scope_chain.cpp

00001 /*
00002  *  This file is part of the KDE libraries
00003  *  Copyright (C) 2003 Apple Computer, Inc.
00004  *
00005  *  This library is free software; you can redistribute it and/or
00006  *  modify it under the terms of the GNU Library General Public
00007  *  License as published by the Free Software Foundation; either
00008  *  version 2 of the License, or (at your option) any later version.
00009  *
00010  *  This library is distributed in the hope that it will be useful,
00011  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
00012  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00013  *  Library General Public License for more details.
00014  *
00015  *  You should have received a copy of the GNU Library General Public License
00016  *  along with this library; see the file COPYING.LIB.  If not, write to
00017  *  the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
00018  *  Boston, MA 02110-1301, USA.
00019  *
00020  */
00021 
00022 #include "scope_chain.h"
00023 
00024 #include "object.h"
00025 
00026 #include <assert.h>
00027 
00028 namespace KJS {
00029 
00030 inline void ScopeChain::ref() const
00031 {
00032     for (ScopeChainNode *n = _node; n; n = n->next) {
00033         if (n->refCount++ != 0)
00034             break;
00035     }
00036 }
00037 
00038 ScopeChain &ScopeChain::operator=(const ScopeChain &c)
00039 {
00040     c.ref();
00041     deref();
00042     _node = c._node;
00043     return *this;
00044 }
00045 
00046 void ScopeChain::push(ObjectImp *o)
00047 {
00048     assert(o);
00049     _node = new ScopeChainNode(_node, o);
00050 }
00051 
00052 void ScopeChain::pop()
00053 {
00054     ScopeChainNode *oldNode = _node;
00055     assert(oldNode);
00056     ScopeChainNode *newNode = oldNode->next;
00057     _node = newNode;
00058     
00059     if (--oldNode->refCount != 0) {
00060         if (newNode)
00061             ++newNode->refCount;
00062     } else {
00063         delete oldNode;
00064     }
00065 }
00066 
00067 void ScopeChain::release()
00068 {
00069     // This function is only called by deref(),
00070     // Deref ensures these conditions are true.
00071     assert(_node && _node->refCount == 0);
00072     ScopeChainNode *n = _node;
00073     do {
00074         ScopeChainNode *next = n->next;
00075         delete n;
00076         n = next;
00077     } while (n && --n->refCount == 0);
00078 }
00079 
00080 void ScopeChain::mark()
00081 {
00082     for (ScopeChainNode *n = _node; n; n = n->next) {
00083         ObjectImp *o = n->object;
00084         if (!o->marked())
00085             o->mark();
00086     }
00087 }
00088 
00089 } // namespace KJS
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