airs-ibusnats

• NATS implementation of ibus interface
• Backpressure is implemented. Next section will not be sent by the service until the sender claimed he is ready to receive it.
• Slow consumer problem is eliminated: the client could be as slow as it want. But the service stops communication if the sender processes a section element longer than 10 seconds

Bus packets binary formats

Response Stream = Response | {MapSection+Elem {Elem} | ArraySection+Elem {Elem} | ObjectSection+Elem} Close | MiscInboxName
Reponse = 0x0 ContentTypeLen_1 ContentType StatusCode_2 Data
MapSection+Elem = 0x2 PathsCount_1 {PathLen_1 Path} LenSectionType_1 SectionType LenElemName_1 ElemName ElemBytes
ArraySection+Elem = 0x3 PathsCount_1 {PathLen_1 Path} LenSectionType_1 SectionType ElemBytes
ObjectSection+Elem = 0x4 PathsCount_1 {PathLen_1 Path} LenSectionType_1 SectionType ElemBytes
Elem = 0x5 [LenElemName_1 ElemName] ElemBytes
Close = 0x1 [ErrorMessage]
MiscInboxName = 0x6 Name

Misc Stream = GoOn | NoConsumer
GoOn = 0x0
NoConsumer = 0x1

Limitations

• ibus.IResultSenderClosable:
  • sectionType, path elem and elementName max length is 255 chars
  • []path max length is 255 elements
• ibus.IResultSenderClosable.Close(): failed to send to NATS -> nothing happens, just error is logged. Requester will get ibus.ErrTimeoutExpired at *secErr
• failed to publish at ibus.SendResponse() -> nothing happens, just error is logged. Requester will get ibus.ErrTimeoutExpired as err
• failed to unsubscribe from the queue on service stop -> nothing happens, just error is logged
• service stops in 10 seconds maximum (message awaiting timeout)