abstract class AccumulatorV2[IN, OUT] extends Serializable
The base class for accumulators, that can accumulate inputs of type IN
, and produce output of
type OUT
.
OUT
should be a type that can be read atomically (e.g., Int, Long), or thread-safely
(e.g., synchronized collections) because it will be read from other threads.
- Source
- AccumulatorV2.scala
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- AccumulatorV2
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- Serializable
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Instance Constructors
- new AccumulatorV2()
Abstract Value Members
-
abstract
def
add(v: IN): Unit
Takes the inputs and accumulates.
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abstract
def
copy(): AccumulatorV2[IN, OUT]
Creates a new copy of this accumulator.
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abstract
def
isZero: Boolean
Returns if this accumulator is zero value or not.
Returns if this accumulator is zero value or not. e.g. for a counter accumulator, 0 is zero value; for a list accumulator, Nil is zero value.
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abstract
def
merge(other: AccumulatorV2[IN, OUT]): Unit
Merges another same-type accumulator into this one and update its state, i.e.
Merges another same-type accumulator into this one and update its state, i.e. this should be merge-in-place.
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abstract
def
reset(): Unit
Resets this accumulator, which is zero value.
Resets this accumulator, which is zero value. i.e. call
isZero
must return true. -
abstract
def
value: OUT
Defines the current value of this accumulator
Concrete Value Members
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final
def
!=(arg0: Any): Boolean
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final
def
##(): Int
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final
def
==(arg0: Any): Boolean
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final
def
asInstanceOf[T0]: T0
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def
clone(): AnyRef
- Attributes
- protected[lang]
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- Annotations
- @throws( ... ) @native()
-
def
copyAndReset(): AccumulatorV2[IN, OUT]
Creates a new copy of this accumulator, which is zero value.
Creates a new copy of this accumulator, which is zero value. i.e. call
isZero
on the copy must return true. -
final
def
eq(arg0: AnyRef): Boolean
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def
equals(arg0: Any): Boolean
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def
finalize(): Unit
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- @throws( classOf[java.lang.Throwable] )
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final
def
getClass(): Class[_]
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- @native()
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def
hashCode(): Int
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- @native()
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final
def
id: Long
Returns the id of this accumulator, can only be called after registration.
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final
def
isInstanceOf[T0]: Boolean
- Definition Classes
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final
def
isRegistered: Boolean
Returns true if this accumulator has been registered.
Returns true if this accumulator has been registered.
- Note
All accumulators must be registered before use, or it will throw exception.
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final
def
name: Option[String]
Returns the name of this accumulator, can only be called after registration.
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final
def
ne(arg0: AnyRef): Boolean
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final
def
notify(): Unit
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final
def
notifyAll(): Unit
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final
def
synchronized[T0](arg0: ⇒ T0): T0
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def
toString(): String
- Definition Classes
- AccumulatorV2 → AnyRef → Any
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final
def
wait(): Unit
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- @throws( ... )
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final
def
wait(arg0: Long, arg1: Int): Unit
- Definition Classes
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- @throws( ... )
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final
def
wait(arg0: Long): Unit
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final
def
writeReplace(): Any
- Attributes
- protected