Package com.yahoo.jrt.slobrok.api

Class Mirror

java.lang.Object

com.yahoo.jrt.slobrok.api.Mirror

All Implemented Interfaces:

IMirror

public class Mirror
extends 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 final class	Mirror.Entry	An Entry contains the name and connection spec for a single service.

Constructor Summary

Constructors

Constructor	Description
Mirror(Supervisor orb, SlobrokList slobroks)	Create a new MirrorAPI using the given Supervisor and slobrok connect specs.
Mirror(Supervisor orb, SlobrokList slobroks, BackOffPolicy bop)	Create a new MirrorAPI using the given Supervisor and slobrok connect specs.

Method Summary

Modifier and Type	Method	Description
boolean	connected()	Returns whether this mirror is connected to the slobrok server at this time or not.
void	dumpState()
long	getIterations()
List<Mirror.Entry>	lookup(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 Details

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 Details

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 List<Mirror.Entry> lookup(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.

dumpState

public void dumpState()

getIterations

public long getIterations()