Fix service behavior when the service is an empty input (e.g. std_srvs/Trigger)
#75
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chachi
commented
Feb 19, 2019
chachi
commented
- Change decoding of service request from a while loop to explicit if statement
- Do not call service handler on tcp probe connection
- Change decoding of service request from a while loop to explicit if statement - Do not call service handler on tcp probe connection
| @@ -157,7 +172,7 @@ where | |||
| // TODO: validate message length | |||
| let _length = stream.read_u32::<LittleEndian>(); | |||
| // Break out of loop in case of failure to read request | |||
| while let Ok(req) = RosMsg::decode(&mut stream) { | |||
| if let Ok(req) = RosMsg::decode(&mut stream) { | |||
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Aren't clients able to send multiple requests via the same connection to a service?
That method greatly reduces communication overhead, since header exchanges can often be much larger than the actual service payloads.
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Yes, good catch, you're right this does prevent persistent connections.
Looks like service_client_link.cpp is where roscpp handles these things. I see two differences from service.rs:
- It looks for "persistent" in the header to know whether there might be more messages.
- It reads the length of the message before each new message is deserialized.
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Could you just leave a TODO above the if line, and I can take on handling both cases
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Nvm, I've just made an issue and will handle it afterwards.
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