Merge remote-tracking branch 'toybox/master' into HEAD

[android-x86/external-toybox.git] / lib / llist.c

diff --git a/lib/llist.c b/lib/llist.c
index 8d6fd26..dbb5352 100644 (file)
--- a/lib/llist.c
+++ b/lib/llist.c
@@ -1,32 +1,130 @@
-/* vi: set sw=4 ts=4 :
- * llist.c - Linked list functions
+/* llist.c - Linked list functions
  *
  * Linked list structures have a next pointer as their first element.
  */
 
 #include "toys.h"
 
-// Free all the elements of a linked list
-// if freeit!=NULL call freeit() on each element before freeing it.
+// Callback function to free data pointer of double_list or arg_list
 
-void llist_free(void *list, void (*freeit)(void *data))
+void llist_free_arg(void *node)
 {
-       while (list) {
-               void *pop = llist_pop(&list);
-               if (freeit) freeit(pop);
-       }
+  struct arg_list *d = node;
+
+  free(d->arg);
+  free(d);
+}
+
+void llist_free_double(void *node)
+{
+  struct double_list *d = node;
+
+  free(d->data);
+  free(d);
+}
+
+// Call a function (such as free()) on each element of a linked list.
+void llist_traverse(void *list, void (*using)(void *node))
+{
+  void *old = list;
+
+  while (list) {
+    void *pop = llist_pop(&list);
+    using(pop);
+
+    // End doubly linked list too.
+    if (old == list) break;
+  }
 }
 
 // Return the first item from the list, advancing the list (which must be called
 // as &list)
 void *llist_pop(void *list)
 {
-       // I'd use a void ** for the argument, and even accept the typecast in all
-       // callers as documentation you need the &, except the stupid compiler
-       // would then scream about type-punned pointers.  Screw it.
-       void **llist = (void **)list;
-       void **next = (void **)*llist;
-       *llist = *next;
+  // I'd use a void ** for the argument, and even accept the typecast in all
+  // callers as documentation you need the &, except the stupid compiler
+  // would then scream about type-punned pointers.  Screw it.
+  void **llist = (void **)list;
+  void **next = (void **)*llist;
+  *llist = *next;
+
+  return (void *)next;
+}
+
+void *dlist_pop(void *list)
+{
+  struct double_list **pdlist = (struct double_list **)list, *dlist = *pdlist;
+
+  if (dlist->next == dlist) *pdlist = 0;
+  else {
+    dlist->next->prev = dlist->prev;
+    dlist->prev->next = *pdlist = dlist->next;
+  }
+
+  return dlist;
+}
+
+void dlist_add_nomalloc(struct double_list **list, struct double_list *new)
+{
+  if (*list) {
+    new->next = *list;
+    new->prev = (*list)->prev;
+    (*list)->prev->next = new;
+    (*list)->prev = new;
+  } else *list = new->next = new->prev = new;
+}
+
+
+// Add an entry to the end of a doubly linked list
+struct double_list *dlist_add(struct double_list **list, char *data)
+{
+  struct double_list *new = xmalloc(sizeof(struct double_list));
+
+  new->data = data;
+  dlist_add_nomalloc(list, new);
+
+  return new;
+}
+
+// Terminate circular list for traversal in either direction. Returns end *.
+void *dlist_terminate(void *list)
+{
+  struct double_list *end = list;
+
+  if (!list) return 0;
+
+  end = end->prev;
+  end->next->prev = 0;
+  end->next = 0;
+
+  return end;
+}
+
+// Find num in cache
+struct num_cache *get_num_cache(struct num_cache *cache, long long num)
+{
+  while (cache) {
+    if (num==cache->num) return cache;
+    cache = cache->next;
+  }
+
+  return 0;
+}
+
+// Uniquely add num+data to cache. Updates *cache, returns pointer to existing
+// entry if it was already there.
+struct num_cache *add_num_cache(struct num_cache **cache, long long num,
+  void *data, int len)
+{
+  struct num_cache *old = get_num_cache(*cache, num);
+
+  if (old) return old;
+
+  old = xzalloc(sizeof(struct num_cache)+len);
+  old->next = *cache;
+  old->num = num;
+  memcpy(old->data, data, len);
+  *cache = old;
 
-       return (void *)next;
+  return 0;
 }