src/filter_z3950_client.cpp

   1 /* $Id: filter_z3950_client.cpp,v 1.19 2006-01-11 11:51:50 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         m_package->response() = odr.create_close(Z_Close_peerAbort, 0);
 112         m_package->session().close();
 113     }
 114 }
 115
 116 void yf::Z3950Client::Assoc::timeoutNotify()
 117 {
 118     m_time_elapsed++;
 119     if (m_time_elapsed >= m_time_max)
 120     {
 121         m_waiting = false;
 122
 123         yp2::odr odr;
 124
 125         if (m_package)
 126         {
 127             if (m_connected)
 128                 m_package->response() = odr.create_close(Z_Close_lackOfActivity, 0);
 129             else
 130                 m_package->response() = odr.create_close(Z_Close_peerAbort, 0);
 131
 132             m_package->session().close();
 133         }
 134     }
 135 }
 136
 137 void yf::Z3950Client::Assoc::recv_GDU(Z_GDU *gdu, int len)
 138 {
 139     m_waiting = false;
 140
 141     if (m_package)
 142         m_package->response() = gdu;
 143 }
 144
 145 yazpp_1::IPDU_Observer *yf::Z3950Client::Assoc::sessionNotify(
 146     yazpp_1::IPDU_Observable *the_PDU_Observable,
 147     int fd)
 148 {
 149     return 0;
 150 }
 151
 152
 153 yf::Z3950Client::Z3950Client() :  m_p(new yf::Z3950Client::Rep)
 154 {
 155     m_p->m_timeout_sec = 30;
 156 }
 157
 158 yf::Z3950Client::~Z3950Client() {
 159 }
 160
 161 yf::Z3950Client::Assoc *yf::Z3950Client::Rep::get_assoc(Package &package)
 162 {
 163     // only one thread messes with the clients list at a time
 164     boost::mutex::scoped_lock lock(m_mutex);
 165
 166     std::map<yp2::Session,yf::Z3950Client::Assoc *>::iterator it;
 167
 168     Z_GDU *gdu = package.request().get();
 169     // only deal with Z39.50
 170     if (!gdu || gdu->which != Z_GDU_Z3950)
 171     {
 172         package.move();
 173         return 0;
 174     }
 175     it = m_clients.find(package.session());
 176     if (it != m_clients.end())
 177     {
 178         it->second->m_queue_len++;
 179         while(true)
 180         {
 181 #if 0
 182             if (gdu && gdu->which == Z_GDU_Z3950 &&
 183                 gdu->u.z3950->which == Z_APDU_initRequest)
 184             {
 185                 yazpp_1::SocketManager *s = it->second->m_socket_manager;
 186                 delete it->second;  // destroy Z_Assoc
 187                 delete s;    // then manager
 188                 m_clients.erase(it);
 189                 break;
 190             }
 191 #endif
 192             if (!it->second->m_in_use)
 193             {
 194                 it->second->m_in_use = true;
 195                 return it->second;
 196             }
 197             m_cond_session_ready.wait(lock);
 198         }
 199     }
 200     // new Z39.50 session ..
 201     Z_APDU *apdu = gdu->u.z3950;
 202     // check that it is init. If not, close
 203     if (apdu->which != Z_APDU_initRequest)
 204     {
 205         yp2::odr odr;
 206
 207         package.response() = odr.create_close(Z_Close_protocolError,
 208                                               "First PDU was not an "
 209                                               "Initialize Request");
 210         package.session().close();
 211         return 0;
 212     }
 213     // check virtual host
 214     const char *vhost =
 215         yaz_oi_get_string_oidval(&apdu->u.initRequest->otherInfo,
 216                                  VAL_PROXY,
 217                                  /* categoryValue */ 1, /* delete */ 1);
 218     if (!vhost)
 219     {
 220         yp2::odr odr;
 221         package.response() = odr.create_initResponse(
 222             YAZ_BIB1_INIT_NEGOTIATION_OPTION_REQUIRED,
 223             "Virtual host not given");
 224
 225         package.session().close();
 226         return 0;
 227     }
 228
 229     yazpp_1::SocketManager *sm = new yazpp_1::SocketManager;
 230     yazpp_1::PDU_Assoc *pdu_as = new yazpp_1::PDU_Assoc(sm);
 231     yf::Z3950Client::Assoc *as = new yf::Z3950Client::Assoc(sm, pdu_as, vhost,
 232                                                             m_timeout_sec);
 233     m_clients[package.session()] = as;
 234     return as;
 235 }
 236
 237 void yf::Z3950Client::Rep::send_and_receive(Package &package,
 238                                             yf::Z3950Client::Assoc *c)
 239 {
 240     Z_GDU *gdu = package.request().get();
 241
 242     if (c->m_destroyed)
 243         return;
 244
 245     if (!gdu || gdu->which != Z_GDU_Z3950)
 246         return;
 247
 248     c->m_time_elapsed = 0;
 249     c->m_package = &package;
 250     c->m_waiting = true;
 251     if (!c->m_connected)
 252     {
 253         c->client(c->m_host.c_str());
 254         c->timeout(1);
 255
 256         while (!c->m_destroyed && c->m_waiting
 257                && c->m_socket_manager->processEvent() > 0)
 258             ;
 259     }
 260     if (!c->m_connected)
 261     {
 262         return;
 263     }
 264
 265     // prepare response
 266     c->m_time_elapsed = 0;
 267     c->m_waiting = true;
 268
 269     // relay the package  ..
 270     int len;
 271     c->send_GDU(gdu, &len);
 272
 273     switch(gdu->u.z3950->which)
 274     {
 275     case Z_APDU_triggerResourceControlRequest:
 276         // request only..
 277         break;
 278     default:
 279         // for the rest: wait for a response PDU
 280         while (!c->m_destroyed && c->m_waiting
 281                && c->m_socket_manager->processEvent() > 0)
 282             ;
 283         break;
 284     }
 285 }
 286
 287 void yf::Z3950Client::Rep::release_assoc(Package &package)
 288 {
 289     boost::mutex::scoped_lock lock(m_mutex);
 290     std::map<yp2::Session,yf::Z3950Client::Assoc *>::iterator it;
 291
 292     it = m_clients.find(package.session());
 293     if (it != m_clients.end())
 294     {
 295         Z_GDU *gdu = package.request().get();
 296         if (gdu && gdu->which == Z_GDU_Z3950)
 297         {   // only Z39.50 packages lock in get_assoc.. release it
 298             it->second->m_in_use = false;
 299             it->second->m_queue_len--;
 300         }
 301
 302         if (package.session().is_closed())
 303         {
 304             // destroy hint (send_and_receive)
 305             it->second->m_destroyed = true;
 306
 307             // wait until no one is waiting for it.
 308             while (it->second->m_queue_len)
 309                 m_cond_session_ready.wait(lock);
 310
 311             // the Z_Assoc and PDU_Assoc must be destroyed before
 312             // the socket manager.. so pull that out.. first..
 313             yazpp_1::SocketManager *s = it->second->m_socket_manager;
 314             delete it->second;  // destroy Z_Assoc
 315             delete s;    // then manager
 316             m_clients.erase(it);
 317         }
 318         m_cond_session_ready.notify_all();
 319     }
 320 }
 321
 322 void yf::Z3950Client::process(Package &package) const
 323 {
 324     yf::Z3950Client::Assoc *c = m_p->get_assoc(package);
 325     if (c)
 326     {
 327         m_p->send_and_receive(package, c);
 328     }
 329     m_p->release_assoc(package);
 330 }
 331
 332 void yf::Z3950Client::configure(const xmlNode *ptr)
 333 {
 334     for (ptr = ptr->children; ptr; ptr = ptr->next)
 335     {
 336         if (ptr->type != XML_ELEMENT_NODE)
 337             continue;
 338         if (!strcmp((const char *) ptr->name, "timeout"))
 339         {
 340             std::string timeout_str = yp2::xml::get_text(ptr);
 341             int timeout_sec = atoi(timeout_str.c_str());
 342             if (timeout_sec < 2)
 343                 throw yp2::filter::FilterException("Bad timeout value "
 344                                                    + timeout_str);
 345             m_p->m_timeout_sec = timeout_sec;
 346         }
 347         else
 348         {
 349             throw yp2::filter::FilterException("Bad element "
 350                                                + std::string((const char *)
 351                                                              ptr->name));
 352         }
 353     }
 354 }
 355
 356 static yp2::filter::Base* filter_creator()
 357 {
 358     return new yp2::filter::Z3950Client;
 359 }
 360
 361 extern "C" {
 362     struct yp2_filter_struct yp2_filter_z3950_client = {
 363         0,
 364         "z3950_client",
 365         filter_creator
 366     };
 367 }
 368
 369 /*
 370  * Local variables:
 371  * c-basic-offset: 4
 372  * indent-tabs-mode: nil
 373  * c-file-style: "stroustrup"
 374  * End:
 375  * vim: shiftwidth=4 tabstop=8 expandtab
 376  */