Status: Draft/Experiment
Proposed new discovery/changegroup protocol
The wire protocol has several flaws:
- it uses the roots of the new branches, this is susceptible to a race (see issue1320) .
- if the client is missing a lot of nodes but doesn't have any local changes, it will still have to do a lot of roundtrips to discover the base nodes.
See WireProtocol for the current protocol.
Overview
The Protocol
The current changegroup() uses base nodes, it should instead use common nodes. changegroup(roots)
- roots = a list of the latest nodes on every service side changeset branch that both the client and server know about.
find all changesets descended from roots and return them as a single changegroup
A changegroup is a single stream containing:
- a changelog group
- a manifest group
- a list of
- filename length
- filename
- file group (terminated by a zero length filename)
A group is a list of chunks:
- chunk length
- self hash, p1 hash, p2 hash, link hash
- uncompressed delta to p1 (or optionally to the previous node)
- (terminated by a zero length chunk)
Wishlist
- Estimate early how much data or items have to be transfered and communicate this to the other side, so a progress indicator could be more useful.
-- ThomasArendsenHein 2008-10-24 14:23:01