view src/share/vm/utilities/utf8.hpp @ 453:c96030fff130

6684579: SoftReference processing can be made more efficient Summary: For current soft-ref clearing policies, we can decide at marking time if a soft-reference will definitely not be cleared, postponing the decision of whether it will definitely be cleared to the final reference processing phase. This can be especially beneficial in the case of concurrent collectors where the marking is usually concurrent but reference processing is usually not. Reviewed-by: jmasa
author ysr
date Thu, 20 Nov 2008 16:56:09 -0800
parents a61af66fc99e
children c18cbe5936b8
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/*
 * Copyright 1997-2003 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
 * CA 95054 USA or visit www.sun.com if you need additional information or
 * have any questions.
 *
 */

// Low-level interface for UTF8 strings

class UTF8 : AllStatic {
 public:
  // returns the unicode length of a 0-terminated uft8 string
  static int unicode_length(const char* uft8_str);

  // returns the unicode length of a non-0-terminated uft8 string
  static int unicode_length(const char* uft8_str, int len);

  // converts a uft8 string to a unicode string
  static void convert_to_unicode(const char* utf8_str, jchar* unicode_buffer, int unicode_length);

  // decodes the current utf8 character, stores the result in value,
  // and returns the end of the current uft8 chararacter.
  static char* next(const char* str, jchar* value);

  // decodes the current utf8 character, gets the supplementary character instead of
  // the surrogate pair when seeing a supplementary character in string,
  // stores the result in value, and returns the end of the current uft8 chararacter.
  static char* next_character(const char* str, jint* value);

  // Utility methods
  static jbyte* strrchr(jbyte* base, int length, jbyte c);
  static bool   equal(jbyte* base1, int length1, jbyte* base2, int length2);
  static bool   is_supplementary_character(const unsigned char* str);
  static jint   get_supplementary_character(const unsigned char* str);
};


// Low-level interface for UNICODE strings

// A unicode string represents a string in the UTF-16 format in which supplementary
// characters are represented by surrogate pairs. Index values refer to char code
// units, so a supplementary character uses two positions in a unicode string.

class UNICODE : AllStatic {
 public:
  // returns the utf8 size of a unicode character
  static int utf8_size(jchar c);

  // returns the utf8 length of a unicode string
  static int utf8_length(jchar* base, int length);

  // converts a unicode string to utf8 string
  static void convert_to_utf8(const jchar* base, int length, char* utf8_buffer);

  // converts a unicode string to a utf8 string; result is allocated
  // in resource area unless a buffer is provided.
  static char* as_utf8(jchar* base, int length);
  static char* as_utf8(jchar* base, int length, char* buf, int buflen);
};