cascading.pipe.assembly
Class MaxBy.MaxPartials
java.lang.Object
cascading.pipe.assembly.MaxBy.MaxPartials
- All Implemented Interfaces:
- AggregateBy.Functor, Serializable
- Enclosing class:
- MaxBy
public static class MaxBy.MaxPartials
- extends Object
- implements AggregateBy.Functor
- See Also:
- Serialized Form
Methods inherited from class java.lang.Object |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
MaxBy.MaxPartials
public MaxBy.MaxPartials(Fields declaredFields)
getDeclaredFields
public Fields getDeclaredFields()
- Description copied from interface:
AggregateBy.Functor
- Method getDeclaredFields returns the declaredFields of this Functor object.
- Specified by:
getDeclaredFields
in interface AggregateBy.Functor
- Returns:
- the declaredFields (type Fields) of this Functor object.
aggregate
public Tuple aggregate(FlowProcess flowProcess,
TupleEntry args,
Tuple context)
- Description copied from interface:
AggregateBy.Functor
- Method aggregate operates on the given args in tandem (optionally) with the given context values.
The context argument is the result of the previous call to this method. Use it to store values between aggregate
calls (the current count, or sum of the args).
On the very first invocation of aggregate for a given grouping key, context will be
null
. All subsequent
invocations context will be the value returned on the previous invocation.
- Specified by:
aggregate
in interface AggregateBy.Functor
- Parameters:
flowProcess
- of type FlowProcessargs
- of type TupleEntrycontext
- of type Tuple @return Tuple
complete
public Tuple complete(FlowProcess flowProcess,
Tuple context)
- Description copied from interface:
AggregateBy.Functor
- Method complete allows the final aggregate computation to be performed before the return value is collected.
The number of values in the returned
Tuple
instance must match the number of declaredFields.
It is safe to return the context object as the result value.
- Specified by:
complete
in interface AggregateBy.Functor
- Parameters:
flowProcess
- of type FlowProcesscontext
- of type Tuple @return Tuple
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