vcf::AsyncWriter::into_inner() missing?

[holtgrewe]

Hello, there is no into_inner() in vcf::AsyncWriter. Effectively, I cannot shutdown the inner writer which is necessary, for ensuring the output stream is flushed and properly shutdown, as far as I can see.

Am I missing something?

[holtgrewe]

Hm, unless I'm missing something, this even looks like a bug. When using a #[tokio::main] function and writing out many lines (say a few thousand) then the last batch will not be written out unless shutdown is called on the writer. It looks like the output file will be truncated in this case.

[zaeleus]

If you're using a buffered async writer, you have to call flush/shutdown before the writer gets dropped. See tokio::io's "Buffered Readers and Writers":

However, you must flush BufWriter to ensure that any buffered data is written.

// ...
    } // Unless flushed or shut down, the contents of the buffer is discarded on drop.
// ...

[zaeleus]

Underlying writer access for vcf::AsyncWriter was implemented in #211, and the methods are now available in noodles 0.55.0 / noodles-vcf 0.43.0.