streamEventSerializer

streamEventSerializer(name, eventSchema, outputTable, [eventTimeField], [commonField])

Serializes events into BLOB and writes them to a heterogeneous stream table.

name is a string indicating the engine name. It consists of letters, digits, and underscores(_) and must start with a letter.

eventSchema is a table or a scalar/vector of class definition of event types, indicating the data to be serialized. If it is a table, it must have the schema as follows:

outputTable is a non-partitioned in-memory table or a stream table for outputting the results. The output columns are in the following order:

(1) A time column of TIMESTAMP type (if eventTimeField is specified);

(2) A SYMBOL or STRING column indicating the events;

(3) A BLOB column that stores the serialized result of each event;

(4) The column(s) with the same names and data types (if commonField specified).

eventTimeField (optional) is a string scalar or vector indicating the name(s) of time field for the event(s).

• If all events share the same time field name, simply specify it as a single string.

• If the time field varies among events, specify a vector with the same length as eventSchema. Each element corresponds to one time field.

commonField (optional) is a string scalar or vector indicating the field(s) with the same name and data type. If specified, the common fields can be filtered out during subscription.

A table object.

class MarketData{
    market :: STRING
    code :: STRING
    price :: DOUBLE
    qty :: INT
    def MarketData(m,c,p,q){
        market = m
        code = c
        price = p
        qty = q
    }
}
class Orders{
    trader :: STRING
    market :: STRING
    code :: STRING
    price :: DOUBLE
    qty :: INT
    def Orders(t, m,c,p,q){
        trader = t
        market = m
        code = c
        price = p
        qty = q
    }
}
class Trades{
    trader :: STRING
    market :: STRING
    code :: STRING
    price :: DOUBLE
    qty :: INT
    def Trades(t, m,c,p,q){
        trader = t
        market = m
        code = c
        price = p
        qty = q
    }
}
share streamTable(array(STRING, 0) as eventType, array(BLOB, 0) as blobs) as events
serializer = streamEventSerializer(name=`serOutput, eventSchema=[MarketData, Orders, Trades], outputTable=events)