X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=buffer_tree.c;h=b0cd6665416627806d922cda50fac2e2eeeab17f;hp=cc2bb511696f2e65240a17bbc4962b20c9f0930b;hb=06d0c50525fc14e8127916481a74c14a2f7098af;hpb=07fdaa7973c1b97ded3ebd200ef845728547f94e

diff --git a/buffer_tree.c b/buffer_tree.c
index cc2bb511..b0cd6665 100644
--- a/buffer_tree.c
+++ b/buffer_tree.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2009-2012 Andre Noll <maan@systemlinux.org>
+ * Copyright (C) 2009 Andre Noll <maan@tuebingen.mpg.de>
  *
  * Licensed under the GPL v2. For licencing details see COPYING.
  */
@@ -544,14 +544,16 @@ static bool btr_no_children(struct btr_node *btrn)
 }
 
 /**
- * Find out whether a node is an orphan node.
+ * Find out whether a node is an orphan.
  *
  * \param btrn The buffer tree node.
  *
  * \return True if \a btrn has no parent.
  *
- * This function will always return true for the root node.  However in case
- * nodes have been removed from the tree, other nodes may become orphans too.
+ * This function returns true for the root node and false for any other node.
+ *
+ * After a (non-leaf) node was removed removed from the tree, the function
+ * returns true for all child nodes.
  */
 bool btr_no_parent(struct btr_node *btrn)
 {
@@ -769,6 +771,12 @@ void btr_drain(struct btr_node *btrn)
 		btr_drop_buffer_reference(br);
 }
 
+static void btr_free_node(struct btr_node *btrn)
+{
+	free(btrn->name);
+	free(btrn);
+}
+
 /**
  * Remove a node from a buffer tree.
  *
@@ -796,8 +804,7 @@ void btr_remove_node(struct btr_node **btrnp)
 	btr_drain(btrn);
 	if (btrn->parent)
 		list_del(&btrn->node);
-	free(btrn->name);
-	free(btrn);
+	btr_free_node(btrn);
 out:
 	*btrnp = NULL;
 }
@@ -833,7 +840,7 @@ size_t btr_get_input_queue_size(struct btr_node *btrn)
 /**
  * Remove a node from the buffer tree, reconnecting parent and children.
  *
- * \param btrn The node to splice out.
+ * \param btrnp The node to splice out.
  *
  * This function is used by buffer tree nodes that do not exist during the
  * whole lifetime of the buffer tree. Unlike btr_remove_node(), calling
@@ -841,9 +848,9 @@ size_t btr_get_input_queue_size(struct btr_node *btrn)
  * but reconnects the buffer tree by making all child nodes of \a btrn children
  * of the parent of \a btrn.
  */
-void btr_splice_out_node(struct btr_node *btrn)
+void btr_splice_out_node(struct btr_node **btrnp)
 {
-	struct btr_node *ch, *tmp;
+	struct btr_node *btrn = *btrnp, *ch, *tmp;
 
 	assert(btrn);
 	PARA_NOTICE_LOG("splicing out %s\n", btrn->name);
@@ -856,9 +863,12 @@ void btr_splice_out_node(struct btr_node *btrn)
 		ch->parent = btrn->parent;
 		if (btrn->parent)
 			list_move(&ch->node, &btrn->parent->children);
+		else
+			list_del(&ch->node);
 	}
 	assert(list_empty(&btrn->children));
-	btrn->parent = NULL;
+	btr_free_node(btrn);
+	*btrnp = NULL;
 }
 
 /**
@@ -1199,21 +1209,20 @@ int btr_node_status(struct btr_node *btrn, size_t min_iqs,
 	size_t iqs;
 
 	assert(btrn);
-	if (type != BTR_NT_LEAF) {
-		if (btr_no_children(btrn))
-			return -E_BTR_NO_CHILD;
-		if (btr_get_output_queue_size(btrn) > BTRN_MAX_PENDING)
-			return 0;
-	}
-	if (type != BTR_NT_ROOT) {
-		if (btr_eof(btrn))
-			return -E_BTR_EOF;
-		iqs = btr_get_input_queue_size(btrn);
-		if (iqs == 0) /* we have a parent, because not eof */
-			return 0;
-		if (iqs < min_iqs && !btr_no_parent(btrn))
-			return 0;
-	}
+	if (type != BTR_NT_LEAF && btr_no_children(btrn))
+		return -E_BTR_NO_CHILD;
+	if (type != BTR_NT_ROOT && btr_eof(btrn))
+		return -E_BTR_EOF;
+
+	if (btr_get_output_queue_size(btrn) > BTRN_MAX_PENDING)
+		return 0;
+	if (type == BTR_NT_ROOT)
+		return 1;
+	iqs = btr_get_input_queue_size(btrn);
+	if (iqs == 0) /* we have a parent, because not eof */
+		return 0;
+	if (iqs < min_iqs && !btr_no_parent(btrn))
+		return 0;
 	return 1;
 }
 
@@ -1230,6 +1239,16 @@ void btr_get_node_start(struct btr_node *btrn, struct timeval *tv)
 	*tv = btrn->start;
 }
 
+/**
+ * Get the parent node of a buffer tree node.
+ *
+ * \param btrn The node whose parent should be returned.
+ *
+ * \a btrn must not be \p NULL.
+ *
+ * \return The parent of \a btrn, or \p NULL if \a btrn is the
+ * root node of the buffer tree.
+ */
 struct btr_node *btr_parent(struct btr_node *btrn)
 {
 	return btrn->parent;