Object -
streams
:
StreamJoinProcessor
The StreamJoinProcessor
object is responsible for performing SQLish joins between two or more streams.
The onConditionFunc
is the lambda function which represents the where clause in the join clause. The joining
happens only if the condition is statified. nextProcessor
is the process
function of the next processor, which
can be a Select
processor, Aggregator
processor, Having
processor.. etc. The lhsStream
is the left hand side
stream of the join and its attached window is 'lhsWindow
. The rhsStream
is the right hand side stream of the join
and its attached window is 'rhsWindow
. The unidirectionalStream
stream defines the stream by which the joining is
triggered when the events are received. Usually it is lhsStream
, in rare cases it can be rhsStream
. The
joinType
is the type of the join and it can be any value defined by streams:JoinType
.
Constructor
__init
( function(StreamEvent?[]) returns (())
nextProcessor, JoinType joinType, function(map, map) returns (boolean)
onConditionFunc)
- nextProcessor
function(StreamEvent?[]) returns (())
- joinType JoinType
- onConditionFunc
function(map, map) returns (boolean)
Methods
Process the events from both lhsStream
and the rhsStream
and perform the joining.
Sets the left hand side stream name and the respective window instance.
Sets the right hand side stream name and the respective window instance.
Sets the stream by which the joining is triggered.
Fields
Process the events from both lhsStream
and the rhsStream
and perform the joining.
Parameters
- streamEvents StreamEvent?[]
-
Stream events being joined.
Sets the left hand side stream name and the respective window instance.
Parameters
- streamName string
-
The name of the left hand side stream.
- windowInstance Window
-
The window attached to the left hand side stream.
Sets the right hand side stream name and the respective window instance.
Parameters
- streamName string
-
The name of the right hand side stream.
- windowInstance Window
-
The window attached to the right hand side stream.
Sets the stream by which the joining is triggered.
Parameters
- streamName string
-
The name of the stream. In most cases, the joining is triggered when the events are received by the left hand side stream even if the right hand side stream receives the events before the left hand side stream receives events.