Object -
streams
:
DelayWindow
This window will delay the incoming events for a given amount of time.
E.g.
from inputStream window delay(4000)
select inputStream.name, inputStream.age, sum(inputStream.age) as sumAge, count() as count
group by inputStream.name => (TeacherOutput [] teachers) {
foreach var t in teachers {
outputStream.publish(t);
}
}
The delay
window should only have one parameter (
Constructor
__init
( function(StreamEvent[]) returns (())
nextProcessPointer, any windowParameters)
- nextProcessPointer
function(StreamEvent[]) returns (())
- windowParameters any
Methods
The process
function process the incoming events to the events and update the current state of the window.
Returns the events(State) which match with the where condition in the join clause for a given event.
Return current state to be saved as a map of any
typed values.
Restores the saved state which is passed as a map of any
typed values.
Fields
- delayInMilliSeconds int
-
description
- windowParameters any
-
description
- delayedEventQueue LinkedList
-
description
- lastTimestamp int 0
-
description
- nextProcessPointer
function(StreamEvent[]) returns (())
-
description
- scheduler Scheduler? ()
-
description
The process
function process the incoming events to the events and update the current state of the window.
Parameters
- streamEvents StreamEvent[]
-
The array of stream events to be processed.
getCandidateEvents
(StreamEvent originEvent, function(map, map) returns (boolean)
conditionFunc, boolean isLHSTrigger)
Returns the events(State) which match with the where condition in the join clause for a given event.
Parameters
- originEvent StreamEvent
-
The event against which the state or the events being held by the window is matched.
-
conditionFunc
function(map, map) returns (boolean)
-
The function pointer to the lambda function which contain the condition logic in where clause.
- isLHSTrigger boolean (default true)
-
Specify if the join is triggered when the lhs stream received the events, if so it should be true. Most of the time it is true. In rare cases, where the join is triggered when the rhs stream receives events this should be false.
-
Return Type
([StreamEvent?, StreamEvent?]) Returns an array of 2 element tuples of events. A tuple contains the matching events one from lhs stream and one from rhs stream.
Return current state to be saved as a map of any
typed values.
-
Return Type
(map) A map of
any
typed values.