HttpTransThread::AddRequestToCatchList,请求id和请求的内存堆，好像都有问题

[Janeny2013]

HttpRequestID HttpTransThread::AddRequestToCatchList(const HttpRequestSharedPtr &request)
{
nbase::NAutoLock autolock(&message_loop_flag_lock_);
request_current_sn_ -= 1;
if (request_current_sn_ == INVALID_HTTPREQUESTID)
request_current_sn_ = kREQUEST_ID_BASE;
request_list_.insert(std::make_pair(request_current_sn_, std::make_pair(request.get(), request)));
request->attach_release(ToWeakCallback(std::bind(&HttpTransThread::OnRequestRelease, this, request.get())));
return request_current_sn_;
}

[Janeny2013]

request_list_.insert(std::make_pair(request_current_sn_, std::make_pair(request.get(), request)));
map本身不管理内存，pair的second是监控生命期。这个不是问题了，在回话管理中管理生命期
但request_current_sn_还是没理解，这个id哪里变更

[nmgwddj]

HttpRequestID HttpTransThread::AddRequestToCatchList(const HttpRequestSharedPtr &request)
{
    nbase::NAutoLock autolock(&message_loop_flag_lock_);
+   request_current_sn_ -= 1;
    if (request_current_sn_ == INVALID_HTTPREQUESTID)
    request_current_sn_ = kREQUEST_ID_BASE;
    request_list_.insert(std::make_pair(request_current_sn_, std::make_pair(request.get(), request)));
    request->attach_release(ToWeakCallback(std::bind(&HttpTransThread::OnRequestRelease, this, request.get())));
    return request_current_sn_;
}

高亮处的 -= 就是变更。