parquet-format-async-temp

This is a temporary crate containing a subset of rust's thirft library and parquet to support native async parquet read and write.

Specifically, it:

• supports async read API (via futures)
• supports async write API (via futures)
• the write API returns the number of written bytes

It must be used with the fork of thrift's compiler available at https://github.com/jorgecarleitao/thrift/tree/write_size .

Why

To read and write files with thrift (e.g. parquet) without commiting to a particular runtime (e.g. tokio, hyper, etc.), the protocol needs to support AsyncRead + AsyncSeek and AsyncWrite respectively.

To not require Seek and AsyncSeek on write, the protocol must return the number of written bytes on its write_* API.

This crate addresses these two concerns for parquet. It is essentially: * https://github.com/apache/thrift/pull/2426 applied on latest thrift * a modification for the written bytes to be outputed on all write_* APIs