supervisor sessions work in progress

supervisor/session/svsessions.lua

@@ -0,0 +1,141 @@
+-- #REQUIRES mqueue.lua
+-- #REQUIRES log.lua
+
+-- Supervisor Sessions Handler
+
+SESSION_TYPE = {
+    RTU_SESSION = 0,
+    PLC_SESSION = 1,
+    COORD_SESSION = 2
+}
+
+local self = {
+    num_reactors = 0,
+    rtu_sessions = {},
+    plc_sessions = {},
+    coord_sessions = {},
+    next_rtu_id = 0,
+    next_plc_id = 0,
+    next_coord_id = 0
+}
+
+function alloc_reactor_plcs(num_reactors)
+    self.num_reactors = num_reactors
+    for i = 1, num_reactors do
+        table.insert(self.plc_sessions, false)
+    end
+end
+
+function find_session(stype, remote_port)
+    if stype == SESSION_TYPE.RTU_SESSION then
+        for i = 1, #self.rtu_sessions do
+            if self.rtu_sessions[i].r_host == remote_port then
+                return self.rtu_sessions[i]
+            end
+        end
+    elseif stype == SESSION_TYPE.PLC_SESSION then
+        for i = 1, #self.plc_sessions do
+            if self.plc_sessions[i].r_host == remote_port then
+                return self.plc_sessions[i]
+            end
+        end
+    elseif stype == SESSION_TYPE.COORD_SESSION then
+        for i = 1, #self.coord_sessions do
+            if self.coord_sessions[i].r_host == remote_port then
+                return self.coord_sessions[i]
+            end
+        end
+    else
+        log._error("cannot search for unknown session type " .. stype, true)
+    end
+
+    return nil
+end
+
+function get_reactor_session(reactor)
+    local session = nil
+
+    for i = 1, #self.plc_sessions do
+        if self.plc_sessions[i].reactor == reactor then
+            session = self.plc_sessions[i]
+        end
+    end
+
+    return session
+end
+
+function establish_plc_session(remote_port, for_reactor)
+    if get_reactor_session(for_reactor) == nil then 
+        local plc_s = {
+            open = true,
+            reactor = for_reactor,
+            r_host = remote_port,
+            in_queue = mqueue.new(),
+            out_queue = mqueue.new(),
+            instance = nil
+        }
+
+        plc_s.instance = plc.new_session(next_plc_id, plc_s.in_queue, plc_s.out_queue)
+        table.insert(self.plc_sessions, plc_s)
+        next_plc_id = next_plc_id + 1
+
+        -- success
+        return plc_s.instance.get_id()
+    else
+        -- reactor already assigned to a PLC
+        return false
+    end
+end
+
+local function _iterate(sessions)
+    for i = 1, #sessions do
+        local session = sessions[i]
+        if session.open then
+            local ok = session.instance.iterate()
+            if not ok then
+                session.open = false
+                session.instance.close()
+            end
+        end
+    end
+end
+
+function iterate_all()
+    -- iterate RTU sessions
+    _iterate(self.rtu_sessions)
+
+    -- iterate PLC sessions
+    _iterate(self.plc_sessions)
+
+    -- iterate coordinator sessions
+    _iterate(self.coord_sessions)
+end
+
+local function _free_closed(sessions)
+    local move_to = 1
+    for i = 1, #sessions do
+        local session = sessions[i]
+        if session ~= nil then
+            if sessions[i].open then
+                if sessions[move_to] == nil then
+                    sessions[move_to] = session
+                    sessions[i] = nil
+                end
+                move_to = move_to + 1
+            else
+                sessions[i] = nil
+            end
+        end
+    end
+end
+
+function free_all_closed()
+    -- free closed RTU sessions
+    _free_closed(self.rtu_sessions)
+
+    -- free closed PLC sessions
+    _free_closed(self.plc_sessions)
+
+    -- free closed coordinator sessions
+    _free_closed(self.coord_sessions)
+end