[PATCH 1 of 8] obsstore: add some documentation about the marker fields

[Pierre-Yves David]

# HG changeset patch
# User Pierre-Yves David <pierre-yves.david at fb.com>
# Date 1408484528 25200
#      Tue Aug 19 14:42:08 2014 -0700
# Node ID 4f98bcae042935c4b51336dfc5971458826bbcbf
# Parent  33d51be18d45556179966cd3d66833764f4c6de2
obsstore: add some documentation about the marker fields

As the number of field growth it make sense to start documenting their content.

diff --git a/mercurial/obsolete.py b/mercurial/obsolete.py
--- a/mercurial/obsolete.py
+++ b/mercurial/obsolete.py
@@ -241,10 +241,15 @@ class obsstore(object):
     - precursors[x] -> set(markers on precursors edges of x)
     - successors[x] -> set(markers on successors edges of x)
     """
 
     fields = ('prec', 'succs', 'flag', 'meta', 'date')
+    # prec:   nodeid, precursor changesets
+    # succes: tuple of nodeid, successors changesets (0-N length)
+    # flag:   integer, flag field carrying modifier for the markers (see doc)
+    # meta:   binary blob, encoded metadata dictionnary
+    # date:   (float, int) tuple, date of markers creation
 
     def __init__(self, sopener):
         # caches for various obsolescence related cache
         self.caches = {}
         self._all = []