* Add classifiers pre-selection script

conf/lua/rspamd.classifiers.lua

@@ -0,0 +1,48 @@
+-- Detect language of message and selects appropriate statfiles for it
+
+classifiers['bayes'] = function(classifier, task, is_learn, is_spam)
+	-- Subfunction for detection of message's language
+	local detect_language = function(task)
+		local parts = task:get_text_parts()
+		for _,p in ipairs(parts) do
+			local l = p:get_language()
+			if l then
+				return l
+			end
+		end
+		return nil
+	end
+
+	-- Main procedure
+	language = detect_language(task)
+	if language then
+		-- Find statfiles with specified language
+		local selected = {}
+		for _,st in pairs(classifier:get_statfiles()) do
+			local st_l = st:get_param('language')
+			if st_l and st_l == language then
+			    -- Insert statfile with specified language    
+			    table.insert(selected, st)
+			end
+		end
+		if table.maxn(selected) > 1 then
+			return selected
+		end
+	else
+		-- Language not detected
+		local selected = {}
+		for _,st in ipairs(classifier:get_statfiles()) do
+			local st_l = st:get_param('language')
+			-- Insert only statfiles without language
+			if not st_l then
+				table.insert(selected, st)
+			end
+		end
+		if table.maxn(selected) > 1 then
+			return selected
+		end
+	end
+
+	return nil
+end
+

conf/lua/rspamd.lua

@@ -82,3 +82,7 @@ end
 if file_exists('rspamd.local.lua') then
 	dofile('rspamd.local.lua')
 end
+
+if file_exists('rspamd.classifiers.lua') then
+	dofile('rspamd.classifiers.lua')
+end