A MutStreamingIterator that reads column chunks one by one, returning a PageReader per column.

Decompressor that allows re-using the page buffer of PageIterator.

A fallible Iterator of CompressedDataPage. This iterator leverages page indexes to skip pages that are not needed. Consequently, the pages from this iterator always have Some [CompressedDataPage::rows()]

PageReader

A fallible Iterator of CompressedDataPage. This iterator reads pages back to back until all pages have been consumed. The pages from this iterator always have None [CompressedDataPage::rows()] since filter pushdown is not supported without a pre-computed page index.

ReadColumnIterator

A MutStreamingIterator of pre-read column chunks

Enums

State

State of MutStreamingIterator.

Traits

ColumnChunkIter

Trait describing a MutStreamingIterator of column chunks.

MutStreamingIterator

A special kind of fallible streaming iterator where advance consumes the iterator.

PageIterator

Functions

decompress

Decompresses the page, using buffer for decompression. If page.buffer.len() == 0, there was no decompression and the buffer was moved. Else, decompression took place.

filter_row_groups

Filters row group metadata to only those row groups, for which the predicate function returns true

get_column_iterator

Returns a ColumnIterator of column chunks corresponding to field. Contrarily to get_page_iterator that returns a single iterator of pages, this iterator returns multiple iterators, one per physical column of the field. For primitive fields (e.g. i64), ColumnIterator yields exactly one column. For complex fields, it yields multiple columns.

get_field_columns

Returns an Iterator of ColumnChunkMetaData corresponding to the columns from field at row_group. For primitive fields (e.g. i64), the iterator has exactly one item.

get_page_iterator

Returns a new PageReader by seeking reader to the begining of column_chunk.

get_page_stream

Returns a stream of compressed data pages

read_columns_indexes

Reads the column indexes of all ColumnChunkMetaData and deserializes them into Index. Returns an empty vector if indexes are not available

read_metadata

Reads a file’s metadata.

read_metadata_async

Asynchronously reads the files’ metadata

read_pages_locations

Read PageLocations from the ColumnChunkMetaDatas. Returns an empty vector if indexes are not available