new function combox.file.node_path.

This function takes the path to the file in the combox and returns the
path of its first shard in the node directory. If the the given
argument is a directory (inside the combox directory), the function
returns the corresponding path of the directory under the first node
directory.

Test for the function was also written.

	modified:   combox/file.py
	modified:   tests/file_test.py

1 files changed, 22 insertions, 0 deletions

diff --git a/combox/file.py b/combox/file.py
index 3b3219e..959954a 100644
--- a/combox/file.py
+++ b/combox/file.py
@@ -69,6 +69,28 @@ def cb_path(node_path, config):
     return file_cb_path
 
 
+def node_path(cb_path, config):
+    """Returns abs. path of file (in node dir.) given the cb_path (combox dir. path).
+
+    If cb_path is a file, it returns the path to its first shard in
+    the first node directory.
+
+    """
+
+    if path.isfile(cb_path):
+        # partition function is used to remove the `.shard.N' from the
+        # file name.
+        rel_file_path = relative_path(cb_path, config)
+        file_node_path = path.join(get_nodedirs(config)[0],
+                                 rel_file_path)
+        file_node_path = "%s.shard0" % file_node_path
+    else:
+        file_node_path = path.join(get_nodedirs(config)[0],
+                                   relative_path(cb_path, config))
+
+    return file_node_path
+
+
 def mk_nodedir(directory, config):
     """
     Creates directory `directory' inside the nodes.