udp: add into_parts to RecvDgram
#710
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If `RecvDgram` can not be driven to completion it may become necessary to get back the `UdpSocket` it contains which is currently not possible. This commit adds `into_inner` to do just that and `into_parts` to get the socket as well as the buffer back. Both methods consume `RecvDgram`. Note that after the future has completed, neither `into_inner` nor `into_parts` must be used, or else a panic will happen.
for `RecvDgram::into_inner` and `RecvDgram::into_parts`
tokio-udp/src/recv_dgram.rs
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| /// | ||
| /// If called after the future has completed. | ||
| pub fn into_inner(mut self) -> UdpSocket { | ||
| let state = self.state |
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How about adding common private function to get the state?
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I am not sure it would be an improvement. It would essentially look like this:
fn into_state(mut self, msg: &str) -> RcvDgramInner {
self.state.take().expect(msg)
}and the calls would be self.into_state("into_inner called after completion") and self.into_state("into_parts called after completion") which does not really seem clearer to me. Would you really like me to make this change?
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@tobz: It is true that |
As suggested during review, `into_inner` is considered redundant and should be removed.
twittner
changed the title
into_inner and into_parts to RecvDgraminto_parts to RecvDgram
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FYI: CI is failing with an internal compiler error (rustc 1.31.0-nightly) when compiling hyper which is unrelated to this PR. |
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Although now I'm not sure I can merge this if it doesn't pass CI... |
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The strategy of returning a tuple isn't very forwards compatbile. If That said, Do you think it is worth returning a |
To help future extensibility, avoid returning a tuple from `RecvDgram::into_parts` and instead return a struct whose components can be extracted by field name.
I think it is. |
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CI failure is caused by rust-lang/rust#55376. |
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@kpp, @tobz, @carllerche: Is there anything else I should address? |
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@twittner Nope, I think this is good. Unfortunately, with failing checks, only @carllerche has the power to merge it. I'll try and ping him to get it merged. 👍 |
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@tobz: CI was successful. Maybe you can merge this now? |
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All set! 👍 |
Add
methodsRecvDgram::into_innerandRecvDgram::into_partsto allow deconstructing aRecvDgramfuture in case it can not be driven to completion.Motivation
If the
RecvDgramfuture can not be driven to completion, it may become necessary to get back theUdpSocketand buffer, which is currently not possible. Since UDP is unreliable, it is advisable to use timeouts when receiving datagrams. After a timeout, one would probably retry sending and receiving, which requires the socket, however since it cannot be pulled out ofRecvDgramagain,RecvDgramis virtually impossible to use together with timeouts.Solution
With
into_innerandinto_partsthe socket and buffer can be retrieved by consuming the future. This allows to continue using those values.