interceptors diagram [skip ci]

Author: Alexander Furer

README.adoc

@@ -281,32 +281,22 @@ Error handling interceptor has the highest precedence.
 
 The way grpc interceptor works is that it intercepts the call and returns the server call listener, which in turn can intercept the request message as well, before forwarding it to the actual service call handler :
 
-****
-`interceptor_1(interceptCall)` -> `interceptor_2(interceptCall)` -> `interceptor_3(interceptCall)` -> +
-`interceptor_1(On_Message)`-> `interceptor_2(On_Message)`-> `interceptor_3(On_Message)`-> +
-`actual service call`
-****
+image:./images/interceptors_001.png[]
+
 
 By setting  `grpc.security.auth.fail-fast`  property to `false` all downstream interceptors as well as all upstream interceptors (On_Message) will still be executed in case of authentication/authorization failure +
 
 Assuming `interceptor_2` is `securityInterceptor` :
 
 * For failed authentication/authorization with  `grpc.security.auth.fail-fast=true`(default): +
 +
+image:./images/interceptors_002.png[]
 
-****
-`interceptor_1(interceptCall)` -> `securityInterceptor(interceptCall)` - *Call is Closed* -> +++<del>+++ `interceptor_3(interceptCall)` -> +
-`interceptor_1(On_Message)`-> `securityInterceptor(On_Message)`->`interceptor_3(On_Message)`-> +
-`actual service call`+++</del>+++
-****
 
 * For failed authentication/authorization with `grpc.security.auth.fail-fast=false`: +
 +
-****
-`interceptor_1(interceptCall)` -> `securityInterceptor(interceptCall)` -> `interceptor_3(interceptCall)` ->
-`interceptor_1(On_Message)`-> `securityInterceptor(On_Message)` - *Call is Closed*  +++<del>+++-> `interceptor_3(On_Message)`-> +
-`actual service call`+++</del>+++
-****
+image:./images/interceptors_003.png[]
+
 
 === Distributed tracing support (Spring Cloud Sleuth integration)
 

images/interceptors.txt

@@ -1,22 +1,124 @@
+' to generate png files : download the latest jar from https://github.com/plantuml/plantuml/releases  and run  java -jar plantuml-1.2021.13.jar intercepts.txt
+
 @startdef(id=main)
-participant interceptor_1 $color
+participant $interceptorName1 as interceptor_1
+participant $interceptorName2 as interceptor_2
+participant $interceptorName3 as interceptor_3
+
+[-> interceptor_1 : start call
+activate interceptor_1
+
+interceptor_1 $arrow1_2  interceptor_2: $intStyle1_2 intercept $intStyle1_2
+activate interceptor_2
+
+interceptor_2 $arrow2_3 interceptor_3: $intStyle2_3 intercept $intStyle2_3
+activate interceptor_3
+
+interceptor_3 $arrow3_3 interceptor_3: $intStyle3_3 intercept $intStyle3_3
+return  $intReturn2
+return  $intReturn1
+
+deactivate interceptor_3
+deactivate interceptor_2
+[<-  interceptor_1 : $intResponseStyle return listener $intResponseStyle
+deactivate interceptor_1
+
+
 
-interceptor_1 -> interceptor_2 :intercept
-interceptor_2 -> interceptor_3 :intercept
-interceptor_3 -> interceptor_3 :intercept
+[-> interceptor_1 : $reqStyle request $reqStyle
+activate interceptor_1
+
+interceptor_1 $msgArrow1_2 interceptor_2   :$msgStyle1_2 onMessage $msgStyle1_2
+activate interceptor_2
+
+interceptor_2 $msgArrow2_3 interceptor_3   : $msgStyle2_3 onMessage $msgStyle2_3
+activate interceptor_3
+
+interceptor_3 $msgArrow3 service : $msgStyle3 actual call $msgStyle3
+return $msgReturn2
+return $msgReturn1
+[<-  interceptor_1 : $responseStyle response $responseStyle
+
+deactivate interceptor_3
+deactivate interceptor_2
+deactivate interceptor_1
 
-interceptor_1 -> interceptor_2 :onMessage
-interceptor_2 -> interceptor_3 :onMessage
-interceptor_3 -> interceptor_3 :onMessage
-interceptor_3 -> service : actual call
 @enddef
 
 @startuml
-!$color = "#red"
+!$arrow1_2  = "->"
+!$arrow2_3  = "->"
+!$arrow3_3  = "->"
+!$intStyle1_2  = ""
+!$intStyle2_3  = ""
+!$intStyle3_3  = ""
+!$msgArrow1_2  = "->"
+!$msgArrow2_3  = "->"
+!$msgArrow3    = "->"
+!$msgStyle1_2  = ""
+!$msgStyle2_3  = ""
+!$msgStyle3    = ""
+!$reqStyle           = ""
+!$responseStyle      = ""
+!$intResponseStyle   = ""
+!$intReturn1   = ""
+!$intReturn2   = ""
+!$msgReturn1  = ""
+!$msgReturn2  = ""
+!$interceptorName1  = "interceptor_1"
+!$interceptorName2  = "interceptor_2"
+!$interceptorName3  = "interceptor_3"
+!includedef  main
+@enduml
+
+@startuml
+!$arrow1_2 = "->"
+!$arrow2_3 = "x->"
+!$arrow3_3 = "x->"
+!$intStyle1_2 = ""
+!$intStyle2_3 = "---"
+!$intStyle3_3 = "---"
+!$msgArrow1_2 = "x->"
+!$msgArrow2_3 = "x->"
+!$msgArrow3 = "x->"
+!$msgStyle1_2 = "---"
+!$msgStyle2_3 = "---"
+!$msgStyle3 = "---"
+!$reqStyle = "---"
+!$responseStyle = "---"
+!$intResponseStyle = "---"
+!$intReturn1 = "close call"
+!$intReturn2 = ""
+!$msgReturn1 = ""
+!$msgReturn2 = ""
+!$interceptorName1 = "interceptor_1"
+!$interceptorName2 = "securityInterceptor"
+!$interceptorName3 = "interceptor_3"
 !includedef  main
 @enduml
 
 @startuml
-!$color = "#Blue"
+!$arrow1_2 = "->"
+!$arrow2_3 = "->"
+!$arrow3_3 = "->"
+!$intStyle1_2= ""
+!$intStyle2_3= ""
+!$intStyle3_3= ""
+!$msgArrow1_2 = "->"
+!$msgArrow2_3 = "x->"
+!$msgArrow3 = "x->"
+!$msgStyle1_2 = ""
+!$msgStyle2_3 = "---"
+!$msgStyle3 = "---"
+!$reqStyle = ""
+!$responseStyle = "---"
+!$intResponseStyle= ""
+!$intReturn1 = ""
+!$intReturn2 = ""
+!$msgReturn1 = "close call"
+!$msgReturn2 = ""
+!$interceptorName1 = "interceptor_1"
+!$interceptorName2 = "securityInterceptor"
+!$interceptorName3 = "interceptor_3"
 !includedef  main
 @enduml