com.twitter.scalding

Grouped

class Grouped [K, T] extends KeyedList[K, T] with Serializable

Represents a grouping which is the transition from map to reduce phase in hadoop. Grouping is on a key of type K by ordering Ordering[K].

go to: companion
linear super types: Serializable, KeyedList[K, T], AnyRef, Any
Ordering
  1. Alphabetic
  2. By inheritance
Inherited
  1. Hide All
  2. Show all
  1. Grouped
  2. Serializable
  3. KeyedList
  4. AnyRef
  5. Any
Visibility
  1. Public
  2. All
Impl.
  1. Concrete
  2. Abstract

Instance constructors

  1. new Grouped (pipe: Pipe, ordering: Ordering[K], streamMapFn: Option[(Iterator[TupleEntry]) ⇒ Iterator[T]], valueSort: Option[(Fields, Boolean)], reducers: Int =)

Value Members

  1. def != (arg0: AnyRef) : Boolean

    attributes: final
    definition classes: AnyRef
  2. def != (arg0: Any) : Boolean

    o != arg0 is the same as !(o == (arg0)).

    o != arg0 is the same as !(o == (arg0)).

    arg0

    the object to compare against this object for dis-equality.

    returns

    false if the receiver object is equivalent to the argument; true otherwise.

    attributes: final
    definition classes: Any
  3. def ## () : Int

    attributes: final
    definition classes: AnyRef → Any
  4. def $asInstanceOf [T0] () : T0

    attributes: final
    definition classes: AnyRef
  5. def $isInstanceOf [T0] () : Boolean

    attributes: final
    definition classes: AnyRef
  6. def == (arg0: AnyRef) : Boolean

    o == arg0 is the same as if (o eq null) arg0 eq null else o.equals(arg0).

    o == arg0 is the same as if (o eq null) arg0 eq null else o.equals(arg0).

    arg0

    the object to compare against this object for equality.

    returns

    true if the receiver object is equivalent to the argument; false otherwise.

    attributes: final
    definition classes: AnyRef
  7. def == (arg0: Any) : Boolean

    o == arg0 is the same as o.equals(arg0).

    o == arg0 is the same as o.equals(arg0).

    arg0

    the object to compare against this object for equality.

    returns

    true if the receiver object is equivalent to the argument; false otherwise.

    attributes: final
    definition classes: Any
  8. def asInstanceOf [T0] : T0

    This method is used to cast the receiver object to be of type T0.

    This method is used to cast the receiver object to be of type T0.

    Note that the success of a cast at runtime is modulo Scala's erasure semantics. Therefore the expression1.asInstanceOf[String] will throw a ClassCastException at runtime, while the expressionList(1).asInstanceOf[List[String]] will not. In the latter example, because the type argument is erased as part of compilation it is not possible to check whether the contents of the list are of the requested typed.

    returns

    the receiver object.

    attributes: final
    definition classes: Any
  9. def clone () : AnyRef

    This method creates and returns a copy of the receiver object.

    This method creates and returns a copy of the receiver object.

    The default implementation of the clone method is platform dependent.

    returns

    a copy of the receiver object.

    attributes: protected
    definition classes: AnyRef
  10. def count (fn: (T) ⇒ Boolean) : TypedPipe[(K, Long)]

    definition classes: KeyedList
  11. def eq (arg0: AnyRef) : Boolean

    This method is used to test whether the argument (arg0) is a reference to the receiver object (this).

    This method is used to test whether the argument (arg0) is a reference to the receiver object (this).

    The eq method implements an [http://en.wikipedia.org/wiki/Equivalence_relation equivalence relation] on non-null instances of AnyRef: * It is reflexive: for any non-null instance x of type AnyRef, x.eq(x) returns true. * It is symmetric: for any non-null instances x and y of type AnyRef, x.eq(y) returns true if and only if y.eq(x) returns true. * It is transitive: for any non-null instances x, y, and z of type AnyRef if x.eq(y) returns true and y.eq(z) returns true, then x.eq(z) returns true.

    Additionally, the eq method has three other properties. * It is consistent: for any non-null instances x and y of type AnyRef, multiple invocations of x.eq(y) consistently returns true or consistently returns false. * For any non-null instance x of type AnyRef, x.eq(null) and null.eq(x) returns false. * null.eq(null) returns true.

    When overriding the equals or hashCode methods, it is important to ensure that their behavior is consistent with reference equality. Therefore, if two objects are references to each other (o1 eq o2), they should be equal to each other (o1 == o2) and they should hash to the same value (o1.hashCode == o2.hashCode).

    arg0

    the object to compare against this object for reference equality.

    returns

    true if the argument is a reference to the receiver object; false otherwise.

    attributes: final
    definition classes: AnyRef
  12. def equals (arg0: Any) : Boolean

    This method is used to compare the receiver object (this) with the argument object (arg0) for equivalence.

    This method is used to compare the receiver object (this) with the argument object (arg0) for equivalence.

    The default implementations of this method is an [http://en.wikipedia.org/wiki/Equivalence_relation equivalence relation]: * It is reflexive: for any instance x of type Any, x.equals(x) should return true. * It is symmetric: for any instances x and y of type Any, x.equals(y) should return true if and only if y.equals(x) returns true. * It is transitive: for any instances x, y, and z of type AnyRef if x.equals(y) returns true and y.equals(z) returns true, then x.equals(z) should return true.

    If you override this method, you should verify that your implementation remains an equivalence relation. Additionally, when overriding this method it is often necessary to override hashCode to ensure that objects that are "equal" (o1.equals(o2) returns true) hash to the same scala.Int (o1.hashCode.equals(o2.hashCode)).

    arg0

    the object to compare against this object for equality.

    returns

    true if the receiver object is equivalent to the argument; false otherwise.

    definition classes: AnyRef → Any
  13. def finalize () : Unit

    This method is called by the garbage collector on the receiver object when garbage collection determines that there are no more references to the object.

    This method is called by the garbage collector on the receiver object when garbage collection determines that there are no more references to the object.

    The details of when and if the finalize method are invoked, as well as the interaction between finalizeand non-local returns and exceptions, are all platform dependent.

    attributes: protected
    definition classes: AnyRef
  14. def foldLeft [B] (z: B)(fn: (B, T) ⇒ B) : TypedPipe[(K, B)]

    definition classes: KeyedList
  15. def forall (fn: (T) ⇒ Boolean) : TypedPipe[(K, Boolean)]

    definition classes: KeyedList
  16. def getClass () : java.lang.Class[_]

    Returns a representation that corresponds to the dynamic class of the receiver object.

    Returns a representation that corresponds to the dynamic class of the receiver object.

    The nature of the representation is platform dependent.

    returns

    a representation that corresponds to the dynamic class of the receiver object.

    attributes: final
    definition classes: AnyRef
  17. val groupKey : Fields

    attributes: protected
  18. def hashCode () : Int

    Returns a hash code value for the object.

    Returns a hash code value for the object.

    The default hashing algorithm is platform dependent.

    Note that it is allowed for two objects to have identical hash codes (o1.hashCode.equals(o2.hashCode)) yet not be equal (o1.equals(o2) returns false). A degenerate implementation could always return 0. However, it is required that if two objects are equal (o1.equals(o2) returns true) that they have identical hash codes (o1.hashCode.equals(o2.hashCode)). Therefore, when overriding this method, be sure to verify that the behavior is consistent with the equals method.

    returns

    the hash code value for the object.

    definition classes: AnyRef → Any
  19. def isInstanceOf [T0] : Boolean

    This method is used to test whether the dynamic type of the receiver object is T0.

    This method is used to test whether the dynamic type of the receiver object is T0.

    Note that the test result of the test is modulo Scala's erasure semantics. Therefore the expression1.isInstanceOf[String] will return false, while the expression List(1).isInstanceOf[List[String]] will return true. In the latter example, because the type argument is erased as part of compilation it is not possible to check whether the contents of the list are of the requested typed.

    returns

    true if the receiver object is an instance of erasure of type T0; false otherwise.

    attributes: final
    definition classes: Any
  20. def join [W] (smaller: Grouped[K, W]) : InnerCoGrouped2[K, T, W]

  21. def leftJoin [W] (smaller: Grouped[K, W]) : LeftCoGrouped2[K, T, W]

  22. def mapValueStream [V] (nmf: (Iterator[T]) ⇒ Iterator[V]) : Grouped[K, V]

    Operate on a Stream[T] of all the values for each key at one time.

    Operate on a Stream[T] of all the values for each key at one time. Avoid accumulating the whole list in memory if you can. Prefer reduce.

    definition classes: GroupedKeyedList
  23. def mapValues [V] (fn: (T) ⇒ V) : Grouped[K, V]

    This is a special case of mapValueStream, but can be optimized because it doesn't need all the values for a given key at once.

    This is a special case of mapValueStream, but can be optimized because it doesn't need all the values for a given key at once. An unoptimized implementation would be: mapValueStream { _.map { fn } } but for Grouped we can avoid resorting to mapValueStream

    definition classes: GroupedKeyedList
  24. def max [B >: T] (implicit cmp: Ordering[B]) : TypedPipe[(K, T)]

    definition classes: KeyedList
  25. def maxBy [B] (fn: (T) ⇒ B)(implicit cmp: Ordering[B]) : TypedPipe[(K, T)]

    definition classes: KeyedList
  26. def min [B >: T] (implicit cmp: Ordering[B]) : TypedPipe[(K, T)]

    definition classes: KeyedList
  27. def minBy [B] (fn: (T) ⇒ B)(implicit cmp: Ordering[B]) : TypedPipe[(K, T)]

    definition classes: KeyedList
  28. def ne (arg0: AnyRef) : Boolean

    o.ne(arg0) is the same as !(o.eq(arg0)).

    o.ne(arg0) is the same as !(o.eq(arg0)).

    arg0

    the object to compare against this object for reference dis-equality.

    returns

    false if the argument is not a reference to the receiver object; true otherwise.

    attributes: final
    definition classes: AnyRef
  29. def notify () : Unit

    Wakes up a single thread that is waiting on the receiver object's monitor.

    Wakes up a single thread that is waiting on the receiver object's monitor.

    attributes: final
    definition classes: AnyRef
  30. def notifyAll () : Unit

    Wakes up all threads that are waiting on the receiver object's monitor.

    Wakes up all threads that are waiting on the receiver object's monitor.

    attributes: final
    definition classes: AnyRef
  31. def operate [T1] (fn: (GroupBuilder) ⇒ GroupBuilder) : TypedPipe[(K, T1)]

    attributes: protected
  32. def outerJoin [W] (smaller: Grouped[K, W]) : OuterCoGrouped2[K, T, W]

  33. val pipe : Pipe

  34. def product (implicit ring: Ring[T]) : TypedPipe[(K, T)]

    definition classes: KeyedList
  35. def reduce (fn: (T, T) ⇒ T) : TypedPipe[(K, T)]

    reduce with fn which must be associative and commutative.

    reduce with fn which must be associative and commutative. Like the above this can be optimized in some Grouped cases.

    definition classes: GroupedKeyedList
  36. def reduceLeft (fn: (T, T) ⇒ T) : TypedPipe[(K, T)]

    definition classes: KeyedList
  37. def reverse : Grouped[K, T]

  38. def rightJoin [W] (smaller: Grouped[K, W]) : RightCoGrouped2[K, T, W]

  39. def scanLeft [B] (z: B)(fn: (B, T) ⇒ B) : KeyedList[K, B]

    definition classes: KeyedList
  40. def size : TypedPipe[(K, Long)]

    definition classes: KeyedList
  41. def sortBy [B] (fn: (T) ⇒ B)(implicit ord: Ordering[B]) : Grouped[K, T]

  42. def sortIfNeeded (gb: GroupBuilder) : GroupBuilder

    attributes: protected
  43. def sortWith (lt: (T, T) ⇒ Boolean) : Grouped[K, T]

  44. def sum (implicit monoid: Monoid[T]) : TypedPipe[(K, T)]

    definition classes: KeyedList
  45. def synchronized [T0] (arg0: T0) : T0

    attributes: final
    definition classes: AnyRef
  46. def toList : TypedPipe[(K, List[T])]

    definition classes: KeyedList
  47. def toSet : TypedPipe[(K, Set[T])]

    definition classes: KeyedList
  48. def toString () : String

    Returns a string representation of the object.

    Returns a string representation of the object.

    The default representation is platform dependent.

    returns

    a string representation of the object.

    definition classes: AnyRef → Any
  49. lazy val toTypedPipe : TypedPipe[(K, T)]

    definition classes: GroupedKeyedList
  50. def wait () : Unit

    attributes: final
    definition classes: AnyRef
  51. def wait (arg0: Long, arg1: Int) : Unit

    attributes: final
    definition classes: AnyRef
  52. def wait (arg0: Long) : Unit

    attributes: final
    definition classes: AnyRef
  53. def withReducers (red: Int) : Grouped[K, T]

  54. def withSortOrdering (so: Ordering[T]) : Grouped[K, T]

Inherited from Serializable

Inherited from KeyedList[K, T]

Inherited from AnyRef

Inherited from Any