src/filter_z3950_client.cpp

   1 /* $Id: filter_z3950_client.cpp,v 1.20 2006-01-13 15:09:35 adam Exp $
   2    Copyright (c) 2005, Index Data.
   3
   4 %LICENSE%
   5  */
   6
   7 #include "config.hpp"
   8
   9 #include "filter.hpp"
  10 #include "package.hpp"
  11 #include "util.hpp"
  12 #include "filter_z3950_client.hpp"
  13
  14 #include <map>
  15 #include <stdexcept>
  16 #include <list>
  17 #include <iostream>
  18
  19 #include <boost/thread/mutex.hpp>
  20 #include <boost/thread/condition.hpp>
  21
  22 #include <yaz/zgdu.h>
  23 #include <yaz/log.h>
  24 #include <yaz/otherinfo.h>
  25 #include <yaz/diagbib1.h>
  26
  27 #include <yaz++/socket-manager.h>
  28 #include <yaz++/pdu-assoc.h>
  29 #include <yaz++/z-assoc.h>
  30
  31 namespace yf = yp2::filter;
  32
  33 namespace yp2 {
  34     namespace filter {
  35         class Z3950Client::Assoc : public yazpp_1::Z_Assoc{
  36             friend class Rep;
  37             Assoc(yazpp_1::SocketManager *socket_manager,
  38                   yazpp_1::IPDU_Observable *PDU_Observable,
  39                   std::string host, int timeout);
  40             ~Assoc();
  41             void connectNotify();
  42             void failNotify();
  43             void timeoutNotify();
  44             void recv_GDU(Z_GDU *gdu, int len);
  45             yazpp_1::IPDU_Observer* sessionNotify(
  46                 yazpp_1::IPDU_Observable *the_PDU_Observable,
  47                 int fd);
  48
  49             yazpp_1::SocketManager *m_socket_manager;
  50             yazpp_1::IPDU_Observable *m_PDU_Observable;
  51             Package *m_package;
  52             bool m_in_use;
  53             bool m_waiting;
  54             bool m_destroyed;
  55             bool m_connected;
  56             int m_queue_len;
  57             int m_time_elapsed;
  58             int m_time_max;
  59             std::string m_host;
  60         };
  61
  62         class Z3950Client::Rep {
  63         public:
  64             int m_timeout_sec;
  65             boost::mutex m_mutex;
  66             boost::condition m_cond_session_ready;
  67             std::map<yp2::Session,Z3950Client::Assoc *> m_clients;
  68             Z3950Client::Assoc *get_assoc(Package &package);
  69             void send_and_receive(Package &package,
  70                                   yf::Z3950Client::Assoc *c);
  71             void release_assoc(Package &package);
  72         };
  73     }
  74 }
  75
  76 using namespace yp2;
  77
  78 yf::Z3950Client::Assoc::Assoc(yazpp_1::SocketManager *socket_manager,
  79                               yazpp_1::IPDU_Observable *PDU_Observable,
  80                               std::string host, int timeout_sec)
  81     :  Z_Assoc(PDU_Observable),
  82        m_socket_manager(socket_manager), m_PDU_Observable(PDU_Observable),
  83        m_package(0), m_in_use(true), m_waiting(false),
  84        m_destroyed(false), m_connected(false), m_queue_len(1),
  85        m_time_elapsed(0), m_time_max(timeout_sec),
  86        m_host(host)
  87 {
  88     // std::cout << "create assoc " << this << "\n";
  89 }
  90
  91 yf::Z3950Client::Assoc::~Assoc()
  92 {
  93     // std::cout << "destroy assoc " << this << "\n";
  94 }
  95
  96 void yf::Z3950Client::Assoc::connectNotify()
  97 {
  98     m_waiting = false;
  99
 100     m_connected = true;
 101 }
 102
 103 void yf::Z3950Client::Assoc::failNotify()
 104 {
 105     m_waiting = false;
 106
 107     yp2::odr odr;
 108
 109     if (m_package)
 110     {
 111         Z_GDU *gdu = m_package->request().get();
 112         Z_APDU *apdu = 0;
 113         if (gdu && gdu->which == Z_GDU_Z3950)
 114             apdu = gdu->u.z3950;
 115
 116         m_package->response() = odr.create_close(apdu, Z_Close_peerAbort, 0);
 117         m_package->session().close();
 118     }
 119 }
 120
 121 void yf::Z3950Client::Assoc::timeoutNotify()
 122 {
 123     m_time_elapsed++;
 124     if (m_time_elapsed >= m_time_max)
 125     {
 126         m_waiting = false;
 127
 128         yp2::odr odr;
 129
 130         if (m_package)
 131         {
 132             Z_GDU *gdu = m_package->request().get();
 133             Z_APDU *apdu = 0;
 134             if (gdu && gdu->which == Z_GDU_Z3950)
 135                 apdu = gdu->u.z3950;
 136
 137             if (m_connected)
 138                 m_package->response() =
 139                     odr.create_close(apdu, Z_Close_lackOfActivity, 0);
 140             else
 141                 m_package->response() =
 142                     odr.create_close(apdu, Z_Close_peerAbort, 0);
 143
 144             m_package->session().close();
 145         }
 146     }
 147 }
 148
 149 void yf::Z3950Client::Assoc::recv_GDU(Z_GDU *gdu, int len)
 150 {
 151     m_waiting = false;
 152
 153     if (m_package)
 154         m_package->response() = gdu;
 155 }
 156
 157 yazpp_1::IPDU_Observer *yf::Z3950Client::Assoc::sessionNotify(
 158     yazpp_1::IPDU_Observable *the_PDU_Observable,
 159     int fd)
 160 {
 161     return 0;
 162 }
 163
 164
 165 yf::Z3950Client::Z3950Client() :  m_p(new yf::Z3950Client::Rep)
 166 {
 167     m_p->m_timeout_sec = 30;
 168 }
 169
 170 yf::Z3950Client::~Z3950Client() {
 171 }
 172
 173 yf::Z3950Client::Assoc *yf::Z3950Client::Rep::get_assoc(Package &package)
 174 {
 175     // only one thread messes with the clients list at a time
 176     boost::mutex::scoped_lock lock(m_mutex);
 177
 178     std::map<yp2::Session,yf::Z3950Client::Assoc *>::iterator it;
 179
 180     Z_GDU *gdu = package.request().get();
 181     // only deal with Z39.50
 182     if (!gdu || gdu->which != Z_GDU_Z3950)
 183     {
 184         package.move();
 185         return 0;
 186     }
 187     it = m_clients.find(package.session());
 188     if (it != m_clients.end())
 189     {
 190         it->second->m_queue_len++;
 191         while(true)
 192         {
 193 #if 0
 194             if (gdu && gdu->which == Z_GDU_Z3950 &&
 195                 gdu->u.z3950->which == Z_APDU_initRequest)
 196             {
 197                 yazpp_1::SocketManager *s = it->second->m_socket_manager;
 198                 delete it->second;  // destroy Z_Assoc
 199                 delete s;    // then manager
 200                 m_clients.erase(it);
 201                 break;
 202             }
 203 #endif
 204             if (!it->second->m_in_use)
 205             {
 206                 it->second->m_in_use = true;
 207                 return it->second;
 208             }
 209             m_cond_session_ready.wait(lock);
 210         }
 211     }
 212     // new Z39.50 session ..
 213     Z_APDU *apdu = gdu->u.z3950;
 214     // check that it is init. If not, close
 215     if (apdu->which != Z_APDU_initRequest)
 216     {
 217         yp2::odr odr;
 218
 219         package.response() = odr.create_close(apdu,
 220                                               Z_Close_protocolError,
 221                                               "First PDU was not an "
 222                                               "Initialize Request");
 223         package.session().close();
 224         return 0;
 225     }
 226     // check virtual host
 227     const char *vhost =
 228         yaz_oi_get_string_oidval(&apdu->u.initRequest->otherInfo,
 229                                  VAL_PROXY,
 230                                  /* categoryValue */ 1, /* delete */ 1);
 231     if (!vhost)
 232     {
 233         yp2::odr odr;
 234         package.response() = odr.create_initResponse(
 235             apdu,
 236             YAZ_BIB1_INIT_NEGOTIATION_OPTION_REQUIRED,
 237             "Virtual host not given");
 238
 239         package.session().close();
 240         return 0;
 241     }
 242
 243     yazpp_1::SocketManager *sm = new yazpp_1::SocketManager;
 244     yazpp_1::PDU_Assoc *pdu_as = new yazpp_1::PDU_Assoc(sm);
 245     yf::Z3950Client::Assoc *as = new yf::Z3950Client::Assoc(sm, pdu_as, vhost,
 246                                                             m_timeout_sec);
 247     m_clients[package.session()] = as;
 248     return as;
 249 }
 250
 251 void yf::Z3950Client::Rep::send_and_receive(Package &package,
 252                                             yf::Z3950Client::Assoc *c)
 253 {
 254     Z_GDU *gdu = package.request().get();
 255
 256     if (c->m_destroyed)
 257         return;
 258
 259     if (!gdu || gdu->which != Z_GDU_Z3950)
 260         return;
 261
 262     c->m_time_elapsed = 0;
 263     c->m_package = &package;
 264     c->m_waiting = true;
 265     if (!c->m_connected)
 266     {
 267         c->client(c->m_host.c_str());
 268         c->timeout(1);
 269
 270         while (!c->m_destroyed && c->m_waiting
 271                && c->m_socket_manager->processEvent() > 0)
 272             ;
 273     }
 274     if (!c->m_connected)
 275     {
 276         return;
 277     }
 278
 279     // prepare response
 280     c->m_time_elapsed = 0;
 281     c->m_waiting = true;
 282
 283     // relay the package  ..
 284     int len;
 285     c->send_GDU(gdu, &len);
 286
 287     switch(gdu->u.z3950->which)
 288     {
 289     case Z_APDU_triggerResourceControlRequest:
 290         // request only..
 291         break;
 292     default:
 293         // for the rest: wait for a response PDU
 294         while (!c->m_destroyed && c->m_waiting
 295                && c->m_socket_manager->processEvent() > 0)
 296             ;
 297         break;
 298     }
 299 }
 300
 301 void yf::Z3950Client::Rep::release_assoc(Package &package)
 302 {
 303     boost::mutex::scoped_lock lock(m_mutex);
 304     std::map<yp2::Session,yf::Z3950Client::Assoc *>::iterator it;
 305
 306     it = m_clients.find(package.session());
 307     if (it != m_clients.end())
 308     {
 309         Z_GDU *gdu = package.request().get();
 310         if (gdu && gdu->which == Z_GDU_Z3950)
 311         {   // only Z39.50 packages lock in get_assoc.. release it
 312             it->second->m_in_use = false;
 313             it->second->m_queue_len--;
 314         }
 315
 316         if (package.session().is_closed())
 317         {
 318             // destroy hint (send_and_receive)
 319             it->second->m_destroyed = true;
 320
 321             // wait until no one is waiting for it.
 322             while (it->second->m_queue_len)
 323                 m_cond_session_ready.wait(lock);
 324
 325             // the Z_Assoc and PDU_Assoc must be destroyed before
 326             // the socket manager.. so pull that out.. first..
 327             yazpp_1::SocketManager *s = it->second->m_socket_manager;
 328             delete it->second;  // destroy Z_Assoc
 329             delete s;    // then manager
 330             m_clients.erase(it);
 331         }
 332         m_cond_session_ready.notify_all();
 333     }
 334 }
 335
 336 void yf::Z3950Client::process(Package &package) const
 337 {
 338     yf::Z3950Client::Assoc *c = m_p->get_assoc(package);
 339     if (c)
 340     {
 341         m_p->send_and_receive(package, c);
 342     }
 343     m_p->release_assoc(package);
 344 }
 345
 346 void yf::Z3950Client::configure(const xmlNode *ptr)
 347 {
 348     for (ptr = ptr->children; ptr; ptr = ptr->next)
 349     {
 350         if (ptr->type != XML_ELEMENT_NODE)
 351             continue;
 352         if (!strcmp((const char *) ptr->name, "timeout"))
 353         {
 354             std::string timeout_str = yp2::xml::get_text(ptr);
 355             int timeout_sec = atoi(timeout_str.c_str());
 356             if (timeout_sec < 2)
 357                 throw yp2::filter::FilterException("Bad timeout value "
 358                                                    + timeout_str);
 359             m_p->m_timeout_sec = timeout_sec;
 360         }
 361         else
 362         {
 363             throw yp2::filter::FilterException("Bad element "
 364                                                + std::string((const char *)
 365                                                              ptr->name));
 366         }
 367     }
 368 }
 369
 370 static yp2::filter::Base* filter_creator()
 371 {
 372     return new yp2::filter::Z3950Client;
 373 }
 374
 375 extern "C" {
 376     struct yp2_filter_struct yp2_filter_z3950_client = {
 377         0,
 378         "z3950_client",
 379         filter_creator
 380     };
 381 }
 382
 383 /*
 384  * Local variables:
 385  * c-basic-offset: 4
 386  * indent-tabs-mode: nil
 387  * c-file-style: "stroustrup"
 388  * End:
 389  * vim: shiftwidth=4 tabstop=8 expandtab
 390  */