sos.dated.util
Interface DatedSet

All Superinterfaces:

DatedCollection, DatedObject

All Known Subinterfaces:

DatedSortedSet

All Known Implementing Classes:

AbstractDatedSet, sos.dated.util.AbstractMapBackedSet, HashSetByDate, HashSetByElement, TreeSetByDate, TreeSetByElement

public interface DatedSet

extends DatedCollection

A set of elements over time. A dated set is a dated collection with the additional requirement that an element appear at most once at a given date. This interface is based on the interface java.util.Set. The following table compares the efficiencies of the four implementations in this package. Each cell is the average big-Oh notation, where T denotes the number of dates in the set and N denotes the number of elements at any given date.

	HashSetByDate	HashSetByKey	TreeSetByDate	TreeSetByKey
add	T*N	T	T*N	T+log(N)
clear	T	T*N	T	T*N
contains	log(T)	log(T)	log(T)+log(N)	log(T)+log(N)
containsThroughout	T	T	T*log(N)	T+log(N)
dateIterator	log(T)	T*N	log(T)	T*N
hashCode	T*N	T*N	T*N	T*N
hashCode(d)	log(T)+N	log(T)*N	log(T)+N	log(T)*N
remove	T*N	T	T*N	T+log(N)
size	log(T)	log(T)	log(T)	log(T)

This interface does not extend java.util.Set directly because at least one date is needed. To make a dated set appear like a non-dated set, use Adapters.asSet(DatedSet,Date). Similarly, to treat a non-dated set as dated, use Adapters.asDatedSet(Set,Date,Date).

Since:

1.0

See Also:

HashSetByDate, HashSetByElement, TreeSetByDate, TreeSetByElement, Adapters.asSet(DatedSet,Date), Adapters.asDatedSet(Set,Date,Date)

Field Summary

Fields inherited from interface sos.dated.util.DatedObject

MAX_DATE, MIN_DATE

Method Summary

boolean	equals(java.util.Date date, DatedObject obj, java.util.Date objDate) Indicates if this dated set at date is equal to obj at objDate.
int	hashCode(java.util.Date date) Returns a hash code value of this dated set at the specified date.

Methods inherited from interface sos.dated.util.DatedCollection

add, addAll, clear, contains, containsAll, containsThroughout, excludesThroughout, hasSizeThroughout, isEmpty, isEmptyThroughout, iterator, remove, removeAll, retainAll, size, toArray, toArray

Methods inherited from interface sos.dated.util.DatedObject

dateIterator, dateIterator, equals, hashCode, toString

Method Detail

equals

public boolean equals(java.util.Date date,
                      DatedObject obj,
                      java.util.Date objDate)

Indicates if this dated set at date is equal to obj at objDate. Two sets are equivalent at the specified dates if their sizes are equal and one set contains all elements of the other set.

Specified by:

equals in interface DatedObject

Parameters:

date - date at which this object should be tested

obj - the other dated object to be compared to

objDate - the date of the other dated object

Returns:

true if this dated set at date equals another dated object at objDate

Throws:

java.lang.NullPointerException - if any argument is null

hashCode

public int hashCode(java.util.Date date)

Returns a hash code value of this dated set at the specified date. The hash code of a DatedSet at a date is calculated the same way as in hashCode of java.util.Set.

Specified by:

hashCode in interface DatedObject

Parameters:

date - date to which the value should correspond

Returns:

the hash code value of this dated object at the specified date

Throws:

java.lang.NullPointerException - if date is null