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connection_base.hxx

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00001 /*-------------------------------------------------------------------------
00002  *
00003  *   FILE
00004  *      pqxx/connection_base.hxx
00005  *
00006  *   DESCRIPTION
00007  *      definition of the pqxx::connection_base abstract base class.
00008  *   pqxx::connection_base encapsulates a frontend to backend connection
00009  *   DO NOT INCLUDE THIS FILE DIRECTLY; include pqxx/connection_base instead.
00010  *
00011  * Copyright (c) 2001-2005, Jeroen T. Vermeulen <jtv@xs4all.nl>
00012  *
00013  * See COPYING for copyright license.  If you did not receive a file called
00014  * COPYING with this source code, please notify the distributor of this mistake,
00015  * or contact the author.
00016  *
00017  *-------------------------------------------------------------------------
00018  */
00019 #include "pqxx/libcompiler.h"
00020 
00021 #include <map>
00022 #include <memory>
00023 
00024 #ifdef _WIN32
00025 #include <winsock2.h>   // for fd_set
00026 #endif  // _WIN32
00027 
00028 #include "pqxx/except"
00029 #include "pqxx/util"
00030 
00031 
00032 /* Use of the libpqxx library starts here.
00033  *
00034  * Everything that can be done with a database through libpqxx must go through
00035  * a connection object derived from connection_base.
00036  */
00037 
00038 /* Methods tested in eg. self-test program test1 are marked with "//[t1]"
00039  */
00040 
00041 namespace pqxx
00042 {
00043 class result;
00044 class transaction_base;
00045 class trigger;
00046 
00047 
00049 
00053 struct PQXX_LIBEXPORT noticer : PGSTD::unary_function<const char[], void>
00054 {
00055   virtual ~noticer() throw () {}
00056   virtual void operator()(const char Msg[]) throw () =0;
00057 };
00058 
00059 
00061 struct PQXX_LIBEXPORT nonnoticer : noticer
00062 {
00063   virtual void operator()(const char []) throw () {}
00064 };
00065 
00066 
00068 
00088 class PQXX_LIBEXPORT connection_base
00089 {
00090 public:
00092 
00102   explicit connection_base(const PGSTD::string &ConnInfo);              //[t2]
00103 
00105 
00109   explicit connection_base(const char ConnInfo[]);                      //[t2]
00110 
00112   virtual ~connection_base() =0;                                        //[t1]
00113 
00115   void disconnect() throw ();                                           //[t2]
00116 
00118 
00122   bool is_open() const throw ();                                        //[t1]
00123 
00125 
00133   template<typename TRANSACTOR>
00134   void perform(const TRANSACTOR &T, int Attempts);                      //[t4]
00135 
00137 
00144   template<typename TRANSACTOR>
00145   void perform(const TRANSACTOR &T) { perform(T, 3); }
00146 
00147   // TODO: Define a default noticer (mainly to help out Windows users)
00149 
00161   PGSTD::auto_ptr<noticer> set_noticer(PGSTD::auto_ptr<noticer> N)
00162     throw ();                                                           //[t14]
00163   noticer *get_noticer() const throw () { return m_Noticer.get(); }     //[t14]
00164 
00166   void process_notice(const char[]) throw ();                           //[t14]
00168   void process_notice(const PGSTD::string &) throw ();                  //[t14]
00169 
00171   void trace(FILE *) throw ();                                          //[t3]
00172 
00174 
00178   int get_notifs();                                                     //[t4]
00179 
00180   // Miscellaneous query functions (probably not needed very often)
00181 
00183   const char *dbname()                                                  //[t1]
00184         { activate(); return PQdb(m_Conn); }
00185 
00187   const char *username()                                                //[t1]
00188         { activate(); return  PQuser(m_Conn); }
00189 
00191   const char *hostname()                                                //[t1]
00192         { activate(); return PQhost(m_Conn); }
00193 
00195   const char *port()                                                    //[t1]
00196         { activate(); return PQport(m_Conn); }
00197 
00199   const char *options() const throw ()                                  //[t1]
00200         { return m_ConnInfo.c_str(); }
00201 
00202 
00204 
00213   int backendpid() const throw ()                                       //[t1]
00214         { return m_Conn ? PQbackendPID(m_Conn) : 0; }
00215 
00217 
00227   void activate();                                                      //[t12]
00228 
00230 
00238   void deactivate();                                                    //[t12]
00239 
00241 
00247   void set_client_encoding(const PGSTD::string &Encoding)               //[t7]
00248         { set_variable("CLIENT_ENCODING", Encoding); }
00249 
00251 
00267   void set_variable(const PGSTD::string &Var,
00268                     const PGSTD::string &Value);                        //[t60]
00269 
00271 
00278   PGSTD::string get_variable(const PGSTD::string &);                    //[t60]
00279 
00281 
00284   int await_notification();                                             //[t78]
00285 
00287 
00291   int await_notification(long seconds, long microseconds);              //[t79]
00292 
00293 #ifdef PQXX_DEPRECATED_HEADERS
00294 
00295   void Disconnect() throw () { disconnect(); }
00297   template<typename TRANSACTOR> void Perform(const TRANSACTOR &T, int A=3)
00298         { return perform(T,A); }
00300   PGSTD::auto_ptr<noticer> SetNoticer(PGSTD::auto_ptr<noticer> N)
00301         { return set_noticer(N); }
00303   noticer *GetNoticer() const throw ()
00304         { return get_noticer(); }
00306   void ProcessNotice(const char msg[]) throw () { return process_notice(msg); }
00308   void ProcessNotice(const PGSTD::string &msg) throw ()
00309         { return process_notice(msg); }
00311   void Trace(FILE *F) { trace(F); }
00313   void GetNotifs() { get_notifs(); }
00315   const char *DbName() { return dbname(); }
00317   const char *UserName() { return username(); }
00319   const char *HostName() { return hostname(); }
00321   const char *Port() { return port(); }
00323   const char *Options() const throw () { return options(); }
00325   int BackendPID() const { return backendpid(); }
00327   void Activate() { activate(); }
00329   void Deactivate() { deactivate(); }
00331   void SetClientEncoding(const PGSTD::string &E) { set_client_encoding(E); }
00333   void SetVariable(const PGSTD::string &Var, const PGSTD::string &Val)
00334         { set_variable(Var, Val); }
00335 #endif
00336 
00337 
00338 protected:
00340 
00341   virtual void startconnect() =0;
00342 
00344 
00345   virtual void completeconnect() =0;
00346 
00348 
00349   virtual void dropconnect() throw () {}
00350 
00352   internal::pq::PGconn *get_conn() const throw () { return m_Conn; }
00353 
00355   void set_conn(internal::pq::PGconn *C) throw () { m_Conn = C; }
00356 
00357   void close() throw ();
00358   void wait_read() const;
00359   void wait_read(long seconds, long microseconds) const;
00360   void wait_write() const;
00361 
00362 private:
00363   void SetupState();
00364 
00365   void InternalSetTrace() throw ();
00366   int Status() const throw () { return PQXXPQ::PQstatus(m_Conn); }
00367   const char *ErrMsg() const throw ();
00368   void Reset();
00369   void RestoreVars();
00370   int set_fdmask() const;
00371   void clear_fdmask() throw ();
00372   PGSTD::string RawGetVar(const PGSTD::string &);
00373   void process_notice_raw(const char msg[]) throw ();
00374 
00375 
00377   PGSTD::string m_ConnInfo;
00378 
00380   internal::pq::PGconn *m_Conn;
00382   internal::unique<transaction_base> m_Trans;
00383 
00385   PGSTD::auto_ptr<noticer> m_Noticer;
00387   FILE *m_Trace;
00388 
00389   typedef PGSTD::multimap<PGSTD::string, pqxx::trigger *> TriggerList;
00391   TriggerList m_Triggers;
00392 
00394   PGSTD::map<PGSTD::string, PGSTD::string> m_Vars;
00395 
00396   mutable fd_set m_fdmask;
00397 
00398   friend class transaction_base;
00399   result Exec(const char[], int Retries);
00400   result exec_prepared(const char[],
00401       int NumParams,
00402       const char *const *Params,
00403       int Retries);
00404   void RegisterTransaction(transaction_base *);
00405   void UnregisterTransaction(transaction_base *) throw ();
00406   void MakeEmpty(result &);
00407   bool ReadCopyLine(PGSTD::string &);
00408   void WriteCopyLine(const PGSTD::string &);
00409   void EndCopyWrite();
00410   void start_exec(const PGSTD::string &);
00411   internal::pq::PGresult *get_result();
00412 
00413   void RawSetVar(const PGSTD::string &Var, const PGSTD::string &Value);
00414   void AddVariables(const PGSTD::map<PGSTD::string, PGSTD::string> &);
00415 
00416   friend class largeobject;
00417   internal::pq::PGconn *RawConnection() const { return m_Conn; }
00418 
00419   friend class trigger;
00420   void AddTrigger(trigger *);
00421   void RemoveTrigger(trigger *) throw ();
00422 
00423   friend class pipeline;
00424   void consume_input() throw () { PQconsumeInput(m_Conn); }
00425   bool is_busy() const throw () { return PQisBusy(m_Conn); }
00426 
00427   // Not allowed:
00428   connection_base(const connection_base &);
00429   connection_base &operator=(const connection_base &);
00430 };
00431 
00432 
00433 // Put this here so on Windows, any noticers can be deleted in caller's context
00434 inline connection_base::~connection_base()
00435 {
00436   // Visual C++ seems to have a problem with output during destructors!
00437 #ifdef PQXX_QUIET_DESTRUCTORS
00438   set_noticer(PGSTD::auto_ptr<noticer>(new nonnoticer()));
00439 #endif
00440 }
00441 
00442 
00443 namespace internal
00444 {
00445 
00447 
00453 class PQXX_LIBEXPORT scoped_noticer
00454 {
00455 public:
00457 
00461   scoped_noticer(connection_base &c, PGSTD::auto_ptr<noticer> t) throw () :
00462     m_c(c), m_org(c.set_noticer(t)) { }
00463 
00464   ~scoped_noticer() { m_c.set_noticer(m_org); }
00465 
00466 private:
00467   connection_base &m_c;
00468   PGSTD::auto_ptr<noticer> m_org;
00469 
00471   scoped_noticer();
00472   scoped_noticer(const scoped_noticer &);
00473   scoped_noticer operator=(const scoped_noticer &);
00474 };
00475 
00476 
00478 class PQXX_LIBEXPORT disable_noticer : scoped_noticer
00479 {
00480 public:
00481   explicit disable_noticer(connection_base &c) :
00482     scoped_noticer(c, PGSTD::auto_ptr<noticer>(new nonnoticer)) {}
00483 };
00484 
00485 
00486 } // namespace pqxx::internal
00487 
00488 
00489 } // namespace pqxx
00490 

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