getUdfEngineVariable

getUdfEngineVariable(engine, name)

Query the current value of a specified external variable in a given DStream::udfEngine.

Return value: The current value of the specified variable. Its type and format depend on the variable itself.

engine A STRING scalar indicating the name of the user-defined engine created in the stream graph by DStream::udfEngine.

name A STRING scalar indicating the name of the external variable, which must be one of the variables defined in variableNames when creating DStream::udfEngine.

def callTimes(mutable cnt, msg) {
    cnt += 1;
    return msg
}
g = createStreamGraph("indicators")
g.source("trade", 1024:0, `price`volume, [DOUBLE,INT])
    .udfEngine(callTimes, [`price,`volume] ,[`number], [5])
    .setEngineName("udf")
    .sink("output111")
g.submit()

go
n = 1000
price = rand(100, n)
volume = rand(1000, n)
t = table(price, volume)
appendOrcaStreamTable("trade", t)

// Obtain the current value of number
useOrcaStreamEngine("udf", getUdfEngineVariable, "number")
// output: 1005

Related function: DStream::udfEngine