content: /*
   * 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.beam.runners.fnexecution.control;
  
  import static org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.base.Preconditions.checkNotNull;
  
  import java.util.HashMap;
  import java.util.Map;
  import java.util.function.BiConsumer;
  import org.apache.beam.runners.core.StateNamespace;
  import org.apache.beam.runners.core.StateNamespaces;
  import org.apache.beam.runners.core.TimerInternals;
  import org.apache.beam.runners.core.TimerInternals.TimerData;
  import org.apache.beam.runners.fnexecution.control.ProcessBundleDescriptors.TimerSpec;
  import org.apache.beam.sdk.coders.Coder;
  import org.apache.beam.sdk.fn.data.FnDataReceiver;
  import org.apache.beam.sdk.transforms.windowing.BoundedWindow;
  import org.apache.beam.sdk.util.construction.Timer;
  import org.apache.beam.sdk.values.KV;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /**
   * A factory that passes timers to {@link TimerReceiverFactory#timerDataConsumer}.
   *
   * <p>The constructed timers uses {@code len(transformId):transformId:timerId} as the timer id to
   * prevent string collisions. See {@link #encodeToTimerDataTimerId} and {@link
   * #decodeTimerDataTimerId} for functions to aid with encoding and decoding.
   *
   * <p>If the incoming timer is being cleared, the {@link TimerData} sets the fire and hold
   * timestamps to {@link BoundedWindow#TIMESTAMP_MAX_VALUE}.
   */
  @SuppressWarnings({
    "rawtypes", // TODO(https://github.com/apache/beam/issues/20447)
    "nullness" // TODO(https://github.com/apache/beam/issues/20497)
  })
  public class TimerReceiverFactory {
    private static final Logger LOG = LoggerFactory.getLogger(TimerReceiverFactory.class);
  
    /** (PTransform, Timer Local Name) => TimerReference. */
    private final HashMap<KV<String, String>, TimerSpec> transformAndTimerIdToSpecMap;
  
    private final BiConsumer<Timer<?>, TimerData> timerDataConsumer;
    private final Coder windowCoder;
  
    public TimerReceiverFactory(
        StageBundleFactory stageBundleFactory,
        BiConsumer<Timer<?>, TimerInternals.TimerData> timerDataConsumer,
        Coder windowCoder) {
      this.transformAndTimerIdToSpecMap = new HashMap<>();
      // Create a lookup map using the transform and timerId as the key.
      for (Map<String, ProcessBundleDescriptors.TimerSpec> transformTimerMap :
          stageBundleFactory.getProcessBundleDescriptor().getTimerSpecs().values()) {
        for (ProcessBundleDescriptors.TimerSpec timerSpec : transformTimerMap.values()) {
          transformAndTimerIdToSpecMap.put(
              KV.of(timerSpec.transformId(), timerSpec.timerId()), timerSpec);
        }
      }
      this.timerDataConsumer = timerDataConsumer;
      this.windowCoder = windowCoder;
    }
  
    // @Override
    public <K> FnDataReceiver<Timer<K>> create(String transformId, String timerFamilyId) {
      final ProcessBundleDescriptors.TimerSpec timerSpec =
          transformAndTimerIdToSpecMap.get(KV.of(transformId, timerFamilyId));
  
      return receivedElement -> {
        Timer timer =
            checkNotNull(
                receivedElement, "Received null Timer from SDK harness: %s", receivedElement);
        LOG.debug("Timer received: {}", timer);
        for (Object window : timer.getWindows()) {
          StateNamespace namespace = StateNamespaces.window(windowCoder, (BoundedWindow) window);
          TimerInternals.TimerData timerData =
              TimerInternals.TimerData.of(
                  timer.getDynamicTimerTag(),
                  encodeToTimerDataTimerId(timerSpec.transformId(), timerSpec.timerId()),
                  namespace,
                  timer.getClearBit() ? BoundedWindow.TIMESTAMP_MAX_VALUE : timer.getFireTimestamp(),
                  timer.getClearBit() ? BoundedWindow.TIMESTAMP_MAX_VALUE : timer.getHoldTimestamp(),
                  timerSpec.getTimerSpec().getTimeDomain());
          timerDataConsumer.accept(timer, timerData);
        }
      };
    }
  
    /**
     * Encodes transform and timer family ids into a single string which retains the human readable
     * format {@code len(transformId):transformId:timerId}. See {@link #decodeTimerDataTimerId} for
     * decoding.
     */
    public static String encodeToTimerDataTimerId(String transformId, String timerFamilyId) {
      return transformId.length() + ":" + transformId + ":" + timerFamilyId;
    }
  
    /**
     * Decodes a string into the transform and timer family ids. See {@link #encodeToTimerDataTimerId}
     * for encoding.
     */
    public static KV<String, String> decodeTimerDataTimerId(String timerDataTimerId) {
      int transformIdLengthSplit = timerDataTimerId.indexOf(":");
      if (transformIdLengthSplit <= 0) {
        throw new IllegalArgumentException(
            String.format(
                "Invalid encoding, expected len(transformId):transformId:timerId as the encoding but received %s",
                timerDataTimerId));
      }
      int transformIdLength = Integer.parseInt(timerDataTimerId.substring(0, transformIdLengthSplit));
      String transformId =
          timerDataTimerId.substring(
              transformIdLengthSplit + 1, transformIdLengthSplit + 1 + transformIdLength);
      String timerFamilyId =
          timerDataTimerId.substring(transformIdLengthSplit + 1 + transformIdLength + 1);
      return KV.of(transformId, timerFamilyId);
    }
  }
  