feat: support to struct datatype

src/arrow_reader/column.rs

@@ -1,15 +1,16 @@
 use std::io::{Read, Seek, SeekFrom};
 use std::sync::Arc;
 
+use arrow::datatypes::Field;
 use bytes::Bytes;
 use snafu::{OptionExt, ResultExt};
 use tokio::io::{AsyncRead, AsyncReadExt, AsyncSeek, AsyncSeekExt};
 
 use crate::error::{self, Result};
 use crate::proto::stream::Kind;
 use crate::proto::{ColumnEncoding, StripeFooter, StripeInformation};
-use crate::reader::decompress::{Compression, Decompressor};
-use crate::reader::schema::TypeDescription;
+
+use crate::reader::schema::{create_field, TypeDescription};
 use crate::reader::Reader;
 
 pub mod binary;
@@ -19,19 +20,24 @@
 pub mod int;
 pub mod present;
 pub mod string;
+pub mod struct_column;
 pub mod timestamp;
 pub mod tinyint;
 
 #[derive(Debug)]
 pub struct Column {
-    data: Bytes,
     number_of_rows: u64,
-    compression: Option<Compression>,
     footer: Arc<StripeFooter>,
     name: String,
     column: Arc<TypeDescription>,
 }
 
+impl From<Column> for Field {
+    fn from(value: Column) -> Self {
+        create_field((&value.name, &value.column))
+    }
+}
+
 macro_rules! impl_read_stream {
     ($reader:ident,$start:ident,$length:ident $($_await:tt)*) => {{
         $reader
@@ -98,67 +104,18 @@
         Ok((start, length))
     }
 
-    pub fn new<R: Read + Seek>(
-        reader: &mut Reader<R>,
-        compression: Option<Compression>,
+    pub fn new(
         name: &str,
         column: &Arc<TypeDescription>,
         footer: &Arc<StripeFooter>,
         stripe: &StripeInformation,
-    ) -> Result<Self> {
-        let (start, length) = Column::get_stream_info(name, column, footer, stripe)?;
-        let data = Column::read_stream(reader, start, length)?;
-
-        Ok(Self {
-            data,
+    ) -> Self {
+        Self {
             number_of_rows: stripe.number_of_rows(),
-            compression,
             footer: footer.clone(),
             column: column.clone(),
             name: name.to_string(),
-        })
-    }
-
-    pub async fn new_async<R: AsyncRead + AsyncSeek + Unpin + Send>(
-        reader: &mut Reader<R>,
-        compression: Option<Compression>,
-        name: &str,
-        column: &Arc<TypeDescription>,
-        footer: &Arc<StripeFooter>,
-        stripe: &StripeInformation,
-    ) -> Result<Self> {
-        let (start, length) = Column::get_stream_info(name, column, footer, stripe)?;
-        let data = Column::read_stream_async(reader, start, length).await?;
-
-        Ok(Self {
-            data,
-            number_of_rows: stripe.number_of_rows(),
-            compression,
-            footer: footer.clone(),
-            column: column.clone(),
-            name: name.to_string(),
-        })
-    }
-
-    pub fn stream(&self, kind: Kind) -> Option<Result<Decompressor>> {
-        let mut start = 0; // the start of the stream
-
-        let column_id = self.column.column_id() as u32;
-        self.footer
-            .streams
-            .iter()
-            .filter(|stream| stream.column() == column_id && stream.kind() != Kind::RowIndex)
-            .map(|stream| {
-                start += stream.length() as usize;
-                stream
-            })
-            .find(|stream| stream.kind() == kind)
-            .map(|stream| {
-                let length = stream.length() as usize;
-                let data = self.data.slice((start - length)..start);
-                Decompressor::new(data, self.compression, vec![])
-            })
-            .map(Ok)
+        }
     }
 
     pub fn dictionary_size(&self) -> usize {
@@ -181,9 +138,30 @@
         self.column.kind()
     }
 
     pub fn name(&self) -> &str {
         &self.name
     }
+
+    pub fn column_id(&self) -> u32 {
+        self.column.column_id() as u32
+    }
+
+    pub fn children(&self) -> Vec<Column> {
+        let children = self.column.children();
+
+        let mut columns = Vec::with_capacity(children.len());
+
+        for (name, column) in children {
+            columns.push(Column {
+                number_of_rows: self.number_of_rows,
+                footer: self.footer.clone(),
+                name,
+                column,
+            });
+        }
+
+        columns
+    }
 }
 
 pub struct NullableIterator<T> {
@@ -211,3 +189,24 @@
         }
     }
 }
+
+impl<T> NullableIterator<T> {
+    pub fn collect_chunk(&mut self, chunk: usize) -> Option<Result<Vec<Option<T>>>> {
+        let mut buf = Vec::with_capacity(chunk);
+        for _ in 0..chunk {
+            match self.next() {
+                Some(Ok(value)) => {
+                    buf.push(value);
+                }
+                Some(Err(err)) => return Some(Err(err)),
+                None => break,
+            }
+        }
+
+        if buf.is_empty() {
+            return None;
+        }
+
+        Some(Ok(buf))
+    }
+}

src/arrow_reader/column/binary.rs

@@ -16,23 +16,28 @@ use snafu::OptionExt;
 
 use crate::arrow_reader::column::present::new_present_iter;
 use crate::arrow_reader::column::{Column, NullableIterator};
+use crate::arrow_reader::Stripe;
 use crate::error;
 use crate::proto::stream::Kind;
 use crate::reader::decode::get_direct_unsigned_rle_reader;
 use crate::reader::decode::variable_length::Values;
 use crate::reader::decompress::Decompressor;
 
-pub fn new_binary_iterator(column: &Column) -> error::Result<NullableIterator<Vec<u8>>> {
-    let null_mask = new_present_iter(column)?.collect::<error::Result<Vec<_>>>()?;
+pub fn new_binary_iterator(
+    column: &Column,
+    stripe: &Stripe,
+) -> error::Result<NullableIterator<Vec<u8>>> {
+    let null_mask = new_present_iter(column, stripe)?.collect::<error::Result<Vec<_>>>()?;
 
-    let values = column
-        .stream(Kind::Data)
-        .transpose()?
+    let values = stripe
+        .stream_map
+        .get(column, Kind::Data)
         .map(|reader| Box::new(Values::new(reader, vec![])))
         .context(error::InvalidColumnSnafu { name: &column.name })?;
-    let lengths = column
-        .stream(Kind::Length)
-        .transpose()?
+
+    let lengths = stripe
+        .stream_map
+        .get(column, Kind::Length)
         .map(|reader| get_direct_unsigned_rle_reader(column, reader))
         .context(error::InvalidColumnSnafu { name: &column.name })??;
 

src/arrow_reader/column/boolean.rs

@@ -2,17 +2,18 @@ use snafu::OptionExt;
 
 use crate::arrow_reader::column::present::new_present_iter;
 use crate::arrow_reader::column::{Column, NullableIterator};
+use crate::arrow_reader::Stripe;
 use crate::error::{InvalidColumnSnafu, Result};
 use crate::proto::stream::Kind;
 use crate::reader::decode::boolean_rle::BooleanIter;
 
-pub fn new_boolean_iter(column: &Column) -> Result<NullableIterator<bool>> {
-    let present = new_present_iter(column)?.collect::<Result<Vec<_>>>()?;
+pub fn new_boolean_iter(column: &Column, stripe: &Stripe) -> Result<NullableIterator<bool>> {
+    let present = new_present_iter(column, stripe)?.collect::<Result<Vec<_>>>()?;
     let rows: usize = present.iter().filter(|&p| *p).count();
 
-    let iter = column
-        .stream(Kind::Data)
-        .transpose()?
+    let iter = stripe
+        .stream_map
+        .get(column, Kind::Data)
         .map(|reader| {
             Box::new(BooleanIter::new(reader, rows))
                 as Box<dyn Iterator<Item = Result<bool>> + Send>

src/arrow_reader/column/date.rs

@@ -3,6 +3,7 @@ use snafu::OptionExt;
 
 use crate::arrow_reader::column::present::new_present_iter;
 use crate::arrow_reader::column::{Column, NullableIterator};
+use crate::arrow_reader::Stripe;
 use crate::error::{self, Result};
 use crate::proto::stream::Kind;
 use crate::reader::decode::get_direct_signed_rle_reader;
@@ -37,12 +38,12 @@ impl Iterator for DateIterator {
     }
 }
 
-pub fn new_date_iter(column: &Column) -> Result<NullableIterator<NaiveDate>> {
-    let present = new_present_iter(column)?.collect::<Result<Vec<_>>>()?;
+pub fn new_date_iter(column: &Column, stripe: &Stripe) -> Result<NullableIterator<NaiveDate>> {
+    let present = new_present_iter(column, stripe)?.collect::<Result<Vec<_>>>()?;
 
-    let data = column
-        .stream(Kind::Data)
-        .transpose()?
+    let data = stripe
+        .stream_map
+        .get(column, Kind::Data)
         .map(|reader| get_direct_signed_rle_reader(column, reader))
         .context(error::InvalidColumnSnafu { name: &column.name })??;
 

src/arrow_reader/column/float.rs

@@ -2,19 +2,20 @@ use snafu::OptionExt;
 
 use crate::arrow_reader::column::present::new_present_iter;
 use crate::arrow_reader::column::{Column, NullableIterator};
+use crate::arrow_reader::Stripe;
 use crate::error::{InvalidColumnSnafu, Result};
 use crate::proto::stream::Kind;
 use crate::reader::decode::float::FloatIter;
 
 macro_rules! impl_float_iter {
     ($tp:ident) => {
         paste::item! {
-            pub fn [<new_ $tp _iter>] (column: &Column) -> Result<NullableIterator<$tp>> {
-                let present = new_present_iter(column)?.collect::<Result<Vec<_>>>()?;
+            pub fn [<new_ $tp _iter>] (column: &Column, stripe: &Stripe) -> Result<NullableIterator<$tp>> {
+                let present = new_present_iter(column, stripe)?.collect::<Result<Vec<_>>>()?;
                 let rows: usize = present.iter().filter(|&p| *p).count();
-                let iter = column
-                    .stream(Kind::Data)
-                    .transpose()?
+                let iter =  stripe
+                    .stream_map
+                    .get(column, Kind::Data)
                     .map(|reader| Box::new(FloatIter::<$tp, _>::new(reader, rows)))
                     .context(InvalidColumnSnafu { name: &column.name })?;
 

src/arrow_reader/column/int.rs

@@ -2,16 +2,17 @@ use snafu::OptionExt;
 
 use crate::arrow_reader::column::present::new_present_iter;
 use crate::arrow_reader::column::{Column, NullableIterator};
+use crate::arrow_reader::Stripe;
 use crate::error::{InvalidColumnSnafu, Result};
 use crate::proto::stream::Kind;
 use crate::reader::decode::get_direct_signed_rle_reader;
 
-pub fn new_i64_iter(column: &Column) -> Result<NullableIterator<i64>> {
-    let present = new_present_iter(column)?.collect::<Result<Vec<_>>>()?;
+pub fn new_i64_iter(column: &Column, stripe: &Stripe) -> Result<NullableIterator<i64>> {
+    let present = new_present_iter(column, stripe)?.collect::<Result<Vec<_>>>()?;
 
-    let iter = column
-        .stream(Kind::Data)
-        .transpose()?
+    let iter = stripe
+        .stream_map
+        .get(column, Kind::Data)
         .map(|reader| get_direct_signed_rle_reader(column, reader))
         .context(InvalidColumnSnafu { name: &column.name })??;
 

src/arrow_reader/column/present.rs

@@ -1,13 +1,17 @@
 use crate::arrow_reader::column::Column;
+use crate::arrow_reader::Stripe;
 use crate::error::Result;
 use crate::proto::stream::Kind;
 use crate::reader::decode::boolean_rle::BooleanIter;
 
-pub fn new_present_iter(column: &Column) -> Result<Box<dyn Iterator<Item = Result<bool>>>> {
+pub fn new_present_iter(
+    column: &Column,
+    stripe: &Stripe,
+) -> Result<Box<dyn Iterator<Item = Result<bool>>>> {
     let rows = column.number_of_rows as usize;
-    let iter = column
-        .stream(Kind::Present)
-        .transpose()?
+    let iter = stripe
+        .stream_map
+        .get(column, Kind::Present)
         .map(|reader| {
             Box::new(BooleanIter::new(reader, rows)) as Box<dyn Iterator<Item = Result<bool>>>
         })