Allow using user-supplied buffer for encoding data?

[repnop]

Hi, I'm working on building a SNMP client and as an optimization to prevent allocating memory on every send/receive, I want to internally store a Vec in my client, however there doesn't appear to be a way to provide the Encoder a &mut Vec<u8> or &mut [u8] to encode into, which would be really useful!

[repnop]

An alternative might be to allow passing a Vec<u8> into a constructor for Encoder, which would allow me to core::mem::take(&mut self.my_buffer); then swap it back after encoding -- not entirely ideal, but definitely workable and much easier to adapt Encoder to. If you'd be fine with this method if the above seems more difficult to support, I'd happily PR it!

[XAMPPRocky]

Thank you for your issue! Sorry for the late reply. Overall I'm open to adding a way for to re-use the encoder buffer and would accept a PR adding this functionality. I'll only note that this won't entirely prevent allocating on every send/receive depending on the data. There are ASN.1 types that rasn always has to allocate in order to handle correctly at the layer its operating at (the main one being SET types). Being able to re-use the buffer would still be useful for cases where those types aren't present however.

[repnop]

Awesome! I'll see if I can find some spare time and send in a PR for that 👍