/*
 * Copyright (c) 1997, 2018 Oracle and/or its affiliates. All rights reserved.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Distribution License v. 1.0, which is available at
 * http://www.eclipse.org/org/documents/edl-v10.php.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */

/* FROM mail.jar */
package org.jvnet.mimepull;

final class ASCIIUtility {

    // Private constructor so that this class is not instantiated
    private ASCIIUtility() { }
	
    
Convert the bytes within the specified range of the given byte 
array into a signed integer in the given radix . The range extends 
from start till, but not including end. 

Based on java.lang.Integer.parseInt()
/**
     * Convert the bytes within the specified range of the given byte 
     * array into a signed integer in the given radix . The range extends 
     * from <code>start</code> till, but not including <code>end</code>. <p>
     *
     * Based on java.lang.Integer.parseInt()
     */
    public static int parseInt(byte[] b, int start, int end, int radix)
		throws NumberFormatException {
	if (b == null) {
            throw new NumberFormatException("null");
        }
	
	int result = 0;
	boolean negative = false;
	int i = start;
	int limit;
	int multmin;
	int digit;

	if (end > start) {
	    if (b[i] == '-') {
		negative = true;
		limit = Integer.MIN_VALUE;
		i++;
	    } else {
		limit = -Integer.MAX_VALUE;
	    }
	    multmin = limit / radix;
	    if (i < end) {
		digit = Character.digit((char)b[i++], radix);
		if (digit < 0) {
		    throw new NumberFormatException(
			"illegal number: " + toString(b, start, end)
			);
		} else {
		    result = -digit;
		}
	    }
	    while (i < end) {
		// Accumulating negatively avoids surprises near MAX_VALUE
		digit = Character.digit((char)b[i++], radix);
		if (digit < 0) {
		    throw new NumberFormatException("illegal number");
		}
		if (result < multmin) {
		    throw new NumberFormatException("illegal number");
		}
		result *= radix;
		if (result < limit + digit) {
		    throw new NumberFormatException("illegal number");
		}
		result -= digit;
	    }
	} else {
	    throw new NumberFormatException("illegal number");
	}
	if (negative) {
	    if (i > start + 1) {
		return result;
	    } else {	/* Only got "-" */
		throw new NumberFormatException("illegal number");
	    }
	} else {
	    return -result;
	}
    }

    
Convert the bytes within the specified range of the given byte 
array into a String. The range extends from start
till, but not including end. 

/**
     * Convert the bytes within the specified range of the given byte 
     * array into a String. The range extends from <code>start</code>
     * till, but not including <code>end</code>. <p>
     */
    public static String toString(byte[] b, int start, int end) {
	int size = end - start;
	char[] theChars = new char[size];

	for (int i = 0, j = start; i < size; ) {
            theChars[i++] = (char)(b[j++]&0xff);
        }
	
	return new String(theChars);
    }

}