NuPlayer从服务端获取应答消息流程

本文主要是介绍NuPlayer从服务端获取应答消息流程，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！

　　本文具体介绍NuPlayer获取应答消息的代码流程，流程设计到的每一个行数的详细介绍在之前的文章都有介绍。
　　下一篇文章介绍接收到服务端发送来的应答消息后的处理过程：
　　ARTSPConnection::notifyResponseListener函数完成这个流程。
　　

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void ARTSPConnection::performConnect(const sp<AMessage> &reply,AString host, unsigned port) {struct hostent *ent = gethostbyname(host.c_str());if (ent == NULL) {ALOGE("Unknown host %s", host.c_str());reply->setInt32("result", -ENOENT);reply->post();mState = DISCONNECTED;return;}mSocket = socket(AF_INET, SOCK_STREAM, 0);if (mUIDValid) {HTTPBase::RegisterSocketUserTag(mSocket, mUID,(uint32_t)*(uint32_t*) "RTSP");HTTPBase::RegisterSocketUserMark(mSocket, mUID);}MakeSocketBlocking(mSocket, false);struct sockaddr_in remote;memset(remote.sin_zero, 0, sizeof(remote.sin_zero));remote.sin_family = AF_INET;remote.sin_addr.s_addr = *(in_addr_t *)ent->h_addr;remote.sin_port = htons(port);int err = ::connect(mSocket, (const struct sockaddr *)&remote, sizeof(remote));reply->setInt32("server-ip", ntohl(remote.sin_addr.s_addr));if (err < 0) {if (errno == EINPROGRESS) {sp<AMessage> msg = new AMessage(kWhatCompleteConnection, this);msg->setMessage("reply", reply);msg->setInt32("connection-id", mConnectionID);msg->post();return;}reply->setInt32("result", -errno);mState = DISCONNECTED;if (mUIDValid) {HTTPBase::UnRegisterSocketUserTag(mSocket);HTTPBase::UnRegisterSocketUserMark(mSocket);}close(mSocket);mSocket = -1;} else {reply->setInt32("result", OK);mState = CONNECTED;mNextCSeq = 1;//==>postReceiveReponseEvent();}reply->post();
}　==>
void ARTSPConnection::postReceiveReponseEvent() {if (mReceiveResponseEventPending) {return;}sp<AMessage> msg = new AMessage(kWhatReceiveResponse, this);msg->post();mReceiveResponseEventPending = true;
}　==>
void ARTSPConnection::onMessageReceived(const sp<AMessage> &msg) {switch (msg->what()) {case kWhatConnect:onConnect(msg);break;case kWhatDisconnect:onDisconnect(msg);break;case kWhatCompleteConnection:onCompleteConnection(msg);break;case kWhatSendRequest:onSendRequest(msg);break;case kWhatReceiveResponse://==>onReceiveResponse();break;case kWhatObserveBinaryData:{CHECK(msg->findMessage("reply", &mObserveBinaryMessage));break;}default:TRESPASS();break;}
}==>
void ARTSPConnection::onReceiveResponse() {mReceiveResponseEventPending = false;if (mState != CONNECTED) {return;}struct timeval tv;tv.tv_sec = 0;tv.tv_usec = kSelectTimeoutUs;fd_set rs;FD_ZERO(&rs);FD_SET(mSocket, &rs);int res = select(mSocket + 1, &rs, NULL, NULL, &tv);if (res == 1) {MakeSocketBlocking(mSocket, true);//==>bool success = receiveRTSPReponse();MakeSocketBlocking(mSocket, false);if (!success) {// Something horrible, irreparable has happened.flushPendingRequests();return;}}postReceiveReponseEvent();
}==>
bool ARTSPConnection::receiveRTSPReponse() {AString statusLine;if (!receiveLine(&statusLine)) {return false;}if (statusLine == "$") {sp<ABuffer> buffer = receiveBinaryData();if (buffer == NULL) {return false;}if (mObserveBinaryMessage != NULL) {sp<AMessage> notify = mObserveBinaryMessage->dup();notify->setBuffer("buffer", buffer);notify->post();} else {ALOGW("received binary data, but no one cares.");}return true;}sp<ARTSPResponse> response = new ARTSPResponse;response->mStatusLine = statusLine;ALOGI("status: %s", response->mStatusLine.c_str());ssize_t space1 = response->mStatusLine.find(" ");if (space1 < 0) {return false;}ssize_t space2 = response->mStatusLine.find(" ", space1 + 1);if (space2 < 0) {return false;}bool isRequest = false;if (!IsRTSPVersion(AString(response->mStatusLine, 0, space1))) {CHECK(IsRTSPVersion(AString(response->mStatusLine,space2 + 1,response->mStatusLine.size() - space2 - 1)));isRequest = true;response->mStatusCode = 0;} else {AString statusCodeStr(response->mStatusLine, space1 + 1, space2 - space1 - 1);if (!ParseSingleUnsignedLong(statusCodeStr.c_str(), &response->mStatusCode)|| response->mStatusCode < 100 || response->mStatusCode > 999) {return false;}}AString line;ssize_t lastDictIndex = -1;for (;;) {if (!receiveLine(&line)) {break;}if (line.empty()) {break;}ALOGV("line: '%s'", line.c_str());if (line.c_str()[0] == ' ' || line.c_str()[0] == '\t') {// Support for folded header values.if (lastDictIndex < 0) {// First line cannot be a continuation of the previous one.return false;}AString &value = response->mHeaders.editValueAt(lastDictIndex);value.append(line);continue;}ssize_t colonPos = line.find(":");if (colonPos < 0) {// Malformed header line.return false;}AString key(line, 0, colonPos);key.trim();key.tolower();line.erase(0, colonPos + 1);lastDictIndex = response->mHeaders.add(key, line);}for (size_t i = 0; i < response->mHeaders.size(); ++i) {response->mHeaders.editValueAt(i).trim();}unsigned long contentLength = 0;ssize_t i = response->mHeaders.indexOfKey("content-length");if (i >= 0) {AString value = response->mHeaders.valueAt(i);if (!ParseSingleUnsignedLong(value.c_str(), &contentLength)) {return false;}}if (contentLength > 0) {response->mContent = new ABuffer(contentLength);if (receive(response->mContent->data(), contentLength) != OK) {return false;}}if (response->mStatusCode == 401) {if (mAuthType == NONE && mUser.size() > 0&& parseAuthMethod(response)) {ssize_t i;CHECK_EQ((status_t)OK, findPendingRequest(response, &i));CHECK_GE(i, 0);sp<AMessage> reply = mPendingRequests.valueAt(i);mPendingRequests.removeItemsAt(i);AString request;CHECK(reply->findString("original-request", &request));sp<AMessage> msg = new AMessage(kWhatSendRequest, this);msg->setMessage("reply", reply);msg->setString("request", request.c_str(), request.size());ALOGI("re-sending request with authentication headers...");onSendRequest(msg);return true;}}//==>return isRequest? handleServerRequest(response): notifyResponseListener(response);
}==>
bool ARTSPConnection::notifyResponseListener(const sp<ARTSPResponse> &response) {ssize_t i;status_t err = findPendingRequest(response, &i);if (err == OK && i < 0) {// An unsolicited server response is not a problem.return true;}if (err != OK) {return false;}sp<AMessage> reply = mPendingRequests.valueAt(i);mPendingRequests.removeItemsAt(i);reply->setInt32("result", OK);reply->setObject("response", response);reply->post();return true;
}