Package org.apache.catalina.tribes.tipis

Interface ReplicatedMapEntry

All Superinterfaces:
Serializable
All Known Implementing Classes:
DeltaSession
public interface ReplicatedMapEntry extends 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);

  • Method Summary

    Modifier and Type
    Method
    Description
    void
    accessEntry()
    Access to an existing object.
    void
    applyDiff(byte[] diff, int offset, int length)
    Applies a diff to an existing object.
    byte[]
    getDiff()
    Returns a diff and sets the dirty map to false
    long
    getLastTimeReplicated()
     
    long
    getVersion()
    For accuracy checking, a serialized attribute can contain a version number This number increases as modifications are made to the data.
    boolean
    isAccessReplicate()
    If this returns true, to replicate that an object has been accessed
    boolean
    isDiffable()
    If this returns true, the map will extract the diff using getDiff() Otherwise it will serialize the entire object.
    boolean
    isDirty()
    Has the object changed since last replication and is not in a locked state
    void
    lock()
    Lock during serialization
    void
    resetDiff()
    Resets the current diff state and resets the dirty flag
    void
    setLastTimeReplicated(long lastTimeReplicated)
    Set the last replicate time.
    void
    setOwner(Object owner)
    This method is called after the object has been created on a remote map.
    void
    setVersion(long version)
    Forces a certain version to a replicated map entry
    void
    unlock()
    Unlock after serialization

  • Method Details

    • isDirty

      boolean isDirty()
      Has the object changed since last replication and is not in a locked state
      Returns:
      boolean

    • isDiffable

      boolean isDiffable()
      If this returns true, the map will extract the diff using getDiff() Otherwise it will serialize the entire object.
      Returns:
      boolean

    • getDiff

      byte[] getDiff() throws IOException
      Returns a diff and sets the dirty map to false
      Returns:
      Serialized diff data
      Throws:
      IOException - IO error serializing

    • applyDiff

      void applyDiff(byte[] diff, int offset, int length) throws IOException, ClassNotFoundException
      Applies a diff to an existing object.
      Parameters:
      diff - Serialized diff data
      offset - Array offset
      length - Array length
      Throws:
      IOException - IO error deserializing
      ClassNotFoundException - Serialization error

    • resetDiff

      void resetDiff()
      Resets the current diff state and resets the dirty flag

    • lock

      void lock()
      Lock during serialization

    • unlock

      void unlock()
      Unlock after serialization

    • setOwner

      void setOwner(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
      Parameters:
      owner - Object

    • getVersion

      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
      Returns:
      long - the version number or -1 if the data is not versioned

    • setVersion

      void setVersion(long version)
      Forces a certain version to a replicated map entry
      Parameters:
      version - long

    • getLastTimeReplicated

      long getLastTimeReplicated()
      Returns:
      the last replicate time.

    • setLastTimeReplicated

      void setLastTimeReplicated(long lastTimeReplicated)
      Set the last replicate time.
      Parameters:
      lastTimeReplicated - New timestamp

    • isAccessReplicate

      boolean isAccessReplicate()
      If this returns true, to replicate that an object has been accessed
      Returns:
      boolean

    • accessEntry

      void accessEntry()
      Access to an existing object.