scummvm/common/str.cpp

/* ScummVM - Scumm Interpreter
 * Copyright (C) 2002 The ScummVM project
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program 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 for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 *
 * $Header$
 */

#include "stdafx.h"
#include "str.h"


namespace ScummVM {

String::String(const char *str)
{
	_refCount = new int(1);
	if (str) {
		_capacity = _len = strlen(str);
		_str = (char *)calloc(1, _capacity+1);
		memcpy(_str, str, _len+1);
	} else {
		_capacity = _len = 0;
		_str = 0;
	}
}

String::String(const String &str)
{
	++(*str._refCount);

	_refCount = str._refCount;
	_capacity = str._capacity;
	_len = str._capacity;
	_str = str._str;
}

String::~String()
{
	decRefCount();
}

void String::decRefCount()
{
	--(*_refCount);
	if (*_refCount <= 0) {
		delete _refCount;
		if (_str)
			free(_str);
	}
}

String& String::operator  =(const char* str)
{
	int len = strlen(str);
	if (len > 0) {
		ensureCapacity(len, false);
		
		_len = len;
		memcpy(_str, str, _len + 1);
	} else if (_len > 0) {
		decRefCount();
		
		_refCount = new int(1);
		_capacity = 0;
		_len = 0;
		_str = 0;
	}
	return *this;
}

String& String::operator  =(const String& str)
{
	++(*str._refCount);

	decRefCount();
	
	_refCount = str._refCount;
	_capacity = str._capacity;
	_len = str._len;
	_str = str._str;

	return *this;
}

String& String::operator +=(const char* str)
{
	int len = strlen(str);
	if (len > 0) {
		ensureCapacity(_len + len, true);

		memcpy(_str + _len, str, len + 1);
		_len += len;
	}
	return *this;
}

String& String::operator +=(const String& str)
{
	int len = str._len;
	if (len > 0) {
		ensureCapacity(_len + len, true);

		memcpy(_str + _len, str._str, len + 1);
		_len += len;
	}
	return *this;
}

String& String::operator +=(char c)
{
	ensureCapacity(_len + 1, true);
	
	_str[_len++] = c;
	_str[_len] = 0;

	return *this;
}

bool String::operator ==(const String& x) const
{
	return (_len == x._len) && ((_len == 0) || (0 == strcmp(_str, x._str)));
}

bool String::operator ==(const char* x) const
{
	if (_str == 0)
		return (x == 0) || (*x == 0);
	if (x == 0)
		return (_len == 0);
	return (0 != strcmp(_str, x));
}

bool String::operator !=(const String& x) const
{
	return (_len != x._len) || ((_len != 0) && (0 != strcmp(_str, x._str)));
}

bool String::operator !=(const char* x) const
{
	if (_str == 0)
		return (x != 0) && (*x != 0);
	if (x == 0)
		return (_len != 0);
	return (0 == strcmp(_str, x));
}

bool String::operator < (const String& x) const
{
	if (!_len || !x._len)	// Any or both particpants are empty?
		return !_len && x._len;	// Less only if this string is empty and the other isn't
	return strcmp(_str, x._str) < 0;
}

bool String::operator <= (const String& x) const
{
	if (!_len || !x._len)	// Any or both particpants are empty?
		return !_len;	// Less or equal unless the other string is empty and this one isn't
	return strcmp(_str, x._str) <= 0;
}

bool String::operator > (const String& x) const
{
	return (x < *this);
}

bool String::operator >= (const String& x) const
{
	return (x <= *this);
}

void String::deleteLastChar() {
	if (_len > 0) {
		ensureCapacity(_len - 1, true);
		_str[--_len] = 0;
	}
}

void String::clear()
{
	if (_capacity) {
		decRefCount();
		
		_refCount = new int(1);
		_capacity = 0;
		_len = 0;
		_str = 0;
	}
}

void String::ensureCapacity(int new_len, bool keep_old)
{
	// If there is not enough space, or if we are not the only owner 
	// of the current data, then we have to reallocate it.
	if (new_len <= _capacity && *_refCount == 1)
		return;

	int		newCapacity = (new_len <= _capacity) ? _capacity : new_len + 32;
	char	*newStr = (char *)calloc(1, newCapacity+1);

	if (keep_old && _str)
		memcpy(newStr, _str, _len + 1);
	else
		_len = 0;

	decRefCount();
	
	_refCount = new int(1);
	_capacity = newCapacity;
	_str = newStr;
}

bool operator == (const char* y, const String& x)
{
	return (x == y);
}

bool operator != (const char* y, const String& x)
{
	return x != y;
}

};	// End of namespace ScummVM