C++ UdpServer类代码示例

// this must always be called sometime AFTER handleRequest() is called
void sendReply ( UdpSlot *slot , Msg39 *msg39 , char *reply , long replyLen ,
		 long replyMaxSize , bool hadError ) {
	// debug msg
	if ( g_conf.m_logDebugQuery || (msg39&&msg39->m_debug) ) 
		logf(LOG_DEBUG,"query: msg39: [%lu] Sending reply len=%li.",
		     (long)msg39,replyLen);

	// sanity
	if ( hadError && ! g_errno ) { char *xx=NULL;*xx=0; }

	// no longer in use. msg39 will be NULL if ENOMEM or something
	if ( msg39 ) msg39->m_inUse = false;

	// . if we enter from a local call and not from handling a udp slot
	//   then execute this logic here to return control to caller.
	// . do not delete ourselves because we will be re-used probably and
	//   caller handles that now.
	if ( msg39 && msg39->m_callback ) {
		// if we blocked call user callback
		if ( msg39->m_blocked ) msg39->m_callback ( msg39->m_state );
		// if not sending back a udp reply, return now
		return;
	}

	// . now we can free the lists before sending
	// . may help a little bit...
	//if ( msg39 ) {
	//	for ( long j = 0 ; j < msg39->m_msg2.m_numLists ; j++ ) 
	//		msg39->m_lists[j].freeList();
	//}
	// get the appropriate UdpServer for this niceness level
	UdpServer *us = &g_udpServer;
	// i guess clear this
	long err = g_errno;
	g_errno = 0;
	// send an error reply if g_errno is set
	if ( err ) us->sendErrorReply ( slot , err ) ; 
	else       us->sendReply_ass ( reply    , 
				       replyLen , 
				       reply    , 
				       replyMaxSize , 
				       slot     );
	// always delete ourselves when done handling the request
	if ( msg39 ) {
		mdelete ( msg39 , sizeof(Msg39) , "Msg39" );
		delete (msg39);
	}
}

UINT __stdcall UdpServerForIpWorker(PVOID context)
{
	UdpServer server;
	if (server.Init("127.0.0.1", (int)context)) {
		std::vector<UCHAR> buffer;
		buffer.resize(0x1000);
		for (;;) {
			sockaddr_in addr;
			int recv_length = server.Recv((char *)buffer.data(), buffer.size(), &addr);
			if (recv_length == -1) {
				break;
			}

			server.Send("OK", 3, &addr);
		}
	}

	return 0;
}

// g_errno may be set when this is called
void addedList ( UdpSlot *slot , Rdb *rdb ) {
	// no memory means to try again
	if ( g_errno == ENOMEM ) g_errno = ETRYAGAIN;
	// doing a full rebuid will add collections
	if ( g_errno == ENOCOLLREC &&
	     g_repairMode > 0 )
	     //g_repair.m_fullRebuild )
		g_errno = ETRYAGAIN;
	// . if we got a ETRYAGAIN cuz the buffer we add to was full
	//   then we should sleep and try again!
	// . return false cuz this blocks for a period of time
	//   before trying again
	// . but now to free the udp slot when we are doing an urgent merge
	//   let's send an error back!
	//if ( g_errno == ETRYAGAIN ) {
		// debug msg
		//log("REGISTERING SLEEP CALLBACK");
		// try adding again in 1 second
	//	g_loop.registerSleepCallback ( 1000, slot, tryAgainWrapper );
		// return now
	//	return;
	//}
	// random test
	//if ( (rand() % 10) == 1 ) g_errno = ETRYAGAIN;
	//long niceness = slot->getNiceness() ;
	// select udp server based on niceness
	UdpServer *us = &g_udpServer ;
	//if ( niceness == 0 ) us = &g_udpServer2;
	//else                 us = &g_udpServer ;
	// chalk it up
	rdb->sentReplyAdd ( 0 );
	// are we done
	if ( ! g_errno ) {
		// . send an empty (non-error) reply as verification
		// . slot should be auto-nuked on transmission/timeout of reply
		// . udpServer should free the readBuf
		us->sendReply_ass ( NULL , 0 , NULL , 0 , slot ) ;
		return;
	}
	// on other errors just send the err code back
	us->sendErrorReply ( slot , g_errno );
}

void* UdpServer::startThread(void *obj)
{
	UdpServer *instance = reinterpret_cast<UdpServer *>(obj);

	socklen_t londesde;
	londesde = sizeof(sockaddr_in);

	while(true)
	{
		int size;
		londesde = sizeof(sockaddr_in);

		(instance->getUDPRespSock())->sin_port = htons (instance->getUDPPort());

		//cerr<<"UDPSERV: listening"<<endl;

		if ( (size = recvfrom(instance->getUDPSocket(), instance->getUDPBuffer(), MAXMSGSIZE, 0, (sockaddr *)instance->getUDPRespSock(), &londesde))  < 0 ) {
			cerr<<"UDPSERV: Error calling recvfrom()"<<endl;
			return NULL;
		}

		if(size>0)
			instance->UDPmanageRecv(size);
	}
	
}

// . did we receive a checkoff request from a fellow twin?
// . request is a list of checkoff request keys ("a" keys)
void handleRequest5d ( UdpSlot *slot , long netnice ) {
	// get the sending hostid
	long sid = slot->m_hostId;
	// sanity check
	if ( sid < 0 ) { char *xx=NULL; *xx=0; }
	// get the request buffer
	//key128_t *keys = (key128_t *)slot->m_readBuf;
	long      nk   = slot->m_readBufSize / 16;
	// shortcut
	UdpServer *us = &g_udpServer;
	// if tree gets full, then return false forever
	if ( ! g_syncdb.m_qt.hasRoomForKeys ( nk ) ) { 
		us->sendErrorReply ( slot , ETRYAGAIN );
		return; 
	}
	for ( long i = 0 ; i < nk ; i++ ) {
		// get the key
		key128_t k = g_syncdb.m_keys[i];
		// sanity check. must be a negative key.
		if ( (k.n0 & 0x1) != 0x0 ) { char *xx=NULL;*xx=0; }
		// get the anti key. the "need to recv checkoff request"
		// key which is the positive
		key128_t pk = k;
		// make it positive
		pk.n0 |= 0x01;
		// is it in there?
		long nn = g_syncdb.m_qt.getNode ( 0 , (char *)&pk );
		// if yes, nuke it. they annihilate.
		if ( nn >= 0 ) {
			g_syncdb.m_qt.deleteNode ( nn , true );
			continue;
		}
		// . otherwise, add right to the tree
		// . should always succeed!
		if ( g_syncdb.m_qt.addKey(&k)<0) { char *xx=NULL;*xx=0; }
	}
	// return empty reply to mean success
	us->sendReply_ass ( NULL , 0 , NULL , 0 , slot );
}

void * UdpServer::OperatorThread(void * pParam)
{
    if(!pParam)
    {
        return 0;
    }

    UdpServer * pThis = (UdpServer*)pParam;
    pthread_mutex_lock(&pThis->mMutex);
    MsgInfo data;
    if(pThis->mDataList.size() > 0)
    {
        data = pThis->mDataList.front();
        pThis->mDataList.pop_front();
        if(pThis->mOperaFunc)
        {
            pThis->mOperaFunc(data.Content, data.Fd, data.Time);
        }
        pThis->OnReceiveMessage(data.Content, data.Fd, data.Time);
    }
    pthread_mutex_unlock(&pThis->mMutex);
    return 0;
}

//.........这里部分代码省略.........
	//   no, not anymore, we commented out that request peeking code
	char *p = m_request;
	*(int64_t *) p = syncPoint        ; p += 8;
	//*(key_t     *) p = m_startKey       ; p += sizeof(key_t);
	//*(key_t     *) p = m_endKey         ; p += sizeof(key_t);
	*(int32_t      *) p = m_minRecSizes    ; p += 4;
	*(int32_t      *) p = startFileNum     ; p += 4;
	*(int32_t      *) p = numFiles         ; p += 4;
	*(int32_t      *) p = maxCacheAge      ; p += 4;
	if ( p - m_request != RDBIDOFFSET ) { char *xx=NULL;*xx=0; }
	*p               = m_rdbId          ; p++;
	*p               = addToCache       ; p++;
	*p               = doErrorCorrection; p++;
	*p               = includeTree      ; p++;
	*p               = (char)niceness   ; p++;
	*p               = (char)m_allowPageCache; p++;
	KEYSET(p,m_startKey,m_ks);          ; p+=m_ks;
	KEYSET(p,m_endKey,m_ks);            ; p+=m_ks;
	// NULL terminated collection name
	//strcpy ( p , coll ); p += gbstrlen ( coll ); *p++ = '\0';
	*(collnum_t *)p = m_collnum; p += sizeof(collnum_t);
	m_requestSize    = p - m_request;
	// ask an individual host for this list if hostId is NOT -1
	if ( m_hostId != -1 ) {
		// get Host
		Host *h = g_hostdb.getHost ( m_hostId );
		if ( ! h ) { 
			g_errno = EBADHOSTID; 
			log(LOG_LOGIC,"net: msg0: Bad hostId of %"INT64".",
			    m_hostId);
			return true;
		}
		// if niceness is 0, use the higher priority udpServer
		UdpServer *us ;
		uint16_t port;
		QUICKPOLL(m_niceness);
		//if ( niceness <= 0 || netnice == 0 ) { 
		//if ( realtime ) {
		//	us = &g_udpServer2; port = h->m_port2; }
		//else                 { 
		us = &g_udpServer ; port = h->m_port ; 
		// . returns false on error and sets g_errno, true otherwise
		// . calls callback when reply is received (or error)
		// . we return true if it returns false
		if ( ! us->sendRequest ( m_request     ,
					 m_requestSize ,
					 0x00          , // msgType
					 h->m_ip       ,
					 port          ,
					 m_hostId      ,
					 NULL          , // the slotPtr
					 this          ,
					 gotSingleReplyWrapper ,
					 timeout       ,
					 -1            , // backoff
					 -1            , // maxwait
					 replyBuf      ,
					 replyBufMaxSize ,
					 m_niceness     ) ) // cback niceness
			return true;
		// return false cuz it blocked
		return false;
	}
	// timing debug
	if ( g_conf.m_logTimingNet )
		m_startTime = gettimeofdayInMilliseconds();

// . reply to a request for an RdbList
// . MUST call g_udpServer::sendReply or sendErrorReply() so slot can
//   be destroyed
void handleRequest0 ( UdpSlot *slot , int32_t netnice ) {
	// if niceness is 0, use the higher priority udpServer
	UdpServer *us = &g_udpServer;
	//if ( netnice == 0 ) us = &g_udpServer2;
	// get the request
	char *request     = slot->m_readBuf;
	int32_t  requestSize = slot->m_readBufSize;
	// collection is now stored in the request, so i commented this out
	//if ( requestSize != MSG0_REQ_SIZE ) {
	//	log("net: Received bad data request size of %"INT32" bytes. "
	//	    "Should be %"INT32".", requestSize ,(int32_t)MSG0_REQ_SIZE);
	//	us->sendErrorReply ( slot , EBADREQUESTSIZE );
	//	return;
	//}
	// parse the request
	char *p                  = request;
	int64_t syncPoint          = *(int64_t *)p ; p += 8;
	//key_t     startKey           = *(key_t     *)p ; p += sizeof(key_t);
	//key_t     endKey             = *(key_t     *)p ; p += sizeof(key_t);
	int32_t      minRecSizes        = *(int32_t      *)p ; p += 4;
	int32_t      startFileNum       = *(int32_t      *)p ; p += 4;
	int32_t      numFiles           = *(int32_t      *)p ; p += 4;
	int32_t      maxCacheAge        = *(int32_t      *)p ; p += 4;
	char      rdbId              = *p++;
	char      addToCache         = *p++;
	char      doErrorCorrection  = *p++;
	char      includeTree        = *p++;
	// this was messing up our niceness conversion logic
	int32_t      niceness           = slot->m_niceness;//(int32_t)(*p++);
	// still need to skip it though!
	p++;
	bool      allowPageCache     = (bool)(*p++);
	char ks = getKeySizeFromRdbId ( rdbId );
	char     *startKey           = p; p+=ks;
	char     *endKey             = p; p+=ks;
	// then null terminated collection
	//char     *coll               = p;
	collnum_t collnum = *(collnum_t *)p; p += sizeof(collnum_t);

	CollectionRec *xcr = g_collectiondb.getRec ( collnum );
	if ( ! xcr ) g_errno = ENOCOLLREC;
	
	// error set from XmlDoc::cacheTermLists()?
	if ( g_errno ) {
		us->sendErrorReply ( slot , EBADRDBID ); return;}

	// is this being called from callWaitingHandlers()
	//bool isRecall = (netnice == 99);

	// . get the rdb we need to get the RdbList from
	// . returns NULL and sets g_errno on error
	//Msg0 msg0;
	//Rdb *rdb = msg0.getRdb ( rdbId );
	Rdb *rdb = getRdbFromId ( rdbId );
	if ( ! rdb ) { 
		us->sendErrorReply ( slot , EBADRDBID ); return;}

	// keep track of stats
	rdb->readRequestGet ( requestSize );

	/*
	// keep track of stats
	if ( ! isRecall ) rdb->readRequestGet ( requestSize );

	int64_t singleDocId2 = 0LL;
	if ( rdbId == RDB_POSDB && maxCacheAge ) {
		int64_t d1 = g_posdb.getDocId(startKey);
		int64_t d2 = g_posdb.getDocId(endKey);
		if ( d1+1 == d2 ) singleDocId2 = d1;
	}

	// have we parsed this docid and cached its termlists?
	bool shouldBeCached2 = false;
	if ( singleDocId2 && 
	     isDocIdInTermListCache ( singleDocId2 , coll ) ) 
		shouldBeCached2 = true;

	// if in the termlist cache, send it back right away
	char *trec;
	int32_t trecSize;
	if ( singleDocId2 &&
	     getRecFromTermListCache(coll,
				     startKey,
				     endKey,
				     maxCacheAge,
				     &trec,
				     &trecSize) ) {
		// if in cache send it back!
		us->sendReply_ass(trec,trecSize,trec,trecSize,slot);
		return;
	}

	// if should be cached but was not found then it's probably a
	// synonym form not in the doc content. make an empty list then.
	if ( shouldBeCached2 ) {
		// send back an empty termlist
		us->sendReply_ass(NULL,0,NULL,0,slot);
//.........这里部分代码省略.........

// . slot should be auto-nuked upon transmission or error
// . TODO: ensure if this sendReply() fails does it really nuke the slot?
void gotListWrapper ( void *state , RdbList *listb , Msg5 *msg5xx ) {
	// get the state
	State00 *st0 = (State00 *)state;
	// extract the udp slot and list and msg5
	UdpSlot   *slot =  st0->m_slot;
	RdbList   *list = &st0->m_list;
	Msg5      *msg5 = &st0->m_msg5;
	UdpServer *us   =  st0->m_us;
	// sanity check -- ensure they match
	//if ( niceness != st0->m_niceness )
	//	log("Msg0: niceness mismatch");
	// debug msg
	//if ( niceness != 0 ) 
	//	log("HEY! niceness is not 0");
	// timing debug
	if ( g_conf.m_logTimingNet || g_conf.m_logDebugNet ) {
		//log("Msg0:hndled request %"UINT64"",gettimeofdayInMilliseconds());
		int32_t size = -1;
		if ( list ) size     = list->getListSize();
		log(LOG_TIMING|LOG_DEBUG,
		    "net: msg0: Handled request for data. "
		    "Now sending data termId=%"UINT64" size=%"INT32""
		    " transId=%"INT32" ip=%s port=%i took=%"INT64" "
		    "(niceness=%"INT32").",
		    g_posdb.getTermId(msg5->m_startKey),
		    size,slot->m_transId,
		    iptoa(slot->m_ip),slot->m_port,
		    gettimeofdayInMilliseconds() - st0->m_startTime ,
		    st0->m_niceness );
	}
	// debug
	//if ( ! msg5->m_includeTree )
	//	log("hotit\n");
	// on error nuke the list and it's data
	if ( g_errno ) {
		mdelete ( st0 , sizeof(State00) , "Msg0" );
		delete (st0);
		// TODO: free "slot" if this send fails
		us->sendErrorReply ( slot , g_errno );
		return;
	}

	QUICKPOLL(st0->m_niceness);
	// point to the serialized list in "list"
	char *data      = list->getList();
	int32_t  dataSize  = list->getListSize();
	char *alloc     = list->getAlloc();
	int32_t  allocSize = list->getAllocSize();
	// tell list not to free the data since it is a reply so UdpServer
	// will free it when it destroys the slot
	list->setOwnData ( false );
	// keep track of stats
	Rdb *rdb = getRdbFromId ( st0->m_rdbId );
	if ( rdb ) rdb->sentReplyGet ( dataSize );
	// TODO: can we free any memory here???

	// keep track of how long it takes to complete the send
	st0->m_startTime = gettimeofdayInMilliseconds();
	// debug point
	int32_t oldSize = msg5->m_minRecSizes;
	int32_t newSize = msg5->m_minRecSizes + 20;
	// watch for wrap around
	if ( newSize < oldSize ) newSize = 0x7fffffff;
	if ( dataSize > newSize && list->getFixedDataSize() == 0 &&
	     // do not annoy me with these linkdb msgs
	     dataSize > newSize+100 ) 
		log(LOG_LOGIC,"net: msg0: Sending more data than what was "
		    "requested. Ineffcient. Bad engineer. dataSize=%"INT32" "
		    "minRecSizes=%"INT32".",dataSize,oldSize);
	/*
	// always compress these lists
	if ( st0->m_rdbId == RDB_SECTIONDB ) { // && 1 == 3) {

		// get sh48, the sitehash
		key128_t *startKey = (key128_t *)msg5->m_startKey ;
		int64_t sh48 = g_datedb.getTermId(startKey);

		// debug
		//log("msg0: got sectiondblist from disk listsize=%"INT32"",
		//    list->getListSize());

		if ( dataSize > 50000 )
			log("msg0: sending back list rdb=%"INT32" "
			    "listsize=%"INT32" sh48=0x%"XINT64"",
			    (int32_t)st0->m_rdbId,
			    dataSize,
			    sh48);

		// save it
		int32_t origDataSize = dataSize;
		// store compressed list on itself
		char *dst = list->m_list;
		// warn if niceness is 0!
		if ( st0->m_niceness == 0 )
			log("msg0: compressing sectiondb list at niceness 0!");
		// compress the list
		uint32_t lastVoteHash32 = 0LL;
		SectionVote *lastVote = NULL;
//.........这里部分代码省略.........

//接收socket连接线程
void * UdpServer::AcceptThread(void * pParam)
{
    if(0 == pParam)
    {
        cout << "param is null." << endl;
        return 0;
    }
    UdpServer * pThis = (UdpServer*)pParam;

    int maxFd = 0;
    struct sockaddr_in cliAddr;
    while(true)
    {
        FD_ZERO(&pThis->mReadFd);
        FD_SET(pThis->mServerSocket, &pThis->mReadFd);
        maxFd = (pThis->mServerSocket > maxFd)? pThis->mServerSocket : maxFd;

        for(list<int>::iterator itor = pThis->mCliList.begin(); itor != pThis->mCliList.end(); itor++)
        {
            FD_SET(*itor, &pThis->mReadFd);
            maxFd = (*itor > maxFd)? *itor : maxFd;
        }

        int res = select(maxFd + 1, &pThis->mReadFd, 0, 0, NULL);
        if(-1 == res)
        {
            cout << "select failed." << endl;
        }


        if(-1 != pThis->mServerSocket && FD_ISSET(pThis->mServerSocket , &pThis->mReadFd))
        {
            int sin_size = sizeof(struct sockaddr_in);
            int clientSoc = accept(pThis->mServerSocket, (struct sockaddr *)(&cliAddr), (socklen_t*)&sin_size);
            if(-1 == clientSoc)
            {
                cout << "accept error." << endl;
                continue;
            }
            if(DEBUG) cout << "Accept new client : " << clientSoc << endl;
            pThis->mCliList.push_front(clientSoc);

            string ip = inet_ntoa(cliAddr.sin_addr);
            char tmp[16] = {0};
            sprintf(tmp, "%d", ntohs(cliAddr.sin_port));
            string port = tmp;
            if(0 != pThis->mAcceptFunc)
            {
                pThis->mAcceptFunc(ip, port, clientSoc);
            }
            pThis->OnClientConnect(ip, port, clientSoc);
        }

        for(list<int>::iterator itor = pThis->mCliList.begin(); itor != pThis->mCliList.end(); itor++)
        {
            if(-1 != *itor && FD_ISSET(*itor , &pThis->mReadFd))
            {
                char buf[MAX_MESSAGE_LEN] = {0};
                int res = recv(*itor, buf, sizeof(buf), 0);
                if(0 < res)
                {
                    if(DEBUG) cout << "Receive data : " << buf << endl;
                    pthread_mutex_lock(&pThis->mMutex);
                    pThis->mDataList.push_back(MsgInfo(*itor, buf));
                    pthread_mutex_unlock(&pThis->mMutex);
                }
                else if(0 == res)
                {
                    cout << "client quit." << endl;
                    pthread_mutex_lock(&pThis->mMutex);
                    pThis->mCliList.remove(*itor);
                    itor--;
                    pThis->mDisconnectFunc(*itor);
                    pThis->OnClientDisconnect(*itor);
                    pthread_mutex_unlock(&pThis->mMutex);
                }
                else
                {
                    cout << "receive failed." << endl;
                }
            }
        }
    }
}

//.........这里部分代码省略.........

	// if docid based assume it was a query reindex and keep it short!
	// otherwise we end up waiting 120 seconds for a query reindex to
	// go through on a docid we just spidered. TODO: use m_urlIsDocId
	// MDW: check this out
	if ( url && is_digit(url[0]) ) ct = 2;

	// . this seems to be messing us up and preventing us from adding new
	//   requests into doledb when only spidering a few IPs.
	// . make it random in the case of twin contention
	ct = rand() % 10;

	// . check our cache to avoid repetitive asking
	// . use -1 for maxAge to indicate no max age
	// . returns -1 if not in cache
	// . use maxage of two minutes, 120 seconds
	int32_t lockTime ;
	lockTime = g_spiderLoop.m_lockCache.getLong(0,m_lockKeyUh48,ct,true);
	// if it was in the cache and less than 2 minutes old then return
	// true now with m_hasLock set to false.
	if ( lockTime >= 0 ) {
		if ( g_conf.m_logDebugSpider )
			logf(LOG_DEBUG,"spider: cached missed lock for %s "
			     "lockkey=%" PRIu64, m_url,m_lockKeyUh48);
		return true;
	}

	if ( g_conf.m_logDebugSpider )
		logf(LOG_DEBUG,"spider: sending lock request for %s "
		     "lockkey=%" PRIu64,  m_url,m_lockKeyUh48);

	// now the locking group is based on the probable docid
	//m_lockGroupId = g_hostdb.getGroupIdFromDocId(m_lockKey);
	// ptr to list of hosts in the group
	//Host *hosts = g_hostdb.getGroup ( m_lockGroupId );
	// the same group (shard) that has the spiderRequest/Reply is
	// the one responsible for locking.
	Host *hosts = g_hostdb.getMyShard();

	// shortcut
	UdpServer *us = &g_udpServer;


	static int32_t s_lockSequence = 0;
	// remember the lock sequence # in case we have to call remove locks
	m_lockSequence = s_lockSequence++;

	LockRequest *lr = &m_lockRequest;
	lr->m_lockKeyUh48 = m_lockKeyUh48;
	lr->m_firstIp = m_firstIp;
	lr->m_removeLock = 0;
	lr->m_lockSequence = m_lockSequence;
	lr->m_collnum = collnum;

	// reset counts
	m_numRequests = 0;
	m_numReplies  = 0;

	// point to start of the 12 byte request buffer
	char *request = (char *)lr;//m_lockKey;
	int32_t  requestSize = sizeof(LockRequest);//12;

	// loop over hosts in that shard
	for ( int32_t i = 0 ; i < hpg ; i++ ) {
		// get a host
		Host *h = &hosts[i];
		// skip if dead! no need to get a reply from dead guys
		if ( g_hostdb.isDead (h) ) continue;
		// note it
		if ( g_conf.m_logDebugSpider )
			logf(LOG_DEBUG,"spider: sent lock "
			     "request #%" PRId32" for lockkey=%" PRIu64" %s to "
			     "hid=%" PRId32,m_numRequests,m_lockKeyUh48,
			     m_url,h->m_hostId);
		// send request to him
		if ( ! us->sendRequest ( request      ,
					 requestSize  ,
					 0x12         , // msgType
					 h->m_ip      ,
					 h->m_port    ,
					 h->m_hostId  ,
					 NULL         , // retSlotPtrPtr
					 this         , // state data
					 gotLockReplyWrapper ,
					 udpserver_sendrequest_infinite_timeout ) ) 
			// udpserver returns false and sets g_errno on error
			return true;
		// count them
		m_numRequests++;
	}
	// block?
	if ( m_numRequests > 0 ) return false;
	// i guess nothing... hmmm... all dead?
	//char *xx=NULL; *xx=0; 
	// m_hasLock should be false... all lock hosts seem dead... wait
	if ( g_conf.m_logDebugSpider )
		logf(LOG_DEBUG,"spider: all lock hosts seem dead for %s "
		     "lockkey=%" PRIu64, m_url,m_lockKeyUh48);
	return true;
}

bool Msg12::removeAllLocks ( ) {

	// ensure not in use. not msg12 replies outstanding.
	if ( m_numRequests != m_numReplies ) { char *xx=NULL;*xx=0; }

	// no longer use this
	char *xx=NULL;*xx=0;

	// skip if injecting
	//if ( m_sreq->m_isInjecting ) return true;
	if ( g_conf.m_logDebugSpider )
		logf(LOG_DEBUG,"spider: removing all locks for %s %" PRIu64,
		     m_url,m_lockKeyUh48);
	// we are now removing 
	m_removing = true;

	LockRequest *lr = &m_lockRequest;
	lr->m_lockKeyUh48 = m_lockKeyUh48;
	lr->m_lockSequence = m_lockSequence;
	lr->m_firstIp = m_firstIp;
	lr->m_removeLock = 1;

	// reset counts
	m_numRequests = 0;
	m_numReplies  = 0;

	// make that the request
	// . point to start of the 12 byte request buffer
	// . m_lockSequence should still be valid
	char *request     = (char *)lr;//m_lockKey;
	int32_t  requestSize = sizeof(LockRequest);//12;

	// now the locking group is based on the probable docid
	//uint32_t groupId = g_hostdb.getGroupIdFromDocId(m_lockKeyUh48);
	// ptr to list of hosts in the group
	//Host *hosts = g_hostdb.getGroup ( groupId );
	Host *hosts = g_hostdb.getMyShard();
	// this must select the same group that is going to spider it!
	// i.e. our group! because we check our local lock table to see
	// if a doled url is locked before spidering it ourselves.
	//Host *hosts = g_hostdb.getMyGroup();
	// shortcut
	UdpServer *us = &g_udpServer;
	// set the hi bit though for this one
	//m_lockKey |= 0x8000000000000000LL;
	// get # of hosts in each mirror group
	int32_t hpg = g_hostdb.getNumHostsPerShard();
	// loop over hosts in that shard
	for ( int32_t i = 0 ; i < hpg ; i++ ) {
		// get a host
		Host *h = &hosts[i];
		// skip if dead! no need to get a reply from dead guys
		if ( g_hostdb.isDead ( h ) ) continue;
		// send request to him
		if ( ! us->sendRequest ( request      ,
					 requestSize  ,
					 0x12         , // msgType
					 h->m_ip      ,
					 h->m_port    ,
					 h->m_hostId  ,
					 NULL         , // retSlotPtrPtr
					 this         , // state data
					 gotLockReplyWrapper ,
					 udpserver_sendrequest_infinite_timeout ) ) 
			// udpserver returns false and sets g_errno on error
			return true;
		// count them
		m_numRequests++;
	}
	// block?
	if ( m_numRequests > 0 ) return false;
	// did not block
	return true;
}

//.........这里部分代码省略.........
	char *p = m_request;
	*(int64_t *) p = syncPoint        ; p += 8;
	//*(key_t     *) p = m_startKey       ; p += sizeof(key_t);
	//*(key_t     *) p = m_endKey         ; p += sizeof(key_t);
	*(int32_t      *) p = m_minRecSizes    ; p += 4;
	*(int32_t      *) p = startFileNum     ; p += 4;
	*(int32_t      *) p = numFiles         ; p += 4;
	*(int32_t      *) p = maxCacheAge      ; p += 4;
	if ( p - m_request != RDBIDOFFSET ) { char *xx=NULL;*xx=0; }
	*p               = m_rdbId          ; p++;
	*p               = addToCache       ; p++;
	*p               = doErrorCorrection; p++;
	*p               = includeTree      ; p++;
	*p               = (char)niceness   ; p++;
	*p               = (char)m_allowPageCache; p++;
	KEYSET(p,m_startKey,m_ks);          ; p+=m_ks;
	KEYSET(p,m_endKey,m_ks);            ; p+=m_ks;
	// NULL terminated collection name
	//strcpy ( p , coll ); p += gbstrlen ( coll ); *p++ = '\0';
	*(collnum_t *)p = m_collnum; p += sizeof(collnum_t);
	m_requestSize    = p - m_request;
	// ask an individual host for this list if hostId is NOT -1
	if ( m_hostId != -1 ) {
		// get Host
		Host *h = g_hostdb.getHost ( m_hostId );
		if ( ! h ) { 
			g_errno = EBADHOSTID; 
			log(LOG_LOGIC,"net: msg0: Bad hostId of %" PRId64".", m_hostId);
			logTrace( g_conf.m_logTraceMsg0, "END, return true. Bad hostId" );
			return true;
		}
		
		// if niceness is 0, use the higher priority udpServer
		UdpServer *us ;
		uint16_t port;
		QUICKPOLL(m_niceness);

		us = &g_udpServer ; port = h->m_port ; 
		// . returns false on error and sets g_errno, true otherwise
		// . calls callback when reply is received (or error)
		// . we return true if it returns false
		if ( ! us->sendRequest ( m_request     ,
					 m_requestSize ,
					 0x00          , // msgType
					 h->m_ip       ,
					 port          ,
					 m_hostId      ,
					 NULL          , // the slotPtr
					 this          ,
					 gotSingleReplyWrapper ,
					 timeout       ,
					 -1            , // backoff
					 -1            , // maxwait
					 replyBuf      ,
					 replyBufMaxSize ,
					 m_niceness     ) ) { // cback niceness
			logTrace( g_conf.m_logTraceMsg0, "END, return true. Request sent" );
			return true;
		}
		
		// return false cuz it blocked
		logTrace( g_conf.m_logTraceMsg0, "END, return false. sendRequest blocked" );
		return false;
	}
	// timing debug
	if ( g_conf.m_logTimingNet )

void handleRequest22 ( UdpSlot *slot , int32_t netnice ) {
	// shortcut
	UdpServer *us = &g_udpServer;
	// get the request
	Msg22Request *r = (Msg22Request *)slot->m_readBuf;

	// sanity check
	int32_t  requestSize = slot->m_readBufSize;
	if ( requestSize < r->getMinSize() ) {
		log("db: Got bad request size of %" PRId32" bytes for title record. "
		    "Need at least 28.",  requestSize );
		log(LOG_ERROR,"%s:%s:%d: call sendErrorReply.", __FILE__, __func__, __LINE__);
		us->sendErrorReply ( slot , EBADREQUESTSIZE );
		return;
	}

	// get base, returns NULL and sets g_errno to ENOCOLLREC on error
	RdbBase *tbase = getRdbBase( RDB_TITLEDB, r->m_collnum );
	if ( ! tbase ) {
		log("db: Could not get title rec in collection # %" PRId32" because rdbbase is null.", (int32_t)r->m_collnum);
		g_errno = EBADENGINEER;
		log(LOG_ERROR,"%s:%s:%d: call sendErrorReply.", __FILE__, __func__, __LINE__);
		us->sendErrorReply ( slot , g_errno ); 
		return; 
	}

	// overwrite what is in there so niceness conversion algo works
	r->m_niceness = netnice;

	// if just checking tfndb, do not do the cache lookup in clusterdb
	if ( r->m_justCheckTfndb ) {
		r->m_maxCacheAge = 0;
	}

	g_titledb.getRdb()->readRequestGet  (requestSize);

	// breathe
	QUICKPOLL ( r->m_niceness);

	// sanity check
	if ( r->m_collnum < 0 ) { char *xx=NULL;*xx=0; }


	// make the state now
	State22 *st ;
	try { st = new (State22); }
	catch ( ... ) {
		g_errno = ENOMEM;
		log("query: Msg22: new(%" PRId32"): %s", (int32_t)sizeof(State22),
		mstrerror(g_errno));
		log(LOG_ERROR,"%s:%s:%d: call sendErrorReply.", __FILE__, __func__, __LINE__);
		us->sendErrorReply ( slot , g_errno );
		return;
	}
	mnew ( st , sizeof(State22) , "Msg22" );

	// store ptr to the msg22request
	st->m_r = r;
	// save for sending back reply
	st->m_slot = slot;

	// then tell slot not to free it since m_r references it!
	// so we'll have to free it when we destroy State22
	st->m_slotAllocSize = slot->m_readBufMaxSize;
	st->m_slotReadBuf   = slot->m_readBuf;
	slot->m_readBuf = NULL;

	// . if docId was explicitly specified...
	// . we may get multiple tfndb recs
	if ( ! r->m_url[0] ) {
	   st->m_docId1 = r->m_docId;
	   st->m_docId2 = r->m_docId;
	}

	// but if we are requesting an available docid, it might be taken
	// so try the range
	if ( r->m_getAvailDocIdOnly ) {
	   int64_t pd = r->m_docId;
	   int64_t d1 = g_titledb.getFirstProbableDocId ( pd );
	   int64_t d2 = g_titledb.getLastProbableDocId  ( pd );
	   // sanity - bad url with bad subdomain?
	   if ( pd < d1 || pd > d2 ) { char *xx=NULL;*xx=0; }
	   // make sure we get a decent sample in titledb then in
	   // case the docid we wanted is not available
	   st->m_docId1 = d1;
	   st->m_docId2 = d2;
	}

	// . otherwise, url was given, like from Msg15
	// . we may get multiple tfndb recs
	if ( r->m_url[0] ) {
	   int32_t  dlen = 0;
	   // this causes ip based urls to be inconsistent with the call
	   // to getProbableDocId(url) below
	   char *dom  = getDomFast ( r->m_url , &dlen );
	   // bogus url?
	   if ( ! dom ) {
	       log("msg22: got bad url in request: %s from "
		   "hostid %" PRId32" for msg22 call ",
		   r->m_url,slot->m_host->m_hostId);
//.........这里部分代码省略.........

// . destroys the slot if false is returned
// . this is registered in Msg1::set() to handle add rdb record msgs
// . seems like we should always send back a reply so we don't leave the
//   requester's slot hanging, unless he can kill it after transmit success???
// . TODO: need we send a reply back on success????
// . NOTE: Must always call g_udpServer::sendReply or sendErrorReply() so
//   read/send bufs can be freed
void handleRequest1 ( UdpSlot *slot , int32_t netnice ) {


	// extract what we read
	char *readBuf     = slot->m_readBuf;
	int32_t  readBufSize = slot->m_readBufSize;
	int32_t niceness = slot->m_niceness;

	// select udp server based on niceness
	UdpServer *us = &g_udpServer;
	// must at least have an rdbId
	if ( readBufSize <= 4 ) {
		g_errno = EREQUESTTOOSHORT;
		log(LOG_ERROR,"%s:%s:%d: call sendErrorReply. Request too short", __FILE__, __func__, __LINE__);
		us->sendErrorReply ( slot , g_errno );
		return;
	}
	char *p    = readBuf;
	char *pend = readBuf + readBufSize;
	// extract rdbId
	char rdbId = *p++;
	// get the rdb to which it belongs, use Msg0::getRdb()
	Rdb *rdb = getRdbFromId ( (char) rdbId );
	if ( ! rdb ) { 
		log(LOG_ERROR,"%s:%s:%d: call sendErrorReply. Bad rdbid", __FILE__, __func__, __LINE__);
		us->sendErrorReply ( slot, EBADRDBID ); 
		return;
	}
	// keep track of stats
	rdb->readRequestAdd ( readBufSize );
	// reset g_errno
	g_errno = 0;
	// are we injecting some title recs?
	bool injecting;
	if ( *p & 0x80 ) injecting = true;
	else             injecting = false;
	p++;
	// then collection
	//char *coll = p;
	//p += strlen (p) + 1;
	collnum_t collnum = *(collnum_t *)p;
	p += sizeof(collnum_t);
	// . make a list from this data
	// . skip over the first 4 bytes which is the rdbId
	// . TODO: embed the rdbId in the msgtype or something...
	RdbList list;
	// set the list
	list.set ( p        , // readBuf     + 4         ,
		   pend - p , // readBufSize - 4         ,
		   p        , // readBuf     + 4         ,
		   pend - p , // readBufSize - 4         ,
		   rdb->getFixedDataSize() ,
		   false                   ,  // ownData?
		   rdb->useHalfKeys()      ,
		   rdb->getKeySize ()      ); 
	// note it
	//log("msg1: handlerequest1 calling addlist niceness=%" PRId32,niceness);
	//log("msg1: handleRequest1 niceness=%" PRId32,niceness);
	// this returns false and sets g_errno on error
	rdb->addList ( collnum , &list , niceness);
	// if titledb, add tfndb recs to map the title recs
	//if ( ! g_errno && rdb == g_titledb.getRdb() && injecting ) 
	//	updateTfndb ( coll , &list , true, 0);
	// but if deleting a "new" and unforced record from spiderdb
	// then only delete tfndb record if it was tfn=255
	//if ( ! g_errno && rdb == g_spiderdb.getRdb() )
	//	updateTfndb2 ( coll , &list , false );
	// retry on some errors
	addedList ( slot , rdb );
}