rsys

commit 50ca94e819c603cf483d2af98dd9c5bbb5f3b140
parent c72250ab04b1663d31a285068e12655414bf24fc
Author: vaplv <vaplv@free.fr>
Date:   Tue, 26 Nov 2013 17:24:51 +0100

Begin the implementation of a free_list

Diffstat:
A
src/free_list.h
 | 
85
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

1 file changed, 85 insertions(+), 0 deletions(-)
diff --git a/src/free_list.h b/src/free_list.h
@@ -0,0 +1,85 @@
+#ifndef FREE_LIST_H
+#define FREE_LIST_H
+
+#ifndef FREE_ITEM_TYPE
+  #error Missing arguments
+#endif
+
+struct free_id {
+  uint32_t index; /* Index into the free list */
+  uint32_t name; /* Unique id that identifies this item */
+};
+
+#define FREE_ITEM                                                              \
+  struct {                                                                     \
+    struct free_id id;                                                         \
+    uint32_t next;                                                             \
+  } free_item__
+
+struct free_list {
+  uint32_t head;
+  uint32_t name_next;
+  FREE_ITEM_TYPE* items;
+  uint32_t nitems;
+};
+
+static FINLINE void
+free_list_init(struct free_list* list)
+{
+  ASSERT(list);
+  list->head = UINT32_MAX;
+  list->name_next = 0;
+  list->items = NULL;
+  list->nitems = 0;
+}
+
+static FINLINE bool
+free_list_hold(struct free_list* list, struct free_id* id)
+{
+  ASSERT(list && id);
+  return list->items[id->index].free_item__.id.name == id->name;
+}
+
+static FINLINE FREE_ITEM*
+free_list_get(struct free_list* list, struct free_id* id)
+{
+  ASSERT(list && id);
+  if(free_list_hold(list, id)) {
+    return list->mem[id->index];
+  } else {
+    return NULL;
+  }
+}
+
+static FINLINE struct free_id
+free_list_add(struct free_list* list)
+{
+  struct free_id id;
+  ASSERT(list);
+
+  id.name = list.name_next++;
+  if(list.head != UINT32_MAX) {
+    id.index = list.head;
+    list.head = list.items[list.head].free_item__.next;
+  } else {
+    FREE_ITEM item;
+    memset(&item, 0, sizeof(FREE_ITEM));
+    id.index = list->nitems;
+    item.free_item__.id = id;
+    list.items = MEM_REALLOC(list.items, nitems * 2 * sizeof(FREE_ITEM_TYPE));
+  }
+  return id;
+}
+
+static FINLINE void
+free_list_del(struct free_list* list, struct free_id* id)
+{
+  ASSERT(list && id);
+  FREE_ITEM* item = free_list_get(list, id);
+  item->free_item__.id.name = UINT32_MAX;
+  item->free_item__.next = list->head;
+  list->head = item->free_item__.id.index;
+}
+
+#endif /* FREE_LIST_H */
+