Add a linkedlist macro that maintains a sorted list

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@111036 65c4cc65-6c06-0410-ace0-fbb531ad65f3

1 files changed, 33 insertions, 0 deletions

diff --git a/include/asterisk/linkedlists.h b/include/asterisk/linkedlists.h
index 1f3285dfa..32d0cbe0b 100644
--- a/include/asterisk/linkedlists.h
+++ b/include/asterisk/linkedlists.h
@@ -456,6 +456,7 @@ struct {								\
   \li AST_LIST_INSERT_AFTER()
   \li AST_LIST_INSERT_HEAD()
   \li AST_LIST_INSERT_TAIL()
+  \li AST_LIST_INSERT_SORTALPHA()
 */
 #define AST_LIST_TRAVERSE(head,var,field) 				\
 	for((var) = (head)->first; (var); (var) = (var)->field.next)
@@ -695,6 +696,38 @@ struct {								\
 #define AST_RWLIST_INSERT_TAIL AST_LIST_INSERT_TAIL
 
 /*!
+ * \brief Inserts a list entry into a alphabetically sorted list
+ * \param head Pointer to the list head structure
+ * \param elm Pointer to the entry to be inserted
+ * \param field Name of the list entry field (declared using AST_LIST_ENTRY())
+ * \param sortfield Name of the field on which the list is sorted
+ */
+#define AST_LIST_INSERT_SORTALPHA(head, elm, field, sortfield) do { \
+	if (!(head)->first) {                                           \
+		(head)->first = (elm);                                      \
+		(head)->last = (elm);                                       \
+	} else {                                                        \
+		typeof((head)->first) cur = (head)->first, prev = NULL;     \
+		while (cur && strcmp(cur->sortfield, elm->sortfield) < 0) { \
+			prev = cur;                                             \
+			cur = cur->field.next;                                  \
+		}                                                           \
+		if (!prev) {       /* Same as INSERT_HEAD */                \
+			(elm)->field.next = (head)->first;                      \
+			(head)->first = (elm);                                  \
+		} else if (!cur) { /* Same as INSERT_TAIL */                \
+			(head)->last->field.next = (elm);                       \
+			(head)->last = (elm);                                   \
+		} else {                                                    \
+			(elm)->field.next = cur;                                \
+			(prev)->field.next = (elm);                             \
+		}                                                           \
+	}                                                               \
+} while (0)
+
+#define AST_RWLIST_INSERT_SORTALPHA	AST_LIST_INSERT_SORTALPHA
+
+/*!
   \brief Appends a whole list to the tail of a list.
   \param head This is a pointer to the list head structure
   \param list This is a pointer to the list to be appended.