From 8e8b3f650d48f7a24e334e401ca9d68f397b1f50 Mon Sep 17 00:00:00 2001
From: 20kdc <asdd2808@gmail.com>
Date: Mon, 20 Mar 2017 16:14:36 +0000
Subject: [PATCH] Make relib relatively backend-independent, increase the max
 timers to 0x400.

relib now relies on an additional parameter which should be
 require("culib"), but could instead be a Copper-like library.
---
 oc/occure.lua |  8 +++++---
 relib.lua     | 38 ++++++++++++++++++++++++++++++--------
 2 files changed, 35 insertions(+), 11 deletions(-)

diff --git a/oc/occure.lua b/oc/occure.lua
index 7bdad9f..c382d59 100644
--- a/oc/occure.lua
+++ b/oc/occure.lua
@@ -19,6 +19,7 @@ if package.loaded["occure"] then
   error("Already installed")
 end
 
+local culib = require("culib")
 local node = require("relib")(host, function (tgt, data)
   for _, v in ipairs(modems) do
     if tgt then
@@ -29,15 +30,16 @@ local node = require("relib")(host, function (tgt, data)
   end
 end, function (...)
   computer.pushSignal("copper_packet", ...)
-end, computer.uptime)
-
-package.loaded["occure"] = node
+end, computer.uptime, culib)
 
 for v, _ in component.list("modem") do
   local m = component.proxy(v)
   table.insert(modems, m)
   m.open(4957)
 end
+
+package.loaded["occure"] = node
+
 event.listen("modem_message", function (et, adto, adfrom, port, dist, magic, data)
   if et ~= "modem_message" then return end
   if port == 4957 then
diff --git a/relib.lua b/relib.lua
index 2e15a08..9add9f9 100644
--- a/relib.lua
+++ b/relib.lua
@@ -4,16 +4,34 @@
 -- Copper Reliability Layer
 -- Notably, this should be instantiated rather than the normal Copper instance.
 
-local culib = require("culib")
+-- The Copper node constructor (which could be replaced with something else,
+--  should you decide to run the Reliability layer over another transport)
+--  is passed as function (hostname, transmit, onReceive, time),
+--  where hostname is the hostname given,
+--  transmit is the (target/nil (for broadcast), data) function as given,
+--  onReceive is the (nfrom. nto, ndata) function
+--   internal to the Reliability Layer to translate packets for onRReceive
+--   and acknowledge packets that need to be acknowledged,
+--  and time is the function-that-returns-current-time-in-seconds
+--   function as given.
+
+-- The resulting Copper-like node should have the following fields:
+-- node.hostname: Editable hostname.
+-- node.refresh(): Do various timed cleanup tasks.
+-- node.input(...): relib.input is set to this for convenience.
+--                  Ought to be function (opaqueFrom, data).
+-- node.output(nFrom, nTo, data): The normal Copper send function.
 
 -- onRReceive is now: (from, to, port, data, unreliablePacket)
--- where to can be anything for unreliable packets, but otherwise is the current hostname.
-return function (hostname, transmit, onRReceive, time)
+-- where to can be anything for unreliable packets,
+--  but otherwise is the current hostname.
+return function (hostname, transmit, onRReceive, time, culib)
 	-- node.hostname should be used for hostname generally.
 	local node
 
-	-- The maximum amount of timers (used to cap memory usage)
-	local tuningMaxTimers = 0x200
+	-- The maximum amount of timers (used to cap memory usage).
+	-- Assuming 16 bytes per key, this should be 64k.
+	local tuningMaxTimers = 0x400
 	local tuningClearAntiduplicate = 60
 	local tuningAttempts = 12
 	local tuningAttemptTime = 2.5
@@ -78,15 +96,19 @@ return function (hostname, transmit, onRReceive, time)
 			if nto ~= node.hostname then return end
 			node.output(nto, nfrom, data:sub(1, 6) .. "\x02")
 		end
+		-- Ignore ACKs for our packets that aren't going our way.
+		-- (Just a fringe case of packet ID reuse)
+		if nto ~= node.hostname then
+			return
+		end
 		if (tp == 0x02) and needsAck[nfrom .. globalId] then
 			needsAck[nfrom .. globalId][1](nfrom)
 			killTimer(needsAck[nfrom .. globalId][2])
 			needsAck[nfrom .. globalId] = nil
 		end
-		if nto ~= node.hostname then
-			return
-		end
 	end
+
+	-- Instantiate the node or lookalike.
 	node = culib(hostname, transmit, onReceive, time)
 
 	local relib = {}