todo

chord 源码 http://pdos.csail.mit.edu/chord/

RFCs:
http://www.eyrie.org/~eagle/nntp/rfcs/rfc977.txt
http://www.ietf.org/rfc/rfc2980.txt
http://www.faqs.org/rfcs/rfc1036.html

rfc1036:
 check for headers: from, subject, newsgroups
 add certain headers when accepting or sending news articles
  Date, Message-ID, Path, NNTP-Posting-host
 handle control messages:
  cancel, version, checkgroups, sendsys, newgroup, rmgroup, ihave/sendme

+fix line counts
+filter out (potential) tabs in XOVER responses

better record format for group_db. currently is a flat list
+add timeouts to nntp connections
+recheck fdcb output
store in DHash. plan:
  receive article
+  split into header and body.
+  store both in dhash
+  feed header to indexing code
   send header to other nodes
  receive header
   feed header to indexing code
   send header to other nodes
+ msg overview
+  fetch header info from header_db
+ read article by num
+  fetch record from group_db
+  use chordID to fetch article from dhash
+  read article by msgid
+   fetch header from header_db??
+   use chordID to fetch article from dhash

===
Maybe switch to optionally storing with inodes.  Maybe add support for
statistics... log size of articles.

Need a good logging scheme.

Add a hook to record an incoming NNTP stream? with timestamps for each
command??  And then a tool to replay it.


===
garbage:
 send article plan:
  broadcast server public key once per day
  use public key for log of article headers

 get header plan:
  receive server keys and cache them
  check other logs several times per day??