bzp2010 commented on code in PR #6995: URL: https://github.com/apache/apisix/pull/6995#discussion_r872117347
########## apisix/core/pubsub.lua: ########## @@ -0,0 +1,167 @@ +-- +-- Licensed to the Apache Software Foundation (ASF) under one or more +-- contributor license agreements. See the NOTICE file distributed with +-- this work for additional information regarding copyright ownership. +-- The ASF licenses this file to You 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. +-- + +--- Extensible framework to support publish-and-subscribe scenarios +-- +-- @module core.pubsub + +local log = require("apisix.core.log") +local ws_server = require("resty.websocket.server") +local protoc = require("protoc") +local pb = require("pb") +local setmetatable = setmetatable +local pcall = pcall +local pairs = pairs + +protoc.reload() +pb.option("int64_as_string") +local pubsub_protoc = protoc.new() + + +local _M = { version = 0.1 } +local mt = { __index = _M } + + +--- +-- Create pubsub module instance +-- +-- @function core.pubsub.new +-- @treturn pubsub module instance +-- @treturn string|nil error message if present +-- @usage +-- local pubsub, err = core.pubsub.new() +function _M.new() + -- compile the protobuf file on initial load module + -- ensure that each worker is loaded once + if not pubsub_protoc.loaded["pubsub.proto"] then + pubsub_protoc:addpath("apisix/include/apisix/model") + local ok, err = pcall(pubsub_protoc.loadfile, pubsub_protoc, "pubsub.proto") + if not ok then + pubsub_protoc:reset() + return nil, "failed to load pubsub protocol: "..err + end + end + + local ws, err = ws_server:new() + if not ws then + return nil, err + end + + local obj = setmetatable({ + ws_server = ws, + cmd_handler = {}, + }, mt) + + return obj +end + + +--- +-- Add command callbacks to pubsub module instances +-- +-- The callback function prototype: function (params) +-- The params in the parameters contain the data defined in the requested command. +-- Its first return value is the data, which needs to contain the data needed for +-- the particular resp, returns nil if an error exists. +-- Its second return value is a string type error message, no need to return when +-- no error exists. +-- +-- @function core.pubsub.on +-- @usage +-- pubsub:on(command, function (params) +-- return data, err +-- end) +function _M.on(self, command, handler) + self.cmd_handler[command] = handler +end + + +--- +-- Put the pubsub instance into an event loop, waiting to process client commands +-- +-- @function core.pubsub.wait +-- @treturn string|nil error message if present, will terminate the event loop +-- @usage +-- local err = pubsub:wait() +function _M.wait(self) + local ws = self.ws_server + while true do + -- read raw data frames from websocket connection + local raw_data, raw_type, err = ws:recv_frame() + if err then + -- terminate the event loop when a fatal error occurs + if ws.fatal then + ws:send_close() + return "websocket server: "..err + end + + -- skip this loop for non-fatal errors + log.error("failed to receive websocket frame: "..err) + goto continue + end + + -- handle client close connection + if raw_type == "close" then + ws:send_close() + return + end + + -- the pub-sub messages use binary, if the message is not + -- binary, skip this message + if raw_type ~= "binary" then + goto continue + end + + local data = pb.decode("PubSubReq", raw_data) Review Comment: checkd -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
