Add documentation for readnode().

1 files changed, 9 insertions, 0 deletions

diff --git a/c_src/permdb.c b/c_src/permdb.c
index 08052fc..3928e1d 100644
--- a/c_src/permdb.c
+++ b/c_src/permdb.c
@@ -569,6 +569,15 @@ iserrornode(node_object node)
                 && node.data[3] == NODE_ENTRY_ERROR_NODE;
 }
 
+/*
+ * Returns node at OFFSET in the index file.
+ *
+ * If CACHEKEY is not NULL, looks for CACHEKEY in the dirtynodes list
+ * and the cache before reading the index file.
+ *
+ * If CACHEKEY is not NULL, the node is put in the cache under that
+ * key.
+ */
 static node_object
 readnode(permdb_object *state, node_offset offset, const ps_string *cachekey)
 {