聊聊jesque的几个dao

/**
 * FailureDAO provides access to job failures.
 * 
 * @author Greg Haines
 */
public interface FailureDAO {

    /**
     * @return total number of failures
     */
    long getCount();

    /**
     * @param offset offset into the failures
     * @param count number of failures to return
     * @return a sub-list of the failures
     */
    List<JobFailure> getFailures(long offset, long count);

    /**
     * Clear the list of failures.
     */
    void clear();

    /**
     * Re-queue a job for execution.
     * @param index the index into the failure list
     * @return the date the job was re-queued
     */
    Date requeue(long index);

    /**
     * Remove a failure from the list.
     * @param index the index of the failure to remove
     */
    void remove(long index);
}

/**
 * KeysDAO provides access to available keys.
 * 
 * @author Greg Haines
 */
public interface KeysDAO {

    /**
     * Get basic key info.
     * @param key the key name
     * @return the key information or null if the key did not exist
     */
    KeyInfo getKeyInfo(String key);

    /**
     * Get basic key info plus a sub-list of the array value for the key, if applicable.
     * @param key the key name
     * @param offset the offset into the array
     * @param count the number of values to return
     * @return the key information or null if the key did not exist
     */
    KeyInfo getKeyInfo(String key, int offset, int count);

    /**
     * Get basic info on all keys.
     * @return a list of key informations
     */
    List<KeyInfo> getKeyInfos();

    /**
     * @return information about the backing Redis database
     */
    Map<String, String> getRedisInfo();
}

/**
 * QueueInfoDAO provides access to the queues in use by Jesque.
 * 
 * @author Greg Haines
 */
public interface QueueInfoDAO {

    /**
     * @return the list of queue names
     */
    List<String> getQueueNames();

    /**
     * @return total number of jobs pending in all queues
     */
    long getPendingCount();

    /**
     * @return total number of jobs processed
     */
    long getProcessedCount();

    /**
     * @return the list of queue informations
     */
    List<QueueInfo> getQueueInfos();

    /**
     * @param name the queue name
     * @param jobOffset the offset into the queue
     * @param jobCount the number of jobs to return
     * @return the queue information or null if the queue does not exist
     */
    QueueInfo getQueueInfo(String name, long jobOffset, long jobCount);

    /**
     * Delete the given queue.
     * @param name the name of the queue
     */
    void removeQueue(String name);
}

/**
 * WorkerInfoDAO provides access to information about workers.
 * 
 * @author Greg Haines
 */
public interface WorkerInfoDAO {

    /**
     * @return total number of workers known
     */
    long getWorkerCount();

    /**
     * @return number of active workers
     */
    long getActiveWorkerCount();

    /**
     * @return number of paused workers
     */
    long getPausedWorkerCount();

    /**
     * @return information about all active workers
     */
    List<WorkerInfo> getActiveWorkers();

    /**
     * @return information about all paused workers
     */
    List<WorkerInfo> getPausedWorkers();

    /**
     * @return information about all workers
     */
    List<WorkerInfo> getAllWorkers();

    /**
     * @param workerName the name of the worker
     * @return information about the given worker or null if that worker does not exist
     */
    WorkerInfo getWorker(String workerName);

    /**
     * @return a map of worker informations by hostname
     */
    Map<String, List<WorkerInfo>> getWorkerHostMap();

    /**
     * Removes the metadata about a worker.
     * 
     * @param workerName
     *            The worker name to remove
     */
    void removeWorker(String workerName);
}