Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Cherry pick Extract method to drive PageIterator -> RecordReader to active_release #1056

Merged
merged 1 commit into from
Dec 20, 2021
Merged

Cherry pick Extract method to drive PageIterator -> RecordReader to active_release #1056

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
88 changes: 37 additions & 51 deletions parquet/src/arrow/array_reader.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -100,6 +100,36 @@ pub trait ArrayReader {
fn get_rep_levels(&self) -> Option<&[i16]>;
}

/// Uses `record_reader` to read up to `batch_size` records from `pages`
///
/// Returns the number of records read, which can be less than batch_size if
/// pages is exhausted.
fn read_records<T: DataType>(
record_reader: &mut RecordReader<T>,
pages: &mut dyn PageIterator,
batch_size: usize,
) -> Result<usize> {
let mut records_read = 0usize;
while records_read < batch_size {
let records_to_read = batch_size - records_read;

let records_read_once = record_reader.read_records(records_to_read)?;
records_read += records_read_once;

// Record reader exhausted
if records_read_once < records_to_read {
if let Some(page_reader) = pages.next() {
// Read from new page reader (i.e. column chunk)
record_reader.set_page_reader(page_reader?)?;
} else {
// Page reader also exhausted
break;
}
}
}
Ok(records_read)
}

/// A NullArrayReader reads Parquet columns stored as null int32s with an Arrow
/// NullArray type.
pub struct NullArrayReader<T: DataType> {
Expand All @@ -114,14 +144,8 @@ pub struct NullArrayReader<T: DataType> {

impl<T: DataType> NullArrayReader<T> {
/// Construct null array reader.
pub fn new(
mut pages: Box<dyn PageIterator>,
column_desc: ColumnDescPtr,
) -> Result<Self> {
let mut record_reader = RecordReader::<T>::new(column_desc.clone());
if let Some(page_reader) = pages.next() {
record_reader.set_page_reader(page_reader?)?;
}
pub fn new(pages: Box<dyn PageIterator>, column_desc: ColumnDescPtr) -> Result<Self> {
let record_reader = RecordReader::<T>::new(column_desc.clone());

Ok(Self {
data_type: ArrowType::Null,
Expand All @@ -148,25 +172,8 @@ impl<T: DataType> ArrayReader for NullArrayReader<T> {

/// Reads at most `batch_size` records into array.
fn next_batch(&mut self, batch_size: usize) -> Result<ArrayRef> {
let mut records_read = 0usize;
while records_read < batch_size {
let records_to_read = batch_size - records_read;

// NB can be 0 if at end of page
let records_read_once = self.record_reader.read_records(records_to_read)?;
records_read += records_read_once;

// Record reader exhausted
if records_read_once < records_to_read {
if let Some(page_reader) = self.pages.next() {
// Read from new page reader
self.record_reader.set_page_reader(page_reader?)?;
} else {
// Page reader also exhausted
break;
}
}
}
let records_read =
read_records(&mut self.record_reader, self.pages.as_mut(), batch_size)?;

// convert to arrays
let array = arrow::array::NullArray::new(records_read);
Expand Down Expand Up @@ -206,7 +213,7 @@ pub struct PrimitiveArrayReader<T: DataType> {
impl<T: DataType> PrimitiveArrayReader<T> {
/// Construct primitive array reader.
pub fn new(
mut pages: Box<dyn PageIterator>,
pages: Box<dyn PageIterator>,
column_desc: ColumnDescPtr,
arrow_type: Option<ArrowType>,
) -> Result<Self> {
Expand All @@ -218,10 +225,7 @@ impl<T: DataType> PrimitiveArrayReader<T> {
.clone(),
};

let mut record_reader = RecordReader::<T>::new(column_desc.clone());
if let Some(page_reader) = pages.next() {
record_reader.set_page_reader(page_reader?)?;
}
let record_reader = RecordReader::<T>::new(column_desc.clone());

Ok(Self {
data_type,
Expand All @@ -248,25 +252,7 @@ impl<T: DataType> ArrayReader for PrimitiveArrayReader<T> {

/// Reads at most `batch_size` records into array.
fn next_batch(&mut self, batch_size: usize) -> Result<ArrayRef> {
let mut records_read = 0usize;
while records_read < batch_size {
let records_to_read = batch_size - records_read;

// NB can be 0 if at end of page
let records_read_once = self.record_reader.read_records(records_to_read)?;
records_read += records_read_once;

// Record reader exhausted
if records_read_once < records_to_read {
if let Some(page_reader) = self.pages.next() {
// Read from new page reader
self.record_reader.set_page_reader(page_reader?)?;
} else {
// Page reader also exhausted
break;
}
}
}
read_records(&mut self.record_reader, self.pages.as_mut(), batch_size)?;

let target_type = self.get_data_type().clone();
let arrow_data_type = match T::get_physical_type() {
Expand Down