diff options
Diffstat (limited to 'src/channel.moon')
| -rw-r--r-- | src/channel.moon | 25 |
1 files changed, 15 insertions, 10 deletions
diff --git a/src/channel.moon b/src/channel.moon index 968ae09..6f87d46 100644 --- a/src/channel.moon +++ b/src/channel.moon @@ -34,26 +34,31 @@ class FaultyChannel extends Channel @avg_latency = 0 -- in ms @latency_std = 0 -- Latency can never be below 0, but can go up as much as it likes - @avg_loss = 0 -- between 0 (never) and 1 (always) - @loss_std = 0.1 - -- Loss is always a percentage between 0 and 1 + @loss = 0.1 -- between 0 (never) and 1 (always) super(settings) - normal: (avg, std, n) => + @normal_at: (avg, std, n) -> assert(avg and std and n, string.format("normal(avg, std, n) called with %q %q %q", tostring(avg), tostring(std), tostring(n))) -- Normal curve probability at N (1/ (math.sqrt(2*math.pi) * avg)) * math.exp(-(n - avg)^2 / (2 * (std^2))) + @normal: (avg, std) => + -- Box-Muller transform + bm = math.sqrt(-2 * math.log(math.random())) * math.cos(2 * math.pi * math.random()) + -- Box-Muller gives us std = e^-0.5 , avg = 0 + ((bm / math.exp(-1/2)) * std) + avg poll: => @pump! #@buffer > 0 send: (message) => -- Do we deliver? - if @normal(@avg_loss, @loss_std, math.random()) < 0.5 + rng = math.random() + if @loss > rng return -- How long does it take? - time = @normal(@avg_latency, @latency_std, math.random()) + -- Only uses the positive half of the normal distribution, double the standard deviation? + time = @@normal(@avg_latency, @latency_std * 2, math.random()) if time < 0 then time = 0 -- We can't deliver messages in the past - table.insert(@to_deliver, {message,time}) + table.insert(@to_deliver, {message,@@time + time}) recv: => @pump! table.remove(@buffer, 1) @@ -62,11 +67,11 @@ class FaultyChannel extends Channel deliver_len = #@to_deliver for k,tbl in ipairs(@to_deliver) {m, t} = tbl + @to_deliver[defrag] = tbl if @@time > t - @to_deliver[k] = nil table.insert(@buffer, m) - if @to_deliver[defrag] == nil - @to_deliver[defrag] = tbl + else + defrag = defrag + 1 for i = defrag, deliver_len do @to_deliver[i] = nil |