find methods for linked lists

2 files changed, 105 insertions, 0 deletions

diff --git a/src/libstrongswan/utils/linked_list.c b/src/libstrongswan/utils/linked_list.c
index 5cd8ffd7a..63e1bcfbf 100644
--- a/src/libstrongswan/utils/linked_list.c
+++ b/src/libstrongswan/utils/linked_list.c
@@ -677,6 +677,52 @@ static status_t get_last(private_linked_list_t *this, void **item)
 }
 
 /**
+ * Implementation of linked_list_t.find_first.
+ */
+static status_t find_first(private_linked_list_t *this, linked_list_match_t match,
+		void **item, void *d1, void *d2, void *d3, void *d4, void *d5)
+{
+	element_t *current = this->first;
+	
+	while (current)
+	{
+		if (match(current->value, d1, d2, d3, d4, d5))
+		{
+			if (item != NULL)
+			{
+				*item = current->value;
+			}
+			return SUCCESS;
+		}
+		current = current->next;
+	}
+	return NOT_FOUND;
+}
+
+/**
+ * Implementation of linked_list_t.find_last.
+ */
+static status_t find_last(private_linked_list_t *this, linked_list_match_t match,
+		void **item, void *d1, void *d2, void *d3, void *d4, void *d5)
+{
+	element_t *current = this->last;
+	
+	while (current)
+	{
+		if (match(current->value, d1, d2, d3, d4, d5))
+		{
+			if (item != NULL)
+			{
+				*item = current->value;
+			}
+			return SUCCESS;
+		}
+		current = current->previous;
+	}
+	return NOT_FOUND;
+}
+
+/**
  * Implementation of linked_list_t.invoke_offset.
  */
 static void invoke_offset(private_linked_list_t *this, size_t offset)
@@ -843,6 +889,8 @@ linked_list_t *linked_list_create()
 	this->public.create_enumerator = (enumerator_t*(*)(linked_list_t*))create_enumerator;
 	this->public.get_first = (status_t (*) (linked_list_t *, void **item))get_first;
 	this->public.get_last = (status_t (*) (linked_list_t *, void **item))get_last;
+	this->public.find_first = (status_t (*) (linked_list_t *, linked_list_match_t,void**,...))find_first;
+	this->public.find_last = (status_t (*) (linked_list_t *, linked_list_match_t,void**,...))find_last;
 	this->public.insert_first = (void (*) (linked_list_t *, void *item))insert_first;
 	this->public.insert_last = (void (*) (linked_list_t *, void *item))insert_last;
 	this->public.remove_first = (status_t (*) (linked_list_t *, void **item))remove_first;
diff --git a/src/libstrongswan/utils/linked_list.h b/src/libstrongswan/utils/linked_list.h
index ebe5c187c..ac36ef46d 100644
--- a/src/libstrongswan/utils/linked_list.h
+++ b/src/libstrongswan/utils/linked_list.h
@@ -33,6 +33,19 @@ typedef struct linked_list_t linked_list_t;
 #include <utils/iterator.h>
 #include <utils/enumerator.h>
 
+
+/**
+ * Method to match elements in a linked list (used in find_* functions)
+ *
+ * @param item			current list item
+ * @param ...			user supplied data (only pointers, at most 5)
+ * @return
+ * 						- TRUE, if the item matched
+ * 						- FALSE, otherwise
+ * @ingroup utils
+ */
+typedef bool (*linked_list_match_t)(void *item, ...);
+
 /**
  * @brief Class implementing a double linked list.
  *
@@ -187,6 +200,50 @@ struct linked_list_t {
 	 */
 	status_t (*get_last) (linked_list_t *this, void **item);
 	
+	/** @brief Find the first matching element in the list.
+	 * 
+	 * The first object passed to the match function is the current list item,
+	 * followed by the user supplied data.
+	 * If the supplied function returns TRUE this function returns SUCCESS, and
+	 * the current object is returned in the third parameter, otherwise,
+	 * the next item is checked.
+	 * 
+	 * @warning Only use pointers as user supplied data.
+	 *
+	 * @param this			calling object
+	 * @param match			comparison function to call on each object
+	 * @param[out] item		
+	 * 						- the list item, if found
+	 * 						- NULL, otherwise
+	 * @param ...			user data to supply to match function (limited to 5 arguments)
+	 * @return				
+	 * 						- SUCCESS, if found
+	 * 						- NOT_FOUND, otherwise
+	 */
+	status_t (*find_first) (linked_list_t *this, linked_list_match_t match, void **item, ...);
+	
+	/** @brief Find the last matching element in the list.
+	 * 
+	 * The first object passed to the match function is the current list item,
+	 * followed by the user supplied data.
+	 * If the supplied function returns TRUE this function returns SUCCESS, and
+	 * the current object is returned in the third parameter, otherwise,
+	 * the next item is checked.
+	 * 
+	 * @warning Only use pointers as user supplied data.
+	 *
+	 * @param this			calling object
+	 * @param match			comparison function to call on each object
+	 * @param[out] item		
+	 * 						- the list item, if found
+	 * 						- NULL, otherwise
+	 * @param ...			user data to supply to match function (limited to 5 arguments)
+	 * @return				
+	 * 						- SUCCESS, if found
+	 * 						- NOT_FOUND, otherwise
+	 */
+	status_t (*find_last) (linked_list_t *this, linked_list_match_t match, void **item, ...);
+	
 	/**
 	 * @brief Invoke a method on all of the contained objects.
 	 *