使用protobuf 作为网络消息协议

#include <string>#include <iostream>#include <assert.h>#include <stdint.h>#include "person.pb.h"#include "test.pb.h"using namespace std;class ProtoMsgHandle{public:    /*  注册消息处理函数    */    void    initHandles()    {        registerHandle(&ProtoMsgHandle::handleProtoPerson);        registerHandle(&ProtoMsgHandle::handleProtoTest);    }    /*  处理网络消息  */    void    handle(const char* data)    {        bool ret = false;        const char* current = data;        int32_t* p_packetlen = (int32_t*)current;   current += sizeof(*p_packetlen);        int32_t* p_namelen = (int32_t*)current;     current += sizeof(*p_namelen);        const char* p_name = current;        string name(p_name, *p_namelen);            current += *p_namelen;        do        {            msg_handle callback = m_callbacks[name];            assert(callback != NULL);            if(callback == NULL)            {                break;            }            const ::google::protobuf::Descriptor* descriptor = m_descriptors[name];            assert(descriptor != NULL);            if(descriptor == NULL)            {                break;            }            const google::protobuf::Message* prototype = google::protobuf::MessageFactory::generated_factory()->GetPrototype(descriptor);            assert(prototype != NULL);            if(prototype == NULL)            {                break;            }            google::protobuf::Message* msg = prototype->New();            ret = msg->ParseFromArray(current, (*p_packetlen)-sizeof(*p_packetlen)-sizeof(*p_namelen)-*p_namelen);            if(ret)            {                (this->*callback)(msg);            }        }while(0);    }private:    void        handleProtoTest(test* test)    {        cout << test->price() << endl;        cout << test->userid() << endl;        cout << test->time() << endl;    }    void        handleProtoPerson(person* person)    {        cout << person->age() << endl;        cout << person->userid() << endl;        cout << person->name() << endl;    }private:    typedef void (ProtoMsgHandle::*msg_handle)(::google::protobuf::Message*);private:    template<typename MSGTYPE>    void        registerHandle(void (ProtoMsgHandle::*callback)(MSGTYPE*))    {        const ::google::protobuf::Descriptor* des = MSGTYPE::descriptor();        assert(des != NULL);        if(des != NULL)        {            m_callbacks[des->full_name()] = (msg_handle)callback;            m_descriptors[des->full_name()] = des;        }    }private:    map<string, msg_handle>                                 m_callbacks;    map<string, const ::google::protobuf::Descriptor*>      m_descriptors;};class ProtoMsgSender{public:    /*  发送proto msg到指定缓冲区   */    /*  int32_t -   packet_len        int32_t     name_len        char[]      name        char[]      proto_data    */    template<typename MSGTYPE>    void    sentProtoMsg(MSGTYPE& msg, char* buffer, int max_len)    {        char* current = buffer;        int32_t* p_packetlen = (int32_t*)current;                       current += sizeof(*p_packetlen);        int32_t* p_namelen = (int32_t*)current;                         current += sizeof(*p_namelen);        string msg_name = MSGTYPE::descriptor()->full_name();        *p_namelen = msg_name.size();        strcpy(current, msg_name.c_str());                              current += msg_name.size();        /*  判断是否成功  */        msg.SerializeToArray(current, max_len - (current-buffer));      current += msg.GetCachedSize();        *p_packetlen = (current-buffer);    }};int main(){    ProtoMsgSender msgsender;    ProtoMsgHandle msghandle;    msghandle.initHandles();    test t;    t.set_price(100.0);    t.set_userid(110);    t.set_time(123);    person person;    person.set_age(18);    person.set_userid(200508);    person.set_name("irons");    char tmp[10*1024];    msgsender.sentProtoMsg(t, tmp, sizeof(tmp));    msghandle.handle(tmp);    msgsender.sentProtoMsg(person, tmp, sizeof(tmp));    msghandle.handle(tmp);    cin.get();    return 0;}/*message test{required int32 time = 1;required int32 userid = 2;required float price = 3;optional string desc = 4;}message person{required int32 age = 1;required int32 userid = 2;optional string name = 3;}*/