pub struct ArrowReaderMetadata { /* private fields */ }
Expand description
The metadata necessary to construct a ArrowReaderBuilder
Note this structure is cheaply clone-able as it consists of several arcs.
This structure allows
-
Loading metadata for a file once and then using that same metadata to construct multiple separate readers, for example, to distribute readers across multiple threads
-
Using a cached copy of the
ParquetMetadata
rather than reading it from the file each time a reader is constructed.
Implementations§
Source§impl ArrowReaderMetadata
impl ArrowReaderMetadata
Sourcepub fn load<T: ChunkReader>(
reader: &T,
options: ArrowReaderOptions,
) -> Result<Self>
pub fn load<T: ChunkReader>( reader: &T, options: ArrowReaderOptions, ) -> Result<Self>
Loads ArrowReaderMetadata
from the provided ChunkReader
, if necessary
See ParquetRecordBatchReaderBuilder::new_with_metadata
for an
example of how this can be used
§Notes
If options
has ArrowReaderOptions::with_page_index
true, but
Self::metadata
is missing the page index, this function will attempt
to load the page index by making an object store request.
Sourcepub fn try_new(
metadata: Arc<ParquetMetaData>,
options: ArrowReaderOptions,
) -> Result<Self>
pub fn try_new( metadata: Arc<ParquetMetaData>, options: ArrowReaderOptions, ) -> Result<Self>
Create a new ArrowReaderMetadata
§Notes
This function does not attempt to load the PageIndex if not present in the metadata.
See Self::load
for more details.
Sourcepub fn metadata(&self) -> &Arc<ParquetMetaData>
pub fn metadata(&self) -> &Arc<ParquetMetaData>
Returns a reference to the ParquetMetaData
for this parquet file
Sourcepub fn parquet_schema(&self) -> &SchemaDescriptor
pub fn parquet_schema(&self) -> &SchemaDescriptor
Returns the parquet SchemaDescriptor
for this parquet file
Source§impl ArrowReaderMetadata
impl ArrowReaderMetadata
Sourcepub async fn load_async<T: AsyncFileReader>(
input: &mut T,
options: ArrowReaderOptions,
) -> Result<Self>
pub async fn load_async<T: AsyncFileReader>( input: &mut T, options: ArrowReaderOptions, ) -> Result<Self>
Returns a new ArrowReaderMetadata
for this builder
See ParquetRecordBatchStreamBuilder::new_with_metadata
for how this can be used
Trait Implementations§
Source§impl Clone for ArrowReaderMetadata
impl Clone for ArrowReaderMetadata
Source§fn clone(&self) -> ArrowReaderMetadata
fn clone(&self) -> ArrowReaderMetadata
1.0.0 · Source§fn clone_from(&mut self, source: &Self)
fn clone_from(&mut self, source: &Self)
source
. Read more