http://neil.fraser.name/writing/sync/

file persistence could be just another client with deliberate huge

latency to save on disk writes?

    ------------------

    server master

    per-client shadow

    client shadow

    client master

    ------------------

client edits write to clientmaster. client also reads from there.

When the last update is done,

graph: (s1 p1 o1)

client1 writes a loose patch: del (s1 p1 *), add (s1 p1 o2)

client2 gets in another loose patch first: del (s1 p1 *), add (s1 p1 o3)

on the server, we make an invertible patch: del (s1 p1 o1), add (s1 p1 o2)

then another invertible patch: del (s1 p1 o2), add (s1 p1 o3)

some clients need this patch: del (s1 p1 o1), add (s1 p1 o3)

client1 needs this patch: del (s1 p1 o1), add (s1 p1 o2)

---------

graph: ()

client1 writes a patch: add (s1, p1, o1)

client2 writes a patch: add (s1, p1, o1)

on the server, client2's patch is rewritten to no-op.