Method OnReadSome

library/cpp/neh/tcp2.cpp:900–950

must be called only from asio thread

                //must be called only from asio thread
                void OnReadSome(const TErrorCode& ec, size_t amount, IHandlingContext& ctx) {
                    //DBGOUT("OnReadSome(" << ec.Value() << ", " <<  amount << ")");
                    if (Y_UNLIKELY(ec)) {
                        OnErrorCode(ec);

                        return;
                    }

                    while (1) {
                        if (Y_UNLIKELY(!amount)) {
                            OnError("tcp conn. closed");

                            return;
                        }

                        try {
                            const char* buff = Buff_.Get();
                            size_t leftBytes = amount;
                            do {
                                size_t useBytes = Msg_.LoadFrom(buff, leftBytes);
                                leftBytes -= useBytes;
                                buff += useBytes;
                                if (Msg_.IsComplete()) {
                                    //DBGOUT("OnReceiveMessage(" << Msg_.BaseHeader().Id << "): " << leftBytes);
                                    OnReceiveMessage();
                                    Msg_.Clear();
                                }
                            } while (leftBytes);

                            if (amount == BuffSize_) {
                                //try decrease system calls, - re-run ReadSome if has full filled buffer
                                TErrorCode ecR;
                                amount = AS_.ReadSome(Buff_.Get(), BuffSize_, ecR);
                                if (!ecR) {
                                    continue; //process next input data
                                }
                                if (ecR.Value() == EAGAIN || ecR.Value() == EWOULDBLOCK) {
                                    ctx.ContinueUseHandler();
                                } else {
                                    OnErrorCode(ec);
                                }
                            } else {
                                ctx.ContinueUseHandler();
                            }
                        } catch (...) {
                            OnError(CurrentExceptionMessage());
                        }

                        return;
                    }
                }

                //must be called only from asio thread
                void OnErrorCode(TErrorCode ec) {