Operator Export
SPL standard and specialized toolkits > spl 1.2.1 > spl.adapter > Export
The Export operator sends a stream from the current application, making it available to Import operators of applications that are running in the same streaming middleware instance.
The Export operator does not send tuples to the exported stream inside stand-alone SPL applications. The tuples are ignored.
The Export operator does not allow a config clause to be specified.
Checkpointed data
The Export operator does not support checkpointing.
Behavior in a consistent region
The Export operator is not supported in a consistent region.
Checkpointing behavior in an autonomous region
The Export operator does not allow config checkpoint clause to be specified.
Examples
This example uses the Export operator.
composite Main {
graph
stream<int32 i> TechSectorBargains = Beacon() { }
stream<int32 i> HealthCareSectorBargains = Beacon() { }
() as ExportOp1 = Export(TechSectorBargains) {
param properties : { kind="bargains", category="tech",
tickers=["IBM", "GOOG", "MSFT"] };
}
() as ExportOp2 = Export(HealthCareSectorBargains) {
param streamId : "someStreamName";
}
}
Summary
- Ports
- This operator has 1 input port and 0 output ports.
- Windowing
- This operator does not accept any windowing configurations.
- Parameters
- This operator supports 3 parameters.
Optional: properties, streamId, allowFilter
- Metrics
- This operator does not report any metrics.
Properties
- Implementation
- C++
- Threading
- Always - Operator always provides a single threaded execution context.
- Ports (0)
The Export operator has a single input port, which produces tuples from the exported stream. The Export operator does not allow custom port logic to be specified in its invocations.
- Properties
-
- Optional: false
- ControlPort: false
- TupleMutationAllowed: false
- WindowingMode: NonWindowed
- WindowPunctuationInputMode: Oblivious
- properties
Specifies a tuple literal that gives name-value pairs. The supported attribute types are int64, float64, rstring, list<int64>, list<float64>, and list<rstring>.
If the application has user-defined parallelism and the Export operator is replicated in a parallel region, you can use the getChannel() and getMaxChannels() SPL built-in functions in this parameter. The functions are evaluated when the job is submitted.
- Properties
-
- Optional: true
- ExpressionMode: Constant
- streamId
Specifies the external name of the stream that is exported. Only one of streamId or properties can be specified on an Export operator.
If neither properties nor streamId is specified, the Export operator is export by properties, with empty properties.
If the application has user-defined parallelism and the Export operator is replicated in a parallel region, you can use the getChannel() and getMaxChannels() SPL built-in functions in this parameter. The functions are evaluated when the job is submitted.
- Properties
-
- Type: rstring
- Cardinality: 1
- Optional: true
- ExpressionMode: Constant
- allowFilter
If this parameter is set to true or not present, then Import operators with a filter expression that connect to this Export operator pass the filter expression to the Export operator to use.
If this parameter is set to false, then Import operators with a filter expression and whose subscriptions match the Export operator fail to match the Export operator.
- Properties
-
- Type: boolean
- Cardinality: 1
- Optional: true
- ExpressionMode: Constant
- Export with Properties
-
() as ${opInstanceName} = Export(${inputStream}) { param properties: {${paramExpression}}; }
- Export with Stream ID
-
() as ${opInstanceName} = Export(${inputStream}) { param streamId : ${exportedStreamName}; }