API Docs - v1.1.1
Tested Siddhi Core version: 5.1.21
It could also support other Siddhi Core minor versions.
Sinkmapper
protobuf (Sink Mapper)
This output mapper allows you to convert Events to protobuf messages before publishing them. To work with this mapper you have to add auto-generated protobuf classes to the project classpath. When you use this output mapper, you can either define stream attributes as the same names as the protobuf message attributes or you can use custom mapping to map stream definition attributes with the protobuf attributes. Please find the sample proto definition here. When you use this mapper with siddhi-io-grpc you don't have to provide the protobuf message class in the class parameter.
@sink(..., @map(type="protobuf", class="<STRING>")
QUERY PARAMETERS
| Name | Description | Default Value | Possible Data Types | Optional | Dynamic |
|---|---|---|---|---|---|
| class | This specifies the class name of the protobuf message class, If sink type is grpc then it's not necessary to provide this parameter. |
- | STRING | Yes | No |
Examples EXAMPLE 1
@sink(type='inMemory', topic='test01',
@map(type='protobuf', class='io.siddhi.extension.map.protobuf.autogenerated.Request'))
define stream BarStream (stringValue string, intValue int,longValue long,booleanValue bool,floatValue float,doubleValue double);
This will map BarStream values into io.siddhi.extension.map.protobuf.autogenerated.Request protobuf message type.
EXAMPLE 2
@sink(type='grpc', publisher.url = 'grpc://localhost:2000/org.wso2.grpc.test.MyService/process
@map(type='protobuf'))
define stream BarStream (stringValue string, intValue int,longValue long,booleanValue bool,floatValue float,doubleValue double)
Above definition will map BarStream values into the protobuf messages. Since this is a grpc sink, protobuf mapper will get the type of the protobuf class by the publisher.url.
EXAMPLE 3
@sink(type='grpc', publisher.url = 'grpc://localhost:2000/org.wso2.grpc.test.MyService/process
@map(type='protobuf'),
@payload(stringValue='a',longValue='b',intValue='c',booleanValue='d',floatValue = 'e', doubleValue = 'f')))
define stream BarStream (a string, b long, c int,d bool,e float,f double);
This will map BarStream values to request message type of the process method in MyService service. and stream values will map like this,
- value of a will be assign stringValue variable in the message class
- value of b will be assign longValue variable in the message class
- value of c will be assign intValue variable in the message class
- value of d will be assign booleanValue variable in the message class
- value of e will be assign floatValue variable in the message class
- value of f will be assign doubleValue variable in the message class
EXAMPLE 4
@sink(type='inMemory', topic='test01',
@map(type='protobuf' class='io.siddhi.extension.map.protobuf.autogenerated.RequestWithList'))
define stream BarStream (stringValue string,intValue int,stringList object, intList object);
This will map BarStream values into io.siddhi.extension.map.protobuf.autogenerated.RequestWithList. If you want to map data types other than the scalar data types, you have to use object as the data type as shown in above(stringList object).
Sourcemapper
protobuf (Source Mapper)
This input mapper allows you to convert protobuf messages into Events. To work with this input mapper you have to add auto-generated protobuf classes to the project classpath. When you use this input mapper, you can either define stream attributes as the same names as the protobuf message attributes or you can use custom mapping to map stream definition attributes with the protobuf attributes.Please find the sample proto definition here. When you use this mapper with siddhi-io-grpc you don't have to provide the protobuf message class in the class parameter.
@source(..., @map(type="protobuf", class="<STRING>")
QUERY PARAMETERS
| Name | Description | Default Value | Possible Data Types | Optional | Dynamic |
|---|---|---|---|---|---|
| class | This specifies the class name of the protobuf message class, If sink type is grpc then it's not necessary to provide this field. |
- | STRING | Yes | No |
Examples EXAMPLE 1
@source(type='inMemory', topic='test01',
@map(type='protobuf', class='io.siddhi.extension.map.protobuf.autogenerated.Request'))
define stream FooStream (stringValue string, intValue int,longValue long,booleanValue bool,floatValue float,doubleValue double);
This will convert the io.siddhi.extension.map.protobuf.autogenerated.Request protobuf messages into siddhi events.
EXAMPLE 2
source(type='grpc', receiver.url = 'grpc://localhost:8084/org.wso2.grpc.test.MyService/process',
@map(type='protobuf')) define stream FooStream (stringValue string, intValue int,longValue long,booleanValue bool,floatValue float,doubleValue double);
This will convert the protobuf messages that are received to this source into siddhi events. Since this is grpc source we don't need to provide the class parameter
EXAMPLE 3
source(type='grpc', receiver.url = 'grpc://localhost:8084/org.wso2.grpc.test.MyService/process',
@map(type='protobuf', @attributes(a = 'stringValue', b = 'intValue', c = 'longValue',d = 'booleanValue',' e = floatValue', f ='doubleValue')))
define stream FooStream (a string ,c long,b int, d bool,e float,f double);
This will convert the protobuf messages that are received to this source into siddhi events. since there's a mapping available for the stream, protobuf message object will be map like this,
- stringValue of the protobuf message will be assign to the a attribute of the stream
- intValue of the protobuf message will be assign to the b attribute of the stream
- longValue of the protobuf message will be assign to the c attribute of the stream
- booleanValue of the protobuf message will be assign to the d attribute of the stream
- floatValue of the protobuf message will be assign to the e attribute of the stream
- doubleValue of the protobuf message will be assign to the f attribute of the stream
EXAMPLE 4
source((type='inMemory', topic='test01',
@map(type='protobuf', class='io.siddhi.extension.map.protobuf.autogenerated.RequestWithList))
define stream FooStream (stringValue string ,intValue int,stringList object, intList object););
This will convert the io.siddhi.extension.map.protobuf.autogenerated.RequestWithList protobuf messages that are received to this source into siddhi events. If you want to map data types other than the scalar data types, you have to use object as the data type as shown in above(stringList object)