src/filter_z3950_client.cpp

   1 /* $Id: filter_z3950_client.cpp,v 1.22 2006-01-17 16:42:28 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     std::list<std::string> vhosts;
 227     yp2::util::get_vhost_otherinfo(&apdu->u.initRequest->otherInfo,
 228                                    true, vhosts);
 229     size_t no_vhosts = vhosts.size();
 230     if (no_vhosts == 0)
 231     {
 232         yp2::odr odr;
 233         package.response() = odr.create_initResponse(
 234             apdu,
 235             YAZ_BIB1_INIT_NEGOTIATION_OPTION_REQUIRED,
 236             "z3950_client: No virtal host given");
 237
 238         package.session().close();
 239         return 0;
 240     }
 241     if (no_vhosts > 1)
 242     {
 243         yp2::odr odr;
 244         package.response() = odr.create_initResponse(
 245             apdu,
 246             YAZ_BIB1_COMBI_OF_SPECIFIED_DATABASES_UNSUPP,
 247             "z3950_client: Can not cope with multiple vhosts");
 248         package.session().close();
 249         return 0;
 250     }
 251     std::list<std::string>::const_iterator v_it = vhosts.begin();
 252     std::list<std::string> dblist;
 253     std::string host;
 254     yp2::util::split_zurl(*v_it, host, dblist);
 255
 256     if (dblist.size())
 257     {
 258         std::cout << "z3950_client: No databases in vhost supported\n";
 259     }
 260
 261     yazpp_1::SocketManager *sm = new yazpp_1::SocketManager;
 262     yazpp_1::PDU_Assoc *pdu_as = new yazpp_1::PDU_Assoc(sm);
 263     yf::Z3950Client::Assoc *as = new yf::Z3950Client::Assoc(sm, pdu_as,
 264                                                             host.c_str(),
 265                                                             m_timeout_sec);
 266     m_clients[package.session()] = as;
 267     return as;
 268 }
 269
 270 void yf::Z3950Client::Rep::send_and_receive(Package &package,
 271                                             yf::Z3950Client::Assoc *c)
 272 {
 273     Z_GDU *gdu = package.request().get();
 274
 275     if (c->m_destroyed)
 276         return;
 277
 278     if (!gdu || gdu->which != Z_GDU_Z3950)
 279         return;
 280
 281     c->m_time_elapsed = 0;
 282     c->m_package = &package;
 283     c->m_waiting = true;
 284     if (!c->m_connected)
 285     {
 286         c->client(c->m_host.c_str());
 287         c->timeout(1);
 288
 289         while (!c->m_destroyed && c->m_waiting
 290                && c->m_socket_manager->processEvent() > 0)
 291             ;
 292     }
 293     if (!c->m_connected)
 294     {
 295         return;
 296     }
 297
 298     // prepare response
 299     c->m_time_elapsed = 0;
 300     c->m_waiting = true;
 301
 302     // relay the package  ..
 303     int len;
 304     c->send_GDU(gdu, &len);
 305
 306     switch(gdu->u.z3950->which)
 307     {
 308     case Z_APDU_triggerResourceControlRequest:
 309         // request only..
 310         break;
 311     default:
 312         // for the rest: wait for a response PDU
 313         while (!c->m_destroyed && c->m_waiting
 314                && c->m_socket_manager->processEvent() > 0)
 315             ;
 316         break;
 317     }
 318 }
 319
 320 void yf::Z3950Client::Rep::release_assoc(Package &package)
 321 {
 322     boost::mutex::scoped_lock lock(m_mutex);
 323     std::map<yp2::Session,yf::Z3950Client::Assoc *>::iterator it;
 324
 325     it = m_clients.find(package.session());
 326     if (it != m_clients.end())
 327     {
 328         Z_GDU *gdu = package.request().get();
 329         if (gdu && gdu->which == Z_GDU_Z3950)
 330         {   // only Z39.50 packages lock in get_assoc.. release it
 331             it->second->m_in_use = false;
 332             it->second->m_queue_len--;
 333         }
 334
 335         if (package.session().is_closed())
 336         {
 337             // destroy hint (send_and_receive)
 338             it->second->m_destroyed = true;
 339
 340             // wait until no one is waiting for it.
 341             while (it->second->m_queue_len)
 342                 m_cond_session_ready.wait(lock);
 343
 344             // the Z_Assoc and PDU_Assoc must be destroyed before
 345             // the socket manager.. so pull that out.. first..
 346             yazpp_1::SocketManager *s = it->second->m_socket_manager;
 347             delete it->second;  // destroy Z_Assoc
 348             delete s;    // then manager
 349             m_clients.erase(it);
 350         }
 351         m_cond_session_ready.notify_all();
 352     }
 353 }
 354
 355 void yf::Z3950Client::process(Package &package) const
 356 {
 357     yf::Z3950Client::Assoc *c = m_p->get_assoc(package);
 358     if (c)
 359     {
 360         m_p->send_and_receive(package, c);
 361     }
 362     m_p->release_assoc(package);
 363 }
 364
 365 void yf::Z3950Client::configure(const xmlNode *ptr)
 366 {
 367     for (ptr = ptr->children; ptr; ptr = ptr->next)
 368     {
 369         if (ptr->type != XML_ELEMENT_NODE)
 370             continue;
 371         if (!strcmp((const char *) ptr->name, "timeout"))
 372         {
 373             std::string timeout_str = yp2::xml::get_text(ptr);
 374             int timeout_sec = atoi(timeout_str.c_str());
 375             if (timeout_sec < 2)
 376                 throw yp2::filter::FilterException("Bad timeout value "
 377                                                    + timeout_str);
 378             m_p->m_timeout_sec = timeout_sec;
 379         }
 380         else
 381         {
 382             throw yp2::filter::FilterException("Bad element "
 383                                                + std::string((const char *)
 384                                                              ptr->name));
 385         }
 386     }
 387 }
 388
 389 static yp2::filter::Base* filter_creator()
 390 {
 391     return new yp2::filter::Z3950Client;
 392 }
 393
 394 extern "C" {
 395     struct yp2_filter_struct yp2_filter_z3950_client = {
 396         0,
 397         "z3950_client",
 398         filter_creator
 399     };
 400 }
 401
 402 /*
 403  * Local variables:
 404  * c-basic-offset: 4
 405  * indent-tabs-mode: nil
 406  * c-file-style: "stroustrup"
 407  * End:
 408  * vim: shiftwidth=4 tabstop=8 expandtab
 409  */