/*
 * Copyright (c) 2009, 2013, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

package sun.nio.fs;

import java.util.*;
import java.nio.file.*;
import java.nio.charset.Charset;
import sun.security.action.GetPropertyAction;

Utility methods
/**
 * Utility methods
 */

class Util {
    private Util() { }

    private static final Charset jnuEncoding = Charset.forName(
        GetPropertyAction.privilegedGetProperty("sun.jnu.encoding"));

    
Returns Charset corresponding to the sun.jnu.encoding property /**
     * Returns {@code Charset} corresponding to the sun.jnu.encoding property
     */
    static Charset jnuEncoding() {
        return jnuEncoding;
    }

    
Encodes the given String into a sequence of bytes using the Charset specified by the sun.jnu.encoding property. /**
     * Encodes the given String into a sequence of bytes using the {@code Charset}
     * specified by the sun.jnu.encoding property.
     */
    static byte[] toBytes(String s) {
        return s.getBytes(jnuEncoding);
    }

    
Constructs a new String by decoding the specified array of bytes using the Charset specified by the sun.jnu.encoding property. /**
     * Constructs a new String by decoding the specified array of bytes using the
     * {@code Charset} specified by the sun.jnu.encoding property.
     */
    static String toString(byte[] bytes) {
        return new String(bytes, jnuEncoding);
    }


    
Splits a string around the given character. The array returned by this
method contains each substring that is terminated by the character. Use
for simple string spilting cases when needing to avoid loading regex.
/**
     * Splits a string around the given character. The array returned by this
     * method contains each substring that is terminated by the character. Use
     * for simple string spilting cases when needing to avoid loading regex.
     */
    static String[] split(String s, char c) {
        int count = 0;
        for (int i=0; i<s.length(); i++) {
            if (s.charAt(i) == c)
                count++;
        }
        String[] result = new String[count+1];
        int n = 0;
        int last = 0;
        for (int i=0; i<s.length(); i++) {
            if (s.charAt(i) == c) {
                result[n++] = s.substring(last, i);
                last = i + 1;
            }
        }
        result[n] = s.substring(last, s.length());
        return result;
    }

    
Returns a Set containing the given elements.
/**
     * Returns a Set containing the given elements.
     */
    @SafeVarargs
    static <E> Set<E> newSet(E... elements) {
        HashSet<E> set = new HashSet<>();
        for (E e: elements) {
            set.add(e);
        }
        return set;
    }

    
Returns a Set containing all the elements of the given Set plus
the given elements.
/**
     * Returns a Set containing all the elements of the given Set plus
     * the given elements.
     */
    @SafeVarargs
    static <E> Set<E> newSet(Set<E> other, E... elements) {
        HashSet<E> set = new HashSet<>(other);
        for (E e: elements) {
            set.add(e);
        }
        return set;
    }

    
Returns true if symbolic links should be followed /**
     * Returns {@code true} if symbolic links should be followed
     */
    static boolean followLinks(LinkOption... options) {
        boolean followLinks = true;
        for (LinkOption option: options) {
            if (option == LinkOption.NOFOLLOW_LINKS) {
                followLinks = false;
            } else if (option == null) {
                throw new NullPointerException();
            } else {
                throw new AssertionError("Should not get here");
            }
        }
        return followLinks;
    }
}