks/json.rs

@@ -32,6 +32,9 @@ impl SinkNode for NDJsonSinkNode {
     fn is_sink_input_parallel(&self) -> bool {
         true
     }
+    fn do_maintain_order(&self) -> bool {
+        self.sink_options.maintain_order
+    }
 
     fn spawn_sink(
         &mut self,
@@ -59,8 +62,11 @@ impl SinkNode for NDJsonSinkNode {
         // .. -> Encode task
         let rxs = recv_port.parallel();
         // Encode tasks -> IO task
-        let (mut lin_rx, lin_txs) =
-            Linearizer::<Linearized>::new(num_pipelines, DEFAULT_SINK_LINEARIZER_BUFFER_SIZE);
+        let (mut lin_rx, lin_txs) = Linearizer::<Linearized>::new_with_maintain_order(
+            num_pipelines,
+            DEFAULT_SINK_LINEARIZER_BUFFER_SIZE,
+            self.sink_options.maintain_order,
+        );
 
         // 16MB
         const DEFAULT_ALLOCATION_SIZE: usize = 1 << 24;

crates/polars-stream/src/nodes/io_sinks/mod.rs

@@ -185,6 +185,7 @@ fn buffer_and_distribute_columns_task(
 pub trait SinkNode {
     fn name(&self) -> &str;
     fn is_sink_input_parallel(&self) -> bool;
+    fn do_maintain_order(&self) -> bool;
 
     fn spawn_sink(
         &mut self,
@@ -304,7 +305,7 @@ impl ComputeNode for SinkComputeNode {
         let sink_input = if self.sink.is_sink_input_parallel() {
             SinkInputPort::Parallel(recv.parallel())
         } else {
-            SinkInputPort::Serial(recv.serial())
+            SinkInputPort::Serial(recv.serial_with_maintain_order(self.sink.do_maintain_order()))
         };
         join_handles.push(scope.spawn_task(TaskPriority::High, async move {
             let (token, outcome) = PhaseOutcome::new_shared_wait(wait_group.token());

crates/polars-stream/src/nodes/io_sinks/parquet.rs

@@ -78,6 +78,9 @@ impl SinkNode for ParquetSinkNode {
     fn is_sink_input_parallel(&self) -> bool {
         false
     }
+    fn do_maintain_order(&self) -> bool {
+        self.sink_options.maintain_order
+    }
 
     fn spawn_sink(
         &mut self,