Package org.plumelib.util

Class LimitedSizeLongSet

java.lang.Object
org.plumelib.util.LimitedSizeLongSet
All Implemented Interfaces:
Serializable, Cloneable
public class LimitedSizeLongSet extends Object implements Serializable, Cloneable
LimitedSizeLongSet stores up to some maximum number of unique values. If more than that many elements are added, then functionality is degraded: most operations return a conservative estimate (because the internal representation is nulled, in order to save space).

The advantage of this class over LimitedSizeSet<Long> is that it does not autobox the long values, so it takes less memory.

See Also:

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    protected long @Nullable @MinLen(1) []
    values
    If null, then at least numValues distinct values have been seen.

  • Constructor Summary

    Constructors
    Constructor
    Description
    LimitedSizeLongSet(@org.checkerframework.checker.index.qual.Positive int maxValues)
    Create a new LimitedSizeLongSet that can hold maxValues values.

  • Method Summary

    Modifier and Type
    Method
    Description
    void
    add(long elt)
    Add an element to this set.
    void
    addAll(LimitedSizeLongSet s)
    Add all elements of s to this set.
    LimitedSizeLongSet
    clone()
     
    boolean
    contains(long elt)
    Returns true if this set contains the given element.
    @org.checkerframework.checker.index.qual.Positive int
    maxSize()
    An upper bound on how many distinct elements can be individually represented in the set.
    static LimitedSizeLongSet
    merge(@org.checkerframework.checker.index.qual.Positive int maxValues, List<LimitedSizeLongSet> slist)
    Merges a list of LimitedSizeLongSet objects into a single object that represents the values seen by the entire list.
    boolean
    repNulled()
    Returns true if more elements have been added than this set can contain (which is the integer that was passed to the constructor when creating this set).
    int
    size()
    A lower bound on the number of elements in the set.
    String
    toString()
     

    Methods inherited from class java.lang.Object

    equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

  • Field Details

    • values

      protected long @Nullable @MinLen(1) [] values
      If null, then at least numValues distinct values have been seen. The size is not separately stored, because that would take extra space.

  • Constructor Details

    • LimitedSizeLongSet

      public LimitedSizeLongSet(@org.checkerframework.checker.index.qual.Positive int maxValues)
      Create a new LimitedSizeLongSet that can hold maxValues values.
      Parameters:
      maxValues - the maximum number of values this set will be able to hold; must be positive

  • Method Details

    • add

      public void add(long elt)
      Add an element to this set.
      Parameters:
      elt - the element to add to this set

    • addAll

      public void addAll(LimitedSizeLongSet s)
      Add all elements of s to this set.
      Parameters:
      s - the elements to add to this set

    • contains

      @Pure public boolean contains(long elt)
      Returns true if this set contains the given element.
      Parameters:
      elt - the element whose membership to test
      Returns:
      true if this set contains elt

    • size

      @Pure public int size(@GuardSatisfied LimitedSizeLongSet this)
      A lower bound on the number of elements in the set. Returns either the number of elements that have been inserted in the set, or maxSize(), whichever is less.
      Returns:
      a number that is a lower bound on the number of elements added to the set

    • maxSize

      public @org.checkerframework.checker.index.qual.Positive int maxSize()
      An upper bound on how many distinct elements can be individually represented in the set. Returns maxValues+1 (where maxValues is the argument to the constructor).
      Returns:
      maximum capacity of the set representation

    • repNulled

      @EnsuresNonNullIf(result=false, expression="values") @Pure public boolean repNulled(@GuardSatisfied LimitedSizeLongSet this)
      Returns true if more elements have been added than this set can contain (which is the integer that was passed to the constructor when creating this set).
      Returns:
      true if this set has been filled to capacity and its internal representation is nulled

    • clone

      @SideEffectFree public LimitedSizeLongSet clone(@GuardSatisfied LimitedSizeLongSet this)
      Overrides:
      clone in class Object

    • merge

      public static LimitedSizeLongSet merge(@org.checkerframework.checker.index.qual.Positive int maxValues, List<LimitedSizeLongSet> slist)
      Merges a list of LimitedSizeLongSet objects into a single object that represents the values seen by the entire list. Returns the new object, whose maxValues is the given integer.
      Parameters:
      maxValues - the maximum size for the returned LimitedSizeLongSet
      slist - a list of LimitedSizeLongSet, whose elements will be merged
      Returns:
      a LimitedSizeLongSet that merges the elements of slist

    • toString

      @SideEffectFree public String toString(@GuardSatisfied LimitedSizeLongSet this)
      Overrides:
      toString in class Object