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CSP: Two way sync for an arbitrary n inputs from either client

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Nicholas Kariniemi 2015-12-01 20:10:07 +02:00
parent 7d37ea3cf0
commit 6bc934c647
1 changed files with 12 additions and 2 deletions
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csp/sync.csp
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@ -54,7 +54,7 @@ assert SYSTEM :[divergence-free]
-- One way sync: changes on one client will sync to other client
-----------------------------------------
-- Suppose we limit our specification to say that each
-- Suppose we limit our implemenetation to say that each
-- user makes a finite number of changes n.
MaxInputs(0) = STOP
MaxInputs(n) = up?i?t -> MaxInputs(n-1)
@ -102,3 +102,13 @@ TwoWaySyncRender = ((render.0.2 -> render.1.2 -> STOP) |~|
(render.1.2 -> render.0.2 -> STOP))
assert TwoWaySync [FD= (SYSTEM [|{| up |}|] AlternateInputs) \diff(Events, union(union(productions(up.0), productions(up.1)), {render.0.2, render.1.2}))
-- Let's extend this to an arbitrary number of inputs from either client (we don't care which). In the end we expect both to render the same DB state.
-- This is basically the general specification for eventual consistency. We are saying that supposing n finite inputs
-- from either client, eventually both of the clients get in sync and then stop.
Sync(n) = (up.0.0 -> Sync'(n, n-1)) |~| (up.1.0 -> Sync'(n, n-1))
Sync'(n, 0) = (render.0.n -> render.1.n -> STOP) |~| (render.1.n -> render.0.n -> STOP)
Sync'(n, m) = |~| i:CLIENTS, t:TIMES @ up!i!t -> Sync'(n, m-1)
assert Sync(5) [FD= (SYSTEM [|{| up |}|] MaxInputs(5)) \diff(Events, union(productions(up), {render.0.5, render.1.5}))