/*-
*-----------------------------------------------------------------------
* Lst_FindFrom --
* Search for a node starting and ending with the given one on the
* given list using the passed datum and comparison function to
* determine when it has been found.
*
* Results:
* The found node or NILLNODE
*
* Side Effects:
* None.
*
*-----------------------------------------------------------------------
*/
LstNode
Lst_FindFrom(Lst l, LstNode ln, ClientData d,
int (*cProc)(ClientData, ClientData))
{
ListNode tln;
Boolean found = FALSE;
if (!LstValid (l) || LstIsEmpty (l) || !LstNodeValid (ln, l)) {
return (NILLNODE);
}
tln = (ListNode)ln;
do {
if ((*cProc) (tln->datum, d) == 0) {
found = TRUE;
break;
} else {
tln = tln->nextPtr;
}
} while (tln != (ListNode)ln && tln != NilListNode);
if (found) {
return ((LstNode)tln);
} else {
return (NILLNODE);
}
}
/*-
*-----------------------------------------------------------------------
* Lst_InsertBefore --
* Insert a new node with the given piece of data before the given
* node in the given list.
*
* Input:
* l list to manipulate
* ln node before which to insert d
* d datum to be inserted
*
* Results:
* SUCCESS or FAILURE.
*
* Side Effects:
* the firstPtr field will be changed if ln is the first node in the
* list.
*
*-----------------------------------------------------------------------
*/
ReturnStatus
Lst_InsertBefore(Lst l, LstNode ln, void *d)
{
ListNode nLNode; /* new lnode for d */
ListNode lNode = ln;
List list = l;
/*
* check validity of arguments
*/
if (LstValid (l) && (LstIsEmpty (l) && ln == NULL))
goto ok;
if (!LstValid (l) || LstIsEmpty (l) || !LstNodeValid (ln, l)) {
return (FAILURE);
}
ok:
PAlloc (nLNode, ListNode);
nLNode->datum = d;
nLNode->useCount = nLNode->flags = 0;
if (ln == NULL) {
if (list->isCirc) {
nLNode->prevPtr = nLNode->nextPtr = nLNode;
} else {
nLNode->prevPtr = nLNode->nextPtr = NULL;
}
list->firstPtr = list->lastPtr = nLNode;
} else {
nLNode->prevPtr = lNode->prevPtr;
nLNode->nextPtr = lNode;
if (nLNode->prevPtr != NULL) {
nLNode->prevPtr->nextPtr = nLNode;
}
lNode->prevPtr = nLNode;
if (lNode == list->firstPtr) {
list->firstPtr = nLNode;
}
}
return (SUCCESS);
}
/*-
*-----------------------------------------------------------------------
* Lst_InsertAfter --
* Create a new node and add it to the given list after the given node.
*
* Input:
* l affected list
* ln node after which to append the datum
* d said datum
*
* Results:
* SUCCESS if all went well.
*
* Side Effects:
* A new ListNode is created and linked in to the List. The lastPtr
* field of the List will be altered if ln is the last node in the
* list. lastPtr and firstPtr will alter if the list was empty and
* ln was NILLNODE.
*
*-----------------------------------------------------------------------
*/
ReturnStatus
Lst_InsertAfter(Lst l, LstNode ln, ClientData d)
{
List list;
ListNode lNode;
ListNode nLNode;
if (LstValid (l) && (ln == NILLNODE && LstIsEmpty (l))) {
goto ok;
}
if (!LstValid (l) || LstIsEmpty (l) || ! LstNodeValid (ln, l)) {
return (FAILURE);
}
ok:
list = l;
lNode = ln;
PAlloc (nLNode, ListNode);
nLNode->datum = d;
nLNode->useCount = nLNode->flags = 0;
if (lNode == NilListNode) {
if (list->isCirc) {
nLNode->nextPtr = nLNode->prevPtr = nLNode;
} else {
nLNode->nextPtr = nLNode->prevPtr = NilListNode;
}
list->firstPtr = list->lastPtr = nLNode;
} else {
nLNode->prevPtr = lNode;
nLNode->nextPtr = lNode->nextPtr;
lNode->nextPtr = nLNode;
if (nLNode->nextPtr != NilListNode) {
nLNode->nextPtr->prevPtr = nLNode;
}
if (lNode == list->lastPtr) {
list->lastPtr = nLNode;
}
}
return (SUCCESS);
}
/*-
*-----------------------------------------------------------------------
* Lst_Remove --
* Remove the given node from the given list.
*
* Results:
* SUCCESS or FAILURE.
*
* Side Effects:
* The list's firstPtr will be set to NULL if ln is the last
* node on the list. firsPtr and lastPtr will be altered if ln is
* either the first or last node, respectively, on the list.
*
*-----------------------------------------------------------------------
*/
ReturnStatus
Lst_Remove(Lst l, LstNode ln)
{
List list = l;
ListNode lNode = ln;
if (!LstValid (l) ||
!LstNodeValid (ln, l)) {
return (FAILURE);
}
/*
* unlink it from the list
*/
if (lNode->nextPtr != NULL) {
lNode->nextPtr->prevPtr = lNode->prevPtr;
}
if (lNode->prevPtr != NULL) {
lNode->prevPtr->nextPtr = lNode->nextPtr;
}
/*
* if either the firstPtr or lastPtr of the list point to this node,
* adjust them accordingly
*/
if (list->firstPtr == lNode) {
list->firstPtr = lNode->nextPtr;
}
if (list->lastPtr == lNode) {
list->lastPtr = lNode->prevPtr;
}
/*
* Sequential access stuff. If the node we're removing is the current
* node in the list, reset the current node to the previous one. If the
* previous one was non-existent (prevPtr == NULL), we set the
* end to be Unknown, since it is.
*/
if (list->isOpen && (list->curPtr == lNode)) {
list->curPtr = list->prevPtr;
if (list->curPtr == NULL) {
list->atEnd = Unknown;
}
}
/*
* the only way firstPtr can still point to ln is if ln is the last
* node on the list (the list is circular, so lNode->nextptr == lNode in
* this case). The list is, therefore, empty and is marked as such
*/
if (list->firstPtr == lNode) {
list->firstPtr = NULL;
}
/*
* note that the datum is unmolested. The caller must free it as
* necessary and as expected.
*/
if (lNode->useCount == 0) {
free(ln);
} else {
lNode->flags |= LN_DELETED;
}
return (SUCCESS);
}
