com.facebook.presto.common.array

Class IntBigArrays

java.lang.Object

com.facebook.presto.common.array.IntBigArrays

public class IntBigArrays
extends Object

Method Summary

Modifier and Type	Method and Description
static int	displacement(long index) Computes the displacement associated with a given index.
static int	get(int[][] array, long index) Returns the element of the given big array of specified index.
static void	quickSort(int[][] x, long from, long to, IntComparator comp) Sorts the specified range of elements according to the order induced by the specified comparator using quicksort.
static int	segment(long index) Computes the segment associated with a given index.
static void	set(int[][] array, long index, int value) Sets the element of the given big array of specified index.
static void	swap(int[][] array, long first, long second) Swaps the element of the given big array of specified indices.

Methods inherited from class java.lang.Object

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

Method Detail

segment

public static int segment(long index)

Computes the segment associated with a given index.

Parameters:

index - an index into a big array.

Returns:

the associated segment.

displacement

public static int displacement(long index)

Computes the displacement associated with a given index.

Parameters:

index - an index into a big array.

Returns:

the associated displacement (in the associated segment).

get

public static int get(int[][] array,
                      long index)

Returns the element of the given big array of specified index.

Parameters:

array - a big array.

index - a position in the big array.

Returns:

the element of the big array at the specified position.

set

public static void set(int[][] array,
                       long index,
                       int value)

Sets the element of the given big array of specified index.

Parameters:

array - a big array.

index - a position in the big array.

swap

public static void swap(int[][] array,
                        long first,
                        long second)

Swaps the element of the given big array of specified indices.

Parameters:

array - a big array.

first - a position in the big array.

second - a position in the big array.

quickSort

public static void quickSort(int[][] x,
                             long from,
                             long to,
                             IntComparator comp)

Sorts the specified range of elements according to the order induced by the specified comparator using quicksort.

The sorting algorithm is a tuned quicksort adapted from Jon L. Bentley and M. Douglas McIlroy, “Engineering a Sort Function”, Software: Practice and Experience, 23(11), pages 1249−1265, 1993.

Parameters:

x - the big array to be sorted.

from - the index of the first element (inclusive) to be sorted.

to - the index of the last element (exclusive) to be sorted.

comp - the comparator to determine the sorting order.