luci-base: dispatcher.lua: improve bytecode cache invalidation

Signed-off-by: Jo-Philipp Wich <jo@mein.io>

diff --git a/modules/luci-base/luasrc/dispatcher.lua b/modules/luci-base/luasrc/dispatcher.lua
index d14a866737a15e438249e0cb4d71f30363fb6d53..d2552d6db4ef311557f45db4a7a1239d495cdb41 100644 (file)
--- a/modules/luci-base/luasrc/dispatcher.lua
+++ b/modules/luci-base/luasrc/dispatcher.lua
@@ -1034,6 +1034,35 @@ function dispatch(request)
        end
 end
 
+local function hash_filelist(files)
+       local fprint = {}
+       local n = 0
+
+       for i, file in ipairs(files) do
+               local st = fs.stat(file)
+               if st then
+                       fprint[n + 1] = '%x' % st.ino
+                       fprint[n + 2] = '%x' % st.mtime
+                       fprint[n + 3] = '%x' % st.size
+                       n = n + 3
+               end
+       end
+
+       return nixio.crypt(table.concat(fprint, "|"), "$1$"):sub(5):gsub("/", ".")
+end
+
+local function read_cachefile(file, reader)
+       local euid = sys.process.info("uid")
+       local fuid = fs.stat(file, "uid")
+       local mode = fs.stat(file, "modestr")
+
+       if euid ~= fuid or mode ~= "rw-------" then
+               return nil
+       end
+
+       return reader(file)
+end
+
 function createindex()
        local controllers = { }
        local base = "%s/controller/" % util.libpath()
@@ -1047,25 +1076,19 @@ function createindex()
                controllers[#controllers+1] = path
        end
 
+       local cachefile
+
        if indexcache then
-               local cachedate = fs.stat(indexcache, "mtime")
-               if cachedate then
-                       local realdate = 0
-                       for _, obj in ipairs(controllers) do
-                               local omtime = fs.stat(obj, "mtime")
-                               realdate = (omtime and omtime > realdate) and omtime or realdate
-                       end
+               cachefile = "%s.%s.lua" %{ indexcache, hash_filelist(controllers) }
 
-                       if cachedate > realdate and sys.process.info("uid") == 0 then
-                               assert(
-                                       sys.process.info("uid") == fs.stat(indexcache, "uid")
-                                       and fs.stat(indexcache, "modestr") == "rw-------",
-                                       "Fatal: Indexcache is not sane!"
-                               )
+               local res = read_cachefile(cachefile, function(path) return loadfile(path)() end)
+               if res then
+                       index = res
+                       return res
+               end
 
-                               index = loadfile(indexcache)()
-                               return index
-                       end
+               for file in (fs.glob("%s.*.lua" % indexcache) or function() end) do
+                       fs.unlink(file)
                end
        end
 
@@ -1086,8 +1109,8 @@ function createindex()
                end
        end
 
-       if indexcache then
-               local f = nixio.open(indexcache, "w", 600)
+       if cachefile then
+               local f = nixio.open(cachefile, "w", 600)
                f:writeall(util.get_bytecode(index))
                f:close()
        end
@@ -1110,29 +1133,16 @@ function createtree_json()
        }
 
        local files = {}
-       local fprint = {}
        local cachefile
 
        for file in (fs.glob("/usr/share/luci/menu.d/*.json") or function() end) do
                files[#files+1] = file
-
-               if indexcache then
-                       local st = fs.stat(file)
-                       if st then
-                               fprint[#fprint+1] = '%x' % st.ino
-                               fprint[#fprint+1] = '%x' % st.mtime
-                               fprint[#fprint+1] = '%x' % st.size
-                       end
-               end
        end
 
        if indexcache then
-               cachefile = "%s.%s.json" %{
-                       indexcache,
-                       nixio.crypt(table.concat(fprint, "|"), "$1$"):sub(5):gsub("/", ".")
-               }
+               cachefile = "%s.%s.json" %{ indexcache, hash_filelist(files) }
 
-               local res = json.parse(fs.readfile(cachefile) or "")
+               local res = read_cachefile(cachefile, function(path) return json.parse(fs.readfile(path) or "") end)
                if res then
                        return res
                end
@@ -1175,7 +1185,9 @@ function createtree_json()
        end
 
        if cachefile then
-               fs.writefile(cachefile, json.stringify(tree))
+               local f = nixio.open(cachefile, "w", 600)
+               f:writeall(json.stringify(tree))
+               f:close()
        end
 
        return tree