/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
using System;
namespace Lucene.Net.Util
{
/// Methods for manipulating arrays.
public sealed class ArrayUtil
{
/*
Begin Apache Harmony code
Revision taken on Friday, June 12. https://svn.apache.org/repos/asf/harmony/enhanced/classlib/archive/java6/modules/luni/src/main/java/java/lang/Integer.java
*/
/// 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.
///
///
/// a string representation of an int quantity.
///
/// int the value represented by the argument
///
/// NumberFormatException if the argument could not be parsed as an int quantity.
public static int ParseInt(char[] chars)
{
return ParseInt(chars, 0, chars.Length, 10);
}
/// Parses a char array into an int.
/// the character array
///
/// The offset into the array
///
/// The length
///
/// the int
///
/// NumberFormatException if it can't parse
public static int ParseInt(char[] chars, int offset, int len)
{
return ParseInt(chars, offset, len, 10);
}
/// 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.
///
///
/// a string representation of an int quantity.
///
/// the base to use for conversion.
///
/// int the value represented by the argument
///
/// NumberFormatException if the argument could not be parsed as an int quantity.
public static int ParseInt(char[] chars, int offset, int len, int radix)
{
if (chars == null || radix < 2 || radix > 36)
{
throw new System.FormatException();
}
int i = 0;
if (len == 0)
{
throw new System.FormatException("chars length is 0");
}
bool negative = chars[offset + i] == '-';
if (negative && ++i == len)
{
throw new System.FormatException("can't convert to an int");
}
if (negative == true)
{
offset++;
len--;
}
return Parse(chars, offset, len, radix, negative);
}
private static int Parse(char[] chars, int offset, int len, int radix, bool negative)
{
int max = System.Int32.MinValue / radix;
int result = 0;
for (int i = 0; i < len; i++)
{
int digit = (int) System.Char.GetNumericValue(chars[i + offset]);
if (digit == - 1)
{
throw new System.FormatException("Unable to parse");
}
if (max > result)
{
throw new System.FormatException("Unable to parse");
}
int next = result * radix - digit;
if (next > result)
{
throw new System.FormatException("Unable to parse");
}
result = next;
}
/*while (offset < len) {
}*/
if (!negative)
{
result = - result;
if (result < 0)
{
throw new System.FormatException("Unable to parse");
}
}
return result;
}
/*
END APACHE HARMONY CODE
*/
public static int GetNextSize(int targetSize)
{
/* This over-allocates proportional to the list size, making room
* for additional growth. The over-allocation is mild, but is
* enough to give linear-time amortized behavior over a long
* sequence of appends() in the presence of a poorly-performing
* system realloc().
* The growth pattern is: 0, 4, 8, 16, 25, 35, 46, 58, 72, 88, ...
*/
return (targetSize >> 3) + (targetSize < 9?3:6) + targetSize;
}
public static int GetShrinkSize(int currentSize, int targetSize)
{
int newSize = GetNextSize(targetSize);
// Only reallocate if we are "substantially" smaller.
// This saves us from "running hot" (constantly making a
// bit bigger then a bit smaller, over and over):
if (newSize < currentSize / 2)
return newSize;
else
return currentSize;
}
public static int[] Grow(int[] array, int minSize)
{
if (array.Length < minSize)
{
int[] newArray = new int[GetNextSize(minSize)];
Array.Copy(array, 0, newArray, 0, array.Length);
return newArray;
}
else
return array;
}
public static int[] Grow(int[] array)
{
return Grow(array, 1 + array.Length);
}
public static int[] Shrink(int[] array, int targetSize)
{
int newSize = GetShrinkSize(array.Length, targetSize);
if (newSize != array.Length)
{
int[] newArray = new int[newSize];
Array.Copy(array, 0, newArray, 0, newSize);
return newArray;
}
else
return array;
}
public static long[] Grow(long[] array, int minSize)
{
if (array.Length < minSize)
{
long[] newArray = new long[GetNextSize(minSize)];
Array.Copy(array, 0, newArray, 0, array.Length);
return newArray;
}
else
return array;
}
public static long[] Grow(long[] array)
{
return Grow(array, 1 + array.Length);
}
public static long[] Shrink(long[] array, int targetSize)
{
int newSize = GetShrinkSize(array.Length, targetSize);
if (newSize != array.Length)
{
long[] newArray = new long[newSize];
Array.Copy(array, 0, newArray, 0, newSize);
return newArray;
}
else
return array;
}
public static byte[] Grow(byte[] array, int minSize)
{
if (array.Length < minSize)
{
byte[] newArray = new byte[GetNextSize(minSize)];
Array.Copy(array, 0, newArray, 0, array.Length);
return newArray;
}
else
return array;
}
public static byte[] Grow(byte[] array)
{
return Grow(array, 1 + array.Length);
}
public static byte[] Shrink(byte[] array, int targetSize)
{
int newSize = GetShrinkSize(array.Length, targetSize);
if (newSize != array.Length)
{
byte[] newArray = new byte[newSize];
Array.Copy(array, 0, newArray, 0, newSize);
return newArray;
}
else
return array;
}
/// Returns hash of chars in range start (inclusive) to
/// end (inclusive)
///
public static int HashCode(char[] array, int start, int end)
{
int code = 0;
for (int i = end - 1; i >= start; i--)
code = code * 31 + array[i];
return code;
}
/// Returns hash of chars in range start (inclusive) to
/// end (inclusive)
///
public static int HashCode(byte[] array, int start, int end)
{
int code = 0;
for (int i = end - 1; i >= start; i--)
code = code * 31 + array[i];
return code;
}
}
}