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/*
* Licensed to Elasticsearch under one or more contributor
* license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright
* ownership. Elasticsearch 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.
*/
package org.elasticsearch.hadoop.util;
import org.elasticsearch.hadoop.EsHadoopIllegalArgumentException;
// taken from org.apache.lucene.util
public abstract class ArrayUtils {
/**
* Returns true if the two specified array slices of bytes are
* equal to one another. Two array slices are considered equal if both
* slices contain the same number of elements, and all corresponding pairs
* of elements in the two slices are equal. In other words, two slices
* are equal if they contain the same elements in the same order. Also,
* two slice references are considered equal if both are null.
*
* Adapted from the JVM runtime's Array.equals for use with array slices.
*
* @param a one array to be tested for equality
* @param b the other array to be tested for equality
* @return true if the two arrays are equal
*/
public static boolean sliceEquals(byte[] a, int offa, int lena, byte[] b, int offb, int lenb) {
if (a==b)
return true;
if (a==null || b==null)
return false;
if (lena > a.length || lenb > b.length) {
throw new ArrayIndexOutOfBoundsException("Given length is greater than array length");
}
if (offa >= a.length || offb >= b.length) {
throw new ArrayIndexOutOfBoundsException("Given offset is is out of bounds");
}
if (offa + lena > a.length || offb + lenb > b.length) {
throw new ArrayIndexOutOfBoundsException("Given offset and length is out of array bounds");
}
if (lenb != lena)
return false;
for (int i=0; i= 0 : "size must be positive (got " + minSize + "): likely integer overflow?";
if (array.length < minSize) {
byte[] newArray = new byte[oversize(minSize, 1)];
System.arraycopy(array, 0, newArray, 0, array.length);
return newArray;
}
else
return array;
}
static int oversize(int minTargetSize, int bytesPerElement) {
if (minTargetSize < 0) {
// catch usage that accidentally overflows int
throw new EsHadoopIllegalArgumentException("invalid array size " + minTargetSize);
}
if (minTargetSize == 0) {
// wait until at least one element is requested
return 0;
}
// asymptotic exponential growth by 1/8th, favors
// spending a bit more CPU to not tie up too much wasted
// RAM:
int extra = minTargetSize >> 3;
if (extra < 3) {
// for very small arrays, where constant overhead of
// realloc is presumably relatively high, we grow
// faster
extra = 3;
}
int newSize = minTargetSize + extra;
// add 7 to allow for worst case byte alignment addition below:
if (newSize + 7 < 0) {
// int overflowed -- return max allowed array size
return Integer.MAX_VALUE;
}
if (Constants.JRE_IS_64BIT) {
// round up to 8 byte alignment in 64bit env
switch (bytesPerElement) {
case 4:
// round up to multiple of 2
return (newSize + 1) & 0x7ffffffe;
case 2:
// round up to multiple of 4
return (newSize + 3) & 0x7ffffffc;
case 1:
// round up to multiple of 8
return (newSize + 7) & 0x7ffffff8;
case 8:
// no rounding
default:
// odd (invalid?) size
return newSize;
}
}
else {
// round up to 4 byte alignment in 64bit env
switch (bytesPerElement) {
case 2:
// round up to multiple of 2
return (newSize + 1) & 0x7ffffffe;
case 1:
// round up to multiple of 4
return (newSize + 3) & 0x7ffffffc;
case 4:
case 8:
// no rounding
default:
// odd (invalid?) size
return newSize;
}
}
}
}