btr_exec_up(): Also ask given node.

At the moment, the buffer tree walk starts at the parent of the given
node. Users of the btr API can not execute a command for a node unless
it has at least one child.

This unnecessary restriction is removed in this commit by letting
the tree walk start at the given node rather than its parent.
This actually simplifies the code a bit.

diff --git a/buffer_tree.c b/buffer_tree.c
index c62cbf13c3bdc4b621bd891d41e1b74fe24d98fe..5756898bced710406b3c68b8cb1e5cc85a992183 100644 (file)
--- a/buffer_tree.c
+++ b/buffer_tree.c
@@ -878,37 +878,36 @@ size_t btr_get_output_queue_size(struct btr_node *btrn)
 }
 
 /**
- * Execute a inter-node command on a parent node.
+ * Execute a inter-node command on the given node or on a parent node.
  *
  * \param btrn The node to start looking.
  * \param command The command to execute.
  * \param value_result Additional arguments and result value.
  *
- * This function traverses the buffer tree upwards and looks for parent nodes
- * of \a btrn that understands \a command. On the first such node the command
- * is executed, and the result is stored in \a value_result.
+ * This function traverses the buffer tree from \a btrn upwards and looks for
+ * the first node that understands \a command. On this node \a command is
+ * executed, and the result is stored in \a value_result.
  *
  * \return \p -ENOTSUP if no parent node of \a btrn understands \a command.
  * Otherwise the return value of the command handler is returned.
+ *
+ * \sa \ref receiver::execute, filter::execute, writer::execute.
  */
 int btr_exec_up(struct btr_node *btrn, const char *command, char **value_result)
 {
        int ret;
 
        for (; btrn; btrn = btrn->parent) {
-               struct btr_node *parent = btrn->parent;
-               if (!parent)
-                       return -ERRNO_TO_PARA_ERROR(ENOTSUP);
-               if (!parent->execute)
+               if (!btrn->execute)
                        continue;
-               PARA_INFO_LOG("parent: %s, cmd: %s\n", parent->name, command);
-               ret = parent->execute(parent, command, value_result);
+               PARA_INFO_LOG("executing %s on %s\n", command, btrn->name);
+               ret = btrn->execute(btrn, command, value_result);
                if (ret == -ERRNO_TO_PARA_ERROR(ENOTSUP))
                        continue;
                if (ret < 0)
                        return ret;
                if (value_result && *value_result)
-                       PARA_INFO_LOG("%s(%s): %s\n", command, parent->name,
+                       PARA_INFO_LOG("%s(%s): %s\n", command, btrn->name,
                                *value_result);
                return 1;
        }