From 72da7180158c2c566f78dce38b11323c4fe9ef15 Mon Sep 17 00:00:00 2001
From: Mikayla Fischler <mikayla@ky8.io>
Date: Fri, 13 May 2022 11:38:56 -0400
Subject: [PATCH] optimized session lookup

---
 supervisor/session/svsessions.lua | 41 ++++++++++++++++++++++++++++---
 supervisor/startup.lua            |  2 +-
 supervisor/supervisor.lua         | 15 ++++++++---
 3 files changed, 51 insertions(+), 7 deletions(-)

diff --git a/supervisor/session/svsessions.lua b/supervisor/session/svsessions.lua
index 635e81e..88c57cd 100644
--- a/supervisor/session/svsessions.lua
+++ b/supervisor/session/svsessions.lua
@@ -125,10 +125,38 @@ svsessions.link_modem = function (modem)
     self.modem = modem
 end
 
--- find a session by the remote port
+-- find an RTU session by the remote port
+---@param remote_port integer
+---@return rtu_session_struct|nil
+svsessions.find_rtu_session = function (remote_port)
+    -- check RTU sessions
+    for i = 1, #self.rtu_sessions do
+        if self.rtu_sessions[i].r_port == remote_port then
+            return self.rtu_sessions[i]
+        end
+    end
+
+    return nil
+end
+
+-- find a PLC session by the remote port
+---@param remote_port integer
+---@return plc_session_struct|nil
+svsessions.find_plc_session = function (remote_port)
+    -- check PLC sessions
+    for i = 1, #self.plc_sessions do
+        if self.plc_sessions[i].r_port == remote_port then
+            return self.plc_sessions[i]
+        end
+    end
+
+    return nil
+end
+
+-- find a PLC/RTU session by the remote port
 ---@param remote_port integer
 ---@return plc_session_struct|rtu_session_struct|nil
-svsessions.find_session = function (remote_port)
+svsessions.find_device_session = function (remote_port)
     -- check RTU sessions
     for i = 1, #self.rtu_sessions do
         if self.rtu_sessions[i].r_port == remote_port then
@@ -143,6 +171,13 @@ svsessions.find_session = function (remote_port)
         end
     end
 
+    return nil
+end
+
+-- find a coordinator session by the remote port
+---@param remote_port integer
+---@return nil
+svsessions.find_coord_session = function (remote_port)
     -- check coordinator sessions
     for i = 1, #self.coord_sessions do
         if self.coord_sessions[i].r_port == remote_port then
@@ -155,7 +190,7 @@ end
 
 -- get a session by reactor ID
 ---@param reactor integer
----@return plc_session_struct session
+---@return plc_session_struct|nil session
 svsessions.get_reactor_session = function (reactor)
     local session = nil
 
diff --git a/supervisor/startup.lua b/supervisor/startup.lua
index b559bf0..16725b6 100644
--- a/supervisor/startup.lua
+++ b/supervisor/startup.lua
@@ -11,7 +11,7 @@ local svsessions = require("supervisor.session.svsessions")
 local config = require("supervisor.config")
 local supervisor = require("supervisor.supervisor")
 
-local SUPERVISOR_VERSION = "alpha-v0.3.6"
+local SUPERVISOR_VERSION = "alpha-v0.3.7"
 
 local print = util.print
 local println = util.println
diff --git a/supervisor/supervisor.lua b/supervisor/supervisor.lua
index 5596cb8..3a176cb 100644
--- a/supervisor/supervisor.lua
+++ b/supervisor/supervisor.lua
@@ -149,10 +149,10 @@ supervisor.comms = function (num_reactors, modem, dev_listen, coord_listen)
 
             -- device (RTU/PLC) listening channel
             if l_port == self.dev_listen then
-                -- look for an associated session
-                local session = svsessions.find_session(r_port)
-
                 if protocol == PROTOCOLS.MODBUS_TCP then
+                    -- look for an associated session
+                    local session = svsessions.find_rtu_session(r_port)
+
                     -- MODBUS response
                     if session ~= nil then
                         -- pass the packet onto the session handler
@@ -162,6 +162,9 @@ supervisor.comms = function (num_reactors, modem, dev_listen, coord_listen)
                         log.debug("discarding MODBUS_TCP packet without a known session")
                     end
                 elseif protocol == PROTOCOLS.RPLC then
+                    -- look for an associated session
+                    local session = svsessions.find_plc_session(r_port)
+
                     -- reactor PLC packet
                     if session ~= nil then
                         if packet.type == RPLC_TYPES.LINK_REQ then
@@ -200,6 +203,9 @@ supervisor.comms = function (num_reactors, modem, dev_listen, coord_listen)
                         end
                     end
                 elseif protocol == PROTOCOLS.SCADA_MGMT then
+                    -- look for an associated session
+                    local session = svsessions.find_device_session(r_port)
+
                     -- SCADA management packet
                     if session ~= nil then
                         -- pass the packet onto the session handler
@@ -222,6 +228,9 @@ supervisor.comms = function (num_reactors, modem, dev_listen, coord_listen)
                 end
             -- coordinator listening channel
             elseif l_port == self.coord_listen then
+                -- look for an associated session
+                local session = svsessions.find_coord_session(r_port)
+
                 if protocol == PROTOCOLS.SCADA_MGMT then
                     -- SCADA management packet
                 elseif protocol == PROTOCOLS.COORD_DATA then