org.apache.flink.table.runtime.operators.deduplicate

Class RowTimeDeduplicateFunction

java.lang.Object

org.apache.flink.api.common.functions.AbstractRichFunction

org.apache.flink.streaming.api.functions.KeyedProcessFunction<K,IN,OUT>

org.apache.flink.table.runtime.operators.deduplicate.RowTimeDeduplicateFunction

All Implemented Interfaces:

Serializable, Function, RichFunction

public class RowTimeDeduplicateFunction
extends KeyedProcessFunction<K,IN,OUT>

This function is used to deduplicate on keys and keeps only first or last row on row time.

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.flink.streaming.api.functions.KeyedProcessFunction

KeyedProcessFunction.Context, KeyedProcessFunction.OnTimerContext

Field Summary

Fields

Modifier and Type	Field and Description
protected TypeSerializer<OUT>	serializer
protected ValueState<T>	state
protected long	stateRetentionTime
protected TypeInformation<T>	typeInfo

Constructor Summary

Constructors

Constructor and Description
RowTimeDeduplicateFunction(InternalTypeInfo<RowData> typeInfo, long minRetentionTime, int rowtimeIndex, boolean generateUpdateBefore, boolean generateInsert, boolean keepLastRow)

Method Summary

Modifier and Type	Method and Description
static void	deduplicateOnRowTime(ValueState<RowData> state, RowData currentRow, Collector<RowData> out, boolean generateUpdateBefore, boolean generateInsert, int rowtimeIndex, boolean keepLastRow) Processes element to deduplicate on keys with row time semantic, sends current element if it is last or first row, retracts previous element if needed.
void	open(Configuration configure) Initialization method for the function.
void	processElement(RowData input, KeyedProcessFunction.Context ctx, Collector<RowData> out) Process one element from the input stream.

Methods inherited from class org.apache.flink.streaming.api.functions.KeyedProcessFunction

onTimer

Methods inherited from class org.apache.flink.api.common.functions.AbstractRichFunction

close, getIterationRuntimeContext, getRuntimeContext, setRuntimeContext

Methods inherited from class java.lang.Object

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

Field Detail

typeInfo

protected final TypeInformation<T> typeInfo

stateRetentionTime

protected final long stateRetentionTime

serializer

protected final TypeSerializer<OUT> serializer

state

protected ValueState<T> state

Constructor Detail

RowTimeDeduplicateFunction

public RowTimeDeduplicateFunction(InternalTypeInfo<RowData> typeInfo,
                                  long minRetentionTime,
                                  int rowtimeIndex,
                                  boolean generateUpdateBefore,
                                  boolean generateInsert,
                                  boolean keepLastRow)

Method Detail

processElement

public void processElement(RowData input,
                           KeyedProcessFunction.Context ctx,
                           Collector<RowData> out)
                    throws Exception

Description copied from class: KeyedProcessFunction

Process one element from the input stream.

This function can output zero or more elements using the Collector parameter and also update internal state or set timers using the KeyedProcessFunction.Context parameter.

Specified by:

processElement in class KeyedProcessFunction<RowData,RowData,RowData>

Parameters:

input - The input value.

ctx - A KeyedProcessFunction.Context that allows querying the timestamp of the element and getting a TimerService for registering timers and querying the time. The context is only valid during the invocation of this method, do not store it.

out - The collector for returning result values.

Throws:

Exception - This method may throw exceptions. Throwing an exception will cause the operation to fail and may trigger recovery.

deduplicateOnRowTime

public static void deduplicateOnRowTime(ValueState<RowData> state,
                                        RowData currentRow,
                                        Collector<RowData> out,
                                        boolean generateUpdateBefore,
                                        boolean generateInsert,
                                        int rowtimeIndex,
                                        boolean keepLastRow)
                                 throws Exception

Processes element to deduplicate on keys with row time semantic, sends current element if it is last or first row, retracts previous element if needed.

Parameters:

state - state of function

currentRow - latest row received by deduplicate function

out - underlying collector

generateUpdateBefore - flag to generate UPDATE_BEFORE message or not

generateInsert - flag to gennerate INSERT message or not

rowtimeIndex - the index of rowtime field

keepLastRow - flag to keep last row or keep first row

Throws:

Exception

open

public void open(Configuration configure)
          throws Exception

Description copied from interface: RichFunction

Initialization method for the function. It is called before the actual working methods (like map or join) and thus suitable for one time setup work. For functions that are part of an iteration, this method will be invoked at the beginning of each iteration superstep.

The configuration object passed to the function can be used for configuration and initialization. The configuration contains all parameters that were configured on the function in the program composition.

 public class MyFilter extends RichFilterFunction<String> {

     private String searchString;

     public void open(Configuration parameters) {
         this.searchString = parameters.getString("foo");
     }

     public boolean filter(String value) {
         return value.equals(searchString);
     }
 }
 

By default, this method does nothing.

Specified by:

open in interface RichFunction

Overrides:

open in class AbstractRichFunction

Parameters:

configure - The configuration containing the parameters attached to the contract.

Throws:

Exception - Implementations may forward exceptions, which are caught by the runtime. When the runtime catches an exception, it aborts the task and lets the fail-over logic decide whether to retry the task execution.

See Also:

Configuration