__index = function()

in apisix/core/ctx.lua [224:316]

• 76 lines of code
• 21 McCabe index (conditional complexity)

        __index = function(t, key)
            local cached = t._cache[key]
            if cached ~= nil then
                return cached
            end

            if type(key) ~= "string" then
                error("invalid argument, expect string value", 2)
            end

            local val
            local method = var_methods[key]
            if method then
                val = method()

            elseif core_str.has_prefix(key, "cookie_") then
                local cookie = t.cookie
                if cookie then
                    local err
                    val, err = cookie:get(sub_str(key, 8))
                    if err then
                        log.warn("failed to fetch cookie value by key: ",
                                 key, " error: ", err)
                    end
                end

            elseif core_str.has_prefix(key, "arg_") then
                local arg_key = sub_str(key, 5)
                local args = request.get_uri_args()[arg_key]
                if args then
                    if type(args) == "table" then
                        val = args[1]
                    else
                        val = args
                    end
                end

            elseif core_str.has_prefix(key, "post_arg_") then
                
                local content_type = request.header(nil, "Content-Type")
                if content_type ~= nil and core_str.has_prefix(content_type,
                        "application/x-www-form-urlencoded") then
                    local arg_key = sub_str(key, 10)
                    local args = request.get_post_args()[arg_key]
                    if args then
                        if type(args) == "table" then
                            val = args[1]
                        else
                            val = args
                        end
                    end
                end

            elseif core_str.has_prefix(key, "uri_param_") then
                
                
                if t._ctx.curr_req_matched then
                    local arg_key = sub_str(key, 11)
                    val = t._ctx.curr_req_matched[arg_key]
                end

            elseif core_str.has_prefix(key, "http_") then
                key = key:lower()
                key = re_gsub(key, "-", "_", "jo")
                val = get_var(key, t._request)

            elseif core_str.has_prefix(key, "graphql_") then
                
                key = sub_str(key, 9)
                val = get_parsed_graphql()[key]

            else
                local getter = apisix_var_names[key]
                if getter then
                    local ctx = t._ctx
                    if getter == true then
                        val = ctx and ctx[key]
                    else
                        
                        val = getter(ctx)
                    end

                else
                    val = get_var(key, t._request)
                end
            end

            if val ~= nil and not no_cacheable_var_names[key] then
                t._cache[key] = val
            end

            return val
        end,