Class ControlledRealTimeReopenThread<T>

  • All Implemented Interfaces:
    Closeable, AutoCloseable, Runnable

    public class ControlledRealTimeReopenThread<T>
    extends Thread
    implements Closeable
    Utility class that runs a thread to manage periodicc reopens of a ReferenceManager, with methods to wait for a specific index changes to become visible. To use this class you must first wrap your IndexWriter with a TrackingIndexWriter and always use it to make changes to the index, saving the returned generation. Then, when a given search request needs to see a specific index change, call the {#waitForGeneration} to wait for that change to be visible. Note that this will only scale well if most searches do not need to wait for a specific index generation.
    • Constructor Detail

      • ControlledRealTimeReopenThread

        public ControlledRealTimeReopenThread​(TrackingIndexWriter writer,
                                              ReferenceManager<T> manager,
                                              double targetMaxStaleSec,
                                              double targetMinStaleSec)
        Create ControlledRealTimeReopenThread, to periodically reopen the a ReferenceManager.
        Parameters:
        targetMaxStaleSec - Maximum time until a new reader must be opened; this sets the upper bound on how slowly reopens may occur, when no caller is waiting for a specific generation to become visible.
        targetMinStaleSec - Mininum time until a new reader can be opened; this sets the lower bound on how quickly reopens may occur, when a caller is waiting for a specific generation to become visible.
    • Method Detail

      • waitForGeneration

        public void waitForGeneration​(long targetGen)
                               throws InterruptedException
        Waits for the target generation to become visible in the searcher. If the current searcher is older than the target generation, this method will block until the searcher is reopened, by another via ReferenceManager.maybeRefresh() or until the ReferenceManager is closed.
        Parameters:
        targetGen - the generation to wait for
        Throws:
        InterruptedException
      • waitForGeneration

        public boolean waitForGeneration​(long targetGen,
                                         int maxMS)
                                  throws InterruptedException
        Waits for the target generation to become visible in the searcher, up to a maximum specified milli-seconds. If the current searcher is older than the target generation, this method will block until the searcher has been reopened by another thread via ReferenceManager.maybeRefresh(), the given waiting time has elapsed, or until the ReferenceManager is closed.

        NOTE: if the waiting time elapses before the requested target generation is available the current SearcherManager is returned instead.

        Parameters:
        targetGen - the generation to wait for
        maxMS - maximum milliseconds to wait, or -1 to wait indefinitely
        Returns:
        true if the targetGeneration is now available, or false if maxMS wait time was exceeded
        Throws:
        InterruptedException
      • run

        public void run()
        Specified by:
        run in interface Runnable
        Overrides:
        run in class Thread