alamb commented on code in PR #7454:
URL: https://github.com/apache/arrow-rs/pull/7454#discussion_r2084639733
##########
parquet/src/arrow/arrow_reader/selection.rs:
##########
@@ -90,18 +91,32 @@ impl RowSelector {
/// assert_eq!(actual, expected);
/// ```
///
-/// A [`RowSelection`] maintains the following invariants:
-///
-/// * It contains no [`RowSelector`] of 0 rows
-/// * Consecutive [`RowSelector`]s alternate skipping or selecting rows
-///
-/// [`PageIndex`]: crate::file::page_index::index::PageIndex
-#[derive(Debug, Clone, Default, Eq, PartialEq)]
-pub struct RowSelection {
- selectors: Vec<RowSelector>,
+/// [`RowSelection`] is an enum that can be either a list of [`RowSelector`]s
+/// or a [`BooleanArray`] bitmap
+#[derive(Debug, Clone, PartialEq)]
+pub enum RowSelection {
Review Comment:
Given the two different representations have different uses
1. Skip contiguous ranges (basically skip entire data pages)
2. filter out individual rows
I think we may be able to actually keep these as two separate structs rather
than combining them into a single struct.
##########
parquet/src/arrow/async_reader/arrow_reader.rs:
##########
@@ -0,0 +1,756 @@
+// 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::collections::hash_map::Entry;
+use std::collections::HashMap;
+use std::sync::{Mutex, MutexGuard};
+use std::{collections::VecDeque, sync::Arc};
+
+use arrow_array::{cast::AsArray, Array, RecordBatch, RecordBatchReader};
+use arrow_array::{ArrayRef, BooleanArray};
+use arrow_buffer::BooleanBufferBuilder;
+use arrow_schema::{ArrowError, DataType, Schema, SchemaRef};
+use arrow_select::filter::{filter, prep_null_mask_filter};
+
+use crate::basic::PageType;
+use crate::column::page::{Page, PageMetadata, PageReader};
+use crate::errors::ParquetError;
+use crate::{
+ arrow::{
+ array_reader::ArrayReader,
+ arrow_reader::{RowFilter, RowSelection, RowSelector},
+ },
+ file::reader::{ChunkReader, SerializedPageReader},
+};
+
+pub struct FilteredParquetRecordBatchReader {
+ batch_size: usize,
+ array_reader: Box<dyn ArrayReader>,
+ predicate_readers: Vec<Box<dyn ArrayReader>>,
+ schema: SchemaRef,
+ selection: Option<RowSelection>,
+ row_filter: Option<RowFilter>,
+}
+
+fn read_selection(
+ reader: &mut dyn ArrayReader,
+ selection: &RowSelection,
+) -> Result<ArrayRef, ParquetError> {
+ match selection {
+ RowSelection::Ranges(selectors) => {
+ for selector in selectors {
+ if selector.skip {
+ reader.skip_records(selector.row_count)?;
+ } else {
+ reader.read_records(selector.row_count)?;
+ }
+ }
+ reader.consume_batch()
+ }
+
+ RowSelection::BitMap(bitmap) => {
+ let to_read = bitmap.len();
+ reader.read_records(to_read)?;
+ let array = reader.consume_batch()?;
+
+ let filtered_array =
+ filter(&array, bitmap).map_err(|e|
ParquetError::General(e.to_string()))?;
+
+ Ok(filtered_array)
+ }
+ }
+}
+
+fn take_next_selection(
+ selection: &mut Option<RowSelection>,
+ to_select: usize,
+) -> Option<RowSelection> {
+ let current = selection.as_ref()?.clone();
+
+ if let RowSelection::BitMap(bitmap) = current {
+ let take = bitmap.len().min(to_select);
+ let prefix = bitmap.slice(0, take);
+ let suffix_len = bitmap.len() - take;
+ let suffix = if suffix_len > 0 {
+ Some(bitmap.slice(take, suffix_len))
+ } else {
+ None
+ };
+ *selection = suffix.map(RowSelection::BitMap);
+ return Some(RowSelection::BitMap(prefix));
+ }
+
+ let RowSelection::Ranges(runs) = current else {
+ unreachable!()
+ };
+ let mut queue: VecDeque<RowSelector> = runs.into();
+ let mut taken = Vec::new();
+ let mut count = 0;
+
+ while let Some(run) = queue.pop_front() {
+ if run.skip {
+ taken.push(run);
+ continue;
+ }
+ let room = to_select.saturating_sub(count);
+ if room == 0 {
+ queue.push_front(run);
+ break;
+ }
+ if run.row_count <= room {
+ taken.push(run);
+ count += run.row_count;
+ } else {
+ taken.push(RowSelector::select(room));
+ queue.push_front(RowSelector::select(run.row_count - room));
+ break;
+ }
+ }
+
+ *selection = if queue.is_empty() {
+ None
+ } else {
+ Some(RowSelection::Ranges(queue.into_iter().collect()))
+ };
+
+ Some(RowSelection::Ranges(taken))
+}
+
+impl FilteredParquetRecordBatchReader {
+ pub(crate) fn new(
+ batch_size: usize,
+ array_reader: Box<dyn ArrayReader>,
+ selection: Option<RowSelection>,
+ filter_readers: Vec<Box<dyn ArrayReader>>,
+ row_filter: Option<RowFilter>,
+ ) -> Self {
+ let schema = match array_reader.get_data_type() {
+ DataType::Struct(ref fields) => Schema::new(fields.clone()),
+ _ => unreachable!("Struct array reader's data type is not
struct!"),
+ };
+
+ Self {
+ batch_size,
+ array_reader,
+ predicate_readers: filter_readers,
+ schema: Arc::new(schema),
+ selection,
+ row_filter,
+ }
+ }
+
+ pub(crate) fn take_filter(&mut self) -> Option<RowFilter> {
+ self.row_filter.take()
+ }
+
+ fn create_bitmap_from_ranges(&mut self, runs: &[RowSelector]) ->
BooleanArray {
Review Comment:
This code path is unfortunate -- converting from Butmap --> RowSelection. I
have some ideas about how this could be better if we avoided this particular
code path.
##########
parquet/src/arrow/async_reader/arrow_reader.rs:
##########
@@ -0,0 +1,756 @@
+// 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::collections::hash_map::Entry;
+use std::collections::HashMap;
+use std::sync::{Mutex, MutexGuard};
+use std::{collections::VecDeque, sync::Arc};
+
+use arrow_array::{cast::AsArray, Array, RecordBatch, RecordBatchReader};
+use arrow_array::{ArrayRef, BooleanArray};
+use arrow_buffer::BooleanBufferBuilder;
+use arrow_schema::{ArrowError, DataType, Schema, SchemaRef};
+use arrow_select::filter::{filter, prep_null_mask_filter};
+
+use crate::basic::PageType;
+use crate::column::page::{Page, PageMetadata, PageReader};
+use crate::errors::ParquetError;
+use crate::{
+ arrow::{
+ array_reader::ArrayReader,
+ arrow_reader::{RowFilter, RowSelection, RowSelector},
+ },
+ file::reader::{ChunkReader, SerializedPageReader},
+};
+
+pub struct FilteredParquetRecordBatchReader {
+ batch_size: usize,
+ array_reader: Box<dyn ArrayReader>,
+ predicate_readers: Vec<Box<dyn ArrayReader>>,
+ schema: SchemaRef,
+ selection: Option<RowSelection>,
+ row_filter: Option<RowFilter>,
+}
+
+fn read_selection(
+ reader: &mut dyn ArrayReader,
+ selection: &RowSelection,
+) -> Result<ArrayRef, ParquetError> {
+ match selection {
+ RowSelection::Ranges(selectors) => {
+ for selector in selectors {
+ if selector.skip {
+ reader.skip_records(selector.row_count)?;
+ } else {
+ reader.read_records(selector.row_count)?;
+ }
+ }
+ reader.consume_batch()
+ }
+
+ RowSelection::BitMap(bitmap) => {
+ let to_read = bitmap.len();
+ reader.read_records(to_read)?;
+ let array = reader.consume_batch()?;
+
+ let filtered_array =
+ filter(&array, bitmap).map_err(|e|
ParquetError::General(e.to_string()))?;
Review Comment:
This is a a very clever idea (to keep the filter and apply it to the next
decoded batch)
##########
parquet/src/arrow/async_reader/arrow_reader.rs:
##########
@@ -0,0 +1,756 @@
+// 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::collections::hash_map::Entry;
+use std::collections::HashMap;
+use std::sync::{Mutex, MutexGuard};
+use std::{collections::VecDeque, sync::Arc};
+
+use arrow_array::{cast::AsArray, Array, RecordBatch, RecordBatchReader};
+use arrow_array::{ArrayRef, BooleanArray};
+use arrow_buffer::BooleanBufferBuilder;
+use arrow_schema::{ArrowError, DataType, Schema, SchemaRef};
+use arrow_select::filter::{filter, prep_null_mask_filter};
+
+use crate::basic::PageType;
+use crate::column::page::{Page, PageMetadata, PageReader};
+use crate::errors::ParquetError;
+use crate::{
+ arrow::{
+ array_reader::ArrayReader,
+ arrow_reader::{RowFilter, RowSelection, RowSelector},
+ },
+ file::reader::{ChunkReader, SerializedPageReader},
+};
+
+pub struct FilteredParquetRecordBatchReader {
+ batch_size: usize,
+ array_reader: Box<dyn ArrayReader>,
Review Comment:
This is a really nice idea -- to have both `array_readers` and
`predicate_readers` in the same structure. If we push this idea even more this
idea could be used to avoid the second decode entirely and not modify
`RowSelection` at all.
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