cvs commit: xml-xerces/c/src/dom CommonParentNode.cpp

[le...@locus.apache.org]

lehors      00/08/17 16:02:17

  Modified:    c/src/dom CommonParentNode.cpp
  Log:
  rewrote code updating the linked list on node addition and
  removal. I believe it is now easier to read and it uses fewer tests so it
  is also a little faster
  
  Revision  Changes    Path
  1.5       +58 -47    xml-xerces/c/src/dom/CommonParentNode.cpp
  
  Index: CommonParentNode.cpp
  ===================================================================
  RCS file: /home/cvs/xml-xerces/c/src/dom/CommonParentNode.cpp,v
  retrieving revision 1.4
  retrieving revision 1.5
  diff -u -r1.4 -r1.5
  --- CommonParentNode.cpp	2000/08/17 22:47:08	1.4
  +++ CommonParentNode.cpp	2000/08/17 23:02:17	1.5
  @@ -55,7 +55,7 @@
    */
   
   /*
  - * $Id: CommonParentNode.cpp,v 1.4 2000/08/17 22:47:08 lehors Exp $
  + * $Id: CommonParentNode.cpp,v 1.5 2000/08/17 23:02:17 lehors Exp $
    */
   
   
  @@ -232,43 +232,54 @@
       
       else
       {
  +        NodeImpl *oldparent=newInternal->getParentNode();
  +        if(oldparent!=null) {
  +            oldparent->removeChild(newInternal);
  +        }
  +
           // Convert to internal type, to avoid repeated casting
           ChildNode *refInternal = (ChildNode *)refChild;
   
  -        NodeImpl *oldparent=newInternal->getParentNode();
  -        if(oldparent!=null)
  -            oldparent->removeChild(newInternal);
  -        
  -        ChildNode *prev;
  -        // Find the node we're inserting after, if any (null if
  -        // inserting to head of list)
  -        prev = (refInternal == null)
  -            ? lastChild() : refInternal->previousSibling;
  -        
           // Attach up
           newInternal->ownerNode = this;
           newInternal->isOwned(true);
           
  -        // Attach after
  -        newInternal->previousSibling=prev;
  -        if (refInternal == firstChild) {
  +        // Attach before and after
  +        // Note: firstChild.previousSibling == lastChild!!
  +        if (firstChild == null) {
  +            // this our first and only child
               firstChild = newInternal;
  -            if (refInternal != null)
  -                 refInternal->isFirstChild(false);
               newInternal->isFirstChild(true);
  -        } else {
  -            prev->nextSibling = newInternal;
  -        }
  -
  -        // Attach before
  -        newInternal->nextSibling = refInternal;
  -        if(refInternal == null) {
  -            // store lastChild as previous sibling of first child
  -            firstChild->previousSibling = newInternal;
  +            newInternal->previousSibling = newInternal;
           } else {
  -            refInternal->previousSibling = newInternal;
  +            if (refInternal == null) {
  +                // this is an append
  +                ChildNode *lastChild = firstChild->previousSibling;
  +                lastChild->nextSibling = newInternal;
  +                newInternal->previousSibling = lastChild;
  +                firstChild->previousSibling = newInternal;
  +            } else {
  +                // this is an insert
  +                if (refChild == firstChild) {
  +                    // at the head of the list
  +                    firstChild->isFirstChild(false);
  +                    newInternal->nextSibling = firstChild;
  +                    newInternal->previousSibling = firstChild->previousSibling;
  +                    firstChild->previousSibling = newInternal;
  +                    firstChild = newInternal;
  +                    newInternal->isFirstChild(true);
  +                } else {
  +                    // somewhere in the middle
  +                    ChildNode *prev = refInternal->previousSibling;
  +                    newInternal->nextSibling = refInternal;
  +                    prev->nextSibling = newInternal;
  +                    refInternal->previousSibling = newInternal;
  +                    newInternal->previousSibling = prev;
  +                }
  +            }
           }
       }
  +
       changed();
       
       if (this->getOwnerDocument() != null) {
  @@ -322,37 +333,37 @@
       
       ChildNode * oldInternal = (ChildNode *) oldChild;
       
  -    // Patch tree past oldChild
  -    ChildNode *prev = oldInternal->previousSibling;
  -    ChildNode *next = oldInternal->nextSibling;
  -    
  -    if (oldInternal != firstChild)
  -        prev->nextSibling = next;
  -    else {
  +    // Patch linked list around oldChild
  +    // Note: lastChild == firstChild->previousSibling
  +    if (oldInternal == firstChild) {
  +        // removing first child
           oldInternal->isFirstChild(false);
  -        firstChild = next;
  -        if (next != null) {
  -            next->isFirstChild(true);
  -        }
  -    }
  -    
  -    if (next != null)         // oldInternal != lastChild
  -        next->previousSibling = prev;
  -    else {
  +        firstChild = oldInternal->nextSibling;
           if (firstChild != null) {
  -            // store lastChild as previous sibling of first child
  +            firstChild->isFirstChild(true);
  +            firstChild->previousSibling = oldInternal->previousSibling;
  +        }
  +    } else {
  +        ChildNode *prev = oldInternal->previousSibling;
  +        ChildNode *next = oldInternal->nextSibling;
  +        prev->nextSibling = next;
  +        if (next == null) {
  +            // removing last child
               firstChild->previousSibling = prev;
  +        } else {
  +            // removing some other child in the middle
  +            next->previousSibling = prev;
           }
       }
  -    
  -    // Remove oldChild's references to tree
  +
  +    // Remove oldInternal's references to tree
       oldInternal->ownerNode = ownerDocument;
       oldInternal->isOwned(false);
       oldInternal->nextSibling = null;
       oldInternal->previousSibling = null;
  -    
  +
       changed();
  -    
  +
       return oldInternal;
   };