com.github.kagkarlsson.scheduler.task.helper.ScheduleRecurringOnStartup Maven / Gradle / Ivy

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Simple persistent scheduler for scheduled tasks, recurring or ad-hoc.
There is a newer version: 15.0.0
/*
 * Copyright (C) Gustav Karlsson
 *
 * Licensed 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 com.github.kagkarlsson.scheduler.task.helper;

import com.github.kagkarlsson.scheduler.Clock;
import com.github.kagkarlsson.scheduler.ScheduledExecution;
import com.github.kagkarlsson.scheduler.SchedulerClient;
import com.github.kagkarlsson.scheduler.task.ExecutionComplete;
import com.github.kagkarlsson.scheduler.task.Task;
import com.github.kagkarlsson.scheduler.task.TaskInstance;
import com.github.kagkarlsson.scheduler.task.schedule.Schedule;
import java.time.Duration;
import java.time.Instant;
import java.util.Optional;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

class ScheduleRecurringOnStartup implements ScheduleOnStartup {
  private static final Logger LOG = LoggerFactory.getLogger(ScheduleRecurringOnStartup.class);
  private final Schedule schedule;
  private final String instance;
  private final T data;

  ScheduleRecurringOnStartup(String instance, T data, Schedule schedule) {
    this.instance = instance;
    this.data = data;
    this.schedule = schedule;
  }

  @Override
  public void apply(SchedulerClient scheduler, Clock clock, Task task) {
    final TaskInstance instanceWithoutData = task.instance(this.instance);
    final Optional> preexistingExecution =
        scheduler.getScheduledExecution(instanceWithoutData);

    if (schedule.isDisabled()) {
      if (preexistingExecution.isPresent()) {
        LOG.info(
            "Task-instance '{}' has a Schedule that has been marked as disabled. Removing existing execution with execution-time '{}'.",
            instanceWithoutData,
            preexistingExecution.get().getExecutionTime());
        tryCancel(scheduler, instanceWithoutData);
      } else {
        LOG.info(
            "Task-instance '{}' has a Schedule that has been marked as disabled. Will not schedule a new execution",
            instanceWithoutData);
      }
      return;
    }

    if (preexistingExecution.isPresent()) {
      Optional newNextExecutionTime =
          checkForNewExecutionTime(clock, instanceWithoutData, preexistingExecution.get());

      newNextExecutionTime.ifPresent(
          instant -> {
            // Intentionally leaving out data here, since we do not want to update existing data
            scheduler.reschedule(instanceWithoutData, instant);
          });

    } else {
      // No preexisting execution, create initial one
      final Instant initialExecutionTime = schedule.getInitialExecutionTime(clock.now());
      LOG.info(
          "Creating initial execution for task-instance '{}'. Next execution-time: {}",
          instanceWithoutData,
          initialExecutionTime);
      scheduler.schedule(getSchedulableInstance(task), initialExecutionTime);
    }
  }

  private void tryCancel(SchedulerClient scheduler, TaskInstance instanceWithoutData) {
    try {
      scheduler.cancel(instanceWithoutData);
    } catch (RuntimeException e) {
      LOG.warn(
          "Failed to cancel existing execution for a Task with a Scheduled marked as disabled. "
              + "May happen if another instance already did it, or if it is currently executing.",
          e);
    }
  }

  Optional checkForNewExecutionTime(
      Clock clock,
      TaskInstance instanceWithoutData,
      ScheduledExecution