public     interface
      CheckpointHandler
    
     
     
     
      
    
    
    
    
    | Known Indirect Subclasses | 
Wrapper object to read / write a checkpoint. An implementation is expected to throw IOException if reading or writing of the checkpoint fails.
Public Method Summary
| abstract byte[] | 
               
                readCheckpoint(String checkpointName)
                
                 
          Read current value of saved checkpoint. 
                
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| abstract void | 
               
                saveCheckpoint(String checkpointName, byte[] checkpoint)
                
                 
          Saves checkpoint value. 
                
               | 
        
Public Methods
public abstract byte[] readCheckpoint (String checkpointName)
Read current value of saved checkpoint.
Parameters
| checkpointName | the name of the checkpoint to read | 
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Returns
- current value of checkpoint. 
nullif checkpoint is empty or not available 
Throws
| IOException | if checkpoint read fails | 
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public abstract void saveCheckpoint (String checkpointName, byte[] checkpoint)
Saves checkpoint value.
Parameters
| checkpointName | the name of the checkpoint to save | 
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| checkpoint | value to save | 
Throws
| IOException | if checkpoint save fails | 
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