thift源码研究－客户端代码分析

　　这部分代码是用于客户端请求服务器，它由thrift compiler自动生成。

使用与前一篇一样的例子：thrift文件

/**

* gateway service definition.

*/

service GatewayService

{

i32 GetCompereCount( 1:i32 channel_id ),

list< i32 > GetCompereList( 1:i32 channel_id,

2:i32 from, 3:i32 range )

}

由thrift compiler自动生成的客户端代码：

class GatewayServiceClient : virtual public GatewayServiceIf {

public:

GatewayServiceClient(boost::shared_ptr< ::apache::thrift::protocol::TProtocol> prot) :

piprot_(prot),

poprot_(prot) {

iprot_ = prot.get();

oprot_ = prot.get();

}

GatewayServiceClient(boost::shared_ptr< ::apache::thrift::protocol::TProtocol> iprot, boost::shared_ptr< ::apache::thrift::protocol::TProtocol> oprot) :

piprot_(iprot),

poprot_(oprot) {

iprot_ = iprot.get();

oprot_ = oprot.get();

}

boost::shared_ptr< ::apache::thrift::protocol::TProtocol> getInputProtocol() {

return piprot_;

}

boost::shared_ptr< ::apache::thrift::protocol::TProtocol> getOutputProtocol() {

return poprot_;

}

int32_t GetCompereCount(const int32_t channel_id);

void send_GetCompereCount(const int32_t channel_id);

int32_t recv_GetCompereCount();

void GetCompereList(std::vector<int32_t> & _return, const int32_t channel_id, const int32_t from, const int32_t range);

void send_GetCompereList(const int32_t channel_id, const int32_t from, const int32_t range);

void recv_GetCompereList(std::vector<int32_t> & _return);

protected:

boost::shared_ptr< ::apache::thrift::protocol::TProtocol> piprot_;

boost::shared_ptr< ::apache::thrift::protocol::TProtocol> poprot_;

::apache::thrift::protocol::TProtocol* iprot_;

::apache::thrift::protocol::TProtocol* oprot_;

};

其中：

（1）int32_t GetCompereCount(const int32_t channel_id)和void
GetCompereList(std::vector<int32_t> & _return, const int32_t channel_id, const int32_t from, const int32_t range)函数供用户调用；

（2）上述两个函数都会调用对应send和rec函数，如GetCompereCount函数调用send_GetCompereCount和recv_GetCompereCount函数；

代码如下：

int32_t
GatewayServiceClient::GetCompereCount(const int32_t channel_id)

{

send_GetCompereCount(channel_id);

return recv_GetCompereCount();

}

（3）send函数，如send_GetCompereCount

代码如下：

void
GatewayServiceClient::send_GetCompereCount(const int32_t channel_id)

{

int32_t cseqid = 0;

oprot_->writeMessageBegin("GetCompereCount", ::apache::thrift::protocol::T_CALL, cseqid);

GatewayService_GetCompereCount_pargs args;

args.channel_id = &channel_id;

args.write(oprot_);

oprot_->writeMessageEnd();

oprot_->getTransport()->writeEnd();

oprot_->getTransport()->flush();

}

（4）rec函数，如recv_GetCompereCount

代码如下：

int32_t
GatewayServiceClient::recv_GetCompereCount()

{

int32_t rseqid = 0;

std::string fname;

::apache::thrift::protocol::TMessageType mtype;

iprot_->readMessageBegin(fname, mtype, rseqid);

if (mtype == ::apache::thrift::protocol::T_EXCEPTION) {

::apache::thrift::TApplicationException x;

x.read(iprot_);

iprot_->readMessageEnd();

iprot_->getTransport()->readEnd();

throw x;

}

if (mtype != ::apache::thrift::protocol::T_REPLY) {

iprot_->skip(::apache::thrift::protocol::T_STRUCT);

iprot_->readMessageEnd();

iprot_->getTransport()->readEnd();

}

if (fname.compare("GetCompereCount") != 0) {

iprot_->skip(::apache::thrift::protocol::T_STRUCT);

iprot_->readMessageEnd();

iprot_->getTransport()->readEnd();

}

int32_t _return;

GatewayService_GetCompereCount_presult result;

result.success = &_return;

result.read(iprot_);

iprot_->readMessageEnd();

iprot_->getTransport()->readEnd();

if (result.__isset.success) {

return _return;

}

if (result.__isset.err) {

throw result.err;

}

throw ::apache::thrift::TApplicationException(::apache::thrift::TApplicationException::MISSING_RESULT, "GetCompereCount failed: unknown result");

}