Package mondrian.olap.fun.sort

Class Sorter

java.lang.Object
mondrian.olap.fun.sort.Sorter
public class Sorter extends Object

  • Constructor Details

    • Sorter

      public Sorter()

  • Method Details

    • evaluateTuples

      public static Map<List<Member>,Object> evaluateTuples(Evaluator evaluator, Calc exp, TupleList tuples)
      For each tuple in a list, evaluates an expression and creates a map from tuples to values.
      Parameters:
      evaluator - Evaluation context
      exp - Expression to evaluate
      tuples - List of tuples exp != null exp.getType() instanceof ScalarType

    • sortMembers

      public static List<Member> sortMembers(Evaluator evaluator, Iterable<Member> memberIter, List<Member> memberList, Calc exp, boolean desc, boolean brk)
      Helper function to sort a list of members according to an expression.

      NOTE: This function does not preserve the contents of the validator.

      If you do not specify memberList, the method will build its own member list as it iterates over memberIter. It is acceptable if memberList and memberIter are the same list object.

      If you specify memberList, the list is sorted in place, and memberList is returned.

      Parameters:
      evaluator - Evaluator
      memberIter - Iterable over members
      memberList - List of members
      exp - Expression to sort on
      desc - Whether to sort descending
      brk - Whether to break
      Returns:
      sorted list (never null)

    • listEquals

      public static boolean listEquals(List<Member> a1, List<Member> a2)

    • sortMembers

      public static List<Member> sortMembers(Evaluator evaluator, Iterable<Member> memberIter, List<Member> memberList, List<SortKeySpec> keySpecList)
      Sorts a list of members according to a list of SortKeySpecs. An in-place, Stable sort. Helper function for MDX OrderSet function.

      NOTE: Does not preserve the contents of the validator.

    • sortTuples

      public static TupleList sortTuples(Evaluator evaluator, TupleIterable tupleIterable, TupleList tupleList, Calc exp, boolean desc, boolean brk, int arity)
      Sorts a list of Tuples by the value of an applied expression. Stable sort.

      Helper function for MDX functions TopCount, TopSum, TopPercent, BottomCount, BottomSum, BottomPercent, but not the MDX function Order.

      NOTE: This function does not preserve the contents of the validator.

      If you specify tupleList, the list is sorted in place, and tupleList is returned.

      Parameters:
      evaluator - Evaluator
      tupleIterable - Iterator over tuples
      tupleList - List of tuples, if known, otherwise null
      exp - Expression to sort on
      desc - Whether to sort descending
      brk - Whether to break
      arity - Number of members in each tuple
      Returns:
      sorted list (never null)

    • partiallySortMembers

      public static List<Member> partiallySortMembers(Evaluator evaluator, List<Member> list, Calc exp, int limit, boolean desc)
      Partially sorts a list of Members by the value of an applied expression.

      Avoids sorting the whole list, finds only the ntop (or bottom) valued Members, and returns them as a new List. Helper function for MDX functions TopCount and BottomCount.

      NOTE: Does not preserve the contents of the validator.

      Parameters:
      list - a list of members
      exp - a Calc applied to each member to find its sort-key
      evaluator - Evaluator
      limit - maximum count of members to return.
      desc - true to sort descending (and find TopCount), false to sort ascending (and find BottomCount).
      Returns:
      the top or bottom members, as a new list.

    • sortTuples

      public static TupleList sortTuples(Evaluator evaluator, TupleIterable tupleIter, TupleList tupleList, List<SortKeySpec> keySpecList, int arity)
      Helper function to sort a list of tuples according to a list of expressions and a list of sorting flags.

      NOTE: This function does not preserve the contents of the validator.

    • partiallySortTuples

      public static List<List<Member>> partiallySortTuples(Evaluator evaluator, TupleList list, Calc exp, int limit, boolean desc)
      Partially sorts a list of Tuples by the value of an applied expression.

      Avoids sorting the whole list, finds only the n top (or bottom) valued Tuples, and returns them as a new List. Helper function for MDX functions TopCount and BottomCount.

      NOTE: Does not preserve the contents of the validator. The returned list is immutable.

      Parameters:
      evaluator - Evaluator
      list - a list of tuples
      exp - a Calc applied to each tuple to find its sort-key
      limit - maximum count of tuples to return.
      desc - true to sort descending (and find TopCount), false to sort ascending (and find BottomCount).
      Returns:
      the top or bottom tuples, as a new list.

    • hierarchizeMemberList

      public static void hierarchizeMemberList(List<Member> memberList, boolean post)
      Sorts a list of members into hierarchical order. The members must belong to the same dimension.
      Parameters:
      memberList - List of members
      post - Whether to sort in post order; if false, sorts in pre order
      See Also:

    • hierarchizeTupleList

      public static TupleList hierarchizeTupleList(TupleList tupleList, boolean post)
      Sorts a list of tuples into hierarchical order.
      Parameters:
      tupleList - List of tuples
      post - Whether to sort in post order; if false, sorts in pre order
      See Also:

    • compareValues

      public static int compareValues(double d1, double d2)
      Compares double-precision values according to MDX semantics.

      MDX requires a total order:

      -inf < NULL < ... < -1 < ... < 0 < ... < NaN < +inf
      but this is different than Java semantics, specifically with regard to Double.NaN.

    • compareValues

      public static int compareValues(Object value0, Object value1)
      Compares two cell values.

      Nulls compare last, exceptions (including the object which indicates the the cell is not in the cache yet) next, then numbers and strings are compared by value.

      Parameters:
      value0 - First cell value
      value1 - Second cell value
      Returns:
      -1, 0, or 1, depending upon whether first cell value is less than, equal to, or greater than the second

    • box

      public static Double box(double d)
      Converts a double (primitive) value to a Double. DoubleNull becomes null.

    • box

      public static Integer box(int n)
      Converts an int (primitive) value to an Integer. IntegerNull becomes null.

    • compareHierarchically

      public static int compareHierarchically(Member m1, Member m2, boolean post)
      Compares a pair of members according to their positions in a prefix-order (or postfix-order, if post is true) walk over a hierarchy.
      Parameters:
      m1 - First member
      m2 - Second member
      post - Whether to sortMembers in postfix order. If true, a parent will sortMembers immediately after its last child. If false, a parent will sortMembers immediately before its first child.
      Returns:
      -1 if m1 collates before m2, 0 if m1 equals m2, 1 if m1 collates after m2

    • compareSiblingMembers

      public static int compareSiblingMembers(Member m1, Member m2)
      Compares two members which are known to have the same parent.

      First, compare by ordinal. This is only valid now we know they're siblings, because ordinals are only unique within a parent. If the dimension does not use ordinals, both ordinals will be -1.

      If the ordinals do not differ, compare using regular member comparison.

      Parameters:
      m1 - First member
      m2 - Second member
      Returns:
      -1 if m1 collates less than m2, 1 if m1 collates after m2, 0 if m1 == m2.

    • stablePartialSort

      public static <T> List<T> stablePartialSort(List<T> list, Comparator<T> comp, int limit)
      Stable partial sort of a list. Returns the desired head of the list.

    • stablePartialSort

      public static <T> List<T> stablePartialSort(List<T> list, Comparator<T> comp, int limit, int algorithm)
      Stable partial sort of a list, using a specified algorithm.

    • stablePartialSortArray

      public static <T> List<T> stablePartialSortArray(List<T> list, Comparator<T> comp, int limit)
      Partial sort an array by sorting it and returning the first limit elements. Fastest approach if limit is a significant fraction of the list.

    • stablePartialSortMarc

      public static <T> List<T> stablePartialSortMarc(List<T> list, Comparator<T> comp, int limit)
      Marc's original algorithm for stable partial sort of a list. Now superseded by stablePartialSortJulian(java.util.List<T>, java.util.Comparator<T>, int).

    • stablePartialSortJulian

      public static <T> List<T> stablePartialSortJulian(List<T> list, Comparator<T> comp, int limit)
      Julian's algorithm for stable partial sort. Improves Pedro's algorithm by using a heap (priority queue) for the top limit items seen. The items on the priority queue have an ordinal field, so the queue can be used to generate a list of stably sorted items. (Heap sort is not normally stable.)
      Type Parameters:
      T - Element type
      Parameters:
      list - List to sort
      comp - Comparator
      limit - Maximum number of items to return
      Returns:
      Sorted list, containing at most limit items