Package com.yahoo.jrt.slobrok.api

Class Mirror

  • All Implemented Interfaces:
    IMirror
    public class Mirror
extends java.lang.Object
implements IMirror
    A Mirror object is used to keep track of the services registered with a slobrok cluster. Updates to the service repository are fetched in the background. Lookups against this object is done using an internal mirror of the service repository.

    • Nested Class Summary

      Nested Classes 
      Modifier and Type Class Description
      static class  Mirror.Entry
      An Entry contains the name and connection spec for a single service.

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      boolean connected()
      Returns whether this mirror is connected to the slobrok server at this time or not.
      java.util.List<Mirror.Entry> lookup​(java.lang.String pattern)
      Obtain all the services matching a given pattern.
      boolean ready()
      Ask if the MirrorAPI has got any useful information from the Slobrok.
      void shutdown()
      Shut down the Mirror.
      int updates()
      Obtain the number of updates seen by this mirror.

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • Constructor Detail

      • Mirror

        public Mirror​(Supervisor orb,
              SlobrokList slobroks,
              BackOffPolicy bop)
        Create a new MirrorAPI using the given Supervisor and slobrok connect specs.
        Parameters:
        orb - the Supervisor to use
        slobroks - slobrok connect spec list
        bop - custom backoff policy, mostly useful for testing

      • Mirror

        public Mirror​(Supervisor orb,
              SlobrokList slobroks)
        Create a new MirrorAPI using the given Supervisor and slobrok connect specs.
        Parameters:
        orb - the Supervisor to use
        slobroks - slobrok connect spec list

    • Method Detail

      • shutdown

        public void shutdown()
        Shut down the Mirror. This will close any open connections, stop the regular mirror updates, and discard all entries.

      • lookup

        public java.util.List<Mirror.Entry> lookup​(java.lang.String pattern)
        Description copied from interface: IMirror
        Obtain all the services matching a given pattern. The pattern is matched against all service names in the local mirror repository. A service name may contain '/' as a separator token. A pattern may contain '*' to match anything up to the next '/' (or the end of the name). This means that the pattern 'foo/*/baz' would match the service names 'foo/bar/baz' and 'foo/xyz/baz'. The pattern 'foo/b*' would match 'foo/bar', but neither 'foo/xyz' nor 'foo/bar/baz'. The pattern 'a*b' will never match anything. As a special case, a pattern can end in '**' to match the rest of a name including '/' separators.
        Specified by:
        lookup in interface IMirror
        Parameters:
        pattern - The pattern used for matching
        Returns:
        a list of all matching services, with corresponding connect specs

      • updates

        public int updates()
        Description copied from interface: IMirror
        Obtain the number of updates seen by this mirror. The value may wrap, but will never become 0 again. This can be used for name lookup optimization, because the results returned by lookup() will never change unless this number also changes.
        Specified by:
        updates in interface IMirror
        Returns:
        number of slobrok updates seen

      • ready

        public boolean ready()
        Ask if the MirrorAPI has got any useful information from the Slobrok. On application startup it is often useful to run the event loop for some time until this functions returns true (or if it never does, time out and tell the user there was no answer from any Service Location Broker).
        Returns:
        true if the MirrorAPI object has asked for updates from a Slobrok and got any answer back

      • connected

        public boolean connected()
        Returns whether this mirror is connected to the slobrok server at this time or not.