utility function for setting default values

awall-cli

@@ -134,9 +134,7 @@ end
 
 if stringy.endswith(arg[0], '/awall-cli') then
    basedir = arg[0]:sub(1, -11)
-   if not pol_paths.mandatory then
-      pol_paths.mandatory = {'/etc/awall'}
-   end
+   util.setdefault(pol_paths, 'mandatory', {'/etc/awall'})
    table.insert(pol_paths.mandatory, basedir..'/json')
 end
 

awall/model.lua

@@ -24,6 +24,7 @@ local extend = util.extend
 local filter = util.filter
 local listpairs = util.listpairs
 local maplist = util.maplist
+local setdefault = util.setdefault
 
 
 local startswith = require('stringy').startswith
@@ -82,12 +83,9 @@ function M.ConfigObject:uniqueid(key)
    if not key then key = '' end
    if self.uniqueids[key] then return self.uniqueids[key] end
 
-   if not self.context.lastid then self.context.lastid = {} end
-   local lastid = self.context.lastid
-
+   local lastid = setdefault(self.context, 'lastid', {})
    local res = join(key, self.label)
-   if not lastid[res] then lastid[res] = -1 end
-   lastid[res] = lastid[res] + 1
+   lastid[res] = setdefault(lastid, res, -1) + 1
    res = res..'-'..lastid[res]
 
    self.uniqueids[key] = res
@@ -588,7 +586,7 @@ function M.Limit:init(...)
       self.count = self[1]
    end
 
-   if not self.interval then self.interval = 1 end
+   setdefault(self, 'interval', 1)
 end
 
 function M.Limit:rate() return math.ceil(self.count / self.interval) end

awall/modules/filter.lua

@@ -40,7 +40,7 @@ local LoggingRule = class(TranslatingRule)
 
 function LoggingRule:init(...)
    LoggingRule.super(self):init(...)
-   if not self.action then self.action = 'accept' end
+   util.setdefault(self, 'action', 'accept')
    if type(self.log) ~= 'table' then
       self.log = loadclass('log').get(self, self.log, self.action ~= 'accept')
    end

awall/policy.lua

@@ -208,7 +208,7 @@ function PolicySet:load()
 	       raise('Invalid top-level attribute: '..cls..' ('..name..')')
 	    end
 
-	    if not source[cls] then source[cls] = {} end
+	    util.setdefault(source, cls, {})
 
 	    if not input[cls] then
 	       input[cls] = objs

awall/util.lua

@@ -79,6 +79,11 @@ function M.update(tbl1, tbl2)
    return tbl1
 end
 
+function M.setdefault(t, k, v)
+   if t[k] == nil then t[k] = v end
+   return t[k]
+end
+
 function M.copy(tbl) return M.update({}, tbl) end
 
 function M.compare(a, b)