Remove AsyncFileReader::get_metadata_with_options, add options to AsyncFileReader::get_metadata (#7342)

* Remove default implementation for get_metadata_with_options and explain why.

* Improve comment about missing implementation.

* Update get_metadata method to take an optional ArrowReaderOptions.

* Fix handling of unencrypted footer.

* Checking git tests, it seems I missed a couple dead calls. Fixed.

* Fix path with no encryption enabled.

* Make have_decryptor a bit more bullet-proof.

* Update expected error message in test_decrypting_without_decryption_properties_fails.

* Tidy up get_metadata

* Fix merge conflicts.

---------

Co-authored-by: Adam Reeve <adreeve@gmail.com>

Author: corwinjoy

parquet/examples/read_with_rowgroup.rs

@@ -35,7 +35,7 @@ async fn main() -> Result<()> {
     let mut file = File::open(&path).await.unwrap();
 
     // The metadata could be cached in other places, this example only shows how to read
-    let metadata = file.get_metadata().await?;
+    let metadata = file.get_metadata(None).await?;
 
     for rg in metadata.row_groups() {
         let mut rowgroup = InMemoryRowGroup::create(rg.clone(), ProjectionMask::all());

parquet/src/arrow/async_reader/mod.rs

@@ -101,20 +101,11 @@ pub trait AsyncFileReader: Send {
     /// Provides asynchronous access to the [`ParquetMetaData`] of a parquet file,
     /// allowing fine-grained control over how metadata is sourced, in particular allowing
     /// for caching, pre-fetching, catalog metadata, etc...
-    fn get_metadata(&mut self) -> BoxFuture<'_, Result<Arc<ParquetMetaData>>>;
-
-    /// Provides asynchronous access to the [`ParquetMetaData`] of a parquet file,
-    /// allowing fine-grained control over how metadata is sourced, in particular allowing
-    /// for caching, pre-fetching, catalog metadata, decrypting, etc...
-    ///
-    /// By default calls `get_metadata()`
-    fn get_metadata_with_options<'a>(
+    /// ArrowReaderOptions may be provided to supply decryption parameters
+    fn get_metadata<'a>(
         &'a mut self,
-        options: &'a ArrowReaderOptions,
-    ) -> BoxFuture<'a, Result<Arc<ParquetMetaData>>> {
-        let _ = options;
-        self.get_metadata()
-    }
+        options: Option<&'a ArrowReaderOptions>,
+    ) -> BoxFuture<'a, Result<Arc<ParquetMetaData>>>;
 }
 
 /// This allows Box<dyn AsyncFileReader + '_> to be used as an AsyncFileReader,
@@ -127,15 +118,11 @@ impl AsyncFileReader for Box<dyn AsyncFileReader + '_> {
         self.as_mut().get_byte_ranges(ranges)
     }
 
-    fn get_metadata(&mut self) -> BoxFuture<'_, Result<Arc<ParquetMetaData>>> {
-        self.as_mut().get_metadata()
-    }
-
-    fn get_metadata_with_options<'a>(
+    fn get_metadata<'a>(
         &'a mut self,
-        options: &'a ArrowReaderOptions,
+        options: Option<&'a ArrowReaderOptions>,
     ) -> BoxFuture<'a, Result<Arc<ParquetMetaData>>> {
-        self.as_mut().get_metadata_with_options(options)
+        self.as_mut().get_metadata(options)
     }
 }
 
@@ -156,9 +143,9 @@ impl<T: AsyncRead + AsyncSeek + Unpin + Send> AsyncFileReader for T {
         .boxed()
     }
 
-    fn get_metadata_with_options<'a>(
+    fn get_metadata<'a>(
         &'a mut self,
-        options: &'a ArrowReaderOptions,
+        options: Option<&'a ArrowReaderOptions>,
     ) -> BoxFuture<'a, Result<Arc<ParquetMetaData>>> {
         const FOOTER_SIZE_I64: i64 = FOOTER_SIZE as i64;
         async move {
@@ -169,6 +156,7 @@ impl<T: AsyncRead + AsyncSeek + Unpin + Send> AsyncFileReader for T {
 
             let footer = ParquetMetaDataReader::decode_footer_tail(&buf)?;
             let metadata_len = footer.metadata_length();
+
             self.seek(SeekFrom::End(-FOOTER_SIZE_I64 - metadata_len as i64))
                 .await?;
 
@@ -178,43 +166,16 @@ impl<T: AsyncRead + AsyncSeek + Unpin + Send> AsyncFileReader for T {
             let metadata_reader = ParquetMetaDataReader::new();
 
             #[cfg(feature = "encryption")]
-            let metadata_reader = metadata_reader
-                .with_decryption_properties(options.file_decryption_properties.as_ref());
+            let metadata_reader = metadata_reader.with_decryption_properties(
+                options.and_then(|o| o.file_decryption_properties.as_ref()),
+            );
 
             let parquet_metadata = metadata_reader.decode_footer_metadata(&buf, &footer)?;
 
             Ok(Arc::new(parquet_metadata))
         }
         .boxed()
     }
-
-    fn get_metadata(&mut self) -> BoxFuture<'_, Result<Arc<ParquetMetaData>>> {
-        const FOOTER_SIZE_I64: i64 = FOOTER_SIZE as i64;
-        async move {
-            self.seek(SeekFrom::End(-FOOTER_SIZE_I64)).await?;
-
-            let mut buf = [0_u8; FOOTER_SIZE];
-            self.read_exact(&mut buf).await?;
-
-            let footer = ParquetMetaDataReader::decode_footer_tail(&buf)?;
-            let metadata_len = footer.metadata_length();
-
-            if footer.is_encrypted_footer() {
-                return Err(general_err!(
-                    "Parquet file has an encrypted footer but decryption properties were not provided"
-                ));
-            }
-
-            self.seek(SeekFrom::End(-FOOTER_SIZE_I64 - metadata_len as i64))
-                .await?;
-
-            let mut buf = Vec::with_capacity(metadata_len);
-            self.take(metadata_len as _).read_to_end(&mut buf).await?;
-
-            Ok(Arc::new(ParquetMetaDataReader::decode_metadata(&buf)?))
-        }
-        .boxed()
-    }
 }
 
 impl ArrowReaderMetadata {
@@ -233,7 +194,7 @@ impl ArrowReaderMetadata {
     ) -> Result<Self> {
         // TODO: this is all rather awkward. It would be nice if AsyncFileReader::get_metadata
         // took an argument to fetch the page indexes.
-        let mut metadata = input.get_metadata_with_options(&options).await?;
+        let mut metadata = input.get_metadata(Some(&options)).await?;
 
         if options.page_index
             && metadata.column_index().is_none()
@@ -1169,13 +1130,9 @@ mod tests {
             futures::future::ready(Ok(self.data.slice(range))).boxed()
         }
 
-        fn get_metadata(&mut self) -> BoxFuture<'_, Result<Arc<ParquetMetaData>>> {
-            futures::future::ready(Ok(self.metadata.clone())).boxed()
-        }
-
-        fn get_metadata_with_options<'a>(
+        fn get_metadata<'a>(
             &'a mut self,
-            _options: &'a ArrowReaderOptions,
+            _options: Option<&'a ArrowReaderOptions>,
         ) -> BoxFuture<'a, Result<Arc<ParquetMetaData>>> {
             futures::future::ready(Ok(self.metadata.clone())).boxed()
         }

parquet/src/arrow/async_reader/store.rs

@@ -194,35 +194,21 @@ impl AsyncFileReader for ParquetObjectReader {
     // an `impl MetadataFetch` and calls those methods to get data from it. Due to `Self`'s impl of
     // `AsyncFileReader`, the calls to `MetadataFetch::fetch` are just delegated to
     // `Self::get_bytes`.
-    fn get_metadata(&mut self) -> BoxFuture<'_, Result<Arc<ParquetMetaData>>> {
-        Box::pin(async move {
-            let metadata_reader = ParquetMetaDataReader::new()
-                .with_column_indexes(self.preload_column_index)
-                .with_offset_indexes(self.preload_offset_index)
-                .with_prefetch_hint(self.metadata_size_hint);
-            let metadata = if let Some(file_size) = self.file_size {
-                metadata_reader.load_and_finish(self, file_size).await?
-            } else {
-                metadata_reader.load_via_suffix_and_finish(self).await?
-            };
-
-            Ok(Arc::new(metadata))
-        })
-    }
-
-    fn get_metadata_with_options<'a>(
+    fn get_metadata<'a>(
         &'a mut self,
-        options: &'a ArrowReaderOptions,
+        options: Option<&'a ArrowReaderOptions>,
     ) -> BoxFuture<'a, Result<Arc<ParquetMetaData>>> {
         Box::pin(async move {
-            let metadata = ParquetMetaDataReader::new()
+            let mut metadata = ParquetMetaDataReader::new()
                 .with_column_indexes(self.preload_column_index)
                 .with_offset_indexes(self.preload_offset_index)
                 .with_prefetch_hint(self.metadata_size_hint);
 
             #[cfg(feature = "encryption")]
-            let metadata =
-                metadata.with_decryption_properties(options.file_decryption_properties.as_ref());
+            if let Some(options) = options {
+                metadata = metadata
+                    .with_decryption_properties(options.file_decryption_properties.as_ref());
+            }
 
             let metadata = if let Some(file_size) = self.file_size {
                 metadata.load_and_finish(self, file_size).await?

parquet/src/file/metadata/reader.rs

@@ -834,7 +834,7 @@ impl ParquetMetaDataReader {
 
                 file_decryptor = Some(decryptor);
             } else {
-                return Err(general_err!("Parquet file has an encrypted footer but no decryption properties were provided"));
+                return Err(general_err!("Parquet file has an encrypted footer but decryption properties were not provided"));
             }
         }
 

parquet/tests/arrow_reader/encryption.rs

@@ -154,7 +154,7 @@ fn test_decrypting_without_decryption_properties_fails() {
     assert!(result.is_err());
     assert_eq!(
         result.unwrap_err().to_string(),
-        "Parquet error: Parquet file has an encrypted footer but no decryption properties were provided"
+        "Parquet error: Parquet file has an encrypted footer but decryption properties were not provided"
     );
 }
 

parquet/tests/arrow_reader/encryption_async.rs

@@ -239,7 +239,7 @@ async fn test_decrypting_without_decryption_properties_fails() {
     assert!(result.is_err());
     assert_eq!(
         result.unwrap_err().to_string(),
-        "Parquet error: Parquet file has an encrypted footer but no decryption properties were provided"
+        "Parquet error: Parquet file has an encrypted footer but decryption properties were not provided"
     );
 }
 
@@ -277,7 +277,7 @@ async fn test_read_encrypted_file_from_object_store() {
     let options = ArrowReaderOptions::new().with_file_decryption_properties(decryption_properties);
 
     let mut reader = ParquetObjectReader::new(store, meta.location).with_file_size(meta.size);
-    let metadata = reader.get_metadata_with_options(&options).await.unwrap();
+    let metadata = reader.get_metadata(Some(&options)).await.unwrap();
     let builder = ParquetRecordBatchStreamBuilder::new_with_options(reader, options)
         .await
         .unwrap();