TeamTalk梳理概括
文章目录
即时通讯重点概括
展开聊聊单聊消息流转流程
- 消息如何封装
- 怎么解决半包、粘包问题？
- 消息流转流程介绍下？
- 消息序号（msg_id ）在哪里生成以及生成方式
- 怎么保证数据的不丢失以及重复包？
- 接收端收到数据后（收到消息区别于阅读消息）如何应答？
- 消息发送后服务器怎么应答?
- 消息发送时的seq有什么作用（业务层的ack机制）
展开聊聊群聊消息流转流程
- 如何推送群聊
- 群消息计数器（msg_id ）
- 群会话如何更新(每有一个人发送消息,则其他人都需要更新会话消息)
群成员管理
- 如何创建群
- 如何删除群
- 怎么使用redis管理群成员
消息未读计数是怎么实现的？ - 服务器怎么保留消息未读计数（redis 单聊和群聊机制不同）
- 客户端的未读消息计数从何而来
- 客户端未读消息计数清0时向服务器发送了什么？服务器又是怎么清除未读消息计数（单聊和群聊机制不同）
数据库
- 数据库表设计（表达笼统）
- 密码存储方式
- 未读消息如何体现
- 聊天消息分表问题（单聊和群聊消息表）
- 最近会话表
MySQL连接池设计
- 为什么使用连接池
- 连接池设置多大合适?
redis连接池设计
- 为什么使用连接池
- 连接池设置多大合适?
文件传输原理
- 在线传输和离线传输有什么区别
实时性
- Http（登录、图片服务）
- Socket
- websocket
展开聊聊登录流程
并发能力
- 如何做到百万并发
- 如何做到千万并发
db_proxy_server reactor响应处理流程
- 数据入口 reactor CProxyConn:: HandlePduBuf
- 怎么初始化epoll+线程池
- 任务封装
- 把任务放入线程池
- 执行任务
- 把要回应的数据放入回复列表CProxyConn::SendResponsePdulist
- epoll所在线程读取回复列表的数据发给请求端
单聊消息
消息如何封装？如何保证对端完整解析一帧消息？协议格式？
- 答：消息封装采用包头（Header）+包体（Body）的格式。包头自定义格式如下代码所示，包体采用protobuf序列化。
typedef struct {
uint32_t length; // the whole pdu length
uint16_t version; // pdu version number
uint16_t flag; // not used
uint16_t service_id; //
uint16_t command_id; //
uint16_t seq_num; // 包序号
uint16_t reversed; // 保留
} PduHeader_t;
- 答：
- 采用tcp保证数据传输可靠性
- 通过包头的 length 字段标记一帧消息的长度
- 通过service id 和 command id区分不同的命令（比如登录、退出等）
- 解决数据TCP粘包（包头长度字段）、半包（放入网络库的缓冲区）问题
void CImConn::OnRead()
{
for (;;)
{
uint32_t free_buf_len = m_in_buf.GetAllocSize() - m_in_buf.GetWriteOffset();
if (free_buf_len < READ_BUF_SIZE)
m_in_buf.Extend(READ_BUF_SIZE);
int ret = netlib_recv(m_handle, m_in_buf.GetBuffer() + m_in_buf.GetWriteOffset(), READ_BUF_SIZE);
if (ret <= 0)
break;
m_recv_bytes += ret;
m_in_buf.IncWriteOffset(ret);
m_last_recv_tick = get_tick_count();
}
CImPdu* pPdu = NULL;
try
{
while ( ( pPdu = CImPdu::ReadPdu(m_in_buf.GetBuffer(), m_in_buf.GetWriteOffset()) ) )
{
uint32_t pdu_len = pPdu->GetLength();
HandlePdu(pPdu);
m_in_buf.Read(NULL, pdu_len);
delete pPdu;
pPdu = NULL;
// ++g_recv_pkt_cnt;
}
} catch (CPduException& ex) {
log("!!!catch exception, sid=%u, cid=%u, err_code=%u, err_msg=%s, close the connection ",
ex.GetServiceId(), ex.GetCommandId(), ex.GetErrorCode(), ex.GetErrorMsg());
if (pPdu) {
delete pPdu;
pPdu = NULL;
}
OnClose();
}
}
message IMMsgData{
//cmd id: 0x0301
required uint32 from_user_id = 1; //消息发送方
required uint32 to_session_id = 2; //消息接受方
required uint32 msg_id = 3;
required uint32 create_time = 4;
required IM.BaseDefine.MsgType msg_type = 5;
required bytes msg_data = 6;
optional bytes attach_data = 20;
}
message IMMsgDataAck{
//cmd id: 0x0302
required uint32 user_id = 1; //发送此信令的用户id
required uint32 session_id = 2;
required uint32 msg_id = 3;
required IM.BaseDefine.SessionType session_type = 4;
}
消息序号（msg_id ）为什么使用redis生成？
- 消息ID（msg_id ）的作用是防止消息乱序。
- 消息ID（msg_id ）为什么这么设计？
答：msg_id 存储在 unread 连接池所在的redis数据库。单聊 msg_id 的 key涉及到 nRelateId。nRelateId 从关系表（IMRelationShip ：两个用户id的映射关系）中获取。
/**
* 获取会话关系ID
* 对于群组，必须把nUserBId设置为群ID
*
* @param nUserAId <#nUserAId description#>
* @param nUserBId <#nUserBId description#>
* @param bAdd <#bAdd description#>
* @param nStatus 0 获取未被删除会话，1获取所有。
*/
uint32_t CRelationModel::getRelationId(uint32_t nUserAId, uint32_t nUserBId, bool bAdd)
{
uint32_t nRelationId = INVALID_VALUE;
if (nUserAId == 0 || nUserBId == 0) {
log("invalied user id:%u->%u", nUserAId, nUserBId);
return nRelationId;
}
CDBManager* pDBManager = CDBManager::getInstance();
CDBConn* pDBConn = pDBManager->GetDBConn("teamtalk_slave");
if (pDBConn)
{
uint32_t nBigId = nUserAId > nUserBId ? nUserAId : nUserBId;
uint32_t nSmallId = nUserAId > nUserBId ? nUserBId : nUserAId;
string strSql = "select id from IMRelationShip where smallId=" + int2string(nSmallId) + " and bigId="+ int2string(nBigId) + " and status = 0";
CResultSet* pResultSet = pDBConn->ExecuteQuery(strSql.c_str());
if (pResultSet)
{
while (pResultSet->Next())
{
nRelationId = pResultSet->GetInt("id");
}
delete pResultSet;
}
else
{
log("there is no result for sql:%s", strSql.c_str());
}
pDBManager->RelDBConn(pDBConn);
if (nRelationId == INVALID_VALUE && bAdd)
{
nRelationId = addRelation(nSmallId, nBigId);
}
}
else
{
log("no db connection for teamtalk_slave");
}
return nRelationId;
}
- 群聊和单聊msg_id 的区别：key设置不同。
uint32_t CMessageModel::getMsgId(uint32_t nRelateId)
{
uint32_t nMsgId = 0;
CacheManager* pCacheManager = CacheManager::getInstance();
CacheConn* pCacheConn = pCacheManager->GetCacheConn("unread");
if(pCacheConn)
{
string strKey = "msg_id_" + int2string(nRelateId);
nMsgId = pCacheConn->incrBy(strKey, 1);
pCacheManager->RelCacheConn(pCacheConn);
}
return nMsgId;
}
/**
* 获取一个群组的msgId，自增，通过redis控制
* @param nGroupId 群Id
* @return 返回msgId
*/
uint32_t CGroupMessageModel::getMsgId(uint32_t nGroupId)
{
uint32_t nMsgId = 0;
CacheManager* pCacheManager = CacheManager::getInstance();
CacheConn* pCacheConn = pCacheManager->GetCacheConn("unread");
if(pCacheConn)
{
// TODO
string strKey = "group_msg_id_" + int2string(nGroupId);
nMsgId = pCacheConn->incrBy(strKey, 1);
pCacheManager->RelCacheConn(pCacheConn);
}
else
{
log("no cache connection for unread");
}
return nMsgId;
}
展开聊聊单聊消息流转流程
答：两个用户A给B发消息，用户A把聊天消息封装好以后发送给MsgServer；同时把消息进行持久化，将聊天消息发给这个 DBProxy（数据库代理服务），存储消息成功后，DBProxyServer组包应答MsgServer，MsgServer收到回复后组包应答Client A。如果 A 和 B 两个用户不在同一个 MsgServer 上，那么会通过这个 RouteServer 去中转Pdu包数据（广播给所有的MsgServer，MsgServer再广播给Client B），B收到消息后应答MsgServer，至此，流程结束。然后如果是一些热点数据，我们同时也会写Redis。
群聊消息
展开聊聊群聊消息流转流程
群聊消息流转
void CGroupChat::HandleGroupMessage(CImPdu* pPdu)
{
IM::Message::IMMsgData msg;
CHECK_PB_PARSE_MSG(msg.ParseFromArray(pPdu->GetBodyData(), pPdu->GetBodyLength()));
uint32_t from_user_id = msg.from_user_id();
uint32_t to_group_id = msg.to_session_id();
string msg_data = msg.msg_data();
uint32_t msg_id = msg.msg_id();
if (msg_id == 0) {
log("HandleGroupMsg, write db failed, %u->%u. ", from_user_id, to_group_id);
return;
}
uint8_t msg_type = msg.msg_type();
CDbAttachData attach_data((uchar_t*)msg.attach_data().c_str(), msg.attach_data().length());
log("HandleGroupMsg, %u->%u, msg id=%u. ", from_user_id, to_group_id, msg_id);
CMsgConn* pFromConn = CImUserManager::GetInstance()->GetMsgConnByHandle(from_user_id,
attach_data.GetHandle());
if (pFromConn)
{
//接收反馈
IM::Message::IMMsgDataAck msg2;
msg2.set_user_id(from_user_id);
msg2.set_session_id(to_group_id);
msg2.set_msg_id(msg_id);
msg2.set_session_type(::IM::BaseDefine::SESSION_TYPE_GROUP);
CImPdu pdu;
pdu.SetPBMsg(&msg2);
pdu.SetServiceId(SID_MSG);
pdu.SetCommandId(CID_MSG_DATA_ACK);
pdu.SetSeqNum(pPdu->GetSeqNum());
pFromConn->SendPdu(&pdu);
}
CRouteServConn* pRouteConn = get_route_serv_conn();
if (pRouteConn)
{
pRouteConn->SendPdu(pPdu);
}
// 服务器没有群的信息，向DB服务器请求群信息，并带上消息作为附件，返回时在发送该消息给其他群成员
//IM::BaseDefine::GroupVersionInfo group_version_info;
CPduAttachData pduAttachData(ATTACH_TYPE_HANDLE_AND_PDU, attach_data.GetHandle(), pPdu->GetBodyLength(), pPdu->GetBodyData());
IM::Group::IMGroupInfoListReq msg3;
msg3.set_user_id(from_user_id);
IM::BaseDefine::GroupVersionInfo* group_version_info = msg3.add_group_version_list();
group_version_info->set_group_id(to_group_id);
group_version_info->set_version(0);
msg3.set_attach_data(pduAttachData.GetBuffer(), pduAttachData.GetLength());
CImPdu pdu;
pdu.SetPBMsg(&msg3);
pdu.SetServiceId(SID_GROUP);
pdu.SetCommandId(CID_GROUP_INFO_REQUEST);
CDBServConn* pDbConn = get_db_serv_conn();
if(pDbConn)
{
pDbConn->SendPdu(&pdu);
}
}
void CGroupChat::HandleGroupInfoResponse(CImPdu* pPdu)
{
IM::Group::IMGroupInfoListRsp msg;
CHECK_PB_PARSE_MSG(msg.ParseFromArray(pPdu->GetBodyData(), pPdu->GetBodyLength()));
uint32_t user_id = msg.user_id();
uint32_t group_cnt = msg.group_info_list_size();
CPduAttachData pduAttachData((uchar_t*)msg.attach_data().c_str(), msg.attach_data().length());
log("HandleGroupInfoResponse, user_id=%u, group_cnt=%u. ", user_id, group_cnt);
//此处是查询成员时使用，主要用于群消息从数据库获得msg_id后进行发送,一般此时group_cnt = 1
if (pduAttachData.GetPduLength() > 0 && group_cnt > 0)
{
IM::BaseDefine::GroupInfo group_info = msg.group_info_list(0);
uint32_t group_id = group_info.group_id();
log("GroupInfoRequest is send by server, group_id=%u ", group_id);
std::set<uint32_t> group_member_set;
for (uint32_t i = 0; i < group_info.group_member_list_size(); i++)
{
uint32_t member_user_id = group_info.group_member_list(i);
group_member_set.insert(member_user_id);
}
if (group_member_set.find(user_id) == group_member_set.end())
{
log("user_id=%u is not in group, group_id=%u. ", user_id, group_id);
return;
}
IM::Message::IMMsgData msg2;
CHECK_PB_PARSE_MSG(msg2.ParseFromArray(pduAttachData.GetPdu(), pduAttachData.GetPduLength()));
CImPdu pdu;
pdu.SetPBMsg(&msg2);
pdu.SetServiceId(SID_MSG);
pdu.SetCommandId(CID_MSG_DATA);
//Push相关
IM::Server::IMGroupGetShieldReq msg3;
msg3.set_group_id(group_id);
msg3.set_attach_data(pdu.GetBodyData(), pdu.GetBodyLength());
for (uint32_t i = 0; i < group_info.group_member_list_size(); i++)
{
uint32_t member_user_id = group_info.group_member_list(i);
msg3.add_user_id(member_user_id);
CImUser* pToImUser = CImUserManager::GetInstance()->GetImUserById(member_user_id);
if (pToImUser)
{
CMsgConn* pFromConn = NULL;
if( member_user_id == user_id )
{
uint32_t reqHandle = pduAttachData.GetHandle();
if(reqHandle != 0)
pFromConn = CImUserManager::GetInstance()->GetMsgConnByHandle(user_id, reqHandle);
}
pToImUser->BroadcastData(pdu.GetBuffer(), pdu.GetLength(), pFromConn);
}
}
CImPdu pdu2;
pdu2.SetPBMsg(&msg3);
pdu2.SetServiceId(SID_OTHER);
pdu2.SetCommandId(CID_OTHER_GET_SHIELD_REQ);
CDBServConn* pDbConn = get_db_serv_conn();
if (pDbConn)
{
pDbConn->SendPdu(&pdu2);
}
}
else if (pduAttachData.GetPduLength() == 0)
{
//正常获取群信息的返回
CMsgConn* pConn = CImUserManager::GetInstance()->GetMsgConnByHandle(user_id, pduAttachData.GetHandle());
if (pConn)
{
msg.clear_attach_data();
pPdu->SetPBMsg(&msg);
pConn->SendPdu(pPdu);
}
}
}
同步群组聊天信息：群会话如何更新(每有一个人发送消息,则其他人都需要更新会话消息)
分析：
如果和单聊类似，实时更新会有大量操作数据库的成本。
某个群成员发消息时，存储消息成功后，会更新群的最新发言时间。
后续优化，将session放在redis中查询不方便？？？所以要分库分表？？？
void CGroupModel::updateGroupChat(uint32_t nGroupId)
{
CDBManager* pDBManager = CDBManager::getInstance();
CDBConn* pDBConn = pDBManager->GetDBConn("teamtalk_master");
if(pDBConn)
{
uint32_t nNow = (uint32_t)time(NULL);
string strSql = "update IMGroup set lastChated=" + int2string(nNow) + " where id=" + int2string(nGroupId);
pDBConn->ExecuteUpdate(strSql.c_str());
pDBManager->RelDBConn(pDBConn);
}
else
{
log("no db connection for teamtalk_master");
}
}
CSyncCenter类,群会话的更新-独立的线程
CSyncCenter :: doSyncGroupChat
- 根据时间节点将需要更新会话的群id和最近的聊天时间读取出来放到map
- 保存当前时间到CSyncCenter
- 根据群id从redis读取群成员,然后遍历群成员更新会话信息。
/**
* 开启内网数据同步以及群组聊天记录同步
*/
void CSyncCenter::startSync()
{
#ifdef _WIN32
(void)CreateThread(NULL, 0, doSyncGroupChat, NULL, 0, &m_nGroupChatThreadId);
#else
(void)pthread_create(&m_nGroupChatThreadId, NULL, doSyncGroupChat, NULL);
#endif
}
//谈取更新的时间大于之前更新的时间点,把对应的群id-nLastChat读取出来放到mapChangedGroup存储
/**
* 同步群组聊天信息
*
* @param arg NULL
*
* @return NULL
*/
void* CSyncCenter::doSyncGroupChat(void* arg)
{
m_bSyncGroupChatRuning = true;
CDBManager* pDBManager = CDBManager::getInstance();
map<uint32_t, uint32_t> mapChangedGroup;
do{
mapChangedGroup.clear();
CDBConn* pDBConn = pDBManager->GetDBConn("teamtalk_slave");
if(pDBConn)
{
string strSql = "select id, lastChated from IMGroup where status=0 and lastChated >=" + int2string(m_pInstance->getLastUpdateGroup());
CResultSet* pResult = pDBConn->ExecuteQuery(strSql.c_str());
if(pResult)
{
while (pResult->Next()) {
uint32_t nGroupId = pResult->GetInt("id");
uint32_t nLastChat = pResult->GetInt("lastChated");
if(nLastChat != 0)
{
mapChangedGroup[nGroupId] = nLastChat;
}
}
delete pResult;
}
pDBManager->RelDBConn(pDBConn);
}
else
{
log("no db connection for teamtalk_slave");
}
m_pInstance->updateLastUpdateGroup(time(NULL));
for (auto it=mapChangedGroup.begin(); it!=mapChangedGroup.end(); ++it)
{
uint32_t nGroupId =it->first;
list<uint32_t> lsUsers;
uint32_t nUpdate = it->second;
// 读取该群的群成员
CGroupModel::getInstance()->getGroupUser(nGroupId, lsUsers);
//遍历群成员，更新Session
for (auto it1=lsUsers.begin(); it1!=lsUsers.end(); ++it1)
{
uint32_t nUserId = *it1;
uint32_t nSessionId = INVALID_VALUE;
nSessionId = CSessionModel::getInstance()->getSessionId(nUserId, nGroupId, IM::BaseDefine::SESSION_TYPE_GROUP, true);
if(nSessionId != INVALID_VALUE)
{
CSessionModel::getInstance()->updateSession(nSessionId, nUpdate);
}
else
{
CSessionModel::getInstance()->addSession(nUserId, nGroupId, IM::BaseDefine::SESSION_TYPE_GROUP);
}
}
}
// } while (!m_pInstance->m_pCondSync->waitTime(5*1000));
} while (m_pInstance->m_bSyncGroupChatWaitting && !(m_pInstance->m_pCondGroupChat->waitTime(5*1000)));
// } while(m_pInstance->m_bSyncGroupChatWaitting);
m_bSyncGroupChatRuning = false;
return NULL;
}
怎么保证数据的不丢失以及重复包？
- 包头的seq_num字段（包序号），未回复消息列表
- 业务层的ack机制，收到数据会回复ack
消息未读计数是怎么实现的？
服务器怎么保留消息未读计数（单聊和群聊）
7. 单聊和群聊消息未读计数机制为什么不同？
答：加入该群很大，有1000人，999个人的未读消息计数都+1，效率低下。
8. 单聊消息未读计数机制
- key设计：“unread_” + int2string(nToId)；field：int2string(nFromId)，value：自增1
- 发送消息时，将消息写入 mysql 消息表成功后，更新redis。
void CMessageModel::incMsgCount(uint32_t nFromId, uint32_t nToId)
{
CacheManager* pCacheManager = CacheManager::getInstance();
// increase message count
CacheConn* pCacheConn = pCacheManager->GetCacheConn("unread");
if (pCacheConn) {
pCacheConn->hincrBy("unread_" + int2string(nToId), int2string(nFromId), 1);
pCacheManager->RelCacheConn(pCacheConn);
} else {
log("no cache connection to increase unread count: %d->%d", nFromId, nToId);
}
}
9. 群聊消息未读计数机制
- 群总的消息计数key设计：int2string(nGroupId) + _im_group_msg;
- field：count
- 群内某个成员已经读取的消息计数key设计：
int2string(nUserId) + "_" + int2string(nGroupId) + _im_user_group
- field：count
所以：群内某个成员未读消息计数 = 群总消息数量 - 该成员已经读取的消息数量
#define GROUP_TOTAL_MSG_COUNTER_REDIS_KEY_SUFFIX "_im_group_msg"
#define GROUP_USER_MSG_COUNTER_REDIS_KEY_SUFFIX "_im_user_group"
#define GROUP_COUNTER_SUBKEY_COUNTER_FIELD "count"
增加群消息计数
/**
* 增加群消息计数
* @param nUserId 用户Id
* @param nGroupId 群组Id
* @return 成功返回true，失败返回false
*/
bool CGroupMessageModel::incMessageCount(uint32_t nUserId, uint32_t nGroupId)
{
bool bRet = false;
CacheManager* pCacheManager = CacheManager::getInstance();
CacheConn* pCacheConn = pCacheManager->GetCacheConn("unread");
if (pCacheConn)
{
string strGroupKey = int2string(nGroupId) + GROUP_TOTAL_MSG_COUNTER_REDIS_KEY_SUFFIX;
pCacheConn->hincrBy(strGroupKey, GROUP_COUNTER_SUBKEY_COUNTER_FIELD, 1);
map<string, string> mapGroupCount;
bool bRet = pCacheConn->hgetAll(strGroupKey, mapGroupCount);
if(bRet)
{
string strUserKey = int2string(nUserId) + "_" + int2string(nGroupId) + GROUP_USER_MSG_COUNTER_REDIS_KEY_SUFFIX;
string strReply = pCacheConn->hmset(strUserKey, mapGroupCount);
if(!strReply.empty())
{
bRet = true;
}
else
{
log("hmset %s failed !", strUserKey.c_str());
}
}
else
{
log("hgetAll %s failed!", strGroupKey.c_str());
}
pCacheManager->RelCacheConn(pCacheConn);
}
else
{
log("no cache connection for unread");
}
return bRet;
}
获取用户群未读消息计数
/**
* 获取用户群未读消息计数
* @param nUserId 用户Id
* @param nTotalCnt 总条数
* @param lsUnreadCount 每个会话的未读信息包含了条数，最后一个消息的Id，最后一个消息的类型，最后一个消息的类容
*/
void CGroupMessageModel::getUnreadMsgCount(uint32_t nUserId, uint32_t &nTotalCnt, list<IM::BaseDefine::UnreadInfo>& lsUnreadCount)
{
list<uint32_t> lsGroupId;
CGroupModel::getInstance()->getUserGroupIds(nUserId, lsGroupId, 0);
uint32_t nCount = 0;
CacheManager* pCacheManager = CacheManager::getInstance();
CacheConn* pCacheConn = pCacheManager->GetCacheConn("unread");
if (pCacheConn)
{
for(auto it=lsGroupId.begin(); it!=lsGroupId.end(); ++it)
{
uint32_t nGroupId = *it;
string strGroupKey = int2string(nGroupId) + GROUP_TOTAL_MSG_COUNTER_REDIS_KEY_SUFFIX;
string strGroupCnt = pCacheConn->hget(strGroupKey, GROUP_COUNTER_SUBKEY_COUNTER_FIELD);
if(strGroupCnt.empty())
{
// log("hget %s : count failed !", strGroupKey.c_str());
continue;
}
uint32_t nGroupCnt = (uint32_t)(atoi(strGroupCnt.c_str()));
string strUserKey = int2string(nUserId) + "_" + int2string(nGroupId) + GROUP_USER_MSG_COUNTER_REDIS_KEY_SUFFIX;
string strUserCnt = pCacheConn->hget(strUserKey, GROUP_COUNTER_SUBKEY_COUNTER_FIELD);
uint32_t nUserCnt = ( strUserCnt.empty() ? 0 : ((uint32_t)atoi(strUserCnt.c_str())) );
if(nGroupCnt >= nUserCnt) {
nCount = nGroupCnt - nUserCnt;
}
if(nCount > 0)
{
IM::BaseDefine::UnreadInfo cUnreadInfo;
cUnreadInfo.set_session_id(nGroupId);
cUnreadInfo.set_session_type(IM::BaseDefine::SESSION_TYPE_GROUP);
cUnreadInfo.set_unread_cnt(nCount);
nTotalCnt += nCount;
string strMsgData;
uint32_t nMsgId;
IM::BaseDefine::MsgType nType;
uint32_t nFromId;
getLastMsg(nGroupId, nMsgId, strMsgData, nType, nFromId);
if(IM::BaseDefine::MsgType_IsValid(nType))
{
cUnreadInfo.set_latest_msg_id(nMsgId);
cUnreadInfo.set_latest_msg_data(strMsgData);
cUnreadInfo.set_latest_msg_type(nType);
cUnreadInfo.set_latest_msg_from_user_id(nFromId);
lsUnreadCount.push_back(cUnreadInfo);
}
else
{
log("invalid msgType. userId=%u, groupId=%u, msgType=%u, msgId=%u", nUserId, nGroupId, nType, nMsgId);
}
}
}
pCacheManager->RelCacheConn(pCacheConn);
}
else
{
log("no cache connection for unread");
}
}
清除未读消息
单聊和群聊清除未读消息都是调用如下函数
1. 单聊直接删掉key
2. 群聊将该成员的已读消息数量设置成群总消息数量。
m_handler_map.insert(make_pair(uint32_t(CID_MSG_READ_ACK), DB_PROXY::clearUnreadMsgCounter));
void CUserModel::clearUserCounter(uint32_t nUserId, uint32_t nPeerId, IM::BaseDefine::SessionType nSessionType)
{
if(IM::BaseDefine::SessionType_IsValid(nSessionType))
{
CacheManager* pCacheManager = CacheManager::getInstance();
CacheConn* pCacheConn = pCacheManager->GetCacheConn("unread");
if (pCacheConn)
{
// Clear P2P msg Counter
if(nSessionType == IM::BaseDefine::SESSION_TYPE_SINGLE)
{
int nRet = pCacheConn->hdel("unread_" + int2string(nUserId), int2string(nPeerId));
if(!nRet)
{
log("hdel failed %d->%d", nPeerId, nUserId);
}
}
// Clear Group msg Counter
else if(nSessionType == IM::BaseDefine::SESSION_TYPE_GROUP)
{
string strGroupKey = int2string(nPeerId) + GROUP_TOTAL_MSG_COUNTER_REDIS_KEY_SUFFIX;
map<string, string> mapGroupCount;
bool bRet = pCacheConn->hgetAll(strGroupKey, mapGroupCount);
if(bRet)
{
string strUserKey = int2string(nUserId) + "_" + int2string(nPeerId) + GROUP_USER_MSG_COUNTER_REDIS_KEY_SUFFIX;
string strReply = pCacheConn->hmset(strUserKey, mapGroupCount);
if(strReply.empty()) {
log("hmset %s failed !", strUserKey.c_str());
}
}
else
{
log("hgetall %s failed!", strGroupKey.c_str());
}
}
pCacheManager->RelCacheConn(pCacheConn);
}
else
{
log("no cache connection for unread");
}
}
else{
log("invalid sessionType. userId=%u, fromId=%u, sessionType=%u", nUserId, nPeerId, nSessionType);
}
}
群成员管理
- 为什么使用 redis 管理群成员？
答：发群消息需要通知群成员，群成员很多从redis获取，提高效率。 - 群成员管理使用redis 缓存设计，以hash为存储结构，
- key 为 “group_member_”+int2string(nGroupId);
- field 为 userId（用户id）
- Value 为 创建时间：int2string(nCreated)
- 加入成员:insertNewMember，插入mysql数据库的同时也插入redis缓存
/**
* 修改群成员，增加或删除
*
* @param pPdu 收到的packet包指针
* @param conn_uuid 该包过来的socket 描述符
*/
void modifyMember(CImPdu* pPdu, uint32_t conn_uuid)
{
IM::Group::IMGroupChangeMemberReq msg;
IM::Group::IMGroupChangeMemberRsp msgResp;
if(msg.ParseFromArray(pPdu->GetBodyData(), pPdu->GetBodyLength()))
{
uint32_t nUserId = msg.user_id();
uint32_t nGroupId = msg.group_id();
IM::BaseDefine::GroupModifyType nType = msg.change_type();
if (IM::BaseDefine::GroupModifyType_IsValid(nType) &&
CGroupModel::getInstance()->isValidateGroupId(nGroupId)) {
CImPdu* pPduRes = new CImPdu;
uint32_t nCnt = msg.member_id_list_size();
set<uint32_t> setUserId;
for(uint32_t i=0; i<nCnt;++i)
{
setUserId.insert(msg.member_id_list(i));
}
list<uint32_t> lsCurUserId;
bool bRet = CGroupModel::getInstance()->modifyGroupMember(nUserId, nGroupId, nType, setUserId, lsCurUserId);
msgResp.set_user_id(nUserId);
msgResp.set_group_id(nGroupId);
msgResp.set_change_type(nType);
msgResp.set_result_code(bRet?0:1);
if(bRet)
{
for(auto it=setUserId.begin(); it!=setUserId.end(); ++it)
{
msgResp.add_chg_user_id_list(*it);
}
for(auto it=lsCurUserId.begin(); it!=lsCurUserId.end(); ++it)
{
msgResp.add_cur_user_id_list(*it);
}
}
log("userId=%u, groupId=%u, result=%u, changeCount:%u, currentCount=%u",nUserId, nGroupId, bRet?0:1, msgResp.chg_user_id_list_size(), msgResp.cur_user_id_list_size());
msgResp.set_attach_data(msg.attach_data());
pPduRes->SetPBMsg(&msgResp);
pPduRes->SetSeqNum(pPdu->GetSeqNum());
pPduRes->SetServiceId(IM::BaseDefine::SID_GROUP);
pPduRes->SetCommandId(IM::BaseDefine::CID_GROUP_CHANGE_MEMBER_RESPONSE);
CProxyConn::AddResponsePdu(conn_uuid, pPduRes);
}
else
{
log("invalid groupModifyType or groupId. userId=%u, groupId=%u, groupModifyType=%u", nUserId, nGroupId, nType);
}
}
else
{
log("parse pb failed");
}
}
bool CGroupModel::insertNewMember(uint32_t nGroupId, set<uint32_t>& setUsers)
{
bool bRet = false;
uint32_t nUserCnt = (uint32_t)setUsers.size();
if(nGroupId != INVALID_VALUE && nUserCnt > 0)
{
CDBManager* pDBManager = CDBManager::getInstance();
CDBConn* pDBConn = pDBManager->GetDBConn("teamtalk_slave");
if (pDBConn)
{
uint32_t nCreated = (uint32_t)time(NULL);
// 获取 已经存在群里的用户
string strClause;
bool bFirst = true;
for (auto it=setUsers.begin(); it!=setUsers.end(); ++it)
{
if(bFirst)
{
bFirst = false;
strClause = int2string(*it);
}
else
{
strClause += ("," + int2string(*it));
}
}
string strSql = "select userId from IMGroupMember where groupId=" + int2string(nGroupId) + " and userId in (" + strClause + ")";
CResultSet* pResult = pDBConn->ExecuteQuery(strSql.c_str());
set<uint32_t> setHasUser;
if(pResult)
{
while (pResult->Next()) {
setHasUser.insert(pResult->GetInt("userId"));
}
delete pResult;
}
else
{
log("no result for sql:%s", strSql.c_str());
}
pDBManager->RelDBConn(pDBConn);
pDBConn = pDBManager->GetDBConn("teamtalk_master");
if (pDBConn)
{
CacheManager* pCacheManager = CacheManager::getInstance();
CacheConn* pCacheConn = pCacheManager->GetCacheConn("group_member");
if (pCacheConn)
{
// 设置已经存在群中人的状态
if (!setHasUser.empty())
{
strClause.clear();
bFirst = true;
for (auto it=setHasUser.begin(); it!=setHasUser.end(); ++it) {
if(bFirst)
{
bFirst = false;
strClause = int2string(*it);
}
else
{
strClause += ("," + int2string(*it));
}
}
strSql = "update IMGroupMember set status=0, updated="+int2string(nCreated)+" where groupId=" + int2string(nGroupId) + " and userId in (" + strClause + ")";
pDBConn->ExecuteUpdate(strSql.c_str());
}
strSql = "insert into IMGroupMember(`groupId`, `userId`, `status`, `created`, `updated`) values\
(?,?,?,?,?)";
//插入新成员
auto it = setUsers.begin();
uint32_t nStatus = 0;
uint32_t nIncMemberCnt = 0;
for (;it != setUsers.end();)
{
uint32_t nUserId = *it;
if(setHasUser.find(nUserId) == setHasUser.end())
{
CPrepareStatement* pStmt = new CPrepareStatement();
if (pStmt->Init(pDBConn->GetMysql(), strSql))
{
uint32_t index = 0;
pStmt->SetParam(index++, nGroupId);
pStmt->SetParam(index++, nUserId);
pStmt->SetParam(index++, nStatus);
pStmt->SetParam(index++, nCreated);
pStmt->SetParam(index++, nCreated);
pStmt->ExecuteUpdate();
++nIncMemberCnt;
delete pStmt;
}
else
{
setUsers.erase(it++);
delete pStmt;
continue;
}
}
++it;
}
if(nIncMemberCnt != 0)
{
strSql = "update IMGroup set userCnt=userCnt+" + int2string(nIncMemberCnt) + " where id="+int2string(nGroupId);
pDBConn->ExecuteUpdate(strSql.c_str());
}
//更新一份到redis中
string strKey = "group_member_"+int2string(nGroupId);
for(auto it = setUsers.begin(); it!=setUsers.end(); ++it)
{
pCacheConn->hset(strKey, int2string(*it), int2string(nCreated));
}
pCacheManager->RelCacheConn(pCacheConn);
bRet = true;
}
else
{
log("no cache connection");
}
pDBManager->RelDBConn(pDBConn);
}
else
{
log("no db connection for teamtalk_master");
}
}
else
{
log("no db connection for teamtalk_slave");
}
}
return bRet;
}
- 删除成员:removeMember；从mysql数据库删除的同时,也从redis缓存删除
bool CGroupModel::removeMember(uint32_t nGroupId, set<uint32_t> &setUser, list<uint32_t>& lsCurUserId)
{
if(setUser.size() <= 0)
{
return true;
}
bool bRet = false;
CDBManager* pDBManager = CDBManager::getInstance();
CDBConn* pDBConn = pDBManager->GetDBConn("teamtalk_master");
if(pDBConn)
{
CacheManager* pCacheManager = CacheManager::getInstance();
CacheConn* pCacheConn = pCacheManager->GetCacheConn("group_member");
if (pCacheConn)
{
string strClause ;
bool bFirst = true;
for(auto it= setUser.begin(); it!=setUser.end();++it)
{
if (bFirst) {
bFirst = false;
strClause = int2string(*it);
}
else
{
strClause += ("," + int2string(*it));
}
}
string strSql = "update IMGroupMember set status=1 where groupId =" + int2string(nGroupId) + " and userId in(" + strClause + ")";
pDBConn->ExecuteUpdate(strSql.c_str());
//从redis中删除成员
string strKey = "group_member_"+ int2string(nGroupId);
for (auto it=setUser.begin(); it!=setUser.end(); ++it) {
string strField = int2string(*it);
pCacheConn->hdel(strKey, strField);
}
pCacheManager->RelCacheConn(pCacheConn);
bRet = true;
}
else
{
log("no cache connection");
}
pDBManager->RelDBConn(pDBConn);
if (bRet)
{
getGroupUser(nGroupId,lsCurUserId);
}
}
else
{
log("no db connection for teamtalk_master");
}
return bRet;
}
redis连接池设计
6. 为什么使用连接池？
答：对象复用，减小频繁创建链接释放链接的开销时间。
7. CacheInstances=unread,group_set,token,sync,group_member 5 个连接池
8. 为什么分开不同的db redis？
答：方便扩展。
9. pool_name的意义？
答：抽象，不必关注redis是否分布式。
class CacheManager {
public:
virtual ~CacheManager();
static CacheManager* getInstance();
int Init();
CacheConn* GetCacheConn(const char* pool_name);
void RelCacheConn(CacheConn* pCacheConn);
private:
CacheManager();
private:
static CacheManager* s_cache_manager;
map<string, CachePool*> m_cache_pool_map;
};
int CacheManager::Init()
{
CConfigFileReader config_file("dbproxyserver.conf");
//CacheInstances=unread,group_set,token,sync,group_member
char* cache_instances = config_file.GetConfigName("CacheInstances");
if (!cache_instances) {
log("not configure CacheIntance");
return 1;
}
char host[64];
char port[64];
char db[64];
char maxconncnt[64];
CStrExplode instances_name(cache_instances, ',');
for (uint32_t i = 0; i < instances_name.GetItemCnt(); i++) {
char* pool_name = instances_name.GetItem(i);
//printf("%s", pool_name);
snprintf(host, 64, "%s_host", pool_name);
snprintf(port, 64, "%s_port", pool_name);
snprintf(db, 64, "%s_db", pool_name);
snprintf(maxconncnt, 64, "%s_maxconncnt", pool_name);
char* cache_host = config_file.GetConfigName(host);
char* str_cache_port = config_file.GetConfigName(port);
char* str_cache_db = config_file.GetConfigName(db);
char* str_max_conn_cnt = config_file.GetConfigName(maxconncnt);
if (!cache_host || !str_cache_port || !str_cache_db || !str_max_conn_cnt) {
log("not configure cache instance: %s", pool_name);
return 2;
}
CachePool* pCachePool = new CachePool(pool_name, cache_host, atoi(str_cache_port),
atoi(str_cache_db), atoi(str_max_conn_cnt));
if (pCachePool->Init()) {
log("Init cache pool failed");
return 3;
}
m_cache_pool_map.insert(make_pair(pool_name, pCachePool));
}
return 0;
}
原文地址：https://blog.csdn.net/COOL_jack/article/details/142307099
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