feat: Implement compression and skipping for binview IPC

crates/polars-arrow/src/io/ipc/read/array/binview.rs

@@ -65,3 +65,34 @@ pub fn read_binview<T: ViewType + ?Sized, R: Read + Seek>(
     BinaryViewArrayGeneric::<T>::try_new(data_type, views, Arc::from(variadic_buffers), validity)
         .map(|arr| arr.boxed())
 }
+
+pub fn skip_binview(
+    field_nodes: &mut VecDeque<Node>,
+    buffers: &mut VecDeque<IpcBuffer>,
+    variadic_buffer_counts: &mut VecDeque<usize>,
+) -> PolarsResult<()> {
+    let _ = field_nodes.pop_front().ok_or_else(|| {
+        polars_err!(
+            oos = "IPC: unable to fetch the field for utf8. The file or stream is corrupted."
+        )
+    })?;
+
+    let _ = buffers
+        .pop_front()
+        .ok_or_else(|| polars_err!(oos = "IPC: missing validity buffer."))?;
+
+    let _ = buffers
+        .pop_front()
+        .ok_or_else(|| polars_err!(oos = "IPC: missing views buffer."))?;
+
+    let n_variadic = variadic_buffer_counts.pop_front().ok_or_else(
+        || polars_err!(ComputeError: "IPC: unable to fetch the variadic buffers\n\nThe file or stream is corrupted.")
+    )?;
+
+    for _ in 0..n_variadic {
+        let _ = buffers
+            .pop_front()
+            .ok_or_else(|| polars_err!(oos = "IPC: missing variadic buffer"))?;
+    }
+    Ok(())
+}

crates/polars-arrow/src/io/ipc/read/array/fixed_size_list.rs

@@ -66,6 +66,7 @@ pub fn skip_fixed_size_list(
     field_nodes: &mut VecDeque<Node>,
     data_type: &ArrowDataType,
     buffers: &mut VecDeque<IpcBuffer>,
+    variadic_buffer_counts: &mut VecDeque<usize>,
 ) -> PolarsResult<()> {
     let _ = field_nodes.pop_front().ok_or_else(|| {
         polars_err!(oos =
@@ -79,5 +80,10 @@ pub fn skip_fixed_size_list(
 
     let (field, _) = FixedSizeListArray::get_child_and_size(data_type);
 
-    skip(field_nodes, field.data_type(), buffers)
+    skip(
+        field_nodes,
+        field.data_type(),
+        buffers,
+        variadic_buffer_counts,
+    )
 }

crates/polars-arrow/src/io/ipc/read/array/list.rs

@@ -85,6 +85,7 @@ pub fn skip_list<O: Offset>(
     field_nodes: &mut VecDeque<Node>,
     data_type: &ArrowDataType,
     buffers: &mut VecDeque<IpcBuffer>,
+    variadic_buffer_counts: &mut VecDeque<usize>,
 ) -> PolarsResult<()> {
     let _ = field_nodes.pop_front().ok_or_else(|| {
         polars_err!(
@@ -101,5 +102,5 @@ pub fn skip_list<O: Offset>(
 
     let data_type = ListArray::<O>::get_child_type(data_type);
 
-    skip(field_nodes, data_type, buffers)
+    skip(field_nodes, data_type, buffers, variadic_buffer_counts)
 }

crates/polars-arrow/src/io/ipc/read/array/map.rs

@@ -81,6 +81,7 @@ pub fn skip_map(
     field_nodes: &mut VecDeque<Node>,
     data_type: &ArrowDataType,
     buffers: &mut VecDeque<IpcBuffer>,
+    variadic_buffer_counts: &mut VecDeque<usize>,
 ) -> PolarsResult<()> {
     let _ = field_nodes.pop_front().ok_or_else(|| {
         polars_err!(
@@ -97,5 +98,5 @@ pub fn skip_map(
 
     let data_type = MapArray::get_field(data_type).data_type();
 
-    skip(field_nodes, data_type, buffers)
+    skip(field_nodes, data_type, buffers, variadic_buffer_counts)
 }

crates/polars-arrow/src/io/ipc/read/array/struct_.rs

@@ -71,6 +71,7 @@ pub fn skip_struct(
     field_nodes: &mut VecDeque<Node>,
     data_type: &ArrowDataType,
     buffers: &mut VecDeque<IpcBuffer>,
+    variadic_buffer_counts: &mut VecDeque<usize>,
 ) -> PolarsResult<()> {
     let _ = field_nodes.pop_front().ok_or_else(|| {
         polars_err!(
@@ -84,7 +85,12 @@ pub fn skip_struct(
 
     let fields = StructArray::get_fields(data_type);
 
-    fields
-        .iter()
-        .try_for_each(|field| skip(field_nodes, field.data_type(), buffers))
+    fields.iter().try_for_each(|field| {
+        skip(
+            field_nodes,
+            field.data_type(),
+            buffers,
+            variadic_buffer_counts,
+        )
+    })
 }

crates/polars-arrow/src/io/ipc/read/array/union.rs

@@ -97,6 +97,7 @@ pub fn skip_union(
     field_nodes: &mut VecDeque<Node>,
     data_type: &ArrowDataType,
     buffers: &mut VecDeque<IpcBuffer>,
+    variadic_buffer_counts: &mut VecDeque<usize>,
 ) -> PolarsResult<()> {
     let _ = field_nodes.pop_front().ok_or_else(|| {
         polars_err!(
@@ -117,7 +118,12 @@ pub fn skip_union(
 
     let fields = UnionArray::get_fields(data_type);
 
-    fields
-        .iter()
-        .try_for_each(|field| skip(field_nodes, field.data_type(), buffers))
+    fields.iter().try_for_each(|field| {
+        skip(
+            field_nodes,
+            field.data_type(),
+            buffers,
+            variadic_buffer_counts,
+        )
+    })
 }

crates/polars-arrow/src/io/ipc/read/common.rs

@@ -149,7 +149,12 @@ pub fn read_record_batch<R: Read + Seek>(
                     scratch,
                 )?)),
                 ProjectionResult::NotSelected((field, _)) => {
-                    skip(&mut field_nodes, &field.data_type, &mut buffers)?;
+                    skip(
+                        &mut field_nodes,
+                        &field.data_type,
+                        &mut buffers,
+                        &mut variadic_buffer_counts,
+                    )?;
                     Ok(None)
                 },
             })

crates/polars-arrow/src/io/ipc/read/deserialize.rs

@@ -263,6 +263,7 @@ pub fn skip(
     field_nodes: &mut VecDeque<Node>,
     data_type: &ArrowDataType,
     buffers: &mut VecDeque<IpcBuffer>,
+    variadic_buffer_counts: &mut VecDeque<usize>,
 ) -> PolarsResult<()> {
     use PhysicalType::*;
     match data_type.to_physical_type() {
@@ -272,13 +273,15 @@ pub fn skip(
         LargeBinary | Binary => skip_binary(field_nodes, buffers),
         LargeUtf8 | Utf8 => skip_utf8(field_nodes, buffers),
         FixedSizeBinary => skip_fixed_size_binary(field_nodes, buffers),
-        List => skip_list::<i32>(field_nodes, data_type, buffers),
-        LargeList => skip_list::<i64>(field_nodes, data_type, buffers),
-        FixedSizeList => skip_fixed_size_list(field_nodes, data_type, buffers),
-        Struct => skip_struct(field_nodes, data_type, buffers),
+        List => skip_list::<i32>(field_nodes, data_type, buffers, variadic_buffer_counts),
+        LargeList => skip_list::<i64>(field_nodes, data_type, buffers, variadic_buffer_counts),
+        FixedSizeList => {
+            skip_fixed_size_list(field_nodes, data_type, buffers, variadic_buffer_counts)
+        },
+        Struct => skip_struct(field_nodes, data_type, buffers, variadic_buffer_counts),
         Dictionary(_) => skip_dictionary(field_nodes, buffers),
-        Union => skip_union(field_nodes, data_type, buffers),
-        Map => skip_map(field_nodes, data_type, buffers),
-        BinaryView | Utf8View => todo!(),
+        Union => skip_union(field_nodes, data_type, buffers, variadic_buffer_counts),
+        Map => skip_map(field_nodes, data_type, buffers, variadic_buffer_counts),
+        BinaryView | Utf8View => skip_binview(field_nodes, buffers, variadic_buffer_counts),
     }
 }

crates/polars-arrow/src/io/ipc/read/read_basic.rs

@@ -96,12 +96,12 @@ fn read_uncompressed_buffer<T: NativeType, R: Read + Seek>(
 fn read_compressed_buffer<T: NativeType, R: Read + Seek>(
     reader: &mut R,
     buffer_length: usize,
-    length: usize,
+    output_length: Option<usize>,
     is_little_endian: bool,
     compression: Compression,
     scratch: &mut Vec<u8>,
 ) -> PolarsResult<Vec<T>> {
-    if length == 0 {
+    if output_length == Some(0) {
         return Ok(vec![]);
     }
 
@@ -111,10 +111,6 @@ fn read_compressed_buffer<T: NativeType, R: Read + Seek>(
         )
     }
 
-    // It is undefined behavior to call read_exact on un-initialized, https://doc.rust-lang.org/std/io/trait.Read.html#tymethod.read
-    // see also https://github.com/MaikKlein/ash/issues/354#issue-781730580
-    let mut buffer = vec![T::default(); length];
-
     // decompress first
     scratch.clear();
     scratch.try_reserve(buffer_length)?;
@@ -123,6 +119,13 @@ fn read_compressed_buffer<T: NativeType, R: Read + Seek>(
         .take(buffer_length as u64)
         .read_to_end(scratch)?;
 
+    let length = output_length
+        .unwrap_or_else(|| i64::from_le_bytes(scratch[..8].try_into().unwrap()) as usize);
+
+    // It is undefined behavior to call read_exact on un-initialized, https://doc.rust-lang.org/std/io/trait.Read.html#tymethod.read
+    // see also https://github.com/MaikKlein/ash/issues/354#issue-781730580
+    let mut buffer = vec![T::default(); length];
+
     let out_slice = bytemuck::cast_slice_mut(&mut buffer);
 
     let compression = compression
@@ -150,7 +153,7 @@ fn read_compressed_bytes<R: Read + Seek>(
     read_compressed_buffer::<u8, _>(
         reader,
         buffer_length,
-        buffer_length,
+        None,
         is_little_endian,
         compression,
         scratch,
@@ -224,7 +227,7 @@ pub fn read_buffer<T: NativeType, R: Read + Seek>(
         Ok(read_compressed_buffer(
             reader,
             buffer_length,
-            length,
+            Some(length),
             is_little_endian,
             compression,
             scratch,

crates/polars/tests/it/io/ipc.rs

@@ -0,0 +1,23 @@
+use std::io::{Seek, SeekFrom};
+
+use polars::prelude::*;
+
+#[test]
+fn test_ipc_compression_variadic_buffers() {
+    let mut df = df![
+        "foo" => std::iter::repeat("Home delivery vat 24 %").take(3).collect::<Vec<_>>()
+    ]
+    .unwrap();
+
+    let mut file = std::io::Cursor::new(vec![]);
+    IpcWriter::new(&mut file)
+        .with_compression(Some(IpcCompression::LZ4))
+        .with_pl_flavor(true)
+        .finish(&mut df)
+        .unwrap();
+
+    file.seek(SeekFrom::Start(0)).unwrap();
+    let out = IpcReader::new(file).finish().unwrap();
+
+    assert_eq!(out.shape(), (3, 1));
+}

crates/polars/tests/it/io/mod.rs

@@ -9,6 +9,8 @@ mod parquet;
 #[cfg(feature = "avro")]
 mod avro;
 
+#[cfg(feature = "ipc")]
+mod ipc;
 #[cfg(feature = "ipc_streaming")]
 mod ipc_stream;