lib/messages: Add new notmuch_message_list_t to internal interface.

Previously, the notmuch_messages_t object was a linked list built on
top of a linked-list node with the odd name of notmuch_message_list_t.

Now, we've got much more sane naming with notmuch_message_list_t being
a list built on a linked-list node named notmuch_message_node_t. And
now the public notmuch_messages_t object is a separate iterator based
on notmuch_message_node_t. This means the interfaces for the new
notmuch_message_list_t object are now made available to the library
internals.

1 files changed, 52 insertions, 28 deletions

diff --git a/lib/messages.c b/lib/messages.c
index 8b627750..a588f8f8 100644
--- a/lib/messages.c
+++ b/lib/messages.c
@@ -22,72 +22,96 @@
 
 #include <glib.h> /* GList */
 
-typedef struct _message_list {
-    notmuch_message_t *message;
-    struct _message_list *next;
-} message_list_t;
 
 struct _notmuch_messages {
-    message_list_t *head;
-    message_list_t **tail;
+    notmuch_message_node_t *iterator;
 };
 
-/* Create a new notmuch_messages_t object, with 'ctx' as its talloc owner.
+/* Create a new notmuch_message_list_t object, with 'ctx' as its
+ * talloc owner.
  *
  * This function can return NULL in case of out-of-memory.
  */
-notmuch_messages_t *
-_notmuch_messages_create (void *ctx)
+notmuch_message_list_t *
+_notmuch_message_list_create (const void *ctx)
 {
-    notmuch_messages_t *messages;
+    notmuch_message_list_t *list;
 
-    messages = talloc (ctx, notmuch_messages_t);
-    if (unlikely (messages == NULL))
+    list = talloc (ctx, notmuch_message_list_t);
+    if (unlikely (list == NULL))
 	return NULL;
 
-    messages->head = NULL;
-    messages->tail = &messages->head;
+    list->head = NULL;
+    list->tail = &list->head;
 
-    return messages;
+    return list;
 }
 
-/* Add a new message to 'messages'.
+/* Append 'node' (which can of course point to an aribtrarily long
+ * list of nodes) to the end of 'list'.
  */
 void
-_notmuch_messages_add_message (notmuch_messages_t *messages,
-			       notmuch_message_t *message)
+_notmuch_message_list_append (notmuch_message_list_t *list,
+			      notmuch_message_node_t *node)
+{
+    *(list->tail) = node;
+    list->tail = &node->next;
+}
+
+/* Allocate a new node for 'message' and append it to the end of
+ * 'list'.
+ */
+void
+_notmuch_message_list_add_message (notmuch_message_list_t *list,
+				   notmuch_message_t *message)
+{
+    notmuch_message_node_t *node = talloc (list, notmuch_message_node_t);
+
+    node->message = message;
+    node->next = NULL;
+
+    _notmuch_message_list_append (list, node);
+}
+
+notmuch_messages_t *
+_notmuch_messages_create (notmuch_message_list_t *list)
 {
-    message_list_t *new = talloc (messages, message_list_t);
+    notmuch_messages_t *messages;
 
-    new->message = message;
-    new->next = NULL;
+    if (list->head == NULL)
+	return NULL;
 
-    *(messages->tail) = new;
-    messages->tail = &new->next;
+    messages = talloc (list, notmuch_messages_t);
+    if (unlikely (messages == NULL))
+	return NULL;
+
+    messages->iterator = list->head;
+
+    return messages;
 }
 
 notmuch_bool_t
 notmuch_messages_has_more (notmuch_messages_t *messages)
 {
-    return messages->head != NULL;
+    return (messages != NULL && messages->iterator != NULL);
 }
 
 notmuch_message_t *
 notmuch_messages_get (notmuch_messages_t *messages)
 {
-    if (messages->head == NULL)
+    if (messages->iterator == NULL)
 	return NULL;
 
-    return messages->head->message;
+    return messages->iterator->message;
 }
 
 void
 notmuch_messages_advance (notmuch_messages_t *messages)
 {
-    if (messages->head == NULL)
+    if (messages->iterator == NULL)
 	return;
 
-    messages->head = messages->head->next;
+    messages->iterator = messages->iterator->next;
 }
 
 void