/*-
*-----------------------------------------------------------------------
* 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_Duplicate --
* Duplicate an entire list. If a function to copy a void *is
* given, the individual client elements will be duplicated as well.
*
* Input:
* l the list to duplicate
* copyProc A function to duplicate each void *
*
* Results:
* The new Lst structure or NULL if failure.
*
* Side Effects:
* A new list is created.
*-----------------------------------------------------------------------
*/
Lst
Lst_Duplicate(Lst l, DuplicateProc *copyProc)
{
Lst nl;
ListNode ln;
List list = l;
if (!LstValid (l)) {
return NULL;
}
nl = Lst_Init(list->isCirc);
if (nl == NULL) {
return NULL;
}
ln = list->firstPtr;
while (ln != NULL) {
if (copyProc != NULL) {
if (Lst_AtEnd(nl, copyProc(ln->datum)) == FAILURE) {
return NULL;
}
} else if (Lst_AtEnd(nl, ln->datum) == FAILURE) {
return NULL;
}
if (list->isCirc && ln == list->lastPtr) {
ln = NULL;
} else {
ln = ln->nextPtr;
}
}
return (nl);
}
/*-
*-----------------------------------------------------------------------
* 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_IsAtEnd --
* Return true if have reached the end of the given list.
*
* Results:
* TRUE if at the end of the list (this includes the list not being
* open or being invalid) or FALSE if not. We return TRUE if the list
* is invalid or unopend so as to cause the caller to exit its loop
* asap, the assumption being that the loop is of the form
* while (!Lst_IsAtEnd (l)) {
* ...
* }
*
* Side Effects:
* None.
*
*-----------------------------------------------------------------------
*/
Boolean
Lst_IsAtEnd(Lst l)
{
List list = l;
return (!LstValid (l) || !list->isOpen ||
(list->atEnd == Head) || (list->atEnd == Tail));
}
/*-
*-----------------------------------------------------------------------
* 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_Last --
* Return the last node on the list l.
*
* Results:
* The requested node or NILLNODE if the list is empty.
*
* Side Effects:
* None.
*
*-----------------------------------------------------------------------
*/
LstNode
Lst_Last(Lst l)
{
if (!LstValid(l) || LstIsEmpty (l)) {
return (NILLNODE);
} else {
return (l->lastPtr);
}
}
/*-
*-----------------------------------------------------------------------
* Lst_EnQueue --
* Add the datum to the tail of the given list.
*
* Results:
* SUCCESS or FAILURE as returned by Lst_InsertAfter.
*
* Side Effects:
* the lastPtr field is altered all the time and the firstPtr field
* will be altered if the list used to be empty.
*
*-----------------------------------------------------------------------
*/
ReturnStatus
Lst_EnQueue(Lst l, void *d)
{
if (LstValid (l) == FALSE) {
return (FAILURE);
}
return (Lst_InsertAfter(l, Lst_Last(l), d));
}
/*VARARGS2*/
int
Lst_ForEachFrom(Lst l, LstNode ln, int (*proc)(void *, void *),
void *d)
{
ListNode tln = ln;
List list = l;
ListNode next;
Boolean done;
int result;
if (!LstValid (list) || LstIsEmpty (list)) {
return 0;
}
do {
/*
* Take care of having the current element deleted out from under
* us.
*/
next = tln->nextPtr;
/*
* We're done with the traversal if
* - the next node to examine is the first in the queue or
* doesn't exist and
* - nothing's been added after the current node (check this
* after proc() has been called).
*/
done = (next == NULL || next == list->firstPtr);
(void) tln->useCount++;
result = (*proc) (tln->datum, d);
(void) tln->useCount--;
/*
* Now check whether a node has been added.
* Note: this doesn't work if this node was deleted before
* the new node was added.
*/
if (next != tln->nextPtr) {
next = tln->nextPtr;
done = 0;
}
if (tln->flags & LN_DELETED) {
free((char *)tln);
}
tln = next;
} while (!result && !LstIsEmpty(list) && !done);
return result;
}
/*-
*-----------------------------------------------------------------------
* Lst_Open --
* Open a list for sequential access. A list can still be searched,
* etc., without confusing these functions.
*
* Results:
* SUCCESS or FAILURE.
*
* Side Effects:
* isOpen is set TRUE and curPtr is set to NULL so the
* other sequential functions no it was just opened and can choose
* the first element accessed based on this.
*
*-----------------------------------------------------------------------
*/
ReturnStatus
Lst_Open(Lst l)
{
if (LstValid (l) == FALSE) {
return (FAILURE);
}
(l)->isOpen = TRUE;
(l)->atEnd = LstIsEmpty (l) ? Head : Unknown;
(l)->curPtr = NULL;
return (SUCCESS);
}
/*-
*-----------------------------------------------------------------------
* Lst_Next --
* Return the next node for the given list.
*
* Results:
* The next node or NILLNODE if the list has yet to be opened. Also
* if the list is non-circular and the end has been reached, NILLNODE
* is returned.
*
* Side Effects:
* the curPtr field is updated.
*
*-----------------------------------------------------------------------
*/
LstNode
Lst_Next(Lst l)
{
ListNode tln;
List list = l;
if ((LstValid (l) == FALSE) ||
(list->isOpen == FALSE)) {
return (NILLNODE);
}
list->prevPtr = list->curPtr;
if (list->curPtr == NilListNode) {
if (list->atEnd == Unknown) {
/*
* If we're just starting out, atEnd will be Unknown.
* Then we want to start this thing off in the right
* direction -- at the start with atEnd being Middle.
*/
list->curPtr = tln = list->firstPtr;
list->atEnd = Middle;
} else {
tln = NilListNode;
list->atEnd = Tail;
}
} else {
tln = list->curPtr->nextPtr;
list->curPtr = tln;
if (tln == list->firstPtr || tln == NilListNode) {
/*
* If back at the front, then we've hit the end...
*/
list->atEnd = Tail;
} else {
/*
* Reset to Middle if gone past first.
*/
list->atEnd = Middle;
}
}
return (tln);
}
/*-
*-----------------------------------------------------------------------
* 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);
}
/*-
*-----------------------------------------------------------------------
* Lst_IsEmpty --
* Return TRUE if the given list is empty.
*
* Results:
* TRUE if the list is empty, FALSE otherwise.
*
* Side Effects:
* None.
*
* A list is considered empty if its firstPtr == NilListNode (or if
* the list itself is NILLIST).
*-----------------------------------------------------------------------
*/
Boolean
Lst_IsEmpty(Lst l)
{
return ( ! LstValid (l) || LstIsEmpty(l));
}
/*-
*-----------------------------------------------------------------------
* Lst_Concat --
* Concatenate two lists. New elements are created to hold the data
* elements, if specified, but the elements themselves are not copied.
* If the elements should be duplicated to avoid confusion with another
* list, the Lst_Duplicate function should be called first.
* If LST_CONCLINK is specified, the second list is destroyed since
* its pointers have been corrupted and the list is no longer useable.
*
* Input:
* l1 The list to which l2 is to be appended
* l2 The list to append to l1
* flags LST_CONCNEW if LstNode's should be duplicated
* LST_CONCLINK if should just be relinked
*
* Results:
* SUCCESS if all went well. FAILURE otherwise.
*
* Side Effects:
* New elements are created and appended the first list.
*-----------------------------------------------------------------------
*/
ReturnStatus
Lst_Concat(Lst l1, Lst l2, int flags)
{
ListNode ln; /* original LstNode */
ListNode nln; /* new LstNode */
ListNode last; /* the last element in the list. Keeps
* bookkeeping until the end */
List list1 = l1;
List list2 = l2;
if (!LstValid (l1) || !LstValid (l2)) {
return (FAILURE);
}
if (flags == LST_CONCLINK) {
if (list2->firstPtr != NULL) {
/*
* We set the nextPtr of the
* last element of list two to be NIL to make the loop easier and
* so we don't need an extra case should the first list turn
* out to be non-circular -- the final element will already point
* to NIL space and the first element will be untouched if it
* existed before and will also point to NIL space if it didn't.
*/
list2->lastPtr->nextPtr = NULL;
/*
* So long as the second list isn't empty, we just link the
* first element of the second list to the last element of the
* first list. If the first list isn't empty, we then link the
* last element of the list to the first element of the second list
* The last element of the second list, if it exists, then becomes
* the last element of the first list.
*/
list2->firstPtr->prevPtr = list1->lastPtr;
if (list1->lastPtr != NULL) {
list1->lastPtr->nextPtr = list2->firstPtr;
} else {
list1->firstPtr = list2->firstPtr;
}
list1->lastPtr = list2->lastPtr;
}
if (list1->isCirc && list1->firstPtr != NULL) {
/*
* If the first list is supposed to be circular and it is (now)
* non-empty, we must make sure it's circular by linking the
* first element to the last and vice versa
*/
list1->firstPtr->prevPtr = list1->lastPtr;
list1->lastPtr->nextPtr = list1->firstPtr;
}
free(l2);
} else if (list2->firstPtr != NULL) {
/*
* We set the nextPtr of the last element of list 2 to be nil to make
* the loop less difficult. The loop simply goes through the entire
* second list creating new LstNodes and filling in the nextPtr, and
* prevPtr to fit into l1 and its datum field from the
* datum field of the corresponding element in l2. The 'last' node
* follows the last of the new nodes along until the entire l2 has
* been appended. Only then does the bookkeeping catch up with the
* changes. During the first iteration of the loop, if 'last' is nil,
* the first list must have been empty so the newly-created node is
* made the first node of the list.
*/
list2->lastPtr->nextPtr = NULL;
for (last = list1->lastPtr, ln = list2->firstPtr;
ln != NULL;
ln = ln->nextPtr)
{
PAlloc (nln, ListNode);
nln->datum = ln->datum;
if (last != NULL) {
last->nextPtr = nln;
} else {
list1->firstPtr = nln;
}
nln->prevPtr = last;
nln->flags = nln->useCount = 0;
last = nln;
}
/*
* Finish bookkeeping. The last new element becomes the last element
* of list one.
*/
list1->lastPtr = last;
/*
* The circularity of both list one and list two must be corrected
* for -- list one because of the new nodes added to it; list two
* because of the alteration of list2->lastPtr's nextPtr to ease the
* above for loop.
*/
if (list1->isCirc) {
list1->lastPtr->nextPtr = list1->firstPtr;
list1->firstPtr->prevPtr = list1->lastPtr;
} else {
last->nextPtr = NULL;
}
if (list2->isCirc) {
list2->lastPtr->nextPtr = list2->firstPtr;
}
}
return (SUCCESS);
}
