[Project] Start migration of bayes redis backend to Lua

lualib/lua_bayes_redis.lua

@@ -0,0 +1,70 @@
+--[[
+Copyright (c) 2022, Vsevolod Stakhov <vsevolod@rspamd.com>
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+]]
+
+-- This file contains functions to support Bayes statistics in Redis
+
+local exports = {}
+local lua_redis = require "lua_redis"
+local logger = require "rspamd_logger"
+
+local function gen_classify_functor(redis_params, classify_script_id)
+  return function(task, expanded_key, stat_tokens)
+    -- TODO: write this function
+  end
+end
+
+local function gen_learn_functor(redis_params, learn_script_id)
+  return function(task, expanded_key, stat_tokens)
+    -- TODO: write this function
+  end
+end
+
+---
+--- Init bayes classifier
+--- @param classifier_ucl ucl of the classifier config
+--- @param statfile_ucl ucl of the statfile config
+--- @return a pair of (classify_functor, learn_functor) or `nil` in case of error
+exports.lua_bayes_init_classifier = function(classifier_ucl, statfile_ucl)
+  local redis_params
+
+  if classifier_ucl.backend then
+    redis_params = lua_redis.try_load_redis_servers(classifier_ucl.backend, rspamd_config, true)
+  end
+
+  -- Try load from statfile options
+  if not redis_params then
+    if statfile_ucl then
+      redis_params = lua_redis.try_load_redis_servers(statfile_ucl, rspamd_config, true)
+    end
+  end
+
+  -- Load directly from classifier config
+  if not redis_params then
+    redis_params = lua_redis.try_load_redis_servers(classifier_ucl, rspamd_config, false, "statistics")
+  end
+
+  if not redis_params then
+    logger.err(rspamd_config, "cannot load Redis parameters for the classifier")
+    return nil
+  end
+
+  local classify_script_id = lua_redis.load_redis_script_from_file("bayes_classify.lua", redis_params)
+  local learn_script_id = lua_redis.load_redis_script_from_file("bayes_learn.lua", redis_params)
+
+  return gen_classify_functor(redis_params, classify_script_id), gen_learn_functor(redis_params, learn_script_id)
+end
+
+return exports