ustring.h

khtml在gtk上的移植版本

// -*- c-basic-offset: 2 -*-
/*
 *  This file is part of the KDE libraries
 *  Copyright (C) 1999-2000 Harri Porten ([e-mail])
 *  Copyright (C) 2003 Apple Computer, Inc.
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Library General Public
 *  License as published by the Free Software Foundation; either
 *  version 2 of the License, or (at your option) any later version.
 *
 *  This library 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
 *  Library General Public License for more details.
 *
 *  You should have received a copy of the GNU Library General Public License
 *  along with this library; see the file COPYING.LIB.  If not, write to
 *  the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 *  Boston, MA 02111-1307, USA.
 *
 */

#ifndef _KJS_USTRING_H_
#define _KJS_USTRING_H_

#if APPLE_CHANGES
#include <sys/types.h>
#ifndef KWQ_UNSIGNED_TYPES_DEFINED
#define KWQ_UNSIGNED_TYPES_DEFINED
typedef unsigned char uchar;
typedef unsigned long ulong;
#endif
#endif

#include <stdint.h>

/**
 * @internal
 */
namespace DOM {
  class DOMString;
};
class KJScript;
class QString;
class QConstString;

namespace KJS {

  class UCharReference;
  class UString;

  /**
   * @short Unicode character.
   *
   * UChar represents a 16 bit Unicode character. It's internal data
   * representation is compatible to XChar2b and QChar. It's therefore
   * possible to exchange data with X and Qt with shallow copies.
   */
  struct UChar {
    /**
     * Construct a character with uninitialized value.    
     */
    UChar();
    /**
     * Construct a character with the value denoted by the arguments.
     * @param h higher byte
     * @param l lower byte
     */
    UChar(unsigned char h , unsigned char l);
    /**
     * Construct a character with the given value.
     * @param u 16 bit Unicode value
     */
    UChar(char u);
    UChar(unsigned char u);
    UChar(unsigned short u);
    UChar(const UCharReference &c);
    /**
     * @return The higher byte of the character.
     */
    unsigned char high() const { return uc >> 8; }
    /**
     * @return The lower byte of the character.
     */
    unsigned char low() const { return uc; }
    /**
     * @return the 16 bit Unicode value of the character
     */
    unsigned short unicode() const { return uc; }
  public:
    /**
     * @return The character converted to lower case.
     */
    UChar toLower() const;
    /**
     * @return The character converted to upper case.
     */
    UChar toUpper() const;

    unsigned short uc;
#if !KWIQ
  };
#else
  } Q_PACKED;
#endif

  inline UChar::UChar() { }
  inline UChar::UChar(unsigned char h , unsigned char l) : uc(h << 8 | l) { }
  inline UChar::UChar(char u) : uc((unsigned char)u) { }
  inline UChar::UChar(unsigned char u) : uc(u) { }
  inline UChar::UChar(unsigned short u) : uc(u) { }

  /**
   * @short Dynamic reference to a string character.
   *
   * UCharReference is the dynamic counterpart of @ref UChar. It's used when
   * characters retrieved via index from a @ref UString are used in an
   * assignment expression (and therefore can't be treated as being const):
   * <pre>
   * UString s("hello world");
   * s[0] = 'H';
   * </pre>
   *
   * If that sounds confusing your best bet is to simply forget about the
   * existance of this class and treat is as being identical to @ref UChar.
   */
  class UCharReference {
    friend class UString;
    UCharReference(UString *s, unsigned int off) : str(s), offset(off) { }
  public:
    /**
     * Set the referenced character to c.
     */
    UCharReference& operator=(UChar c);
    /**
     * Same operator as above except the argument that it takes.
     */
    UCharReference& operator=(char c) { return operator=(UChar(c)); }
    /**
     * @return Unicode value.
     */
    unsigned short unicode() const { return ref().uc; }
    /**
     * @return Lower byte.
     */
    unsigned char low() const { return ref().uc; }
    /**
     * @return Higher byte.
     */
    unsigned char high() const { return ref().uc >> 8; }
    /**
     * @return Character converted to lower case.
     */
    UChar toLower() const { return ref().toLower(); }
    /**
     * @return Character converted to upper case.
     */
    UChar toUpper() const  { return ref().toUpper(); }
  private:
    // not implemented, can only be constructed from UString
    UCharReference();

    UChar& ref() const;
    UString *str;
    int offset;
  };

  inline UChar::UChar(const UCharReference &c) : uc(c.unicode()) { }

  /**
   * @short 8 bit char based string class
   */
  class CString {
  public:
    CString() : data(0), length(0) { }
    CString(const char *c);
    CString(const char *c, int len);
    CString(const CString &);

    ~CString();

    CString &append(const CString &);
    CString &operator=(const char *c);
    CString &operator=(const CString &);
    CString &operator+=(const CString &c) { return append(c); }

    int size() const { return length; }
    const char *c_str() const { return data; }
  private:
    char *data;
    int length;
  };

  /**
   * @short Unicode string class
   */
  class UString {
    friend bool operator==(const UString&, const UString&);
    friend class UCharReference;
    friend class Identifier;
    friend class PropertyMap;
    friend class PropertyMapHashTableEntry;

    /**
     * @internal
     */
    struct Rep {
      friend class UString;
      friend bool operator==(const UString&, const UString&);
      
      static Rep *create(UChar *d, int l);
      static Rep *create(Rep *base, int offset, int length);
      void destroy();
      
      UChar *data() const { return baseString ? (baseString->buf + baseString->preCapacity + offset) : (buf + preCapacity + offset); }
      int size() const { return len; }
      
      unsigned hash() const { if (_hash == 0) _hash = computeHash(data(), len); return _hash; }
      static unsigned computeHash(const UChar *, int length);
      static unsigned computeHash(const char *);

      void ref() { ++rc; }
      void deref() { if (--rc == 0) destroy(); }

      // unshared data
      int offset;
      int len;
      int rc;
      mutable unsigned _hash;
      bool isIdentifier;
      UString::Rep *baseString;

      // potentially shared data
      UChar *buf;
      int usedCapacity;
      int capacity;
      int usedPreCapacity;
      int preCapacity;
      
      static Rep null;
      static Rep empty;
    };

  public:
    /**
     * Constructs a null string.
     */
    UString();
    /**
     * Constructs a string from the single character c.
     */
    explicit UString(char c);
    /**
     * Constructs a string from a classical zero determined char string.
     */
    UString(const char *c);
    /**
     * Constructs a string from an array of Unicode characters of the specified
     * length.