com.scaleout.client.caching

Interface CacheEntryReduceHandler<K,V,P,R>

Type Parameters:

K - the key type.

V - the value type.

P - the param holder type.

R - the result type.

public interface CacheEntryReduceHandler<K,V,P,R>

Callback that is invoked on each eligible object for a Cache.invoke(String, Duration) call.

Method Summary

Modifier and Type	Method and Description
R	accumulatorFactory() Generate a thread local accumulator for the final result.
R	deserializeResult(byte[] value) Deserialize a result value from binary data.
R	map(K key, R accumulator, OperationContext<K,V,P> ctx) Map a key into the thread-local accumulator and return the accumulated result.
R	reduce(R result1, R result2) Reduce two results into a single result.
byte[]	serializeResult(R value) Serialize a result value into binary data.

Method Detail

accumulatorFactory

R accumulatorFactory()

Generate a thread local accumulator for the final result.

Returns:

an instance of R

map

R map(K key,
      R accumulator,
      OperationContext<K,V,P> ctx)

Map a key into the thread-local accumulator and return the accumulated result.

Parameters:

key - the key.

accumulator - the thread-local result accumulator.

ctx - the OperationContext

Returns:

the accumulated result.

reduce

R reduce(R result1,
         R result2)

Reduce two results into a single result.

The infrastructure will reduce the thread-local results into one host-local result that will be reduced against other hosts' results.

Parameters:

result1 - one result.

result2 - other result.

Returns:

the reduced result.

deserializeResult

R deserializeResult(byte[] value)

Deserialize a result value from binary data. The parameter value for this function is generated through serializeResult(Object).

Parameters:

value - the binary representation of a result.

Returns:

the hydrated result object of type R.

serializeResult

byte[] serializeResult(R value)

Serialize a result value into binary data.

Parameters:

value - the result object.

Returns:

the binary representation of an instance of R.