com.northconcepts.datapipeline.group

Class CloseWindowStrategy

java.lang.Object

com.northconcepts.datapipeline.group.CloseWindowStrategy

public abstract class CloseWindowStrategy
extends Object

Determines when GroupByReader closes an open sliding window.

Field Summary

Fields

Modifier and Type	Field and Description
static long	CLOSE_WINDOW_MARGIN_MILLIS

Constructor Summary

Constructors

Constructor and Description
CloseWindowStrategy()

Method Summary

Modifier and Type	Method and Description
static CloseWindowStrategy	and(CloseWindowStrategy... strategies) Closes windows if all of the supplied strategies request it.
static CloseWindowStrategy	hourlyScheduleInMinutes(int... minutesPastHour) Closes windows at fixed minutes past each hour (for example: 0, 15, 30, and 45 minutes past each hour).
static CloseWindowStrategy	hourlyScheduleInMinutes(String fieldName, int... minutesPastHour) Closes windows at fixed minutes past each hour for the specified datetime field (for example: 0, 15, 30, and 45 minutes past each hour).
boolean	isCloseBeforeAddingRecord() Returns true if the window should be closed before adding the record or false if (the default).
boolean	isPollingRequired() Indicates if the {@link #shouldClose(Window, GroupByReader, Record) method should be called every second for open windows -- even if no new data is present -- to release any data that may have been collected (passing in a null record).
static CloseWindowStrategy	limitedRecords(long count) Closes the window after the specified amount of records has been collected.
static CloseWindowStrategy	limitedTime(long milliseconds) Closes windows after they've been open for the specified time.
static CloseWindowStrategy	limitedTime(String fieldName, long milliseconds) Closes windows after the specified datetime field has increased by a set amount of time since it was first seen.
static CloseWindowStrategy	never() Never closes open windows.
static CloseWindowStrategy	or(CloseWindowStrategy... strategies) Closes windows if any of the supplied strategies request it.
static CloseWindowStrategy	scheduled(Scheduler scheduler) Closes windows on a set clock schedule.
static CloseWindowStrategy	scheduled(String fieldName, Scheduler scheduler) Closes windows on a set clock schedule for the specified datetime field.
abstract boolean	shouldClose(Window window, GroupByReader groupByReader, Record record)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

CLOSE_WINDOW_MARGIN_MILLIS

public static final long CLOSE_WINDOW_MARGIN_MILLIS

See Also:

Constant Field Values

Constructor Detail

CloseWindowStrategy

public CloseWindowStrategy()

Method Detail

shouldClose

public abstract boolean shouldClose(Window window,
                                    GroupByReader groupByReader,
                                    Record record)

isPollingRequired

public boolean isPollingRequired()

Indicates if the {@link #shouldClose(Window, GroupByReader, Record) method should be called every second for open windows -- even if no new data is present -- to release any data that may have been collected (passing in a null record).

isCloseBeforeAddingRecord

public boolean isCloseBeforeAddingRecord()

Returns true if the window should be closed before adding the record or false if (the default).

never

public static CloseWindowStrategy never()

Never closes open windows.

limitedTime

public static CloseWindowStrategy limitedTime(long milliseconds)

Closes windows after they've been open for the specified time.

limitedTime

public static CloseWindowStrategy limitedTime(String fieldName,
                                              long milliseconds)

Closes windows after the specified datetime field has increased by a set amount of time since it was first seen. This is useful for aggregating hourly logs by their timestamp field.

Parameters:

fieldName - the datetime field to test

milliseconds - the amount of time the field should increase before closing the window

limitedRecords

public static CloseWindowStrategy limitedRecords(long count)

Closes the window after the specified amount of records has been collected.

scheduled

public static CloseWindowStrategy scheduled(Scheduler scheduler)

Closes windows on a set clock schedule. For example, every 30 minutes on the hour and half hour.

See Also:

PeriodicScheduler, HourlyScheduler

scheduled

public static CloseWindowStrategy scheduled(String fieldName,
                                            Scheduler scheduler)

Closes windows on a set clock schedule for the specified datetime field. For example, every 30 minutes at 15 and 45 past the hour. This is useful for aggregating hourly logs at set times by their timestamp field.

Parameters:

fieldName - the datetime field to test

scheduler - the scheduler to use

See Also:

PeriodicScheduler, HourlyScheduler

hourlyScheduleInMinutes

public static CloseWindowStrategy hourlyScheduleInMinutes(int... minutesPastHour)

Closes windows at fixed minutes past each hour (for example: 0, 15, 30, and 45 minutes past each hour).

hourlyScheduleInMinutes

public static CloseWindowStrategy hourlyScheduleInMinutes(String fieldName,
                                                          int... minutesPastHour)

Closes windows at fixed minutes past each hour for the specified datetime field (for example: 0, 15, 30, and 45 minutes past each hour).

Parameters:

fieldName - the datetime field to test

minutesPastHour -

Returns:

or

public static CloseWindowStrategy or(CloseWindowStrategy... strategies)

Closes windows if any of the supplied strategies request it.

and

public static CloseWindowStrategy and(CloseWindowStrategy... strategies)

Closes windows if all of the supplied strategies request it.