Package cern.nxcals.api.custom.service.extraction

Class LookupStrategy

java.lang.Object

cern.nxcals.api.custom.service.extraction.LookupStrategy

All Implemented Interfaces:

cern.nxcals.common.utils.TriFunction<java.util.function.Function<TimeWindow,org.apache.spark.sql.Dataset<org.apache.spark.sql.Row>>,java.lang.String,ExtractionProperties,org.apache.spark.sql.Dataset<org.apache.spark.sql.Row>>

public final class LookupStrategy
extends java.lang.Object
implements cern.nxcals.common.utils.TriFunction<java.util.function.Function<TimeWindow,org.apache.spark.sql.Dataset<org.apache.spark.sql.Row>>,java.lang.String,ExtractionProperties,org.apache.spark.sql.Dataset<org.apache.spark.sql.Row>>

Field Summary

Fields

Modifier and Type	Field	Description
static LookupStrategy	LAST_BEFORE_START	Perform data lookup to extract the last available datapoint (if any) prior the actual data that belong to a given time window.
static LookupStrategy	LAST_BEFORE_START_IF_EMPTY	Perform data lookup to extract the last available datapoint (if any) prior the given time window, only if the actual data do not exist.
static LookupStrategy	LAST_BEFORE_START_ONLY	Perform data lookup to extract the first available datapoint (if any) prior the given time window.
static LookupStrategy	NEXT_AFTER_START_ONLY	Perform data lookup to extract the first available datapoint (if any) after the given time window.

Method Summary

Modifier and Type	Method	Description
org.apache.spark.sql.Dataset<org.apache.spark.sql.Row>	apply(java.util.function.Function<TimeWindow,org.apache.spark.sql.Dataset<org.apache.spark.sql.Row>> dataProvider, java.lang.String timestampField, ExtractionProperties properties)	This method retrieves the dataset containing the datapoint accordingly to the lookup strategy.
boolean	equals(java.lang.Object o)
@NonNull java.time.Duration	getDuration()
@NonNull cern.nxcals.api.custom.service.extraction.LookupStrategy.Handler	getHandler()
int	hashCode()
java.lang.String	toString()
LookupStrategy	withLookupDuration(long amount, @NonNull java.time.temporal.TemporalUnit unit)

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

LAST_BEFORE_START

public static final LookupStrategy LAST_BEFORE_START

Perform data lookup to extract the last available datapoint (if any) prior the actual data that belong to a given time window. If such datapoint exists, we query the dataset with the timestamp of that datapoint as the startTime to get the dataset of the time window plus that datapoint.

LAST_BEFORE_START_IF_EMPTY

public static final LookupStrategy LAST_BEFORE_START_IF_EMPTY

Perform data lookup to extract the last available datapoint (if any) prior the given time window, only if the actual data do not exist. In that case a single row dataset would be returned, containing that last datapoint. Otherwise, if data exist for the given time window, this strategy will not perform any data lookup action, thus, only data points matching the query time window would be included on the result.

NEXT_AFTER_START_ONLY

public static final LookupStrategy NEXT_AFTER_START_ONLY

Perform data lookup to extract the first available datapoint (if any) after the given time window. A single row dataset would be returned, containing that first datapoint.

LAST_BEFORE_START_ONLY

public static final LookupStrategy LAST_BEFORE_START_ONLY

Perform data lookup to extract the first available datapoint (if any) prior the given time window. A single row dataset would be returned, containing that first datapoint.

Method Detail

withLookupDuration

public LookupStrategy withLookupDuration(long amount,
                                         @NonNull
                                         @NonNull java.time.temporal.TemporalUnit unit)

apply

public org.apache.spark.sql.Dataset<org.apache.spark.sql.Row> apply(java.util.function.Function<TimeWindow,org.apache.spark.sql.Dataset<org.apache.spark.sql.Row>> dataProvider,
                                                                    java.lang.String timestampField,
                                                                    ExtractionProperties properties)

This method retrieves the dataset containing the datapoint accordingly to the lookup strategy. All three parameters are needed because when the strategy is LAST_BEFORE_START_IF_EMPTY we cannot know beforehand what the startTime will be.

Specified by:

apply in interface cern.nxcals.common.utils.TriFunction<java.util.function.Function<TimeWindow,org.apache.spark.sql.Dataset<org.apache.spark.sql.Row>>,java.lang.String,ExtractionProperties,org.apache.spark.sql.Dataset<org.apache.spark.sql.Row>>

Parameters:

dataProvider - This is used to extract the data

properties - This is used to retrieve the end time of time window we are querying on

Returns:

Dataset<Row> The dataset

getHandler

@NonNull
public @NonNull cern.nxcals.api.custom.service.extraction.LookupStrategy.Handler getHandler()

getDuration

@NonNull
public @NonNull java.time.Duration getDuration()

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

equals

public boolean equals(java.lang.Object o)

Overrides:

equals in class java.lang.Object

hashCode

public int hashCode()

Overrides:

hashCode in class java.lang.Object