refactor: Implement CSV, IPC and NDJson in the MultiScanExec node

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

@@ -41,15 +41,24 @@ pub struct FileMetadata {
 
 /// Read the row count by summing the length of the of the record batches
 pub fn get_row_count<R: Read + Seek>(reader: &mut R) -> PolarsResult<i64> {
-    let mut message_scratch: Vec<u8> = Default::default();
     let (_, footer_len) = read_footer_len(reader)?;
     let footer = read_footer(reader, footer_len)?;
     let (_, blocks) = deserialize_footer_blocks(&footer)?;
 
+    get_row_count_from_blocks(reader, &blocks)
+}
+
+///  Read the row count by summing the length of the of the record batches in blocks
+pub fn get_row_count_from_blocks<R: Read + Seek>(
+    reader: &mut R,
+    blocks: &[arrow_format::ipc::Block],
+) -> PolarsResult<i64> {
+    let mut message_scratch: Vec<u8> = Default::default();
+
     blocks
-        .into_iter()
+        .iter()
         .map(|block| {
-            let message = get_message_from_block(reader, &block, &mut message_scratch)?;
+            let message = get_message_from_block(reader, block, &mut message_scratch)?;
             let record_batch = get_record_batch(message)?;
             record_batch.length().map_err(|e| e.into())
         })

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

@@ -22,8 +22,8 @@ pub(crate) use common::first_dict_field;
 pub use common::{prepare_projection, ProjectionInfo};
 pub use error::OutOfSpecKind;
 pub use file::{
-    deserialize_footer, get_row_count, read_batch, read_file_dictionaries, read_file_metadata,
-    FileMetadata,
+    deserialize_footer, get_row_count, get_row_count_from_blocks, read_batch,
+    read_file_dictionaries, read_file_metadata, FileMetadata,
 };
 use polars_utils::aliases::PlHashMap;
 pub use reader::FileReader;

crates/polars-mem-engine/src/executors/mod.rs

@@ -7,8 +7,8 @@ mod group_by_dynamic;
 mod group_by_partitioned;
 pub(super) mod group_by_rolling;
 mod hconcat;
-mod hive_scan;
 mod join;
+mod multi_file_scan;
 mod projection;
 mod projection_simple;
 mod projection_utils;
@@ -39,8 +39,8 @@ pub(super) use self::group_by_partitioned::*;
 #[cfg(feature = "dynamic_group_by")]
 pub(super) use self::group_by_rolling::GroupByRollingExec;
 pub(super) use self::hconcat::*;
-pub(super) use self::hive_scan::*;
 pub(super) use self::join::*;
+pub(super) use self::multi_file_scan::*;
 pub(super) use self::projection::*;
 pub(super) use self::projection_simple::*;
 pub(super) use self::scan::*;