[FLINK-36936][table] Introduce UpdatableTopNFunction in Rank with Async State API

flink-runtime/src/main/java/org/apache/flink/streaming/api/operators/asyncprocessing/AsyncStateKeyedProcessOperator.java

@@ -0,0 +1,196 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.flink.streaming.api.operators.asyncprocessing;
+
+import org.apache.flink.annotation.Internal;
+import org.apache.flink.runtime.asyncprocessing.operators.AbstractAsyncStateUdfStreamOperator;
+import org.apache.flink.runtime.state.VoidNamespace;
+import org.apache.flink.runtime.state.VoidNamespaceSerializer;
+import org.apache.flink.streaming.api.SimpleTimerService;
+import org.apache.flink.streaming.api.TimeDomain;
+import org.apache.flink.streaming.api.TimerService;
+import org.apache.flink.streaming.api.functions.KeyedProcessFunction;
+import org.apache.flink.streaming.api.operators.InternalTimer;
+import org.apache.flink.streaming.api.operators.InternalTimerService;
+import org.apache.flink.streaming.api.operators.KeyedProcessOperator;
+import org.apache.flink.streaming.api.operators.OneInputStreamOperator;
+import org.apache.flink.streaming.api.operators.StreamOperator;
+import org.apache.flink.streaming.api.operators.TimestampedCollector;
+import org.apache.flink.streaming.api.operators.Triggerable;
+import org.apache.flink.streaming.runtime.streamrecord.StreamRecord;
+import org.apache.flink.util.OutputTag;
+
+import static org.apache.flink.util.Preconditions.checkNotNull;
+import static org.apache.flink.util.Preconditions.checkState;
+
+/**
+ * A {@link StreamOperator} for executing {@link KeyedProcessFunction KeyedProcessFunctions}.
+ *
+ * <p>This class is nearly identical with {@link KeyedProcessOperator}, but extending from {@link
+ * AbstractAsyncStateUdfStreamOperator} to integrate with asynchronous state access. Another
+ * difference is this class is internal.
+ */
+@Internal
+public class AsyncStateKeyedProcessOperator<K, IN, OUT>
+        extends AbstractAsyncStateUdfStreamOperator<OUT, KeyedProcessFunction<K, IN, OUT>>
+        implements OneInputStreamOperator<IN, OUT>, Triggerable<K, VoidNamespace> {
+
+    private static final long serialVersionUID = 1L;
+
+    private transient TimestampedCollector<OUT> collector;
+
+    private transient ContextImpl context;
+
+    private transient OnTimerContextImpl onTimerContext;
+
+    public AsyncStateKeyedProcessOperator(KeyedProcessFunction<K, IN, OUT> function) {
+        super(function);
+    }
+
+    @Override
+    public void open() throws Exception {
+        super.open();
+        collector = new TimestampedCollector<>(output);
+
+        InternalTimerService<VoidNamespace> internalTimerService =
+                getInternalTimerService("user-timers", VoidNamespaceSerializer.INSTANCE, this);
+
+        TimerService timerService = new SimpleTimerService(internalTimerService);
+
+        context = new ContextImpl(userFunction, timerService);
+        onTimerContext = new OnTimerContextImpl(userFunction, timerService);
+    }
+
+    @Override
+    public void onEventTime(InternalTimer<K, VoidNamespace> timer) throws Exception {
+        collector.setAbsoluteTimestamp(timer.getTimestamp());
+        invokeUserFunction(TimeDomain.EVENT_TIME, timer);
+    }
+
+    @Override
+    public void onProcessingTime(InternalTimer<K, VoidNamespace> timer) throws Exception {
+        collector.eraseTimestamp();
+        invokeUserFunction(TimeDomain.PROCESSING_TIME, timer);
+    }
+
+    @Override
+    public void processElement(StreamRecord<IN> element) throws Exception {
+        collector.setTimestamp(element);
+        context.element = element;
+        userFunction.processElement(element.getValue(), context, collector);
+        context.element = null;
+    }
+
+    private void invokeUserFunction(TimeDomain timeDomain, InternalTimer<K, VoidNamespace> timer)
+            throws Exception {
+        onTimerContext.timeDomain = timeDomain;
+        onTimerContext.timer = timer;
+        userFunction.onTimer(timer.getTimestamp(), onTimerContext, collector);
+        onTimerContext.timeDomain = null;
+        onTimerContext.timer = null;
+    }
+
+    private class ContextImpl extends KeyedProcessFunction<K, IN, OUT>.Context {
+
+        private final TimerService timerService;
+
+        private StreamRecord<IN> element;
+
+        ContextImpl(KeyedProcessFunction<K, IN, OUT> function, TimerService timerService) {
+            function.super();
+            this.timerService = checkNotNull(timerService);
+        }
+
+        @Override
+        public Long timestamp() {
+            checkState(element != null);
+
+            if (element.hasTimestamp()) {
+                return element.getTimestamp();
+            } else {
+                return null;
+            }
+        }
+
+        @Override
+        public TimerService timerService() {
+            return timerService;
+        }
+
+        @Override
+        public <X> void output(OutputTag<X> outputTag, X value) {
+            if (outputTag == null) {
+                throw new IllegalArgumentException("OutputTag must not be null.");
+            }
+
+            output.collect(outputTag, new StreamRecord<>(value, element.getTimestamp()));
+        }
+
+        @Override
+        @SuppressWarnings("unchecked")
+        public K getCurrentKey() {
+            return (K) AsyncStateKeyedProcessOperator.this.getCurrentKey();
+        }
+    }
+
+    private class OnTimerContextImpl extends KeyedProcessFunction<K, IN, OUT>.OnTimerContext {
+
+        private final TimerService timerService;
+
+        private TimeDomain timeDomain;
+
+        private InternalTimer<K, VoidNamespace> timer;
+
+        OnTimerContextImpl(KeyedProcessFunction<K, IN, OUT> function, TimerService timerService) {
+            function.super();
+            this.timerService = checkNotNull(timerService);
+        }
+
+        @Override
+        public Long timestamp() {
+            checkState(timer != null);
+            return timer.getTimestamp();
+        }
+
+        @Override
+        public TimerService timerService() {
+            return timerService;
+        }
+
+        @Override
+        public <X> void output(OutputTag<X> outputTag, X value) {
+            if (outputTag == null) {
+                throw new IllegalArgumentException("OutputTag must not be null.");
+            }
+
+            output.collect(outputTag, new StreamRecord<>(value, timer.getTimestamp()));
+        }
+
+        @Override
+        public TimeDomain timeDomain() {
+            checkState(timeDomain != null);
+            return timeDomain;
+        }
+
+        @Override
+        public K getCurrentKey() {
+            return timer.getKey();
+        }
+    }
+}