1 /*

     2  * Copyright 1997-2004 Sun Microsystems, Inc.  All Rights Reserved.

     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

     4  *

     5  * This code is free software; you can redistribute it and/or modify it

     6  * under the terms of the GNU General Public License version 2 only, as

     7  * published by the Free Software Foundation.

     8  *

     9  * This code is distributed in the hope that it will be useful, but WITHOUT

    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    12  * version 2 for more details (a copy is included in the LICENSE file that

    13  * accompanied this code).

    14  *

    15  * You should have received a copy of the GNU General Public License version

    16  * 2 along with this work; if not, write to the Free Software Foundation,

    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    18  *

    19  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

    20  * CA 95054 USA or visit www.sun.com if you need additional information or

    21  * have any questions.

    22  *

    23  */

    24 

    25 # include "incls/_precompiled.incl"

    26 # include "incls/_utf8.cpp.incl"

    27 

    28 // Assume the utf8 string is in legal form and has been

    29 // checked in the class file parser/format checker.

    30 char* UTF8::next(const char* str, jchar* value) {

    31   unsigned const char *ptr = (const unsigned char *)str;

    32   unsigned char ch, ch2, ch3;

    33   int length = -1;              /* bad length */

    34   jchar result;

    35   switch ((ch = ptr[0]) >> 4) {

    36     default:

    37     result = ch;

    38     length = 1;

    39     break;

    40 

    41   case 0x8: case 0x9: case 0xA: case 0xB: case 0xF:

    42     /* Shouldn't happen. */

    43     break;

    44 

    45   case 0xC: case 0xD:

    46     /* 110xxxxx  10xxxxxx */

    47     if (((ch2 = ptr[1]) & 0xC0) == 0x80) {

    48       unsigned char high_five = ch & 0x1F;

    49       unsigned char low_six = ch2 & 0x3F;

    50       result = (high_five << 6) + low_six;

    51       length = 2;

    52       break;

    53     }

    54     break;

    55 

    56   case 0xE:

    57     /* 1110xxxx 10xxxxxx 10xxxxxx */

    58     if (((ch2 = ptr[1]) & 0xC0) == 0x80) {

    59       if (((ch3 = ptr[2]) & 0xC0) == 0x80) {

    60         unsigned char high_four = ch & 0x0f;

    61         unsigned char mid_six = ch2 & 0x3f;

    62         unsigned char low_six = ch3 & 0x3f;

    63         result = (((high_four << 6) + mid_six) << 6) + low_six;

    64         length = 3;

    65       }

    66     }

    67     break;

    68   } /* end of switch */

    69 

    70   if (length <= 0) {

    71     *value = ptr[0];    /* default bad result; */

    72     return (char*)(ptr + 1); // make progress somehow

    73   }

    74 

    75   *value = result;

    76 

    77   // The assert is correct but the .class file is wrong

    78   // assert(UNICODE::utf8_size(result) == length, "checking reverse computation");

    79   return (char *)(ptr + length);

    80 }

    81 

    82 char* UTF8::next_character(const char* str, jint* value) {

    83   unsigned const char *ptr = (const unsigned char *)str;

    84   /* See if it's legal supplementary character:

    85      11101101 1010xxxx 10xxxxxx 11101101 1011xxxx 10xxxxxx */

    86   if (is_supplementary_character(ptr)) {

    87     *value = get_supplementary_character(ptr);

    88     return (char *)(ptr + 6);

    89   }

    90   jchar result;

    91   char* next_ch = next(str, &result);

    92   *value = result;

    93   return next_ch;

    94 }

    95 

    96 // Count bytes of the form 10xxxxxx and deduct this count

    97 // from the total byte count.  The utf8 string must be in

    98 // legal form which has been verified in the format checker.

    99 int UTF8::unicode_length(const char* str, int len) {

   100   int num_chars = len;

   101   for (int i = 0; i < len; i++) {

   102     if ((str[i] & 0xC0) == 0x80) {

   103       --num_chars;

   104     }

   105   }

   106   return num_chars;

   107 }

   108 

   109 // Count bytes of the utf8 string except those in form

   110 // 10xxxxxx which only appear in multibyte characters.

   111 // The utf8 string must be in legal form and has been

   112 // verified in the format checker.

   113 int UTF8::unicode_length(const char* str) {

   114   int num_chars = 0;

   115   for (const char* p = str; *p; p++) {

   116     if (((*p) & 0xC0) != 0x80) {

   117       num_chars++;

   118     }

   119   }

   120   return num_chars;

   121 }

   122 

   123 // Writes a jchar a utf8 and returns the end

   124 static u_char* utf8_write(u_char* base, jchar ch) {

   125   if ((ch != 0) && (ch <=0x7f)) {

   126     base[0] = (u_char) ch;

   127     return base + 1;

   128   }

   129 

   130   if (ch <= 0x7FF) {

   131     /* 11 bits or less. */

   132     unsigned char high_five = ch >> 6;

   133     unsigned char low_six = ch & 0x3F;

   134     base[0] = high_five | 0xC0; /* 110xxxxx */

   135     base[1] = low_six | 0x80;   /* 10xxxxxx */

   136     return base + 2;

   137   }

   138   /* possibly full 16 bits. */

   139   char high_four = ch >> 12;

   140   char mid_six = (ch >> 6) & 0x3F;

   141   char low_six = ch & 0x3f;

   142   base[0] = high_four | 0xE0; /* 1110xxxx */

   143   base[1] = mid_six | 0x80;   /* 10xxxxxx */

   144   base[2] = low_six | 0x80;   /* 10xxxxxx */

   145   return base + 3;

   146 }

   147 

   148 void UTF8::convert_to_unicode(const char* utf8_str, jchar* unicode_str, int unicode_length) {

   149   unsigned char ch;

   150   const char *ptr = (const char *)utf8_str;

   151   int index = 0;

   152 

   153   /* ASCII case loop optimization */

   154   for (; index < unicode_length; index++) {

   155     if((ch = ptr[0]) > 0x7F) { break; }

   156     unicode_str[index] = ch;

   157     ptr = (const char *)(ptr + 1);

   158   }

   159 

   160   for (; index < unicode_length; index++) {

   161     ptr = UTF8::next(ptr, &unicode_str[index]);

   162   }

   163 }

   164 

   165 // Returns NULL if 'c' it not found. This only works as long

   166 // as 'c' is an ASCII character

   167 jbyte* UTF8::strrchr(jbyte* base, int length, jbyte c) {

   168   assert(length >= 0, "sanity check");

   169   assert(c >= 0, "does not work for non-ASCII characters");

   170   // Skip backwards in string until 'c' is found or end is reached

   171   while(--length >= 0 && base[length] != c);

   172   return (length < 0) ? NULL : &base[length];

   173 }

   174 

   175 bool UTF8::equal(jbyte* base1, int length1, jbyte* base2, int length2) {

   176   // Length must be the same

   177   if (length1 != length2) return false;

   178   for (int i = 0; i < length1; i++) {

   179     if (base1[i] != base2[i]) return false;

   180   }

   181   return true;

   182 }

   183 

   184 bool UTF8::is_supplementary_character(const unsigned char* str) {

   185   return ((str[0] & 0xFF) == 0xED) && ((str[1] & 0xF0) == 0xA0) && ((str[2] & 0xC0) == 0x80)

   186       && ((str[3] & 0xFF) == 0xED) && ((str[4] & 0xF0) == 0xB0) && ((str[5] & 0xC0) == 0x80);

   187 }

   188 

   189 jint UTF8::get_supplementary_character(const unsigned char* str) {

   190   return 0x10000 + ((str[1] & 0x0f) << 16) + ((str[2] & 0x3f) << 10)

   191                  + ((str[4] & 0x0f) << 6)  + (str[5] & 0x3f);

   192 }

   193 

   194 

   195 //-------------------------------------------------------------------------------------

   196 

   197 

   198 int UNICODE::utf8_size(jchar c) {

   199   if ((0x0001 <= c) && (c <= 0x007F)) return 1;

   200   if (c <= 0x07FF) return 2;

   201   return 3;

   202 }

   203 

   204 int UNICODE::utf8_length(jchar* base, int length) {

   205   int result = 0;

   206   for (int index = 0; index < length; index++) {

   207     jchar c = base[index];

   208     if ((0x0001 <= c) && (c <= 0x007F)) result += 1;

   209     else if (c <= 0x07FF) result += 2;

   210     else result += 3;

   211   }

   212   return result;

   213 }

   214 

   215 char* UNICODE::as_utf8(jchar* base, int length) {

   216   int utf8_len = utf8_length(base, length);

   217   u_char* result = NEW_RESOURCE_ARRAY(u_char, utf8_len + 1);

   218   u_char* p = result;

   219   for (int index = 0; index < length; index++) {

   220     p = utf8_write(p, base[index]);

   221   }

   222   *p = '\0';

   223   assert(p == &result[utf8_len], "length prediction must be correct");

   224   return (char*) result;

   225 }

   226 

   227 char* UNICODE::as_utf8(jchar* base, int length, char* buf, int buflen) {

   228   u_char* p = (u_char*)buf;

   229   u_char* end = (u_char*)buf + buflen;

   230   for (int index = 0; index < length; index++) {

   231     jchar c = base[index];

   232     if (p + utf8_size(c) >= end) break;      // string is truncated

   233     p = utf8_write(p, base[index]);

   234   }

   235   *p = '\0';

   236   return buf;

   237 }

   238 

   239 void UNICODE::convert_to_utf8(const jchar* base, int length, char* utf8_buffer) {

   240   for(int index = 0; index < length; index++) {

   241     utf8_buffer = (char*)utf8_write((u_char*)utf8_buffer, base[index]);

   242   }

   243   *utf8_buffer = '\0';

   244 }