Package org.apache.lucene.util
Class ArrayUtil
- java.lang.Object
-
- org.apache.lucene.util.ArrayUtil
-
public final class ArrayUtil extends Object
Methods for manipulating arrays.- NOTE: This API is for internal purposes only and might change in incompatible ways in the next release.
-
-
Constructor Summary
Constructors Constructor Description ArrayUtil()
Deprecated.This constructor was not intended to be public and should not be used.
-
Method Summary
All Methods Static Methods Concrete Methods Modifier and Type Method Description static boolean
equals(char[] left, int offsetLeft, char[] right, int offsetRight, int length)
See if two array slices are the same.static boolean
equals(int[] left, int offsetLeft, int[] right, int offsetRight, int length)
See if two array slices are the same.static int
getShrinkSize(int currentSize, int targetSize, int bytesPerElement)
static boolean[]
grow(boolean[] array)
static boolean[]
grow(boolean[] array, int minSize)
static byte[]
grow(byte[] array)
static byte[]
grow(byte[] array, int minSize)
static char[]
grow(char[] array)
static char[]
grow(char[] array, int minSize)
static double[]
grow(double[] array)
static double[]
grow(double[] array, int minSize)
static float[]
grow(float[] array)
static float[][]
grow(float[][] array)
static float[][]
grow(float[][] array, int minSize)
static float[]
grow(float[] array, int minSize)
static int[]
grow(int[] array)
static int[][]
grow(int[][] array)
static int[][]
grow(int[][] array, int minSize)
static int[]
grow(int[] array, int minSize)
static long[]
grow(long[] array)
static long[]
grow(long[] array, int minSize)
static short[]
grow(short[] array)
static short[]
grow(short[] array, int minSize)
static int
hashCode(byte[] array, int start, int end)
Returns hash of bytes in range start (inclusive) to end (inclusive)static int
hashCode(char[] array, int start, int end)
Returns hash of chars in range start (inclusive) to end (inclusive)static <T extends Comparable<? super T>>
voidinsertionSort(T[] a)
Sorts the given array in natural order.static <T extends Comparable<? super T>>
voidinsertionSort(T[] a, int fromIndex, int toIndex)
Sorts the given array slice in natural order.static <T> void
insertionSort(T[] a, int fromIndex, int toIndex, Comparator<? super T> comp)
Sorts the given array slice using theComparator
.static <T> void
insertionSort(T[] a, Comparator<? super T> comp)
Sorts the given array using theComparator
.static <T extends Comparable<? super T>>
voidmergeSort(T[] a)
Sorts the given array in natural order.static <T extends Comparable<? super T>>
voidmergeSort(T[] a, int fromIndex, int toIndex)
Sorts the given array slice in natural order.static <T> void
mergeSort(T[] a, int fromIndex, int toIndex, Comparator<? super T> comp)
Sorts the given array slice using theComparator
.static <T> void
mergeSort(T[] a, Comparator<? super T> comp)
Sorts the given array using theComparator
.static int
oversize(int minTargetSize, int bytesPerElement)
Returns an array size >= minTargetSize, generally over-allocating exponentially to achieve amortized linear-time cost as the array grows.static int
parseInt(char[] chars)
Parses the string argument as if it was an int value and returns the result.static int
parseInt(char[] chars, int offset, int len)
Parses a char array into an int.static int
parseInt(char[] chars, int offset, int len, int radix)
Parses the string argument as if it was an int value and returns the result.static <T extends Comparable<? super T>>
voidquickSort(T[] a)
Sorts the given array in natural order.static <T extends Comparable<? super T>>
voidquickSort(T[] a, int fromIndex, int toIndex)
Sorts the given array slice in natural order.static <T> void
quickSort(T[] a, int fromIndex, int toIndex, Comparator<? super T> comp)
Sorts the given array slice using theComparator
.static <T> void
quickSort(T[] a, Comparator<? super T> comp)
Sorts the given array using theComparator
.static boolean[]
shrink(boolean[] array, int targetSize)
static byte[]
shrink(byte[] array, int targetSize)
static char[]
shrink(char[] array, int targetSize)
static float[][]
shrink(float[][] array, int targetSize)
static int[][]
shrink(int[][] array, int targetSize)
static int[]
shrink(int[] array, int targetSize)
static long[]
shrink(long[] array, int targetSize)
static short[]
shrink(short[] array, int targetSize)
static int[]
toIntArray(Collection<Integer> ints)
-
-
-
Constructor Detail
-
ArrayUtil
@Deprecated public ArrayUtil()
Deprecated.This constructor was not intended to be public and should not be used. This class contains solely a static utility methods. It will be made private in Lucene 4.0
-
-
Method Detail
-
parseInt
public static int parseInt(char[] chars) throws NumberFormatException
Parses the string argument as if it was an int value and returns the result. Throws NumberFormatException if the string does not represent an int quantity.- Parameters:
chars
- a string representation of an int quantity.- Returns:
- int the value represented by the argument
- Throws:
NumberFormatException
- if the argument could not be parsed as an int quantity.
-
parseInt
public static int parseInt(char[] chars, int offset, int len) throws NumberFormatException
Parses a char array into an int.- Parameters:
chars
- the character arrayoffset
- The offset into the arraylen
- The length- Returns:
- the int
- Throws:
NumberFormatException
- if it can't parse
-
parseInt
public static int parseInt(char[] chars, int offset, int len, int radix) throws NumberFormatException
Parses the string argument as if it was an int value and returns the result. Throws NumberFormatException if the string does not represent an int quantity. The second argument specifies the radix to use when parsing the value.- Parameters:
chars
- a string representation of an int quantity.radix
- the base to use for conversion.- Returns:
- int the value represented by the argument
- Throws:
NumberFormatException
- if the argument could not be parsed as an int quantity.
-
oversize
public static int oversize(int minTargetSize, int bytesPerElement)
Returns an array size >= minTargetSize, generally over-allocating exponentially to achieve amortized linear-time cost as the array grows. NOTE: this was originally borrowed from Python 2.4.2 listobject.c sources (attribution in LICENSE.txt), but has now been substantially changed based on discussions from java-dev thread with subject "Dynamic array reallocation algorithms", started on Jan 12 2010.- Parameters:
minTargetSize
- Minimum required value to be returned.bytesPerElement
- Bytes used by each element of the array. See constants inRamUsageEstimator
.- NOTE: This API is for internal purposes only and might change in incompatible ways in the next release.
-
getShrinkSize
public static int getShrinkSize(int currentSize, int targetSize, int bytesPerElement)
-
grow
public static short[] grow(short[] array, int minSize)
-
grow
public static short[] grow(short[] array)
-
grow
public static float[] grow(float[] array, int minSize)
-
grow
public static float[] grow(float[] array)
-
grow
public static double[] grow(double[] array, int minSize)
-
grow
public static double[] grow(double[] array)
-
shrink
public static short[] shrink(short[] array, int targetSize)
-
grow
public static int[] grow(int[] array, int minSize)
-
grow
public static int[] grow(int[] array)
-
shrink
public static int[] shrink(int[] array, int targetSize)
-
grow
public static long[] grow(long[] array, int minSize)
-
grow
public static long[] grow(long[] array)
-
shrink
public static long[] shrink(long[] array, int targetSize)
-
grow
public static byte[] grow(byte[] array, int minSize)
-
grow
public static byte[] grow(byte[] array)
-
shrink
public static byte[] shrink(byte[] array, int targetSize)
-
grow
public static boolean[] grow(boolean[] array, int minSize)
-
grow
public static boolean[] grow(boolean[] array)
-
shrink
public static boolean[] shrink(boolean[] array, int targetSize)
-
grow
public static char[] grow(char[] array, int minSize)
-
grow
public static char[] grow(char[] array)
-
shrink
public static char[] shrink(char[] array, int targetSize)
-
grow
public static int[][] grow(int[][] array, int minSize)
-
grow
public static int[][] grow(int[][] array)
-
shrink
public static int[][] shrink(int[][] array, int targetSize)
-
grow
public static float[][] grow(float[][] array, int minSize)
-
grow
public static float[][] grow(float[][] array)
-
shrink
public static float[][] shrink(float[][] array, int targetSize)
-
hashCode
public static int hashCode(char[] array, int start, int end)
Returns hash of chars in range start (inclusive) to end (inclusive)
-
hashCode
public static int hashCode(byte[] array, int start, int end)
Returns hash of bytes in range start (inclusive) to end (inclusive)
-
equals
public static boolean equals(char[] left, int offsetLeft, char[] right, int offsetRight, int length)
See if two array slices are the same.- Parameters:
left
- The left array to compareoffsetLeft
- The offset into the array. Must be positiveright
- The right array to compareoffsetRight
- the offset into the right array. Must be positivelength
- The length of the section of the array to compare- Returns:
- true if the two arrays, starting at their respective offsets, are equal
- See Also:
Arrays.equals(char[], char[])
-
equals
public static boolean equals(int[] left, int offsetLeft, int[] right, int offsetRight, int length)
See if two array slices are the same.- Parameters:
left
- The left array to compareoffsetLeft
- The offset into the array. Must be positiveright
- The right array to compareoffsetRight
- the offset into the right array. Must be positivelength
- The length of the section of the array to compare- Returns:
- true if the two arrays, starting at their respective offsets, are equal
- See Also:
Arrays.equals(char[], char[])
-
toIntArray
public static int[] toIntArray(Collection<Integer> ints)
-
quickSort
public static <T> void quickSort(T[] a, int fromIndex, int toIndex, Comparator<? super T> comp)
Sorts the given array slice using theComparator
. This method uses the quick sort algorithm, but falls back to insertion sort for small arrays.- Parameters:
fromIndex
- start index (inclusive)toIndex
- end index (exclusive)
-
quickSort
public static <T> void quickSort(T[] a, Comparator<? super T> comp)
Sorts the given array using theComparator
. This method uses the quick sort algorithm, but falls back to insertion sort for small arrays.
-
quickSort
public static <T extends Comparable<? super T>> void quickSort(T[] a, int fromIndex, int toIndex)
Sorts the given array slice in natural order. This method uses the quick sort algorithm, but falls back to insertion sort for small arrays.- Parameters:
fromIndex
- start index (inclusive)toIndex
- end index (exclusive)
-
quickSort
public static <T extends Comparable<? super T>> void quickSort(T[] a)
Sorts the given array in natural order. This method uses the quick sort algorithm, but falls back to insertion sort for small arrays.
-
mergeSort
public static <T> void mergeSort(T[] a, int fromIndex, int toIndex, Comparator<? super T> comp)
Sorts the given array slice using theComparator
. This method uses the merge sort algorithm, but falls back to insertion sort for small arrays.- Parameters:
fromIndex
- start index (inclusive)toIndex
- end index (exclusive)
-
mergeSort
public static <T> void mergeSort(T[] a, Comparator<? super T> comp)
Sorts the given array using theComparator
. This method uses the merge sort algorithm, but falls back to insertion sort for small arrays.
-
mergeSort
public static <T extends Comparable<? super T>> void mergeSort(T[] a, int fromIndex, int toIndex)
Sorts the given array slice in natural order. This method uses the merge sort algorithm, but falls back to insertion sort for small arrays.- Parameters:
fromIndex
- start index (inclusive)toIndex
- end index (exclusive)
-
mergeSort
public static <T extends Comparable<? super T>> void mergeSort(T[] a)
Sorts the given array in natural order. This method uses the merge sort algorithm, but falls back to insertion sort for small arrays.
-
insertionSort
public static <T> void insertionSort(T[] a, int fromIndex, int toIndex, Comparator<? super T> comp)
Sorts the given array slice using theComparator
. This method uses the insertion sort algorithm. It is only recommended to use this algorithm for partially sorted small arrays!- Parameters:
fromIndex
- start index (inclusive)toIndex
- end index (exclusive)
-
insertionSort
public static <T> void insertionSort(T[] a, Comparator<? super T> comp)
Sorts the given array using theComparator
. This method uses the insertion sort algorithm. It is only recommended to use this algorithm for partially sorted small arrays!
-
insertionSort
public static <T extends Comparable<? super T>> void insertionSort(T[] a, int fromIndex, int toIndex)
Sorts the given array slice in natural order. This method uses the insertion sort algorithm. It is only recommended to use this algorithm for partially sorted small arrays!- Parameters:
fromIndex
- start index (inclusive)toIndex
- end index (exclusive)
-
insertionSort
public static <T extends Comparable<? super T>> void insertionSort(T[] a)
Sorts the given array in natural order. This method uses the insertion sort algorithm. It is only recommended to use this algorithm for partially sorted small arrays!
-
-