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ReplicatedMapEntry.java API Doc Apache Tomcat 6.0.14 3729 Fri Jul 20 04:20:34 BST 2007 org.apache.catalina.tribes.tipis

ReplicatedMapEntry

public interface ReplicatedMapEntry implements Serializable

For smarter replication, an object can implement this interface to replicate diffs
The replication logic will call the methods in the following order:


1. if ( entry.isDirty() ) 

try {
2. entry.lock();

3. byte[] diff = entry.getDiff();

4. entry.reset();

} finally {

5. entry.unlock();

}

}

When the data is deserialized the logic is called in the following order


1. ReplicatedMapEntry entry = (ReplicatedMapEntry)objectIn.readObject();

2. if ( isBackup(entry)||isPrimary(entry) ) entry.setOwner(owner);

author: Filip Hanik
version: 1.0

Fields Summary
Constructors Summary
Methods Summary
public void applyDiff(byte[] diff, int offset, int length)
Applies a diff to an existing object.
param
diff byte[]
param
offset int
param
length int
throws
IOException
public byte[] getDiff()
Returns a diff and sets the dirty map to false
return
byte[]
throws
IOException
public long getVersion()
For accuracy checking, a serialized attribute can contain a version number This number increases as modifications are made to the data. The replicated map can use this to ensure accuracy on a periodic basis
return
long - the version number or -1 if the data is not versioned
public boolean isDiffable()
If this returns true, the map will extract the diff using getDiff() Otherwise it will serialize the entire object.
return
boolean
public boolean isDirty()
Has the object changed since last replication and is not in a locked state
return
boolean
public void lock()
Lock during serialization
public void resetDiff()
Resets the current diff state and resets the dirty flag
public void setOwner(java.lang.Object owner)
This method is called after the object has been created on a remote map. On this method, the object can initialize itself for any data that wasn't
param
owner Object
public void setVersion(long version)
Forces a certain version to a replicated map entry
param
version long
public void unlock()
Unlock after serialization