indexlake 0.2.0

An experimental table format with extensible index support.
Documentation
use std::collections::HashSet;
use std::ops::Range;
use std::sync::Arc;

use arrow::array::FixedSizeBinaryArray;
use arrow::datatypes::{Schema, SchemaRef};
use futures::future::BoxFuture;
use futures::{StreamExt, TryStreamExt};
use parquet::arrow::arrow_reader::{ArrowReaderOptions, RowFilter};
use parquet::arrow::async_reader::AsyncFileReader;
use parquet::arrow::async_writer::AsyncFileWriter;
use parquet::arrow::{
    ArrowSchemaConverter, AsyncArrowWriter, ParquetRecordBatchStreamBuilder, ProjectionMask,
};
use parquet::file::metadata::{ParquetMetaData, ParquetMetaDataReader};
use parquet::file::properties::{WriterProperties, WriterVersion};
use uuid::Uuid;

use crate::catalog::DataFileRecord;
use crate::expr::{Expr, ExprPredicate, visited_columns};
use crate::storage::{DataFileFormat, File, Storage};
use crate::utils::{build_projection_from_condition, extract_row_ids_from_record_batch};
use crate::{ILError, ILResult, RecordBatchStream};

impl AsyncFileReader for Box<dyn File> {
    fn get_bytes(
        &mut self,
        range: Range<u64>,
    ) -> BoxFuture<'_, parquet::errors::Result<bytes::Bytes>> {
        Box::pin(async move {
            self.read(range.start..range.end)
                .await
                .map_err(|err| parquet::errors::ParquetError::External(Box::new(err)))
        })
    }

    // TODO respect options
    fn get_metadata(
        &mut self,
        _options: Option<&'_ ArrowReaderOptions>,
    ) -> BoxFuture<'_, parquet::errors::Result<Arc<ParquetMetaData>>> {
        Box::pin(async {
            let reader = ParquetMetaDataReader::new()
                .with_prefetch_hint(None)
                .with_column_indexes(false)
                .with_page_indexes(false)
                .with_offset_indexes(false);
            let size = self
                .metadata()
                .await
                .map_err(|err| parquet::errors::ParquetError::External(Box::new(err)))?
                .size;
            let meta = reader.load_and_finish(self, size).await?;

            Ok(Arc::new(meta))
        })
    }
}

impl AsyncFileWriter for Box<dyn File> {
    fn write(&mut self, bs: bytes::Bytes) -> BoxFuture<'_, parquet::errors::Result<()>> {
        Box::pin(async {
            File::write(self, bs)
                .await
                .map_err(|err| parquet::errors::ParquetError::External(Box::new(err)))
        })
    }

    fn complete(&mut self) -> BoxFuture<'_, parquet::errors::Result<()>> {
        Box::pin(async {
            self.close()
                .await
                .map_err(|err| parquet::errors::ParquetError::External(Box::new(err)))
        })
    }
}

pub(crate) fn build_parquet_writer<W: AsyncFileWriter>(
    writer: W,
    schema: SchemaRef,
    row_group_size: usize,
    data_file_format: DataFileFormat,
) -> ILResult<AsyncArrowWriter<W>> {
    let writer_properties = WriterProperties::builder()
        .set_max_row_group_size(row_group_size)
        .set_writer_version(match data_file_format {
            DataFileFormat::ParquetV1 => WriterVersion::PARQUET_1_0,
            DataFileFormat::ParquetV2 => WriterVersion::PARQUET_2_0,
        })
        .build();
    Ok(AsyncArrowWriter::try_new(
        writer,
        schema,
        Some(writer_properties),
    )?)
}

pub(crate) async fn read_parquet_file_by_record(
    storage: &dyn Storage,
    table_schema: &Schema,
    data_file_record: &DataFileRecord,
    projection: Option<Vec<usize>>,
    filters: Vec<Expr>,
    batch_size: usize,
) -> ILResult<RecordBatchStream> {
    let projection_mask = match projection {
        Some(projection) => {
            let parquet_schema = ArrowSchemaConverter::new().convert(table_schema)?;
            ProjectionMask::roots(&parquet_schema, projection)
        }
        None => ProjectionMask::all(),
    };

    let arrow_predicate_opt = if filters.is_empty() {
        None
    } else {
        let visited_columns = filters
            .iter()
            .flat_map(visited_columns)
            .collect::<HashSet<_>>();
        let mut predicate_projection = Vec::new();
        for visited_column in visited_columns {
            let index = table_schema.index_of(&visited_column)?;
            predicate_projection.push(index);
        }
        let parquet_schema = ArrowSchemaConverter::new().convert(table_schema)?;
        let predicate_projection_mask =
            ProjectionMask::roots(&parquet_schema, predicate_projection);
        Some(ExprPredicate::try_new(filters, predicate_projection_mask)?)
    };

    let input_file = storage.open(&data_file_record.relative_path).await?;
    let mut arrow_reader_builder = ParquetRecordBatchStreamBuilder::new(input_file).await?;

    if let Some(arrow_predicate) = &arrow_predicate_opt {
        arrow_reader_builder = arrow_reader_builder
            .with_row_filter(RowFilter::new(vec![Box::new(arrow_predicate.clone())]));
    }

    let stream = arrow_reader_builder
        .with_row_selection(data_file_record.row_selection())
        .with_projection(projection_mask.clone())
        .with_batch_size(batch_size)
        .build()?
        .map_err(|e| ILError::storage(format!("Failed to read stream: {e:?}")));
    Ok(Box::pin(stream))
}

pub(crate) async fn find_matched_row_ids_from_parquet_file(
    storage: &dyn Storage,
    table_schema: &Schema,
    condition: &Expr,
    data_file_record: &DataFileRecord,
) -> ILResult<HashSet<Uuid>> {
    let mut projection = build_projection_from_condition(table_schema, condition)?;
    // If the condition does not contain the row id column, add it to the projection
    if !projection.contains(&0) {
        projection.insert(0, 0);
    }

    let mut stream = read_parquet_file_by_record(
        storage,
        table_schema,
        data_file_record,
        Some(projection),
        vec![condition.clone()],
        1024,
    )
    .await?;

    let mut matched_row_ids = HashSet::new();
    while let Some(batch) = stream.next().await {
        let batch = batch?;
        let row_ids = extract_row_ids_from_record_batch(&batch)?;
        matched_row_ids.extend(row_ids);
    }
    Ok(matched_row_ids)
}

pub(crate) async fn read_row_id_array_from_parquet(
    storage: &dyn Storage,
    relative_path: &str,
) -> ILResult<FixedSizeBinaryArray> {
    let input_file = storage.open(relative_path).await?;
    let arrow_reader_builder = ParquetRecordBatchStreamBuilder::new(input_file).await?;
    let parquet_schema = arrow_reader_builder.parquet_schema();

    let projection_mask = ProjectionMask::roots(parquet_schema, [0]);

    let stream = arrow_reader_builder
        .with_projection(projection_mask)
        .build()?
        .map_err(ILError::from);

    let batches = stream.try_collect::<Vec<_>>().await?;

    let arrays = batches
        .iter()
        .map(|b| b.column(0).as_ref())
        .collect::<Vec<_>>();
    let array = arrow::compute::concat(&arrays)?;

    let array = array
        .as_any()
        .downcast_ref::<FixedSizeBinaryArray>()
        .ok_or_else(|| {
            ILError::internal("Can not downcast row id array to FixedSizeBinaryArray")
        })?;

    Ok(array.clone())
}