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-rw-r--r--WWW/Library/Implementation/HTList.c402
1 files changed, 402 insertions, 0 deletions
diff --git a/WWW/Library/Implementation/HTList.c b/WWW/Library/Implementation/HTList.c
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+++ b/WWW/Library/Implementation/HTList.c
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+/*
+ * $LynxId: HTList.c,v 1.20 2016/11/24 15:29:50 tom Exp $
+ *
+ * A small List class HTList.c
+ * ==================
+ *
+ * A list is represented as a sequence of linked nodes of type HTList.
+ * The first node is a header which contains no object.
+ * New nodes are inserted between the header and the rest of the list.
+ */
+
+#include <HTUtils.h>
+#include <HTList.h>
+
+#include <LYLeaks.h>
+
+/* Create list.
+*/
+HTList *HTList_new(void)
+{
+ HTList *newList;
+
+ if ((newList = typeMalloc(HTList)) == NULL)
+ outofmem(__FILE__, "HTList_new");
+
+ newList->object = NULL;
+ newList->next = NULL;
+
+ return newList;
+}
+
+/* Delete list.
+*/
+void HTList_delete(HTList *me)
+{
+ HTList *current;
+
+ while ((current = me)) {
+ me = me->next;
+ FREE(current);
+ }
+
+ return;
+}
+
+/* Reverse order of elements in list.
+ */
+HTList *HTList_reverse(HTList *start)
+{
+ HTList *cur, *succ;
+
+ if (!(start && start->next && (cur = start->next->next)))
+ return start;
+ start->next->next = NULL;
+ while (cur) {
+ succ = cur->next;
+ cur->next = start->next;
+ start->next = cur;
+ cur = succ;
+ }
+ return start;
+}
+
+/* Append a list to another.
+ *
+ * If successful, the second list will become empty but not freed.
+ */
+HTList *HTList_appendList(HTList *start,
+ HTList *tail)
+{
+ HTList *temp = start;
+
+ if (!start) {
+ CTRACE((tfp,
+ "HTList: Trying to append list %p to a nonexisting list\n",
+ (void *) tail));
+ return NULL;
+ }
+ if (!(tail && tail->next))
+ return start;
+
+ while (temp->next)
+ temp = temp->next;
+
+ temp->next = tail->next;
+ tail->next = NULL; /* tail is now an empty list */
+ return start;
+}
+
+/* Link object to START of list (so it is pointed to by the head).
+ *
+ * Unlike HTList_addObject(), it does not malloc memory for HTList entry,
+ * it use already allocated memory which should not be free'd by any
+ * list operations (optimization).
+ */
+void HTList_linkObject(HTList *me, void *newObject,
+ HTList *newNode)
+{
+ if (me) {
+ if (newNode->object == NULL && newNode->next == NULL) {
+ /* It is safe: */
+ newNode->object = newObject;
+ newNode->next = me->next;
+ me->next = newNode;
+
+ } else {
+ /*
+ * This node is already linked to some list (probably this one), so
+ * refuse changing node pointers to keep the list valid!!!
+ */
+ CTRACE((tfp, "*** HTList: Refuse linking already linked obj "));
+ CTRACE((tfp, "%p, node %p, list %p\n",
+ (void *) newObject, (void *) newNode, (void *) me));
+ }
+
+ } else {
+ CTRACE((tfp,
+ "HTList: Trying to link object %p to a nonexisting list\n",
+ newObject));
+ }
+
+ return;
+}
+
+/* Add object to START of list (so it is pointed to by the head).
+*/
+void HTList_addObject(HTList *me, void *newObject)
+{
+ HTList *newNode;
+
+ if (me) {
+ if ((newNode = typeMalloc(HTList)) == NULL)
+ outofmem(__FILE__, "HTList_addObject");
+
+ newNode->object = newObject;
+ newNode->next = me->next;
+ me->next = newNode;
+
+ } else {
+ CTRACE((tfp, "HTList: Trying to add object %p to a nonexisting list\n",
+ newObject));
+ }
+
+ return;
+}
+
+/* Append object to END of list (furthest from the head).
+*/
+void HTList_appendObject(HTList *me, void *newObject)
+{
+ HTList *temp = me;
+
+ if (temp && newObject) {
+ while (temp->next)
+ temp = temp->next;
+ HTList_addObject(temp, newObject);
+ }
+
+ return;
+}
+
+/* Insert an object into the list at a specified position.
+ * If position is 0, this places the object at the head of the list
+ * and is equivalent to HTList_addObject().
+ */
+void HTList_insertObjectAt(HTList *me, void *newObject,
+ int pos)
+{
+ HTList *newNode;
+ HTList *temp = me;
+ HTList *prevNode;
+ int Pos = pos;
+
+ if (!temp) {
+ CTRACE((tfp, "HTList: Trying to add object %p to a nonexisting list\n",
+ newObject));
+ return;
+ }
+ if (Pos < 0) {
+ Pos = 0;
+ CTRACE((tfp, "HTList: Treating negative object position %d as %d.\n",
+ pos, Pos));
+ }
+
+ prevNode = temp;
+ while ((temp = temp->next)) {
+ if (Pos == 0) {
+ if ((newNode = typeMalloc(HTList)) == NULL)
+ outofmem(__FILE__, "HTList_addObjectAt");
+
+ newNode->object = newObject;
+ newNode->next = temp;
+ if (prevNode)
+ prevNode->next = newNode;
+ return;
+ }
+ prevNode = temp;
+ Pos--;
+ }
+ if (Pos >= 0)
+ HTList_addObject(prevNode, newObject);
+
+ return;
+}
+
+/* Unlink specified object from list.
+ * It does not free memory.
+ */
+BOOL HTList_unlinkObject(HTList *me, void *oldObject)
+{
+ HTList *temp = me;
+ HTList *prevNode;
+
+ if (temp && oldObject) {
+ while (temp->next) {
+ prevNode = temp;
+ temp = temp->next;
+ if (temp->object == oldObject) {
+ prevNode->next = temp->next;
+ temp->next = NULL;
+ temp->object = NULL;
+ return YES; /* Success */
+ }
+ }
+ }
+ return NO; /* object not found or NULL list */
+}
+
+/* Remove specified object from list.
+*/
+BOOL HTList_removeObject(HTList *me, void *oldObject)
+{
+ HTList *temp = me;
+ HTList *prevNode;
+
+ if (temp && oldObject) {
+ while (temp->next) {
+ prevNode = temp;
+ temp = temp->next;
+ if (temp->object == oldObject) {
+ prevNode->next = temp->next;
+ FREE(temp);
+ return YES; /* Success */
+ }
+ }
+ }
+ return NO; /* object not found or NULL list */
+}
+
+/* Remove object at a given position in the list, where 0 is the
+ * object pointed to by the head (returns a pointer to the element
+ * (->object) for the object, and NULL if the list is empty, or
+ * if it doesn't exist - Yuk!).
+ */
+void *HTList_removeObjectAt(HTList *me, int position)
+{
+ HTList *temp = me;
+ HTList *prevNode;
+ int pos = position;
+ void *result = NULL;
+
+ if (temp != NULL && pos >= 0) {
+ prevNode = temp;
+ while ((temp = temp->next) != NULL) {
+ if (pos == 0) {
+ prevNode->next = temp->next;
+ result = temp->object;
+ FREE(temp);
+ break;
+ }
+ prevNode = temp;
+ pos--;
+ }
+ }
+
+ return result;
+}
+
+/* Unlink object from START of list (the Last one inserted
+ * via HTList_linkObject(), and pointed to by the head).
+ * It does not free memory.
+ */
+void *HTList_unlinkLastObject(HTList *me)
+{
+ HTList *lastNode;
+ void *lastObject;
+
+ if (me && me->next) {
+ lastNode = me->next;
+ lastObject = lastNode->object;
+ me->next = lastNode->next;
+ lastNode->next = NULL;
+ lastNode->object = NULL;
+ return lastObject;
+
+ } else { /* Empty list */
+ return NULL;
+ }
+}
+
+/* Remove object from START of list (the Last one inserted
+ * via HTList_addObject(), and pointed to by the head).
+ */
+void *HTList_removeLastObject(HTList *me)
+{
+ HTList *lastNode;
+ void *lastObject;
+
+ if (me && me->next) {
+ lastNode = me->next;
+ lastObject = lastNode->object;
+ me->next = lastNode->next;
+ FREE(lastNode);
+ return lastObject;
+
+ } else { /* Empty list */
+ return NULL;
+ }
+}
+
+/* Remove object from END of list (the First one inserted
+ * via HTList_addObject(), and furthest from the head).
+ */
+void *HTList_removeFirstObject(HTList *me)
+{
+ HTList *temp = me;
+ HTList *prevNode;
+ void *firstObject;
+
+ if (!temp)
+ return NULL;
+
+ prevNode = temp;
+ if (temp->next) {
+ while (temp->next) {
+ prevNode = temp;
+ temp = temp->next;
+ }
+ firstObject = temp->object;
+ prevNode->next = NULL;
+ FREE(temp);
+ return firstObject;
+
+ } else { /* Empty list */
+ return NULL;
+ }
+}
+
+/* Determine total number of objects in the list,
+ * not counting the head.
+ */
+int HTList_count(HTList *me)
+{
+ HTList *temp = me;
+ int count = 0;
+
+ if (temp)
+ while ((temp = temp->next))
+ count++;
+
+ return count;
+}
+
+/* Determine position of an object in the list (a value of 0
+ * means it is pointed to by the head; returns -1 if not found).
+ */
+int HTList_indexOf(HTList *me, void *object)
+{
+ HTList *temp = me;
+ int position = 0;
+
+ if (temp) {
+ while ((temp = temp->next)) {
+ if (temp->object == object)
+ return position;
+ position++;
+ }
+ }
+
+ return -1; /* Object not in the list */
+}
+
+/* Return pointer to the object at a specified position in the list,
+ * where 0 is the object pointed to by the head (returns NULL if
+ * the list is empty, or if it doesn't exist - Yuk!).
+ */
+void *HTList_objectAt(HTList *me, int position)
+{
+ HTList *temp = me;
+ int pos = position;
+
+ if (!temp || pos < 0)
+ return NULL;
+
+ while ((temp = temp->next)) {
+ if (pos == 0)
+ return temp->object;
+ pos--;
+ }
+
+ return NULL; /* Reached the end of the list */
+}
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