org.apache.river.outrigger

Class IteratorProxy

java.lang.Object

org.apache.river.outrigger.IteratorProxy

All Implemented Interfaces:

AdminIterator

Direct Known Subclasses:

ConstrainableIteratorProxy

class IteratorProxy
extends Object
implements AdminIterator

The iterator that is returned to the client. IteratorProxy uses a RemoteIter reference to talk to the server. The RemoteIter object is its partner on the server side.

Note, because there is no way to duplicate one of these objects, or get a new reference to the underlying iteration one (a situation that is unlikely to change since part of the iteration is local), we don't need to do anything special for equality. The default implementations of equals and hashCode work fine.

Field Summary

Fields

Modifier and Type	Field and Description
private int	fetchSize How many entries to ask for each time we go to the server
private Uuid	iterationUuid The Uuid of the iteration this proxy is associated with.
private Uuid	lastId ID of last entry we got from server
private int	next Index of the next entry in rep to return.
private EntryRep[]	reps Last set of reps we got from the server
(package private) OutriggerAdmin	server Reference to the server.

Constructor Summary

Constructors

Constructor and Description
IteratorProxy(Uuid iterationUuid, OutriggerAdmin server, int fetchSize) Create client side iterator proxy.

Method Summary

Modifier and Type	Method and Description
private void	assertOpen() Throw IllegalStateException if this iterator has been closed; otherwise just return.
void	close() Tell the server that this iterator is no longer in use.
void	delete() The effect of this call depends on the most recent call to next(): If the last call to next() returned an Entry that entry will be removed from the space.
Entry	next() Return the next entry in the sequence.
String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

iterationUuid

private final Uuid iterationUuid

The Uuid of the iteration this proxy is associated with.

server

volatile OutriggerAdmin server

Reference to the server. Only assigned by this class.

reps

private volatile EntryRep[] reps

Last set of reps we got from the server

next

private volatile int next

Index of the next entry in rep to return. If delete() we will call iter.delete() next - 1

fetchSize

private final int fetchSize

How many entries to ask for each time we go to the server

lastId

private volatile Uuid lastId

ID of last entry we got from server

Constructor Detail

IteratorProxy

IteratorProxy(Uuid iterationUuid,
              OutriggerAdmin server,
              int fetchSize)

Create client side iterator proxy.

Parameters:

iterationUuid - The identity of the iteration this proxy is for.

server - reference to remote server for the space.

fetchSize - Number of entries to ask for when it goes to the server

Throws:

NullPointerException - if server or iterationUuid is null.

Method Detail

next

public Entry next()
           throws UnusableEntryException,
                  RemoteException

Description copied from interface: AdminIterator

Return the next entry in the sequence. Returns null if there are no more matching entries in the space.

This method is idempotent in the face of RemoteExceptions.

Specified by:

next in interface AdminIterator

Throws:

UnusableEntryException - if the field of next entry in sequence can't be deserialized (usually this is because the class in question could not be loaded).

RemoteException

delete

public void delete()
            throws RemoteException

Description copied from interface: AdminIterator

The effect of this call depends on the most recent call to next():

• If the last call to next() returned an Entry that entry will be removed from the space.

• If the last call to next() threw a UnusableEntryException the Entry that could not be deserialized will be removed from the space.

• If the last call to next() returned null, threw a RemoteException, or next() has not yet been called on this iterator a IllegalStateException will be thrown and no entry will be removed.

This method is idempotent in the face of RemoteException.

Specified by:

delete in interface AdminIterator

Throws:

RemoteException

close

public void close()
           throws RemoteException

Description copied from interface: AdminIterator

Tell the server that this iterator is no longer in use. All operations on a closed iterator have undefined results, except the close() method.

This method is idempotent in the face of RemoteException.

Specified by:

close in interface AdminIterator

Throws:

RemoteException

assertOpen

private void assertOpen()
                 throws IllegalStateException

Throw IllegalStateException if this iterator has been closed; otherwise just return.

Throws:

IllegalStateException

toString

public String toString()

Overrides:

toString in class Object