CallableCallbackBase.java

/*
 * Copyright 2015-2016 Groupon, Inc
 * Copyright 2015-2016 The Billing Project, LLC
 *
 * The Billing Project 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.killbill.queue.dispatching;

import com.fasterxml.jackson.databind.ObjectMapper;
import org.joda.time.DateTime;
import org.killbill.clock.Clock;
import org.killbill.queue.DBBackedQueue;
import org.killbill.queue.api.PersistentQueueConfig;
import org.killbill.queue.api.PersistentQueueEntryLifecycleState;
import org.killbill.queue.api.QueueEvent;
import org.killbill.queue.dao.EventEntryModelDao;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public abstract class CallableCallbackBase<E extends QueueEvent, M extends EventEntryModelDao> implements CallableCallback<E, M> {

    private static final Logger log = LoggerFactory.getLogger(CallableCallbackBase.class);

    private final DBBackedQueue<M> dao;
    private final Clock clock;
    private final PersistentQueueConfig config;
    private final ObjectMapper objectMapper;

    public CallableCallbackBase(final DBBackedQueue<M> dao, final Clock clock, final PersistentQueueConfig config, final ObjectMapper objectMapper) {
        this.dao = dao;
        this.clock = clock;
        this.config = config;
        this.objectMapper = objectMapper;
    }

    @Override
    public E deserialize(final M modelDao) {
        return deserializeEvent(modelDao, objectMapper);
    }

    @SuppressWarnings("unchecked")
    public static <E extends QueueEvent, M extends EventEntryModelDao> E deserializeEvent(final M modelDao, final ObjectMapper objectMapper) {
        try {
            final Class<?> claz = Class.forName(modelDao.getClassName());
            return (E) objectMapper.readValue(modelDao.getEventJson(), claz);
        } catch (final Exception e) {
            log.error(String.format("Failed to deserialize json object %s for class %s", modelDao.getEventJson(), modelDao.getClassName()), e);
            return null;
        }
    }


    @Override
    public abstract void dispatch(final E event, final M modelDao) throws Exception;

    public abstract M buildEntry(final M modelDao, final DateTime now, final PersistentQueueEntryLifecycleState newState, final long newErrorCount);

    @Override
    public void updateErrorCountOrMoveToHistory(final E event, final M modelDao, final long errorCount, final Throwable lastException) {
        if (lastException == null) {
            moveSuccessfulEventToHistory(modelDao);
            if (log.isDebugEnabled()) {
                log.debug("Done handling notification {}, key = {}", modelDao.getRecordId(), modelDao.getEventJson());
            }
        } else if (errorCount <= config.getMaxFailureRetries()) {
            log.info("Dispatch error, will attempt a retry ", lastException);
            updateRetryCountForFailedEvent(modelDao, errorCount);
        } else {
            log.error("Fatal NotificationQ dispatch error, data corruption...", lastException);
            moveFailedEventToHistory(modelDao);
        }
    }

    private void moveSuccessfulEventToHistory(final M input) {
        final M newEntry = buildEntry(input, clock.getUTCNow(), PersistentQueueEntryLifecycleState.PROCESSED, input.getErrorCount());
        dao.moveEntryToHistory(newEntry);
    }

    private void updateRetryCountForFailedEvent(final M input, final long errorCount) {
        final M newEntry = buildEntry(input, clock.getUTCNow(), PersistentQueueEntryLifecycleState.AVAILABLE, errorCount);
        dao.updateOnError(newEntry);
    }


    private void moveFailedEventToHistory(final M input) {
        final M newEntry = buildEntry(input, clock.getUTCNow(), PersistentQueueEntryLifecycleState.FAILED, input.getErrorCount());
        dao.moveEntryToHistory(newEntry);
    }
}