read to view type using offset_buffer

parquet/src/arrow/array_reader/builder.rs

@@ -19,7 +19,7 @@ use std::sync::Arc;
 
 use arrow_schema::{DataType, Fields, SchemaBuilder};
 
-use crate::arrow::array_reader::byte_view_array::make_byte_view_array_reader;
+use crate::arrow::array_reader::byte_array::make_byte_view_array_reader;
 use crate::arrow::array_reader::empty_array::make_empty_array_reader;
 use crate::arrow::array_reader::fixed_len_byte_array::make_fixed_len_byte_array_reader;
 use crate::arrow::array_reader::{

parquet/src/arrow/array_reader/byte_array.rs

@@ -74,6 +74,36 @@ pub fn make_byte_array_reader(
     }
 }
 
+/// Returns an [`ArrayReader`] that decodes the provided byte array column to view types.
+pub fn make_byte_view_array_reader(
+    pages: Box<dyn PageIterator>,
+    column_desc: ColumnDescPtr,
+    arrow_type: Option<ArrowType>,
+) -> Result<Box<dyn ArrayReader>> {
+    // Check if Arrow type is specified, else create it from Parquet type
+    let data_type = match arrow_type {
+        Some(t) => t,
+        None => match parquet_to_arrow_field(column_desc.as_ref())?.data_type() {
+            ArrowType::Utf8 | ArrowType::Utf8View => ArrowType::Utf8View,
+            _ => ArrowType::BinaryView,
+        },
+    };
+
+    match data_type {
+        ArrowType::BinaryView | ArrowType::Utf8View => {
+            let reader = GenericRecordReader::new(column_desc);
+            Ok(Box::new(ByteArrayReader::<i32>::new(
+                pages, data_type, reader,
+            )))
+        }
+
+        _ => Err(general_err!(
+            "invalid data type for byte array reader read to view type - {}",
+            data_type
+        )),
+    }
+}
+
 /// An [`ArrayReader`] for variable length byte arrays
 struct ByteArrayReader<I: OffsetSizeTrait> {
     data_type: ArrowType,
@@ -588,7 +618,7 @@ mod tests {
     use super::*;
     use crate::arrow::array_reader::test_util::{byte_array_all_encodings, utf8_column};
     use crate::arrow::record_reader::buffer::ValuesBuffer;
-    use arrow_array::{Array, StringArray};
+    use arrow_array::{Array, StringArray, StringViewArray};
     use arrow_buffer::Buffer;
 
     #[test]
@@ -646,6 +676,64 @@ mod tests {
         }
     }
 
+    #[test]
+    fn test_byte_array_string_view_decoder() {
+        let (pages, encoded_dictionary) =
+            byte_array_all_encodings(vec!["hello", "world", "large payload over 12 bytes", "b"]);
+
+        let column_desc = utf8_column();
+        let mut decoder = ByteArrayColumnValueDecoder::new(&column_desc);
+
+        decoder
+            .set_dict(encoded_dictionary, 4, Encoding::RLE_DICTIONARY, false)
+            .unwrap();
+
+        for (encoding, page) in pages {
+            let mut output = OffsetBuffer::<i32>::default();
+            decoder.set_data(encoding, page, 4, Some(4)).unwrap();
+
+            assert_eq!(decoder.read(&mut output, 1).unwrap(), 1);
+
+            assert_eq!(output.values.as_slice(), "hello".as_bytes());
+            assert_eq!(output.offsets.as_slice(), &[0, 5]);
+
+            assert_eq!(decoder.read(&mut output, 1).unwrap(), 1);
+            assert_eq!(output.values.as_slice(), "helloworld".as_bytes());
+            assert_eq!(output.offsets.as_slice(), &[0, 5, 10]);
+
+            assert_eq!(decoder.read(&mut output, 2).unwrap(), 2);
+            assert_eq!(
+                output.values.as_slice(),
+                "helloworldlarge payload over 12 bytesb".as_bytes()
+            );
+            assert_eq!(output.offsets.as_slice(), &[0, 5, 10, 37, 38]);
+
+            assert_eq!(decoder.read(&mut output, 4).unwrap(), 0);
+
+            let valid = [false, false, true, true, false, true, true, false, false];
+            let valid_buffer = Buffer::from_iter(valid.iter().cloned());
+
+            output.pad_nulls(0, 4, valid.len(), valid_buffer.as_slice());
+            let array = output.into_array(Some(valid_buffer), ArrowType::Utf8View);
+            let strings = array.as_any().downcast_ref::<StringViewArray>().unwrap();
+
+            assert_eq!(
+                strings.iter().collect::<Vec<_>>(),
+                vec![
+                    None,
+                    None,
+                    Some("hello"),
+                    Some("world"),
+                    None,
+                    Some("large payload over 12 bytes"),
+                    Some("b"),
+                    None,
+                    None,
+                ]
+            );
+        }
+    }
+
     #[test]
     fn test_byte_array_decoder_skip() {
         let (pages, encoded_dictionary) =
@@ -690,6 +778,60 @@ mod tests {
         }
     }
 
+    #[test]
+    fn test_byte_array_string_view_decoder_skip() {
+        let (pages, encoded_dictionary) =
+            byte_array_all_encodings(vec!["hello", "world", "a", "large payload over 12 bytes"]);
+
+        let column_desc = utf8_column();
+        let mut decoder = ByteArrayColumnValueDecoder::new(&column_desc);
+
+        decoder
+            .set_dict(encoded_dictionary, 4, Encoding::RLE_DICTIONARY, false)
+            .unwrap();
+
+        for (encoding, page) in pages {
+            let mut output = OffsetBuffer::<i32>::default();
+            decoder.set_data(encoding, page, 4, Some(4)).unwrap();
+
+            assert_eq!(decoder.read(&mut output, 1).unwrap(), 1);
+
+            assert_eq!(output.values.as_slice(), "hello".as_bytes());
+            assert_eq!(output.offsets.as_slice(), &[0, 5]);
+
+            assert_eq!(decoder.skip_values(1).unwrap(), 1);
+            assert_eq!(decoder.skip_values(1).unwrap(), 1);
+
+            assert_eq!(decoder.read(&mut output, 1).unwrap(), 1);
+            assert_eq!(
+                output.values.as_slice(),
+                "hellolarge payload over 12 bytes".as_bytes()
+            );
+            assert_eq!(output.offsets.as_slice(), &[0, 5, 32]);
+
+            assert_eq!(decoder.read(&mut output, 4).unwrap(), 0);
+
+            let valid = [false, false, true, true, false, false];
+            let valid_buffer = Buffer::from_iter(valid.iter().cloned());
+
+            output.pad_nulls(0, 2, valid.len(), valid_buffer.as_slice());
+            let array = output.into_array(Some(valid_buffer), ArrowType::Utf8View);
+            let strings = array.as_any().downcast_ref::<StringViewArray>().unwrap();
+
+            assert_eq!(
+                strings.iter().collect::<Vec<_>>(),
+                vec![
+                    None,
+                    None,
+                    Some("hello"),
+                    Some("large payload over 12 bytes"),
+                    None,
+                    None,
+                ]
+            );
+        }
+    }
+
     #[test]
     fn test_byte_array_decoder_nulls() {
         let (pages, encoded_dictionary) = byte_array_all_encodings(Vec::<&str>::new());