mongodb协议透传

由于没时间搞mongodb透传，之前写mongodb的proxy程序时候都是用自带的驱动（mongoclient），然后自己定协议，让其他语言比如php、c++、java、C#去实现，然后做通讯，用了一段时间也没什么问题，但是总觉得很不完美，最近终于个人时间充裕一些，打开mongodb的源码，对应网上牛人的源码解析，开始实现mongodb的协议透传，无废话，上代码：

#include <stdio.h>
#include <sys/wait.h>
#include "mongo/util/net/message_port.h"
#include "mongo/util/net/message_server.h"
#include "DzhMessageServer.h"
#include "DzhMessageHandler.h"

using namespace std;
using namespace mongo;

int main(int argc, const char *argv[]) 
{
    MessageServer::Options opts;
    opts.port = 28686;
    opts.ipList = "10.15.107.155";
    
    DzhMessageHandler handler;        
    DzhMessageServer svr(opts, &handler);    
    svr.run();

    return 0;
}

这是proxy服务的代码入口，mongodb的服务端是基于boost::asio的，所以这段代码看着眼熟吧，DzhMessageServer 实现的是网络服务，DzhMessageHandler实现的是事件处理，MessageServer::Options.port是服务端口，MessageServer::Options.ipList是本机IP地址，代码清晰，一看就懂。

#pragma once

#include "mongo/util/net/message.h"
#include "mongo/util/net/message_port.h"
#include "mongo/util/net/message_server.h"
#include "mongo/util/net/listen.h"
#include "mongo/db/lasterror.h"
#include <boost/thread.hpp>

using namespace mongo;
using namespace boost;

class DzhMessageServer:public MessageServer , public Listener
{
public:
    DzhMessageServer(const MessageServer::Options& opts, MessageHandler* handler):
                            Listener("" , opts.ipList, opts.port), 
                            m_handler(handler) 
    {
        
    }
    
    void HandleIncomingMsg(void* arg)
    {
        scoped_ptr<HandleIncomingMsgParam> himArg(static_cast<HandleIncomingMsgParam*>(arg));
        MessagingPort* inPort = himArg->inPort;
        MessageHandler* handler = himArg->handler;
        
        inPort->psock->setLogLevel(1);
        scoped_ptr<MessagingPort> p( inPort );
        
        string otherSide;
        
        Message m;
        try
        {
            LastError * le = new LastError();
            lastError.reset( le ); // lastError now has ownership

            otherSide = p->psock->remoteString();
        
            handler->connected( p.get() );
            
            while ( ! inShutdown() ) {
                m.reset();
                p->psock->clearCounters();
                if ( ! p->recv(m) ) {
                    if( !cmdLine.quiet ){
                        int conns = 0;//Listener::globalTicketHolder.used()-1;
                        const char* word = (conns == 1 ? " connection" : " connections");
                        log() << "end connection " << otherSide << " (" << conns << word << " now open)" << endl;
                    }
                    p->shutdown();
                    break;
                }
                handler->process( m , p.get() , le );
                //networkCounter.hit( p->psock->getBytesIn() , p->psock->getBytesOut() );
            }
        }
        catch ( AssertionException& e ) {
            log() << "AssertionException handling request, closing client connection: " << e << endl;
            p->shutdown();
        }
        catch ( SocketException& e ) {
            log() << "SocketException handling request, closing client connection: " << e << endl;
            p->shutdown();
        }
        catch ( const DBException& e ) { // must be right above std::exception to avoid catching subclasses
            log() << "DBException handling request, closing client connection: " << e << endl;
            p->shutdown();
        }
        catch ( std::exception &e ) {
            error() << "Uncaught std::exception: " << e.what() << ", terminating" << endl;
            dbexit( EXIT_UNCAUGHT );
        }
        catch ( ... ) {
            error() << "Uncaught exception, terminating" << endl;
            dbexit( EXIT_UNCAUGHT );
        }
        
        handler->disconnected( p.get() );
    }
    
    void run() 
    {
        initAndListen();
    }
    
    void setAsTimeTracker()
    {
        Listener::setAsTimeTracker();
    }
    
    void acceptedMP(MessagingPort *p)
    {
        cout << "acceptedMP start" << endl;
        
        HandleIncomingMsgParam* himParam = new HandleIncomingMsgParam(p, m_handler);
        boost::thread thr(boost::bind(&DzhMessageServer::HandleIncomingMsg, this, himParam));
        
        cout << "acceptedMP end" << endl;
    }
    
private:
    MessageHandler* m_handler;
    
    struct HandleIncomingMsgParam {
        HandleIncomingMsgParam(MessagingPort* inPort,  MessageHandler* handler):
            inPort(inPort), handler(handler) {
        }

        MessagingPort* inPort;
        MessageHandler* handler;
    };
};

这里实现的基本上是消息协议格式的获取和转换，具体处理在DzhMessageHandler中

#pragma once

#include "mongo/util/net/message_server.h"
#include "mongo/db/dbmessage.h"

using namespace mongo;

class DzhMessageHandler:public MessageHandler
{
public:
    DzhMessageHandler()
    {
        
    }
    
    void connected( AbstractMessagingPort* p )
    {
        cout << "connected start" << endl;
        MessagingPort* portptr = (MessagingPort*)p;
        if(portptr)
        {
            cout << "portptr->remote():" << portptr->remote().toString() << endl;
        }
        else
        {
            cout << "connected error!" << endl;
        }
        cout << "connected end" << endl;
    }

    void process( Message& m , AbstractMessagingPort* p , LastError * err )
    {
        cout << "process start" << endl;
        
        cout << "process Message:" << m.toString() << endl;
                
        DbMessage dm(m);        
        QueryMessage q(dm);
        
        try
        {
            cout << "ns:" << q.ns << ".return:" << q.ntoreturn << endl;
            cout << "query:" << q.query.toString(0,0) << endl;
            
            BSONObj ret;
            if(q.query.binaryEqual(BSON("ping" << 1)) ||
                q.query.binaryEqual(BSON("ismaster" << 1)))
            {
                ret = BSON("ok" << 1);
            }
            else if(q.query.binaryEqual(BSON("buildinfo" << 1)))
            {
                vector<string> arrVersion;
                arrVersion.push_back("2");
                arrVersion.push_back("2");
                arrVersion.push_back("0");
                arrVersion.push_back("0");
                
                ret = BSON( "version" << "2.2.0" <<
                            "gitVersion" << "f5e83eae9cfbec7fb7a071321928f00d1b0c5207" <<
                            "sysInfo" << "Linux ip-10-2-29-40 2.6.21.7-2.ec2.v1.2.fc8xen #1 SMP Fri Nov 20 17:48:28 EST 2009 x86_64 BOOST_LIB_VERSION=1_49" << 
                            "versionArray" << arrVersion <<
                            "bits" << 64 << "maxBsonObjectSize" << 16777216 << "ok" << 1);
            }
            
            BufBuilder buf;
            ret.appendSelfToBufBuilder(buf);
            
            replyToQuery(0, p, m, buf.buf(), buf.len(), 1, 0, 0);
            
        }
        catch( AssertionException & e )
        {
            // if ( r.expectResponse() ) {
                // BSONObj err = BSON( "$err" << e.what() << "code" << e.getCode() );
                // replyToQuery( ResultFlag_ErrSet, p , m , err );
            // }
        }
        catch ( DBException& e )
        {
            log() << "DBException in process: " << e.what() << endl;

            // le->raiseError( e.getCode() , e.what() );

            // m.header()->id = r.id();

            // if ( r.expectResponse() ) {
                // BSONObjBuilder b;
                // b.append("$err",e.what()).append("code",e.getCode());
                // if( !e._shard.empty() ) {
                    // b.append("shard",e._shard);
                // }
                // replyToQuery( ResultFlag_ErrSet, p , m , b.obj() );
            // }
        }
        
        cout << "process end" << endl;
    }

    void disconnected( AbstractMessagingPort* p )
    {
        cout << "disconnected start" << endl;
        
        cout << "disconnected end" << endl;
    }
};

处理核心在process中，里面是我写的测试代码，嫌碍眼的可以删掉，为什么会有ping、ismaster、buildinfo命令的捕获呢，我在跟踪C#驱动与Mongodb服务交互的时候，C#驱动会首先提交这三个命令，待确认均ok后，然后才发具体的find命令做查询动作，当然我这里只是实验性的，你也可以用Scope直接从mongodb查结果。

需要的库文件:

mongoclient boost_system boost_thread boost_program_options boost_date_time boost_filesystem

有什么问题可以联系我

Q:7984759