Examples with TaskSupplier org.apache.cassandra.db.compaction.AbstractStrategyHolder.TaskSupplier used on opensource projects

Example 1 with TaskSupplier

use of org.apache.cassandra.db.compaction.AbstractStrategyHolder.TaskSupplier in project cassandra by apache.

the class CompactionStrategyManager method getNextBackgroundTask.

/**
 * Return the next background task
 *
 * Returns a task for the compaction strategy that needs it the most (most estimated remaining tasks)
 */
public AbstractCompactionTask getNextBackgroundTask(int gcBefore) {
    maybeReloadDiskBoundaries();
    readLock.lock();
    try {
        if (!isEnabled())
            return null;
        int numPartitions = getNumTokenPartitions();
        // first try to promote/demote sstables from completed repairs
        AbstractCompactionTask repairFinishedTask;
        repairFinishedTask = pendingRepairs.getNextRepairFinishedTask();
        if (repairFinishedTask != null)
            return repairFinishedTask;
        repairFinishedTask = transientRepairs.getNextRepairFinishedTask();
        if (repairFinishedTask != null)
            return repairFinishedTask;
        // sort compaction task suppliers by remaining tasks descending
        List<TaskSupplier> suppliers = new ArrayList<>(numPartitions * holders.size());
        for (AbstractStrategyHolder holder : holders) suppliers.addAll(holder.getBackgroundTaskSuppliers(gcBefore));
        Collections.sort(suppliers);
        // return the first non-null task
        for (TaskSupplier supplier : suppliers) {
            AbstractCompactionTask task = supplier.getTask();
            if (task != null)
                return task;
        }
        return null;
    } finally {
        readLock.unlock();
    }
}