/***** BEGIN LICENSE BLOCK *****
 * Version: EPL 1.0/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Eclipse Public
 * License Version 1.0 (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.eclipse.org/legal/epl-v10.html
 *
 * Software distributed under the License is distributed on an "AS
 * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
 * implied. See the License for the specific language governing
 * rights and limitations under the License.
 *
 * Copyright (C) 2007, 2008 Ola Bini <ola@ologix.com>
 * 
 * Alternatively, the contents of this file may be used under the terms of
 * either of the GNU General Public License Version 2 or later (the "GPL"),
 * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the EPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the EPL, the GPL or the LGPL.
 ***** END LICENSE BLOCK *****/
package org.jruby.util;

import java.io.File;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Enumeration;
import java.util.List;
import jnr.posix.POSIX;
import org.jruby.RubyEncoding;
import org.jruby.RubyFile;

import org.jruby.platform.Platform;
import java.io.IOException;

/**
 * This class exists as a counterpart to the dir.c file in 
 * MRI source. It contains many methods useful for 
 * File matching and Globbing.
 *
 * @author <a href="mailto:ola.bini@ki.se">Ola Bini</a>
 */
public class Dir {
    public final static boolean DOSISH = Platform.IS_WINDOWS;
    public final static boolean CASEFOLD_FILESYSTEM = DOSISH;

    public final static int FNM_NOESCAPE = 0x01;
    public final static int FNM_PATHNAME = 0x02;
    public final static int FNM_DOTMATCH = 0x04;
    public final static int FNM_CASEFOLD = 0x08;

    public final static int FNM_SYSCASE = CASEFOLD_FILESYSTEM ? FNM_CASEFOLD : 0;

    public final static int FNM_NOMATCH = 1;
    public final static int FNM_ERROR   = 2;

    public final static byte[] EMPTY = new byte[0];
    public final static byte[] SLASH = new byte[]{'/'};
    public final static byte[] STAR = new byte[]{'*'};
    public final static byte[] DOUBLE_STAR = new byte[]{'*','*'};

    private static boolean isdirsep(byte c) {
        return c == '/' || DOSISH && c == '\\';
    }

    private static int rb_path_next(byte[] _s, int s, int send) {
        while(s < send && !isdirsep(_s[s])) {
            s++;
        }
        return s;
    }

    private static int fnmatch_helper(byte[] bytes, int pstart, int pend, byte[] string, int sstart, int send, int flags) {
        char test;
        int s = sstart;
        int pat = pstart;
        boolean escape = (flags & FNM_NOESCAPE) == 0;
        boolean pathname = (flags & FNM_PATHNAME) != 0;
        boolean period = (flags & FNM_DOTMATCH) == 0;
        boolean nocase = (flags & FNM_CASEFOLD) != 0;

        while(pat<pend) {
            byte c = bytes[pat++];
            switch(c) {
            case '?':
                if(s >= send || (pathname && isdirsep(string[s])) || 
                   (period && string[s] == '.' && (s == 0 || (pathname && isdirsep(string[s-1]))))) {
                    return FNM_NOMATCH;
                }
                s++;
                break;
            case '*':
                while(pat < pend && (c = bytes[pat++]) == '*') {}
                if(s < send && (period && string[s] == '.' && (s == 0 || (pathname && isdirsep(string[s-1]))))) {
                    return FNM_NOMATCH;
                }
                if(pat > pend || (pat == pend && c == '*')) {
                    if(pathname && rb_path_next(string, s, send) < send) {
                        return FNM_NOMATCH;
                    } else {
                        return 0;
                    }
                } else if((pathname && isdirsep(c))) {
                    s = rb_path_next(string, s, send);
                    if(s < send) {
                        s++;
                        break;
                    }
                    return FNM_NOMATCH;
                }
                test = (char)((escape && c == '\\' && pat < pend ? bytes[pat] : c)&0xFF);
                test = Character.toLowerCase(test);
                pat--;
                while(s < send) {
                    if((c == '?' || c == '[' || Character.toLowerCase((char) string[s]) == test) &&
                       fnmatch(bytes, pat, pend, string, s, send, flags | FNM_DOTMATCH) == 0) {
                        return 0;
                    } else if((pathname && isdirsep(string[s]))) {
                        break;
                    }
                    s++;
                }
                return FNM_NOMATCH;
            case '[':
                if(s >= send || (pathname && isdirsep(string[s]) || 
                                 (period && string[s] == '.' && (s == 0 || (pathname && isdirsep(string[s-1])))))) {
                    return FNM_NOMATCH;
                }
                pat = range(bytes, pat, pend, (char)(string[s]&0xFF), flags);
                if(pat == -1) {
                    return FNM_NOMATCH;
                }
                s++;
                break;
            case '\\':
                if (escape) {
                    if (pat >= pend) {
                        c = '\\';
                    } else {
                        c = bytes[pat++];
                    }
                }
            default:
                if(s >= send) {
                    return FNM_NOMATCH;
                }
                if(DOSISH && (pathname && isdirsep(c) && isdirsep(string[s]))) {
                } else {
                    if (nocase) {
                        if(Character.toLowerCase((char)c) != Character.toLowerCase((char)string[s])) {
                            return FNM_NOMATCH;
                        }
                        
                    } else {
                        if(c != (char)string[s]) {
                            return FNM_NOMATCH;
                        }
                    }
                    
                }
                s++;
                break;
            }
        }
        return s >= send ? 0 : FNM_NOMATCH;
    }

    public static int fnmatch(
            byte[] bytes, int pstart, int pend,
            byte[] string, int sstart, int send, int flags) {
        
        // This method handles '**/' patterns and delegates to
        // fnmatch_helper for the main work.

        boolean period = (flags & FNM_DOTMATCH) == 0;
        boolean pathname = (flags & FNM_PATHNAME) != 0;

        int pat_pos = pstart;
        int str_pos = sstart;
        int ptmp = -1;
        int stmp = -1;

        if (pathname) {
            while (true) {
                if (isDoubleStarAndSlash(bytes, pat_pos)) {
                    do { pat_pos += 3; } while (isDoubleStarAndSlash(bytes, pat_pos));
                    ptmp = pat_pos;
                    stmp = str_pos;
                }

                int patSlashIdx = nextSlashIndex(bytes, pat_pos, pend);
                int strSlashIdx = nextSlashIndex(string, str_pos, send);

                if (fnmatch_helper(bytes, pat_pos, patSlashIdx,
                        string, str_pos, strSlashIdx, flags) == 0) {
                    if (patSlashIdx < pend && strSlashIdx < send) {
                        pat_pos = ++patSlashIdx;
                        str_pos = ++strSlashIdx;
                        continue;
                    }
                    if (patSlashIdx == pend && strSlashIdx == send) {
                        return 0;
                    }
                }
                /* failed : try next recursion */
                if (ptmp != -1 && stmp != -1 && !(period && string[stmp] == '.')) {
                    stmp = nextSlashIndex(string, stmp, send);
                    if (stmp < send) {
                        pat_pos = ptmp;
                        stmp++;
                        str_pos = stmp;
                        continue;
                    }
                }
                return FNM_NOMATCH;
            }
        } else {
            return fnmatch_helper(bytes, pstart, pend, string, sstart, send, flags);
        }

    }

    // are we at '**/'
    private static boolean isDoubleStarAndSlash(byte[] bytes, int pos) {
        if ((bytes.length - pos) <= 2) {
            return false; // not enough bytes
        }

        return bytes[pos] == '*'
            && bytes[pos + 1] == '*'
            && bytes[pos + 2] == '/';
    }

    // Look for slash, starting from 'start' position, until 'end'.
    private static int nextSlashIndex(byte[] bytes, int start, int end) {
        int idx = start;
        while (idx < end && idx < bytes.length && bytes[idx] != '/') {
            idx++;
        }
        return idx;
    }

    public static int range(byte[] _pat, int pat, int pend, char test, int flags) {
        boolean not;
        boolean ok = false;
        boolean nocase = (flags & FNM_CASEFOLD) != 0;
        boolean escape = (flags & FNM_NOESCAPE) == 0;

        not = _pat[pat] == '!' || _pat[pat] == '^';
        if(not) {
            pat++;
        }

        if (nocase) {
            test = Character.toLowerCase(test);
        }

        while(_pat[pat] != ']') {
            char cstart, cend;
            if(escape && _pat[pat] == '\\') {
                pat++;
            }
            if(pat >= pend) {
                return -1;
            }
            cstart = cend = (char)(_pat[pat++]&0xFF);
            if(_pat[pat] == '-' && _pat[pat+1] != ']') {
                pat++;
                if(escape && _pat[pat] == '\\') {
                    pat++;
                }
                if(pat >= pend) {
                    return -1;
                }

                cend = (char)(_pat[pat++] & 0xFF);
            }

            if (nocase) {
                if (Character.toLowerCase(cstart) <= test
                        && test <= Character.toLowerCase(cend)) {
                    ok = true;
                }
            } else {
                if (cstart <= test && test <= cend) {
                    ok = true;
                }
            }
        }

        return ok == not ? -1 : pat + 1;
    }

    public static List<ByteList> push_glob(POSIX posix, String cwd, ByteList globByteList, int flags) {
        List<ByteList> result = new ArrayList<ByteList>();
        if (globByteList.length() > 0) {
            push_braces(posix, cwd, result, new GlobPattern(globByteList, flags));
        }

        return result;
    }
    
    private static class GlobPattern {
        final byte[] bytes;        
        final int begin;
        final int end;
        
        int flags;
        int index;

        public GlobPattern(ByteList bytelist, int flags) {
            this(bytelist.getUnsafeBytes(), bytelist.getBegin(),  bytelist.getBegin() + bytelist.getRealSize(), flags);
        }
        
        public GlobPattern(byte[] bytes, int index, int end, int flags) {
            this.bytes = bytes;
            this.index = index;
            this.begin = index;
            this.end = end;
            this.flags = flags;
        }
        
        public int findClosingIndexOf(int leftTokenIndex) {
            if (leftTokenIndex == -1 || leftTokenIndex > end) return -1;
            
            byte leftToken = bytes[leftTokenIndex];
            byte rightToken;
            
            switch (leftToken) {
            case '{': rightToken = '}'; break;
            case '[': rightToken = ']'; break;
            default: return -1;
            }
            
            int nest = 1; // leftToken made us start as nest 1
            index = leftTokenIndex + 1;
            while (hasNext()) {
                byte c = next();
                
                if (c == leftToken) {
                    nest++;
                } else if (c == rightToken && --nest == 0) {
                    return index();
                }
            }
            
            return -1;
        }
        
        public boolean hasNext() {
            return index < end;
        }
        
        public void reset() {
            index = begin;
        }
        
        public void setIndex(int value) {
            index = value;
        }
        
        // Get index of last read byte
        public int index() {
            return index - 1;
        }
        
        public int indexOf(byte c) {
            while (hasNext()) if (next() == c) return index();
            
            return -1;
        }
        
        public byte next() {
            return bytes[index++];
        }

    }

    public static interface GlobFunc {
        int call(byte[] ptr, int p, int len, Object ary);
    }

    private static class GlobArgs {
        GlobFunc func;
        int c = -1;
        List<ByteList> v;
        
        public GlobArgs(GlobFunc func, List<ByteList> arg) {
            this.func = func;
            this.v = arg;
        }
    }

    public final static GlobFunc push_pattern = new GlobFunc() {
            @SuppressWarnings("unchecked")
            public int call(byte[] ptr, int p, int len, Object ary) {
                ((List) ary).add(new ByteList(ptr, p, len));
                return 0;
            }
        };
    public final static GlobFunc glob_caller = new GlobFunc() {
        public int call(byte[] ptr, int p, int len, Object ary) {
            GlobArgs args = (GlobArgs)ary;
            args.c = p;
            return args.func.call(ptr, args.c, len, args.v);
        }
    };

    /*
     * Process {}'s (example: Dir.glob("{jruby,jython}/README*") 
     */
    private static int push_braces(POSIX posix, String cwd, List<ByteList> result, GlobPattern pattern) {
        pattern.reset();
        int lbrace = pattern.indexOf((byte) '{'); // index of left-most brace
        int rbrace = pattern.findClosingIndexOf(lbrace);// index of right-most brace

        // No, mismatched or escaped braces..Move along..nothing to see here
        if (lbrace == -1 || rbrace == -1 || 
                lbrace > 0 && pattern.bytes[lbrace-1] == '\\' || 
                rbrace > 0 && pattern.bytes[rbrace-1] == '\\') {
            ByteList unescaped = new ByteList(pattern.bytes.length-1);
            for (int i = pattern.begin; i < pattern.end; i++) {
                byte b = pattern.bytes[i];
                if (b == '\\' && i < pattern.bytes.length - 1) {
                    byte next_b = pattern.bytes[i + 1];
                    if (next_b != '{' && next_b != '}') {
                        unescaped.append(b);
                    }
                } else {
                    unescaped.append(b);
                }
            }
            return push_globs(posix, cwd, result, unescaped.getUnsafeBytes(), unescaped.begin(), unescaped.length(), pattern.flags);
        }

        // Peel onion...make subpatterns out of outer layer of glob and recall with each subpattern 
        // Example: foo{a{c},b}bar -> fooa{c}bar, foobbar
        ByteList buf = new ByteList(20);
        int middleRegionIndex;
        int i = lbrace;
        while (pattern.bytes[i] != '}') {
            middleRegionIndex = i + 1;
            for(i = middleRegionIndex; i < pattern.end && pattern.bytes[i] != '}' && pattern.bytes[i] != ','; i++) {
                if (pattern.bytes[i] == '{') i = pattern.findClosingIndexOf(i); // skip inner braces
            }

            buf.length(0);
            buf.append(pattern.bytes, pattern.begin, lbrace - pattern.begin);
            buf.append(pattern.bytes, middleRegionIndex, i - middleRegionIndex);
            buf.append(pattern.bytes, rbrace + 1, pattern.end - (rbrace + 1));
            int status = push_braces(posix, cwd, result, new GlobPattern(buf.getUnsafeBytes(), buf.getBegin(), buf.getRealSize(),pattern.flags));
            if(status != 0) return status;
        }
        
        return 0; // All braces pushed..
    }

    private static int push_globs(POSIX posix, String cwd, List<ByteList> ary, byte[] pattern, int pbegin, int pend, int pflags) {
        pflags |= FNM_SYSCASE;
        return glob_helper(posix, cwd, pattern, pbegin, pend, -1, pflags, glob_caller, new GlobArgs(push_pattern, ary));
    }

    private static boolean has_magic(byte[] bytes, int begin, int end, int flags) {
        boolean escape = (flags & FNM_NOESCAPE) == 0;
        boolean nocase = (flags & FNM_CASEFOLD) != 0;
        int open = 0;

        for (int i = begin; i < end; i++) {
            switch(bytes[i]) {
            case '?':
            case '*':
                return true;
            case '[':	/* Only accept an open brace if there is a close */
                open++;	/* brace to match it.  Bracket expressions must be */
                continue;	/* complete, according to Posix.2 */
            case ']':
                if (open > 0) return true;

                continue;
            case '\\':
                if (escape && i == end) return false;

                break;
            default:
                if (FNM_SYSCASE == 0 && nocase && Character.isLetter((char)(bytes[i]&0xFF))) return true;
            }
        }

        return false;
    }

    private static int remove_backslashes(byte[] bytes, int index, int len) {
        int t = index;
        
        for (; index < len; index++, t++) {
            if (bytes[index] == '\\' && ++index == len) break;
            
            bytes[t] = bytes[index];
        }
        
        return t;
    }

    private static int strchr(byte[] bytes, int begin, int end, byte ch) {
        for (int i = begin; i < end; i++) {
            if (bytes[i] == ch) return i;
        }
        
        return -1;
    }

    private static byte[] extract_path(byte[] bytes, int begin, int end) {
        int len = end - begin;
        
        if (len > 1 && bytes[end-1] == '/' && (!DOSISH || (len < 2 || bytes[end-2] != ':'))) len--;

        byte[] alloc = new byte[len];
        System.arraycopy(bytes,begin,alloc,0,len);
        return alloc;
    }

    private static byte[] extract_elem(byte[] bytes, int begin, int end) {
        int elementEnd = strchr(bytes, begin, end, (byte)'/');
        if (elementEnd == -1) elementEnd = end;
        
        return extract_path(bytes, begin, elementEnd);
    }
    
    // Win drive letter X:/
    private static boolean beginsWithDriveLetter(byte[] path, int begin, int end) {
        return DOSISH && begin + 2 < end && path[begin + 1] == ':' && isdirsep(path[begin + 2]); 
    }

    // Is this nothing or literally root directory for the OS.
    private static boolean isRoot(byte[] base) {
        int length = base.length;
        
        return length == 0 ||  // empty
               length == 1 && isdirsep(base[0]) || // Just '/'
               length == 3 && beginsWithDriveLetter(base, 0, length); // Just X:/ 
    }
    
    private static boolean isAbsolutePath(byte[] path, int begin, int length) {
        return isdirsep(path[begin]) || beginsWithDriveLetter(path, begin, length);
    }

    private static String[] files(FileResource directory) {
        String[] files = directory.list();
        
        if (files != null) {
            return files;
        } else {
            return new String[0];
        }
    }

    private static final class DirGlobber {
        public final ByteList link;

        public DirGlobber(ByteList link) {
            this.link = link;
        }
    }

    private static boolean isSpecialFile(String name) {
        int length = name.length();
        
        if (length < 1 || length > 3 || name.charAt(0) != '.') return false;
        if (length == 1) return true;
        char c = name.charAt(1);
        if (length == 2 && (c == '.' || c == '/')) return true;
        return c == '.' && name.charAt(2) == '/';
    }

    private static int addToResultIfExists(POSIX posix, String cwd, byte[] bytes, int begin, int end, int flags, GlobFunc func, GlobArgs arg) {
        String fileName = newStringFromUTF8(bytes, begin, end - begin);
        FileResource file = JRubyFile.createResource(posix, cwd, fileName);

        if (file.exists()) {
            boolean trailingSlash = bytes[end - 1] == '/';

            // On case-insenstive file systems any case string will 'exists',
            // but what does it display as if you ls/dir it?
            /* No idea what this is doing =/
             
              if ((flags & FNM_CASEFOLD) != 0 && !isSpecialFile(fileName)) {
                try {
                    String realName = file.getCanonicalFile().getName();

                    // TODO: This is only being done to the name of the file,
                    // but it should do for all parent directories too...
                    // TODO: OMGZ is this ugly
                    int fileNameLength = fileName.length();
                    int newEnd = fileNameLength <= 1 ? -1 : fileName.lastIndexOf('/', fileNameLength - 2);
                    if (newEnd != -1) {
                        realName = fileName.substring(0, newEnd + 1) + realName;
                    }
                    // It came in with a trailing slash preserve that in new name.
                    if (trailingSlash) realName = realName + "/";

                    bytes = realName.getBytes();
                    begin = 0;
                    end = bytes.length;
                } catch (Exception e) {} // Failure will just use what we pass in
            }*/
            
            return func.call(bytes, begin, end - begin, arg);
        }

        return 0;
    }

    private static int glob_helper(POSIX posix, String cwd, byte[] bytes, int begin, int end, int sub, int flags, GlobFunc func, GlobArgs arg) {
        int p,m;
        int status = 0;
        byte[] newpath = null;
        FileResource st;
        p = sub != -1 ? sub : begin;

        if (!has_magic(bytes, p, end, flags)) {
            if (DOSISH || (flags & FNM_NOESCAPE) == 0) {
                newpath = new byte[end];
                System.arraycopy(bytes,0,newpath,0,end);
                if (sub != -1) {
                    p = (sub - begin);
                    end = remove_backslashes(newpath, p, end);
                    sub = p;
                } else {
                    end = remove_backslashes(newpath, 0, end);
                    bytes = newpath;
                }
            }

            if (isAbsolutePath(bytes, begin, end)) {
                status = addToResultIfExists(posix, null, bytes, begin, end, flags, func, arg);
            } else if ((end - begin) > 0) { // Length check is a hack.  We should not be reeiving "" as a filename ever.
                status = addToResultIfExists(posix, cwd, bytes, begin, end, flags, func, arg);
            }

            return status;
        }
        
        ByteList buf = new ByteList(20);
        List<DirGlobber> link = new ArrayList<DirGlobber>();
        mainLoop: while(p != -1 && status == 0) {
            if (bytes[p] == '/') p++;

            m = strchr(bytes, p, end, (byte)'/');
            if(has_magic(bytes, p, m == -1 ? end : m, flags)) {
                finalize: do {
                    byte[] base = extract_path(bytes, begin, p);
                    byte[] dir = begin == p ? new byte[]{'.'} : base; 
                    byte[] magic = extract_elem(bytes,p,end);
                    boolean recursive = false;

                    st = JRubyFile.createResource(posix, cwd, newStringFromUTF8(dir));

                    if (st.isDirectory()) {
                        if(m != -1 && Arrays.equals(magic, DOUBLE_STAR)) {
                            int n = base.length;
                            recursive = true;
                            buf.length(0);
                            buf.append(base);
                            buf.append(bytes, (base.length > 0 ? m : m + 1), end - (base.length > 0 ? m : m + 1));
                            status = glob_helper(posix, cwd, buf.getUnsafeBytes(), buf.getBegin(), buf.getRealSize(), n, flags, func, arg);
                            if(status != 0) {
                                break finalize;
                            }
                        }
                    } else {
                        break mainLoop;
                    }

                    String[] dirp = files(st);

                    for(int i=0;i<dirp.length;i++) {
                        if(recursive) {
                            byte[] bs = getBytesInUTF8(dirp[i]);
                            if (fnmatch(STAR,0,1,bs,0,bs.length,flags) != 0) {
                                continue;
                            }
                            buf.length(0);
                            buf.append(base);
                            buf.append(isRoot(base) ? EMPTY : SLASH );
                            buf.append(getBytesInUTF8(dirp[i]));
                            st = JRubyFile.createResource(posix, cwd, newStringFromUTF8(buf.getUnsafeBytes(), buf.getBegin(), buf.getRealSize()));
                            if(!st.isSymLink() && st.isDirectory() && !".".equals(dirp[i]) && !"..".equals(dirp[i])) {
                                int t = buf.getRealSize();
                                buf.append(SLASH);
                                buf.append(DOUBLE_STAR);
                                buf.append(bytes, m, end - m);
                                status = glob_helper(posix, cwd, buf.getUnsafeBytes(), buf.getBegin(), buf.getRealSize(), t, flags, func, arg);
                                if(status != 0) {
                                    break;
                                }
                            }
                            continue;
                        }
                        byte[] bs = getBytesInUTF8(dirp[i]);
                        if(fnmatch(magic,0,magic.length,bs,0, bs.length,flags) == 0) {
                            buf.length(0);
                            buf.append(base);
                            buf.append(isRoot(base) ? EMPTY : SLASH );
                            buf.append(getBytesInUTF8(dirp[i]));
                            if(m == -1) {
                                status = func.call(buf.getUnsafeBytes(),0, buf.getRealSize(),arg);
                                if(status != 0) {
                                    break;
                                }
                                continue;
                            }
                            link.add(new DirGlobber(buf));
                            buf = new ByteList(20);
                        }
                    }
                } while(false);

                if (link.size() > 0) {
                    for (DirGlobber globber : link) {
                        ByteList b = globber.link;
                        if (status == 0) {
                            st = JRubyFile.createResource(posix, cwd, newStringFromUTF8(b.getUnsafeBytes(), 0, b.getRealSize()));
                            if(st.isDirectory()) {
                                int len = b.getRealSize();
                                buf.length(0);
                                buf.append(b);
                                buf.append(bytes, m, end - m);
                                status = glob_helper(posix, cwd, buf.getUnsafeBytes(),0, buf.getRealSize(),len,flags,func,arg);
                            }
                        }
                    }
                    break mainLoop;
                }
            }
            p = m;
        }
        return status;
    }

    private static ByteList fixBytesForJarInUTF8(byte[] buf, int offset, int len) {
        String path = newStringFromUTF8(buf, offset, len);
        path = path.replace(".jar/", ".jar!");
        return new ByteList(path.getBytes());
    }

    private static byte[] getBytesInUTF8(String s) {
        return RubyEncoding.encodeUTF8(s);
    }

    private static String newStringFromUTF8(byte[] buf, int offset, int len) {
        return RubyEncoding.decodeUTF8(buf, offset, len);
    }

    private static String newStringFromUTF8(byte[] buf) {
        return RubyEncoding.decodeUTF8(buf);
    }
}
