rice.p2p.past
Interface PastContent

All Superinterfaces:

java.io.Serializable

All Known Subinterfaces:

GCPastContent, RawGCPastContent, RawPastContent

All Known Implementing Classes:

Aggregate, ContentHashPastContent, DebugContent, DistPastTestContent, JavaSerializedGCPastContent, JavaSerializedPastContent, MyPastContent, NonAggregate, PastRegrTest.NonMutableTestPastContent, PastRegrTest.NonOverwritingTestPastContent, PastRegrTest.TestPastContent, PastRegrTest.VersionedTestPastContent, RawAggregate, RawPastRegrTest.NonMutableTestPastContent, RawPastRegrTest.NonOverwritingTestPastContent, RawPastRegrTest.TestPastContent, RawPastRegrTest.VersionedTestPastContent

public interface PastContent
extends java.io.Serializable

Version:

$Id: PastContent.java 3524 2007-01-09 14:09:27Z jeffh $

Author:

Alan Mislove, Ansley Post, Peter Druschel

Method Summary

PastContent	checkInsert(Id id, PastContent existingContent) Checks if a insert operation should be allowed.
PastContentHandle	getHandle(Past local) Produces a handle for this content object.
Id	getId() Returns the Id under which this object is stored in Past.
boolean	isMutable() States if this content object is mutable.

Method Detail

checkInsert

PastContent checkInsert(Id id,
                        PastContent existingContent)
                        throws PastException

Checks if a insert operation should be allowed. Invoked when a Past node receives an insert request and it is a replica root for the id; invoked on the object to be inserted. This method determines the effect of an insert operation on an object that already exists: it computes the new value of the stored object, as a function of the new and the existing object.

Parameters:

id - the key identifying the object

newObj - the new object to be stored

existingObj - the existing object stored on this node (null if no object associated with id is stored on this node)

Returns:

null, if the operation is not allowed; else, the new object to be stored on the local node.

Throws:

PastException

getHandle

PastContentHandle getHandle(Past local)

Produces a handle for this content object. The handle is retrieved and returned to the client as a result of the Past.lookupHandles() method.

Parameters:

The - local Past service which the content is on.

Returns:

the handle

getId

Id getId()

Returns the Id under which this object is stored in Past.

Returns:

the id

isMutable

boolean isMutable()

States if this content object is mutable. Mutable objects are not subject to dynamic caching in Past.

Returns:

true if this object is mutable, else false