Module read

APIs to read from ORC

Reading from ORC is essentially composed by:

1. Identify the column type based on the file’s schema
2. Read the stripe (or part of it in projection pushdown)
3. For each column, select the relevant region of the stripe
4. Attach an Iterator to the region

Modules

• decode
  Contains different iterators that receive a reader (std::io::Read) and return values for each of ORC’s physical types (e.g. boolean).
• decompress
  Contains Decompressor

Structs

• Column
  Helper struct used to access the streams associated to an ORC column. Its main use Column::get_stream, to get a stream.
• FileMetadata
  The file’s metadata.

Functions

• read_metadata
• read_stripe_column
  Reads column from the stripe into a Column. scratch becomes owned by Column, which you can recover via into_inner.
• read_stripe_footer
  Reads, decompresses and deserializes the stripe’s footer as StripeFooter using scratch as an intermediary memory region.