function _M.increase()

in apisix/plugins/limit-conn/init.lua [67:130]

• 54 lines of code
• 14 McCabe index (conditional complexity)

function _M.increase(conf, ctx)
    core.log.info("ver: ", ctx.conf_version)
    local lim, err = lrucache(conf, nil, create_limit_obj, conf)
    if not lim then
        core.log.error("failed to instantiate a resty.limit.conn object: ", err)
        if conf.allow_degradation then
            return
        end
        return 500
    end

    local conf_key = conf.key
    local key
    if conf.key_type == "var_combination" then
        local err, n_resolved
        key, err, n_resolved = core.utils.resolve_var(conf_key, ctx.var)
        if err then
            core.log.error("could not resolve vars in ", conf_key, " error: ", err)
        end

        if n_resolved == 0 then
            key = nil
        end
    else
        key = ctx.var[conf_key]
    end

    if key == nil then
        core.log.info("The value of the configured key is empty, use client IP instead")
        
        key = ctx.var["remote_addr"]
    end

    key = key .. ctx.conf_type .. ctx.conf_version
    core.log.info("limit key: ", key)

    local delay, err = lim:incoming(key, true)
    if not delay then
        if err == "rejected" then
            if conf.rejected_msg then
                return conf.rejected_code, { error_msg = conf.rejected_msg }
            end
            return conf.rejected_code or 503
        end

        core.log.error("failed to limit conn: ", err)
        if conf.allow_degradation then
            return
        end
        return 500
    end

    if lim:is_committed() then
        if not ctx.limit_conn then
            ctx.limit_conn = core.tablepool.fetch("plugin#limit-conn", 0, 6)
        end

        core.table.insert_tail(ctx.limit_conn, lim, key, delay, conf.only_use_default_delay)
    end

    if delay >= 0.001 then
        sleep(delay)
    end
end