GafferAdder (uk.gov.gchq.gaffer:gaffer2 2.3.1 API)

java.lang.Object
- uk.gov.gchq.gaffer.flink.operation.handler.GafferAdder

All Implemented Interfaces:

Serializable
```
public class GafferAdder
extends Object
implements Serializable
```
Helper class to add Elements to a Gaffer store.

The Flink sink is given a single element at a time. Adding a single element at a time to Gaffer would be really inefficient so we add these individual elements to a blocking queue that we simultaneously add elements to whilst the Gaffer Store is consuming them.

The queue is a BlockingQueue with a maximum size to prevent the queue from getting too large and running out of memory. If the maximum size is reached Flink will be blocked from adding elements to the queue. The maximum size of the queue can be configured using the operation option: gaffer.flink.operation.handler.max-queue-size. By default the maximum size is 1,000,000. The blocking queue is only blocked on addition, it does not cause the Gaffer Store to block if the queue is empty. In the case where a Kafka queue has just a single Gaffer element the Store can immediately add this rather than blocking and waiting for a batch to fill up. A side affect of this is that AddElements operation may complete if no elements are added to the queue for some time. In this situation we just restart the AddElements operation next time an element is received.

See Also:

Serialized Form

- Field Summary
  
  Fields
  Modifier and Type Field Description
  
  static int MAX_QUEUE_SIZE_DEFAULT
- Constructor Summary
  
  Constructors
  Constructor Description
  
  GafferAdder(OP operation, Store store)
- Method Summary
  
  All Methods Instance Methods Concrete Methods
  Modifier and Type Method Description
  
  void add(Element element)
  
  void initialise()
  - Methods inherited from class java.lang.Object
    equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail
- MAX_QUEUE_SIZE_DEFAULT
```
public static final int MAX_QUEUE_SIZE_DEFAULT
```
  See Also:
  
  Constant Field Values

Constructor Detail

GafferAdder

public GafferAdder(OP operation,
                   Store store)

Method Detail

initialise
```
public void initialise()
```

add
```
public void add(Element element)
```