Package com.atlassian.crowd.util

Class BoundedCount

java.lang.Object
com.atlassian.crowd.util.BoundedCount
public class BoundedCount extends Object
A possibly approximate count of the number of elements in a collection. The collection has at least getCount() elements. A count marked as exact has exactly count elements (see isExact(). This allows APIs to give indications of collection size without committing to expensive operations when an exact count requires significant work. Provided are some example scenarios and what the results mean:
(getCount(), isExact())
result
(5, true)
Count of elements is exactly 5
(5, false)
Count of elements is at least 5
(0, false)
Count of elements is zero or more (could be anything)

  • Method Details

    • exactly

      public static BoundedCount exactly(long count)
      Create a bounded count that exactly represents a number.
      Parameters:
      count - The exact count that this represents; not a bounded number.
      Returns:
      A BoundedCount that is exact.

    • atLeast

      public static BoundedCount atLeast(long count)
      Create a BoundedCount that is at-least as big as a given number. This creates a lower bound on the provided count allowing you to indicate that the collection you are counting is bigger than a given count.
      Parameters:
      count - A number that is at-least as big as the real count of elements in a collection.
      Returns:
      A lower bounded count.

    • fromCountedItemsAndLimit

      public static BoundedCount fromCountedItemsAndLimit(long count, long potentialMaxCount)
      Get a bounded count from counting up to an upper bound.
      Parameters:
      count - The number of elements that were actually counted.
      potentialMaxCount - The maximum number of elements that we counted up to.
      Returns:
      Returns exactly the count given (if less than the upper bound) and returns at-least the upper bound otherwise.

    • getCount

      public long getCount()
      The number of elements counted in a collection.
      Returns:
      If isExact() returns true then it returns the exact size of the collection. Otherwise it returns a lower bound of the size of the collection. The answer will always be non-negative.

    • isExact

      public boolean isExact()
      Returns:
      True if getCount() is known to be the exact number of elements in the collection. It will return False if this count represents a lower bound.

    • equals

      public boolean equals(Object o)
      Overrides:
      equals in class Object

    • hashCode

      public int hashCode()
      Overrides:
      hashCode in class Object

    • toString

      public String toString()
      Overrides:
      toString in class Object