From 25c49be89284972a798a16dab0096240326f48fb Mon Sep 17 00:00:00 2001
From: Bart Van Der Meerssche <bart.vandermeerssche@flukso.net>
Date: Mon, 19 Apr 2010 23:34:07 +0200
Subject: [PATCH] Reversed the chaining order in the flukso daemon

---
 openwrt/package/flukso/src/flukso.lua | 81 +++++++++++++++------------
 1 file changed, 46 insertions(+), 35 deletions(-)

diff --git a/openwrt/package/flukso/src/flukso.lua b/openwrt/package/flukso/src/flukso.lua
index b4df185..9bdea33 100755
--- a/openwrt/package/flukso/src/flukso.lua
+++ b/openwrt/package/flukso/src/flukso.lua
@@ -3,6 +3,7 @@
 --
 -- flukso.lua: flukso deamon running on openwrt
 -- Copyright (c) 2008-2009 jokamajo.org
+--               2010      flukso.net
 --
 -- This program is free software; you can redistribute it and/or
 -- modify it under the terms of the GNU General Public License
@@ -37,8 +38,8 @@ local param = {xmlrpcaddress = 'http://logger.flukso.net/xmlrpc',
                device        = '/dev/ttyS0',
                interval      = 300}
 
-function receive(device, pwraddress, pwrport, pwrenable)
-  return coroutine.wrap(function()
+function receive(child, device, pwraddress, pwrport, pwrenable)
+  return coroutine.create(function()
     -- open the connection to the syslog deamon, specifying our identity
     posix.openlog('flukso')
     posix.syslog(30, 'starting the flukso deamon')
@@ -59,7 +60,7 @@ function receive(device, pwraddress, pwrport, pwrenable)
         os.execute('gpioctl set 4 > /dev/null')
 
         local meter, value = line:sub(5, 36), tonumber(line:sub(38))
-        coroutine.yield(meter, os.time(), value)
+        coroutine.resume(child, meter, os.time(), value)
       elseif line:sub(1, 3) == 'pwr' and line:len() == 47 and line:find(':') == 37 then -- user data + additional data integrity checks
         if pwrenable then udp:send(line) end
       elseif line:sub(1, 3) == 'msg' then -- control data
@@ -74,36 +75,35 @@ function receive(device, pwraddress, pwrport, pwrenable)
   end)
 end
 
-function buffer(source, interval)
-  return coroutine.wrap(function()
+function buffer(child, interval)
+  return coroutine.create(function(meter, timestamp, value)
     local measurements = data.new()
     local threshold = os.time() + interval
 
     while true do
-      local meter, timestamp, value = source()
       if meter ~= nil and timestamp > 1234567890 then measurements:add(meter, timestamp, value) end
       if timestamp > threshold and next(measurements) then  --checking whether table is not empty
-        coroutine.yield(measurements)
+        coroutine.resume(child, measurements)
         threshold = timestamp + interval
       end
+      meter, timestamp, value = coroutine.yield()
     end
   end)
 end
 
-function filter(source, span, offset)
-  return coroutine.wrap(function()
+function filter(child, span, offset)
+  return coroutine.create(function(measurements)
     while true do
-      local measurements = source()
       measurements:filter(span, offset)
-      coroutine.yield(measurements)
+      coroutine.resume(child, measurements)
+      measurements = coroutine.yield()
     end
   end)
 end
 
-function send(source, address, version, method)
-  return coroutine.wrap(function()
+function send(child, address, version, method)
+  return coroutine.create(function(measurements)
     while true do
-      local measurements = source()
       local auth = auth.new()
       auth:load()
       auth:hmac(measurements)
@@ -122,19 +122,29 @@ function send(source, address, version, method)
       else
         posix.syslog(27, tostring(ret_or_err)..' '..address..' '..tostring(res))
       end
-      coroutine.yield(measurements)
+      coroutine.resume(child, measurements)
+      measurements = coroutine.yield()
     end
   end)
 end
 
-function gc(source)
-  return coroutine.wrap(function()
+function gc(child)
+  return coroutine.create(function(measurements)
     while true do
-      local measurements = source()
       posix.syslog(31, tostring(collectgarbage('count')*1024)..' bytes of memory used by Lua before garbage collection cycle')
       collectgarbage() -- force a complete garbage collection cycle
       posix.syslog(31, tostring(collectgarbage('count')*1024)..' bytes of memory used by Lua after garbage collection cycle')
-      coroutine.yield(measurements)
+      coroutine.resume(child, measurements)
+      measurements = coroutine.yield()
+    end
+  end)
+end
+
+function debug()
+  return coroutine.create(function(measurements)
+    while true do
+      dbg.vardump(measurements)
+      measurements = coroutine.yield()
     end
   end)
 end
@@ -144,21 +154,22 @@ end
 -- filter: sweep recursively to filter all redundant entries
 -- send: report the measurements to the server via xmlrpc
 -- gc: perform a full garbage collection cycle
+-- debug: dump measurements table to stdout
 
-local aggregator = gc(
-                     send(
-                       filter(
-                         filter(
-                           filter(
-                             buffer(
-                               receive(param.device, param.pwraddress, param.pwrport, param.pwrenable)
-                             , param.interval)
-                           , 60, 0)
-                         , 900, 7200)
-                       , 86400, 172800)
-                     , param.xmlrpcaddress, param.xmlrpcversion, param.xmlrpcmethod)
-                   )
+local chain = receive(
+                buffer(
+                  filter(
+                    filter(
+                      filter(
+                        send(
+                          gc(
+                            debug()
+                          )
+                        , param.xmlrpcaddress, param.xmlrpcversion, param.xmlrpcmethod)
+                      , 86400, 172800)
+                    , 900, 7200)
+                  , 60, 0)
+                , param.interval)
+              , param.device, param.pwraddress, param.pwrport, param.pwrenable)
 
-while true do
-  dbg.vardump(aggregator())
-end
+coroutine.resume(chain)