From 435ded0c60906c6db23e6567da3ca2c13ce42eb6 Mon Sep 17 00:00:00 2001
From: Nils Schneider <nils@nilsschneider.net>
Date: Mon, 31 Aug 2015 19:56:21 +0200
Subject: [PATCH 1/2] gluon-announce: build a tree of functions first

collect_dir() will now pre-load all files and return a function that will
collect all information.
---
 .../files/usr/lib/lua/gluon/announce.lua      | 28 +++++++++++++------
 .../files/usr/lib/lua/gluon/announced.lua     |  7 ++++-
 2 files changed, 26 insertions(+), 9 deletions(-)

diff --git a/package/gluon-announce/files/usr/lib/lua/gluon/announce.lua b/package/gluon-announce/files/usr/lib/lua/gluon/announce.lua
index 444dbd33..8a91e6f8 100644
--- a/package/gluon-announce/files/usr/lib/lua/gluon/announce.lua
+++ b/package/gluon-announce/files/usr/lib/lua/gluon/announce.lua
@@ -10,24 +10,36 @@ local function collect_entry(entry)
 	if fs.stat(entry, 'type') == 'dir' then
 		return collect_dir(entry)
 	else
-		return setfenv(loadfile(entry), _M)()
+		return loadfile(entry)
 	end
 end
 
 function collect_dir(dir)
-	local ret = { [{}] = true }
+	local fns = {}
 
 	for entry in fs.dir(dir) do
 		if entry:sub(1, 1) ~= '.' then
-			local ok, val = pcall(collect_entry, dir .. '/' .. entry)
-			if ok then
-				ret[entry] = val
+			local fn, err = collect_entry(dir .. '/' .. entry)
+			if fn then
+				fns[entry] = fn
 			else
-				io.stderr:write(val, '\n')
+				io.stderr:write(err, '\n')
 			end
 		end
 	end
 
-	return ret
-end
+	return function ()
+		local ret = { [{}] = true }
 
+		for k, v in pairs(fns) do
+			local ok, val = pcall(setfenv(v, _M))
+			if ok then
+				ret[k] = val
+			else
+				io.stderr:write(val, '\n')
+			end
+		end
+
+		return ret
+	end
+end
diff --git a/package/gluon-announced/files/usr/lib/lua/gluon/announced.lua b/package/gluon-announced/files/usr/lib/lua/gluon/announced.lua
index a9de80e6..af2291fe 100644
--- a/package/gluon-announced/files/usr/lib/lua/gluon/announced.lua
+++ b/package/gluon-announced/files/usr/lib/lua/gluon/announced.lua
@@ -2,9 +2,14 @@ local announce = require 'gluon.announce'
 local deflate = require 'deflate'
 local json = require 'luci.jsonc'
 
+local memoize = {}
 
 local function collect(type)
-  return announce.collect_dir('/lib/gluon/announce/' .. type .. '.d')
+  if not memoize[type] then
+    memoize[type] = announce.collect_dir('/lib/gluon/announce/' .. type .. '.d')
+  end
+
+  return memoize[type]()
 end
 
 

From 9dffb1284ffed3b1efaccca292c6fbe009993f5b Mon Sep 17 00:00:00 2001
From: Nils Schneider <nils@nilsschneider.net>
Date: Tue, 1 Sep 2015 18:09:00 +0200
Subject: [PATCH 2/2] gluon-announce(d): preload functions, collectgarbage

By calling collectgarbage() at various places I was able to reduce heap
usage by ~270kb.
---
 .../files/usr/lib/lua/gluon/announce.lua      |  6 ++++
 .../files/usr/lib/lua/gluon/announced.lua     | 30 +++++++++++++------
 2 files changed, 27 insertions(+), 9 deletions(-)

diff --git a/package/gluon-announce/files/usr/lib/lua/gluon/announce.lua b/package/gluon-announce/files/usr/lib/lua/gluon/announce.lua
index 8a91e6f8..29a1f817 100644
--- a/package/gluon-announce/files/usr/lib/lua/gluon/announce.lua
+++ b/package/gluon-announce/files/usr/lib/lua/gluon/announce.lua
@@ -19,7 +19,9 @@ function collect_dir(dir)
 
 	for entry in fs.dir(dir) do
 		if entry:sub(1, 1) ~= '.' then
+			collectgarbage()
 			local fn, err = collect_entry(dir .. '/' .. entry)
+
 			if fn then
 				fns[entry] = fn
 			else
@@ -32,7 +34,9 @@ function collect_dir(dir)
 		local ret = { [{}] = true }
 
 		for k, v in pairs(fns) do
+			collectgarbage()
 			local ok, val = pcall(setfenv(v, _M))
+
 			if ok then
 				ret[k] = val
 			else
@@ -40,6 +44,8 @@ function collect_dir(dir)
 			end
 		end
 
+		collectgarbage()
+
 		return ret
 	end
 end
diff --git a/package/gluon-announced/files/usr/lib/lua/gluon/announced.lua b/package/gluon-announced/files/usr/lib/lua/gluon/announced.lua
index af2291fe..f6863277 100644
--- a/package/gluon-announced/files/usr/lib/lua/gluon/announced.lua
+++ b/package/gluon-announced/files/usr/lib/lua/gluon/announced.lua
@@ -1,26 +1,29 @@
 local announce = require 'gluon.announce'
 local deflate = require 'deflate'
 local json = require 'luci.jsonc'
+local nixio = require 'nixio'
+local fs = require 'nixio.fs'
 
 local memoize = {}
 
-local function collect(type)
-  if not memoize[type] then
-    memoize[type] = announce.collect_dir('/lib/gluon/announce/' .. type .. '.d')
-  end
+nixio.chdir('/lib/gluon/announce/')
 
-  return memoize[type]()
+for dir in fs.glob('*.d') do
+  local name = dir:sub(1, -3)
+  memoize[name] = announce.collect_dir(dir)
 end
 
+local function collect(type)
+  return memoize[type] and memoize[type]()
+end
 
 module('gluon.announced', package.seeall)
 
 function handle_request(query)
-  if query:match('^nodeinfo$') then
-    return json.stringify(collect('nodeinfo'))
-  end
+  collectgarbage()
 
   local m = query:match('^GET ([a-z ]+)$')
+  local ret
   if m then
     local data = {}
 
@@ -32,7 +35,16 @@ function handle_request(query)
     end
 
     if next(data) then
-      return deflate.compress(json.stringify(data))
+      ret = deflate.compress(json.stringify(data))
+    end
+  elseif query:match('^[a-z]+$') then
+    local ok, data = pcall(collect, query)
+    if ok then
+      ret = json.stringify(data)
     end
   end
+
+  collectgarbage()
+
+  return ret
 end