src/hotspot/share/utilities/utf8.cpp - platform/libcore - Gitiles

 /*
  * Copyright (c) 1997, 2016, 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.
  *
  * 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.
  *
  */

 #include "precompiled.hpp"
 #include "utilities/utf8.hpp"

 // Assume the utf8 string is in legal form and has been
 // checked in the class file parser/format checker.
 template<typename T> char* UTF8::next(const char* str, T* value) {
   unsigned const char *ptr = (const unsigned char *)str;
   unsigned char ch, ch2, ch3;
   int length = -1;              /* bad length */
   jchar result;
   switch ((ch = ptr[0]) >> 4) {
     default:
     result = ch;
     length = 1;
     break;

   case 0x8: case 0x9: case 0xA: case 0xB: case 0xF:
     /* Shouldn't happen. */
     break;

   case 0xC: case 0xD:
     /* 110xxxxx  10xxxxxx */
     if (((ch2 = ptr[1]) & 0xC0) == 0x80) {
       unsigned char high_five = ch & 0x1F;
       unsigned char low_six = ch2 & 0x3F;
       result = (high_five << 6) + low_six;
       length = 2;
       break;
     }
     break;

   case 0xE:
     /* 1110xxxx 10xxxxxx 10xxxxxx */
     if (((ch2 = ptr[1]) & 0xC0) == 0x80) {
       if (((ch3 = ptr[2]) & 0xC0) == 0x80) {
         unsigned char high_four = ch & 0x0f;
         unsigned char mid_six = ch2 & 0x3f;
         unsigned char low_six = ch3 & 0x3f;
         result = (((high_four << 6) + mid_six) << 6) + low_six;
         length = 3;
       }
     }
     break;
   } /* end of switch */

   if (length <= 0) {
     *value = (T)ptr[0];    /* default bad result; */
     return (char*)(ptr + 1); // make progress somehow
   }

   *value = (T)result;

   // The assert is correct but the .class file is wrong
   // assert(UNICODE::utf8_size(result) == length, "checking reverse computation");
   return (char *)(ptr + length);
 }

 char* UTF8::next_character(const char* str, jint* value) {
   unsigned const char *ptr = (const unsigned char *)str;
   /* See if it's legal supplementary character:
      11101101 1010xxxx 10xxxxxx 11101101 1011xxxx 10xxxxxx */
   if (is_supplementary_character(ptr)) {
     *value = get_supplementary_character(ptr);
     return (char *)(ptr + 6);
   }
   jchar result;
   char* next_ch = next(str, &result);
   *value = result;
   return next_ch;
 }

 // Count bytes of the form 10xxxxxx and deduct this count
 // from the total byte count.  The utf8 string must be in
 // legal form which has been verified in the format checker.
 int UTF8::unicode_length(const char* str, int len, bool& is_latin1, bool& has_multibyte) {
   int num_chars = len;
   has_multibyte = false;
   is_latin1 = true;
   unsigned char prev = 0;
   for (int i = 0; i < len; i++) {
     unsigned char c = str[i];
     if ((c & 0xC0) == 0x80) {
       // Multibyte, check if valid latin1 character.
       has_multibyte = true;
       if (prev > 0xC3) {
         is_latin1 = false;
       }
       --num_chars;
     }
     prev = c;
   }
   return num_chars;
 }

 // Count bytes of the utf8 string except those in form
 // 10xxxxxx which only appear in multibyte characters.
 // The utf8 string must be in legal form and has been
 // verified in the format checker.
 int UTF8::unicode_length(const char* str, bool& is_latin1, bool& has_multibyte) {
   int num_chars = 0;
   has_multibyte = false;
   is_latin1 = true;
   unsigned char prev = 0;
   for (const char* p = str; *p; p++) {
     unsigned char c = (*p);
     if ((c & 0xC0) == 0x80) {
       // Multibyte, check if valid latin1 character.
       has_multibyte = true;
       if (prev > 0xC3) {
         is_latin1 = false;
       }
     } else {
       num_chars++;
     }
     prev = c;
   }
   return num_chars;
 }

 // Writes a jchar as utf8 and returns the end
 static u_char* utf8_write(u_char* base, jchar ch) {
   if ((ch != 0) && (ch <=0x7f)) {
     base[0] = (u_char) ch;
     return base + 1;
   }

   if (ch <= 0x7FF) {
     /* 11 bits or less. */
     unsigned char high_five = ch >> 6;
     unsigned char low_six = ch & 0x3F;
     base[0] = high_five | 0xC0; /* 110xxxxx */
     base[1] = low_six | 0x80;   /* 10xxxxxx */
     return base + 2;
   }
   /* possibly full 16 bits. */
   char high_four = ch >> 12;
   char mid_six = (ch >> 6) & 0x3F;
   char low_six = ch & 0x3f;
   base[0] = high_four | 0xE0; /* 1110xxxx */
   base[1] = mid_six | 0x80;   /* 10xxxxxx */
   base[2] = low_six | 0x80;   /* 10xxxxxx */
   return base + 3;
 }

 template<typename T> void UTF8::convert_to_unicode(const char* utf8_str, T* unicode_str, int unicode_length) {
   unsigned char ch;
   const char *ptr = utf8_str;
   int index = 0;

   /* ASCII case loop optimization */
   for (; index < unicode_length; index++) {
     if((ch = ptr[0]) > 0x7F) { break; }
     unicode_str[index] = (T)ch;
     ptr = (const char *)(ptr + 1);
   }

   for (; index < unicode_length; index++) {
     ptr = UTF8::next(ptr, &unicode_str[index]);
   }
 }

 // Explicit instantiation for all supported string types.
 template char* UTF8::next<jchar>(const char* str, jchar* value);
 template char* UTF8::next<jbyte>(const char* str, jbyte* value);
 template void UTF8::convert_to_unicode<jchar>(const char* utf8_str, jchar* unicode_str, int unicode_length);
 template void UTF8::convert_to_unicode<jbyte>(const char* utf8_str, jbyte* unicode_str, int unicode_length);

 // returns the quoted ascii length of a 0-terminated utf8 string
 int UTF8::quoted_ascii_length(const char* utf8_str, int utf8_length) {
   const char *ptr = utf8_str;
   const char* end = ptr + utf8_length;
   int result = 0;
   while (ptr < end) {
     jchar c;
     ptr = UTF8::next(ptr, &c);
     if (c >= 32 && c < 127) {
       result++;
     } else {
       result += 6;
     }
   }
   return result;
 }

 // converts a utf8 string to quoted ascii
 void UTF8::as_quoted_ascii(const char* utf8_str, int utf8_length, char* buf, int buflen) {
   const char *ptr = utf8_str;
   const char *utf8_end = ptr + utf8_length;
   char* p = buf;
   char* end = buf + buflen;
   while (ptr < utf8_end) {
     jchar c;
     ptr = UTF8::next(ptr, &c);
     if (c >= 32 && c < 127) {
       if (p + 1 >= end) break;      // string is truncated
       *p++ = (char)c;
     } else {
       if (p + 6 >= end) break;      // string is truncated
       sprintf(p, "\\u%04x", c);
       p += 6;
     }
   }
   assert(p < end, "sanity");
   *p = '\0';
 }


 const char* UTF8::from_quoted_ascii(const char* quoted_ascii_str) {
   const char *ptr = quoted_ascii_str;
   char* result = NULL;
   while (*ptr != '\0') {
     char c = *ptr;
     if (c < 32 || c >= 127) break;
   }
   if (*ptr == '\0') {
     // nothing to do so return original string
     return quoted_ascii_str;
   }
   // everything up to this point was ok.
   int length = ptr - quoted_ascii_str;
   char* buffer = NULL;
   for (int round = 0; round < 2; round++) {
     while (*ptr != '\0') {
       if (*ptr != '\\') {
         if (buffer != NULL) {
           buffer[length] = *ptr;
         }
         length++;
       } else {
         switch (ptr[1]) {
           case 'u': {
             ptr += 2;
             jchar value=0;
             for (int i=0; i<4; i++) {
               char c = *ptr++;
               switch (c) {
                 case '0': case '1': case '2': case '3': case '4':
                 case '5': case '6': case '7': case '8': case '9':
                   value = (value << 4) + c - '0';
                   break;
                 case 'a': case 'b': case 'c':
                 case 'd': case 'e': case 'f':
                   value = (value << 4) + 10 + c - 'a';
                   break;
                 case 'A': case 'B': case 'C':
                 case 'D': case 'E': case 'F':
                   value = (value << 4) + 10 + c - 'A';
                   break;
                 default:
                   ShouldNotReachHere();
               }
             }
             if (buffer == NULL) {
               char utf8_buffer[4];
               char* next = (char*)utf8_write((u_char*)utf8_buffer, value);
               length += next - utf8_buffer;
             } else {
               char* next = (char*)utf8_write((u_char*)&buffer[length], value);
               length += next - &buffer[length];
             }
             break;
           }
           case 't': if (buffer != NULL) buffer[length] = '\t'; ptr += 2; length++; break;
           case 'n': if (buffer != NULL) buffer[length] = '\n'; ptr += 2; length++; break;
           case 'r': if (buffer != NULL) buffer[length] = '\r'; ptr += 2; length++; break;
           case 'f': if (buffer != NULL) buffer[length] = '\f'; ptr += 2; length++; break;
           default:
             ShouldNotReachHere();
         }
       }
     }
     if (round == 0) {
       buffer = NEW_RESOURCE_ARRAY(char, length + 1);
       ptr = quoted_ascii_str;
     } else {
       buffer[length] = '\0';
     }
   }
   return buffer;
 }


 // Returns NULL if 'c' it not found. This only works as long
 // as 'c' is an ASCII character
 const jbyte* UTF8::strrchr(const jbyte* base, int length, jbyte c) {
   assert(length >= 0, "sanity check");
   assert(c >= 0, "does not work for non-ASCII characters");
   // Skip backwards in string until 'c' is found or end is reached
   while(--length >= 0 && base[length] != c);
   return (length < 0) ? NULL : &base[length];
 }

 bool UTF8::equal(const jbyte* base1, int length1, const jbyte* base2, int length2) {
   // Length must be the same
   if (length1 != length2) return false;
   for (int i = 0; i < length1; i++) {
     if (base1[i] != base2[i]) return false;
   }
   return true;
 }

 bool UTF8::is_supplementary_character(const unsigned char* str) {
   return ((str[0] & 0xFF) == 0xED) && ((str[1] & 0xF0) == 0xA0) && ((str[2] & 0xC0) == 0x80)
       && ((str[3] & 0xFF) == 0xED) && ((str[4] & 0xF0) == 0xB0) && ((str[5] & 0xC0) == 0x80);
 }

 jint UTF8::get_supplementary_character(const unsigned char* str) {
   return 0x10000 + ((str[1] & 0x0f) << 16) + ((str[2] & 0x3f) << 10)
                  + ((str[4] & 0x0f) << 6)  + (str[5] & 0x3f);
 }

 bool UTF8::is_legal_utf8(const unsigned char* buffer, int length,
                          bool version_leq_47) {
   int i = 0;
   int count = length >> 2;
   for (int k=0; k<count; k++) {
     unsigned char b0 = buffer[i];
     unsigned char b1 = buffer[i+1];
     unsigned char b2 = buffer[i+2];
     unsigned char b3 = buffer[i+3];
     // For an unsigned char v,
     // (v | v - 1) is < 128 (highest bit 0) for 0 < v < 128;
     // (v | v - 1) is >= 128 (highest bit 1) for v == 0 or v >= 128.
     unsigned char res = b0 | b0 - 1 |
                         b1 | b1 - 1 |
                         b2 | b2 - 1 |
                         b3 | b3 - 1;
     if (res >= 128) break;
     i += 4;
   }
   for(; i < length; i++) {
     unsigned short c;
     // no embedded zeros
     if (buffer[i] == 0) return false;
     if(buffer[i] < 128) {
       continue;
     }
     if ((i + 5) < length) { // see if it's legal supplementary character
       if (UTF8::is_supplementary_character(&buffer[i])) {
         c = UTF8::get_supplementary_character(&buffer[i]);
         i += 5;
         continue;
       }
     }
     switch (buffer[i] >> 4) {
       default: break;
       case 0x8: case 0x9: case 0xA: case 0xB: case 0xF:
         return false;
       case 0xC: case 0xD:  // 110xxxxx  10xxxxxx
         c = (buffer[i] & 0x1F) << 6;
         i++;
         if ((i < length) && ((buffer[i] & 0xC0) == 0x80)) {
           c += buffer[i] & 0x3F;
           if (version_leq_47 || c == 0 || c >= 0x80) {
             break;
           }
         }
         return false;
       case 0xE:  // 1110xxxx 10xxxxxx 10xxxxxx
         c = (buffer[i] & 0xF) << 12;
         i += 2;
         if ((i < length) && ((buffer[i-1] & 0xC0) == 0x80) && ((buffer[i] & 0xC0) == 0x80)) {
           c += ((buffer[i-1] & 0x3F) << 6) + (buffer[i] & 0x3F);
           if (version_leq_47 || c >= 0x800) {
             break;
           }
         }
         return false;
     }  // end of switch
   } // end of for
   return true;
 }

 //-------------------------------------------------------------------------------------

 bool UNICODE::is_latin1(jchar c) {
   return (c <= 0x00FF);
 }

 bool UNICODE::is_latin1(jchar* base, int length) {
   for (int index = 0; index < length; index++) {
     if (base[index] > 0x00FF) {
       return false;
     }
   }
   return true;
 }

 int UNICODE::utf8_size(jchar c) {
   if ((0x0001 <= c) && (c <= 0x007F)) {
     // ASCII character
     return 1;
   } else  if (c <= 0x07FF) {
     return 2;
   } else {
     return 3;
   }
 }

 int UNICODE::utf8_size(jbyte c) {
   if (c >= 0x01) {
     // ASCII character. Check is equivalent to
     // (0x01 <= c) && (c <= 0x7F) because c is signed.
     return 1;
   } else {
     // Non-ASCII character or 0x00 which needs to be
     // two-byte encoded as 0xC080 in modified UTF-8.
     return 2;
   }
 }

 template<typename T>
 int UNICODE::utf8_length(T* base, int length) {
   int result = 0;
   for (int index = 0; index < length; index++) {
     T c = base[index];
     result += utf8_size(c);
   }
   return result;
 }

 template<typename T>
 char* UNICODE::as_utf8(T* base, int& length) {
   int utf8_len = utf8_length(base, length);
   u_char* buf = NEW_RESOURCE_ARRAY(u_char, utf8_len + 1);
   char* result = as_utf8(base, length, (char*) buf, utf8_len + 1);
   assert((int) strlen(result) == utf8_len, "length prediction must be correct");
   // Set string length to uft8 length
   length = utf8_len;
   return (char*) result;
 }

 char* UNICODE::as_utf8(jchar* base, int length, char* buf, int buflen) {
   u_char* p = (u_char*)buf;
   for (int index = 0; index < length; index++) {
     jchar c = base[index];
     buflen -= utf8_size(c);
     if (buflen <= 0) break; // string is truncated
     p = utf8_write(p, c);
   }
   *p = '\0';
   return buf;
 }

 char* UNICODE::as_utf8(jbyte* base, int length, char* buf, int buflen) {
   u_char* p = (u_char*)buf;
   u_char* end = (u_char*)buf + buflen;
   for (int index = 0; index < length; index++) {
     jbyte c = base[index];
     int sz = utf8_size(c);
     buflen -= sz;
     if (buflen <= 0) break; // string is truncated
     if (sz == 1) {
       // Copy ASCII characters (UTF-8 is ASCII compatible)
       *p++ = c;
     } else {
       // Non-ASCII character or 0x00 which should
       // be encoded as 0xC080 in "modified" UTF8.
       p = utf8_write(p, ((jchar) c) & 0xff);
     }
   }
   *p = '\0';
   return buf;
 }

 void UNICODE::convert_to_utf8(const jchar* base, int length, char* utf8_buffer) {
   for(int index = 0; index < length; index++) {
     utf8_buffer = (char*)utf8_write((u_char*)utf8_buffer, base[index]);
   }
   *utf8_buffer = '\0';
 }

 // returns the quoted ascii length of a unicode string
 template<typename T>
 int UNICODE::quoted_ascii_length(T* base, int length) {
   int result = 0;
   for (int i = 0; i < length; i++) {
     T c = base[i];
     if (c >= 32 && c < 127) {
       result++;
     } else {
       result += 6;
     }
   }
   return result;
 }

 // converts a unicode string to quoted ascii
 template<typename T>
 void UNICODE::as_quoted_ascii(const T* base, int length, char* buf, int buflen) {
   char* p = buf;
   char* end = buf + buflen;
   for (int index = 0; index < length; index++) {
     T c = base[index];
     if (c >= 32 && c < 127) {
       if (p + 1 >= end) break;      // string is truncated
       *p++ = (char)c;
     } else {
       if (p + 6 >= end) break;      // string is truncated
       sprintf(p, "\\u%04x", c);
       p += 6;
     }
   }
   *p = '\0';
 }

 // Explicit instantiation for all supported types.
 template int UNICODE::utf8_length(jbyte* base, int length);
 template int UNICODE::utf8_length(jchar* base, int length);
 template char* UNICODE::as_utf8(jbyte* base, int& length);
 template char* UNICODE::as_utf8(jchar* base, int& length);
 template int UNICODE::quoted_ascii_length<jbyte>(jbyte* base, int length);
 template int UNICODE::quoted_ascii_length<jchar>(jchar* base, int length);
 template void UNICODE::as_quoted_ascii<jbyte>(const jbyte* base, int length, char* buf, int buflen);
 template void UNICODE::as_quoted_ascii<jchar>(const jchar* base, int length, char* buf, int buflen);
	/*
	* Copyright (c) 1997, 2016, 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.
	*
	* 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.
	*
	*/

	#include "precompiled.hpp"
	#include "utilities/utf8.hpp"

	// Assume the utf8 string is in legal form and has been
	// checked in the class file parser/format checker.
	template<typename T> char* UTF8::next(const char* str, T* value) {
	unsigned const char ptr = (const unsigned char )str;
	unsigned char ch, ch2, ch3;
	int length = -1; /* bad length */
	jchar result;
	switch ((ch = ptr[0]) >> 4) {
	default:
	result = ch;
	length = 1;
	break;

	case 0x8: case 0x9: case 0xA: case 0xB: case 0xF:
	/* Shouldn't happen. */
	break;

	case 0xC: case 0xD:
	/* 110xxxxx 10xxxxxx */
	if (((ch2 = ptr[1]) & 0xC0) == 0x80) {
	unsigned char high_five = ch & 0x1F;
	unsigned char low_six = ch2 & 0x3F;
	result = (high_five << 6) + low_six;
	length = 2;
	break;
	}
	break;

	case 0xE:
	/* 1110xxxx 10xxxxxx 10xxxxxx */
	if (((ch2 = ptr[1]) & 0xC0) == 0x80) {
	if (((ch3 = ptr[2]) & 0xC0) == 0x80) {
	unsigned char high_four = ch & 0x0f;
	unsigned char mid_six = ch2 & 0x3f;
	unsigned char low_six = ch3 & 0x3f;
	result = (((high_four << 6) + mid_six) << 6) + low_six;
	length = 3;
	}
	}
	break;
	} /* end of switch */

	if (length <= 0) {
	value = (T)ptr[0]; / default bad result; */
	return (char*)(ptr + 1); // make progress somehow
	}

	*value = (T)result;

	// The assert is correct but the .class file is wrong
	// assert(UNICODE::utf8_size(result) == length, "checking reverse computation");
	return (char *)(ptr + length);
	}

	char* UTF8::next_character(const char* str, jint* value) {
	unsigned const char ptr = (const unsigned char )str;
	/* See if it's legal supplementary character:
	11101101 1010xxxx 10xxxxxx 11101101 1011xxxx 10xxxxxx */
	if (is_supplementary_character(ptr)) {
	*value = get_supplementary_character(ptr);
	return (char *)(ptr + 6);
	}
	jchar result;
	char* next_ch = next(str, &result);
	*value = result;
	return next_ch;
	}

	// Count bytes of the form 10xxxxxx and deduct this count
	// from the total byte count. The utf8 string must be in
	// legal form which has been verified in the format checker.
	int UTF8::unicode_length(const char* str, int len, bool& is_latin1, bool& has_multibyte) {
	int num_chars = len;
	has_multibyte = false;
	is_latin1 = true;
	unsigned char prev = 0;
	for (int i = 0; i < len; i++) {
	unsigned char c = str[i];
	if ((c & 0xC0) == 0x80) {
	// Multibyte, check if valid latin1 character.
	has_multibyte = true;
	if (prev > 0xC3) {
	is_latin1 = false;
	}
	--num_chars;
	}
	prev = c;
	}
	return num_chars;
	}

	// Count bytes of the utf8 string except those in form
	// 10xxxxxx which only appear in multibyte characters.
	// The utf8 string must be in legal form and has been
	// verified in the format checker.
	int UTF8::unicode_length(const char* str, bool& is_latin1, bool& has_multibyte) {
	int num_chars = 0;
	has_multibyte = false;
	is_latin1 = true;
	unsigned char prev = 0;
	for (const char* p = str; *p; p++) {
	unsigned char c = (*p);
	if ((c & 0xC0) == 0x80) {
	// Multibyte, check if valid latin1 character.
	has_multibyte = true;
	if (prev > 0xC3) {
	is_latin1 = false;
	}
	} else {
	num_chars++;
	}
	prev = c;
	}
	return num_chars;
	}

	// Writes a jchar as utf8 and returns the end
	static u_char* utf8_write(u_char* base, jchar ch) {
	if ((ch != 0) && (ch <=0x7f)) {
	base[0] = (u_char) ch;
	return base + 1;
	}

	if (ch <= 0x7FF) {
	/* 11 bits or less. */
	unsigned char high_five = ch >> 6;
	unsigned char low_six = ch & 0x3F;
	base[0] = high_five \| 0xC0; /* 110xxxxx */
	base[1] = low_six \| 0x80; /* 10xxxxxx */
	return base + 2;
	}
	/* possibly full 16 bits. */
	char high_four = ch >> 12;
	char mid_six = (ch >> 6) & 0x3F;
	char low_six = ch & 0x3f;
	base[0] = high_four \| 0xE0; /* 1110xxxx */
	base[1] = mid_six \| 0x80; /* 10xxxxxx */
	base[2] = low_six \| 0x80; /* 10xxxxxx */
	return base + 3;
	}

	template<typename T> void UTF8::convert_to_unicode(const char* utf8_str, T* unicode_str, int unicode_length) {
	unsigned char ch;
	const char *ptr = utf8_str;
	int index = 0;

	/* ASCII case loop optimization */
	for (; index < unicode_length; index++) {
	if((ch = ptr[0]) > 0x7F) { break; }
	unicode_str[index] = (T)ch;
	ptr = (const char *)(ptr + 1);
	}

	for (; index < unicode_length; index++) {
	ptr = UTF8::next(ptr, &unicode_str[index]);
	}
	}

	// Explicit instantiation for all supported string types.
	template char* UTF8::next<jchar>(const char* str, jchar* value);
	template char* UTF8::next<jbyte>(const char* str, jbyte* value);
	template void UTF8::convert_to_unicode<jchar>(const char* utf8_str, jchar* unicode_str, int unicode_length);
	template void UTF8::convert_to_unicode<jbyte>(const char* utf8_str, jbyte* unicode_str, int unicode_length);

	// returns the quoted ascii length of a 0-terminated utf8 string
	int UTF8::quoted_ascii_length(const char* utf8_str, int utf8_length) {
	const char *ptr = utf8_str;
	const char* end = ptr + utf8_length;
	int result = 0;
	while (ptr < end) {
	jchar c;
	ptr = UTF8::next(ptr, &c);
	if (c >= 32 && c < 127) {
	result++;
	} else {
	result += 6;
	}
	}
	return result;
	}

	// converts a utf8 string to quoted ascii
	void UTF8::as_quoted_ascii(const char* utf8_str, int utf8_length, char* buf, int buflen) {
	const char *ptr = utf8_str;
	const char *utf8_end = ptr + utf8_length;
	char* p = buf;
	char* end = buf + buflen;
	while (ptr < utf8_end) {
	jchar c;
	ptr = UTF8::next(ptr, &c);
	if (c >= 32 && c < 127) {
	if (p + 1 >= end) break; // string is truncated
	*p++ = (char)c;
	} else {
	if (p + 6 >= end) break; // string is truncated
	sprintf(p, "\\u%04x", c);
	p += 6;
	}
	}
	assert(p < end, "sanity");
	*p = '\0';
	}


	const char* UTF8::from_quoted_ascii(const char* quoted_ascii_str) {
	const char *ptr = quoted_ascii_str;
	char* result = NULL;
	while (*ptr != '\0') {
	char c = *ptr;
	if (c < 32 \|\| c >= 127) break;
	}
	if (*ptr == '\0') {
	// nothing to do so return original string
	return quoted_ascii_str;
	}
	// everything up to this point was ok.
	int length = ptr - quoted_ascii_str;
	char* buffer = NULL;
	for (int round = 0; round < 2; round++) {
	while (*ptr != '\0') {
	if (*ptr != '\\') {
	if (buffer != NULL) {
	buffer[length] = *ptr;
	}
	length++;
	} else {
	switch (ptr[1]) {
	case 'u': {
	ptr += 2;
	jchar value=0;
	for (int i=0; i<4; i++) {
	char c = *ptr++;
	switch (c) {
	case '0': case '1': case '2': case '3': case '4':
	case '5': case '6': case '7': case '8': case '9':
	value = (value << 4) + c - '0';
	break;
	case 'a': case 'b': case 'c':
	case 'd': case 'e': case 'f':
	value = (value << 4) + 10 + c - 'a';
	break;
	case 'A': case 'B': case 'C':
	case 'D': case 'E': case 'F':
	value = (value << 4) + 10 + c - 'A';
	break;
	default:
	ShouldNotReachHere();
	}
	}
	if (buffer == NULL) {
	char utf8_buffer[4];
	char* next = (char)utf8_write((u_char)utf8_buffer, value);
	length += next - utf8_buffer;
	} else {
	char* next = (char)utf8_write((u_char)&buffer[length], value);
	length += next - &buffer[length];
	}
	break;
	}
	case 't': if (buffer != NULL) buffer[length] = '\t'; ptr += 2; length++; break;
	case 'n': if (buffer != NULL) buffer[length] = '\n'; ptr += 2; length++; break;
	case 'r': if (buffer != NULL) buffer[length] = '\r'; ptr += 2; length++; break;
	case 'f': if (buffer != NULL) buffer[length] = '\f'; ptr += 2; length++; break;
	default:
	ShouldNotReachHere();
	}
	}
	}
	if (round == 0) {
	buffer = NEW_RESOURCE_ARRAY(char, length + 1);
	ptr = quoted_ascii_str;
	} else {
	buffer[length] = '\0';
	}
	}
	return buffer;
	}


	// Returns NULL if 'c' it not found. This only works as long
	// as 'c' is an ASCII character
	const jbyte* UTF8::strrchr(const jbyte* base, int length, jbyte c) {
	assert(length >= 0, "sanity check");
	assert(c >= 0, "does not work for non-ASCII characters");
	// Skip backwards in string until 'c' is found or end is reached
	while(--length >= 0 && base[length] != c);
	return (length < 0) ? NULL : &base[length];
	}

	bool UTF8::equal(const jbyte* base1, int length1, const jbyte* base2, int length2) {
	// Length must be the same
	if (length1 != length2) return false;
	for (int i = 0; i < length1; i++) {
	if (base1[i] != base2[i]) return false;
	}
	return true;
	}

	bool UTF8::is_supplementary_character(const unsigned char* str) {
	return ((str[0] & 0xFF) == 0xED) && ((str[1] & 0xF0) == 0xA0) && ((str[2] & 0xC0) == 0x80)
	&& ((str[3] & 0xFF) == 0xED) && ((str[4] & 0xF0) == 0xB0) && ((str[5] & 0xC0) == 0x80);
	}

	jint UTF8::get_supplementary_character(const unsigned char* str) {
	return 0x10000 + ((str[1] & 0x0f) << 16) + ((str[2] & 0x3f) << 10)
	+ ((str[4] & 0x0f) << 6) + (str[5] & 0x3f);
	}

	bool UTF8::is_legal_utf8(const unsigned char* buffer, int length,
	bool version_leq_47) {
	int i = 0;
	int count = length >> 2;
	for (int k=0; k<count; k++) {
	unsigned char b0 = buffer[i];
	unsigned char b1 = buffer[i+1];
	unsigned char b2 = buffer[i+2];
	unsigned char b3 = buffer[i+3];
	// For an unsigned char v,
	// (v \| v - 1) is < 128 (highest bit 0) for 0 < v < 128;
	// (v \| v - 1) is >= 128 (highest bit 1) for v == 0 or v >= 128.
	unsigned char res = b0 \| b0 - 1 \|
	b1 \| b1 - 1 \|
	b2 \| b2 - 1 \|
	b3 \| b3 - 1;
	if (res >= 128) break;
	i += 4;
	}
	for(; i < length; i++) {
	unsigned short c;
	// no embedded zeros
	if (buffer[i] == 0) return false;
	if(buffer[i] < 128) {
	continue;
	}
	if ((i + 5) < length) { // see if it's legal supplementary character
	if (UTF8::is_supplementary_character(&buffer[i])) {
	c = UTF8::get_supplementary_character(&buffer[i]);
	i += 5;
	continue;
	}
	}
	switch (buffer[i] >> 4) {
	default: break;
	case 0x8: case 0x9: case 0xA: case 0xB: case 0xF:
	return false;
	case 0xC: case 0xD: // 110xxxxx 10xxxxxx
	c = (buffer[i] & 0x1F) << 6;
	i++;
	if ((i < length) && ((buffer[i] & 0xC0) == 0x80)) {
	c += buffer[i] & 0x3F;
	if (version_leq_47 \|\| c == 0 \|\| c >= 0x80) {
	break;
	}
	}
	return false;
	case 0xE: // 1110xxxx 10xxxxxx 10xxxxxx
	c = (buffer[i] & 0xF) << 12;
	i += 2;
	if ((i < length) && ((buffer[i-1] & 0xC0) == 0x80) && ((buffer[i] & 0xC0) == 0x80)) {
	c += ((buffer[i-1] & 0x3F) << 6) + (buffer[i] & 0x3F);
	if (version_leq_47 \|\| c >= 0x800) {
	break;
	}
	}
	return false;
	} // end of switch
	} // end of for
	return true;
	}

	//-------------------------------------------------------------------------------------

	bool UNICODE::is_latin1(jchar c) {
	return (c <= 0x00FF);
	}

	bool UNICODE::is_latin1(jchar* base, int length) {
	for (int index = 0; index < length; index++) {
	if (base[index] > 0x00FF) {
	return false;
	}
	}
	return true;
	}

	int UNICODE::utf8_size(jchar c) {
	if ((0x0001 <= c) && (c <= 0x007F)) {
	// ASCII character
	return 1;
	} else if (c <= 0x07FF) {
	return 2;
	} else {
	return 3;
	}
	}

	int UNICODE::utf8_size(jbyte c) {
	if (c >= 0x01) {
	// ASCII character. Check is equivalent to
	// (0x01 <= c) && (c <= 0x7F) because c is signed.
	return 1;
	} else {
	// Non-ASCII character or 0x00 which needs to be
	// two-byte encoded as 0xC080 in modified UTF-8.
	return 2;
	}
	}

	template<typename T>
	int UNICODE::utf8_length(T* base, int length) {
	int result = 0;
	for (int index = 0; index < length; index++) {
	T c = base[index];
	result += utf8_size(c);
	}
	return result;
	}

	template<typename T>
	char* UNICODE::as_utf8(T* base, int& length) {
	int utf8_len = utf8_length(base, length);
	u_char* buf = NEW_RESOURCE_ARRAY(u_char, utf8_len + 1);
	char* result = as_utf8(base, length, (char*) buf, utf8_len + 1);
	assert((int) strlen(result) == utf8_len, "length prediction must be correct");
	// Set string length to uft8 length
	length = utf8_len;
	return (char*) result;
	}

	char* UNICODE::as_utf8(jchar* base, int length, char* buf, int buflen) {
	u_char* p = (u_char*)buf;
	for (int index = 0; index < length; index++) {
	jchar c = base[index];
	buflen -= utf8_size(c);
	if (buflen <= 0) break; // string is truncated
	p = utf8_write(p, c);
	}
	*p = '\0';
	return buf;
	}

	char* UNICODE::as_utf8(jbyte* base, int length, char* buf, int buflen) {
	u_char* p = (u_char*)buf;
	u_char* end = (u_char*)buf + buflen;
	for (int index = 0; index < length; index++) {
	jbyte c = base[index];
	int sz = utf8_size(c);
	buflen -= sz;
	if (buflen <= 0) break; // string is truncated
	if (sz == 1) {
	// Copy ASCII characters (UTF-8 is ASCII compatible)
	*p++ = c;
	} else {
	// Non-ASCII character or 0x00 which should
	// be encoded as 0xC080 in "modified" UTF8.
	p = utf8_write(p, ((jchar) c) & 0xff);
	}
	}
	*p = '\0';
	return buf;
	}

	void UNICODE::convert_to_utf8(const jchar* base, int length, char* utf8_buffer) {
	for(int index = 0; index < length; index++) {
	utf8_buffer = (char)utf8_write((u_char)utf8_buffer, base[index]);
	}
	*utf8_buffer = '\0';
	}

	// returns the quoted ascii length of a unicode string
	template<typename T>
	int UNICODE::quoted_ascii_length(T* base, int length) {
	int result = 0;
	for (int i = 0; i < length; i++) {
	T c = base[i];
	if (c >= 32 && c < 127) {
	result++;
	} else {
	result += 6;
	}
	}
	return result;
	}

	// converts a unicode string to quoted ascii
	template<typename T>
	void UNICODE::as_quoted_ascii(const T* base, int length, char* buf, int buflen) {
	char* p = buf;
	char* end = buf + buflen;
	for (int index = 0; index < length; index++) {
	T c = base[index];
	if (c >= 32 && c < 127) {
	if (p + 1 >= end) break; // string is truncated
	*p++ = (char)c;
	} else {
	if (p + 6 >= end) break; // string is truncated
	sprintf(p, "\\u%04x", c);
	p += 6;
	}
	}
	*p = '\0';
	}

	// Explicit instantiation for all supported types.
	template int UNICODE::utf8_length(jbyte* base, int length);
	template int UNICODE::utf8_length(jchar* base, int length);
	template char* UNICODE::as_utf8(jbyte* base, int& length);
	template char* UNICODE::as_utf8(jchar* base, int& length);
	template int UNICODE::quoted_ascii_length<jbyte>(jbyte* base, int length);
	template int UNICODE::quoted_ascii_length<jchar>(jchar* base, int length);
	template void UNICODE::as_quoted_ascii<jbyte>(const jbyte* base, int length, char* buf, int buflen);
	template void UNICODE::as_quoted_ascii<jchar>(const jchar* base, int length, char* buf, int buflen);