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PoC use ParquetMetaDataPushDecoder for parquet metadata reading #20857

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PoC use ParquetMetaDataPushDecoder for parquet metadata reading #20857

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98 changes: 60 additions & 38 deletions datafusion/datasource-parquet/src/metadata.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -18,9 +18,7 @@
//! [`DFParquetMetadata`] for fetching Parquet file metadata, statistics
//! and schema information.

use crate::{
ObjectStoreFetch, apply_file_schema_type_coercions, coerce_int96_to_resolution,
};
use crate::{apply_file_schema_type_coercions, coerce_int96_to_resolution};
use arrow::array::{Array, ArrayRef, BooleanArray};
use arrow::compute::and;
use arrow::compute::kernels::cmp::eq;
Expand All @@ -44,10 +42,11 @@ use object_store::{ObjectMeta, ObjectStore};
use parquet::arrow::arrow_reader::statistics::StatisticsConverter;
use parquet::arrow::{parquet_column, parquet_to_arrow_schema};
use parquet::file::metadata::{
PageIndexPolicy, ParquetMetaData, ParquetMetaDataReader, RowGroupMetaData,
PageIndexPolicy, ParquetMetaData, ParquetMetaDataPushDecoder, RowGroupMetaData,
SortingColumn,
};
use parquet::schema::types::SchemaDescriptor;
use parquet::DecodeResult;
use std::any::Any;
use std::collections::HashMap;
use std::sync::Arc;
Expand Down Expand Up @@ -114,25 +113,15 @@ impl<'a> DFParquetMetadata<'a> {

/// Fetch parquet metadata from the remote object store
pub async fn fetch_metadata(&self) -> Result<Arc<ParquetMetaData>> {
let Self {
store,
object_meta,
metadata_size_hint,
decryption_properties,
file_metadata_cache,
coerce_int96: _,
} = self;

let fetch = ObjectStoreFetch::new(*store, object_meta);

// implementation to fetch parquet metadata
let cache_metadata =
!cfg!(feature = "parquet_encryption") || decryption_properties.is_none();
let cache_metadata = !cfg!(feature = "parquet_encryption")
|| self.decryption_properties.is_none();

if cache_metadata
&& let Some(file_metadata_cache) = file_metadata_cache.as_ref()
&& let Some(cached) = file_metadata_cache.get(&object_meta.location)
&& cached.is_valid_for(object_meta)
&& let Some(file_metadata_cache) = self.file_metadata_cache.as_ref()
&& let Some(cached) =
file_metadata_cache.get(&self.object_meta.location)
&& cached.is_valid_for(self.object_meta)
&& let Some(cached_parquet) = cached
.file_metadata
.as_any()
Expand All @@ -141,32 +130,65 @@ impl<'a> DFParquetMetadata<'a> {
return Ok(Arc::clone(cached_parquet.parquet_metadata()));
}

let mut reader =
ParquetMetaDataReader::new().with_prefetch_hint(*metadata_size_hint);
let file_size = self.object_meta.size as u64;
let mut decoder = ParquetMetaDataPushDecoder::try_new(file_size)
.map_err(DataFusionError::from)?;

#[cfg(feature = "parquet_encryption")]
if let Some(decryption_properties) = decryption_properties {
reader = reader
.with_decryption_properties(Some(Arc::clone(decryption_properties)));
}

if cache_metadata && file_metadata_cache.is_some() {
if cache_metadata && self.file_metadata_cache.is_some() {
// Need to retrieve the entire metadata for the caching to be effective.
reader = reader.with_page_index_policy(PageIndexPolicy::Optional);
decoder = decoder.with_page_index_policy(PageIndexPolicy::Optional);
} else {
decoder = decoder.with_page_index_policy(PageIndexPolicy::Skip);
}

let metadata = Arc::new(
reader
.load_and_finish(fetch, object_meta.size)
// If we have a size hint, prefetch that many bytes from the end of the file
if let Some(hint) = self.metadata_size_hint {
let prefetch_start = file_size.saturating_sub(hint as u64);
let prefetch_range = prefetch_start..file_size;
let data = self
.store
.get_ranges(
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@Dandandan Dandandan Mar 10, 2026

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This and next requests can go on a queue.

&self.object_meta.location,
&[prefetch_range.clone()],
)
.await
.map_err(DataFusionError::from)?,
);
.map_err(DataFusionError::from)?;
decoder
.push_ranges(vec![prefetch_range], data)
.map_err(DataFusionError::from)?;
}

let metadata = loop {
match decoder.try_decode().map_err(DataFusionError::from)? {
DecodeResult::Data(metadata) => break metadata,
DecodeResult::NeedsData(ranges) => {
let buffers = self
.store
.get_ranges(&self.object_meta.location, &ranges)
.await
.map_err(DataFusionError::from)?;
decoder
.push_ranges(ranges, buffers)
.map_err(DataFusionError::from)?;
}
DecodeResult::Finished => {
return Err(DataFusionError::Internal(
"ParquetMetaDataPushDecoder finished without producing metadata"
.to_string(),
));
}
}
};

let metadata = Arc::new(metadata);

if cache_metadata && let Some(file_metadata_cache) = file_metadata_cache {
if cache_metadata
&& let Some(file_metadata_cache) = &self.file_metadata_cache
{
file_metadata_cache.put(
&object_meta.location,
&self.object_meta.location,
CachedFileMetadataEntry::new(
(*object_meta).clone(),
self.object_meta.clone(),
Arc::new(CachedParquetMetaData::new(Arc::clone(&metadata))),
),
);
Expand Down
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