用newlisp通过C++动态库访问MongoDB

我想让我的newlisp程序访问MongoDB. 现在已经有MongoDB C driver，但是我没有时间去学习，只想尽快的完成工作。下面是我的方法，用C++创建一个动态库，这个动态库引用了MongoDB C++ driver. 但是会用extern "C" 导出C函数。

一件事情必须知道，MongoDB C++ driver必须用-fPIC选项编译。

首先，创建db.h文件

extern "C" void CheckOnline();
extern "C" void Init(char * mongo_uri);

#include "db.h"
#include 
  
   
#include 
   
     #include 
    
      #include "mongo_session_factory.h" #include "mongo_session.h" #include 
     
       #include 
      
        using namespace std; class Config { public: string mongo_uri; }; Config config; void SetOffline(mongo::DBClientBase& con, mongo::OID const& id) { mongo::BSONObjBuilder condition; condition.append("_id", id); mongo::BSONObjBuilder update_field; update_field.append("status", "offline"); mongo::BSONObjBuilder set_field; set_field.append("$set", update_field.obj()); con.update("kaimei.display", mongo::Query(condition.obj()), set_field.obj()); } /** * Check every sign status */ void CheckOnline() { cout << config.mongo_uri << endl; std::shared_ptr
       
         session = MongoSessionFactory::GetSession(config.mongo_uri); mongo::DBClientBase & con = session->get_db_client_base(); mongo::BSONObjBuilder condition; std::unique_ptr
        
          cursor = con.query("kaimei.display", mongo::Query(condition.obj())); while (cursor->more()) { mongo::BSONObj record = cursor->next(); uint64_t t1 = record.getField("last_active_time").numberLong(); timeva l tv; gettimeofday(&tv,NULL); if (tv.tv_sec - t1 > 300) { SetOffline(con, record.getField("_id").OID()); } } } void Init(char * mongo_uri) { config.mongo_uri = mongo_uri; }
        
       
      
     
    
   
  

好了，现在编译吧，参考build.lsp文件

#!/usr/bin/newlisp
(if (file  "db.so")
    (delete-file "db.so"))
(if (directory  "objects")
    (exec "rm -rf objects"))
(make-dir "objects")
(exec "c++ -g -fPIC -std=c++11 -I./include  -Wall -o ./objects/mongo_session_factory.cc.o -c ./src/mongo_session_factory.cc")
(exec "c++ -g -fPIC -std=c++11 -I./include  -Wall -o ./objects/mongo_session.cc.o -c ./src/mongo_session.cc")
(exec "c++ -g -fPIC -std=c++11 -I./include  -Wall -o ./objects/db.cc.o -c ./src/db.cc")
(exec "c++ -g -fPIC -std=c++11 ./objects/mongo_session_factory.cc.o ./objects/mongo_session.cc.o ./objects/db.cc.o -shared -o db.so -rdynamic -lpthread -lmongoclient -lboost_system -lboost_thread -lboost_filesystem")
(exit)

#!/usr/bin/newlisp 

(set 'db-path "/path/to/your/db.so")
(import db-path "Init")
(import db-path "CheckOnline")
(Init "localhost:27017")
(CheckOnline)
(exit)