public class FastTop1Function extends AbstractTopNFunction implements CheckpointedFunction
AppendOnlyTopNFunction and UpdatableTopNFunction when only Top-1 is desired. This function can handle updating stream
because the RankProcessStrategy is inferred as UpdateFastStrategy, i.e., 1) the upsert key of
input steam contains partition key; 2) the sort field is updated monotonely under the upsert key.KeyedProcessFunction.Context, KeyedProcessFunction.OnTimerContexthitCount, inputRowType, keyContext, outputRankNumber, rankEnd, requestCount, sortKeyComparator, sortKeySelector, ttlConfig| Constructor and Description |
|---|
FastTop1Function(StateTtlConfig ttlConfig,
InternalTypeInfo<RowData> inputRowType,
GeneratedRecordComparator generatedSortKeyComparator,
RowDataKeySelector sortKeySelector,
RankType rankType,
RankRange rankRange,
boolean generateUpdateBefore,
boolean outputRankNumber,
long cacheSize) |
| Modifier and Type | Method and Description |
|---|---|
void |
initializeState(FunctionInitializationContext context)
This method is called when the parallel function instance is created during distributed
execution.
|
void |
open(Configuration parameters)
Initialization method for the function.
|
void |
processElement(RowData input,
KeyedProcessFunction.Context ctx,
Collector<RowData> out)
Process one element from the input stream.
|
void |
snapshotState(FunctionSnapshotContext context)
This method is called when a snapshot for a checkpoint is requested.
|
checkSortKeyInBufferRange, collectDelete, collectDelete, collectInsert, collectInsert, collectUpdateAfter, collectUpdateAfter, collectUpdateBefore, collectUpdateBefore, getDefaultTopNSize, hasOffset, initRankEnd, isInRankEnd, isInRankRange, registerMetric, setKeyContextonTimerclose, getIterationRuntimeContext, getRuntimeContext, setRuntimeContextpublic FastTop1Function(StateTtlConfig ttlConfig, InternalTypeInfo<RowData> inputRowType, GeneratedRecordComparator generatedSortKeyComparator, RowDataKeySelector sortKeySelector, RankType rankType, RankRange rankRange, boolean generateUpdateBefore, boolean outputRankNumber, long cacheSize)
public void open(Configuration parameters) throws Exception
RichFunctionThe 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.
open in interface RichFunctionopen in class AbstractTopNFunctionparameters - The configuration containing the parameters attached to the contract.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.Configurationpublic void processElement(RowData input, KeyedProcessFunction.Context ctx, Collector<RowData> out) throws Exception
KeyedProcessFunctionThis function can output zero or more elements using the Collector parameter and
also update internal state or set timers using the KeyedProcessFunction.Context parameter.
processElement in class KeyedProcessFunction<RowData,RowData,RowData>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.Exception - This method may throw exceptions. Throwing an exception will cause the
operation to fail and may trigger recovery.public void snapshotState(FunctionSnapshotContext context) throws Exception
CheckpointedFunctionFunctionInitializationContext when the Function was initialized, or offered now by FunctionSnapshotContext itself.snapshotState in interface CheckpointedFunctioncontext - the context for drawing a snapshot of the operatorException - Thrown, if state could not be created ot restored.public void initializeState(FunctionInitializationContext context) throws Exception
CheckpointedFunctioninitializeState in interface CheckpointedFunctioncontext - the context for initializing the operatorException - Thrown, if state could not be created ot restored.Copyright © 2014–2023 The Apache Software Foundation. All rights reserved.