Exemplo n.º 1
0
/*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;
}
Exemplo n.º 2
0
/*-
 *-----------------------------------------------------------------------
 * 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);
    }
}
Exemplo n.º 3
0
/*-
 *-----------------------------------------------------------------------
 * 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);
}
Exemplo n.º 4
0
/*-
 *-----------------------------------------------------------------------
 * 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);
}
Exemplo n.º 5
0
/*-
 *-----------------------------------------------------------------------
 * 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);
    }
}
Exemplo n.º 6
0
/*-
 *-----------------------------------------------------------------------
 * 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);
}
Exemplo n.º 7
0
/*-
 *-----------------------------------------------------------------------
 * 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));
}