src/filter_z3950_client.cpp

   1 /* $Id: filter_z3950_client.cpp,v 1.17 2006-01-09 18:19:09 adam Exp $
   2    Copyright (c) 2005, Index Data.
   3
   4 %LICENSE%
   5  */
   6
   7 #include "config.hpp"
   8
   9 #include "xmlutil.hpp"
  10 #include "filter.hpp"
  11 #include "router.hpp"
  12 #include "package.hpp"
  13 #include "util.hpp"
  14 #include "filter_z3950_client.hpp"
  15
  16 #include <map>
  17 #include <stdexcept>
  18 #include <list>
  19 #include <iostream>
  20
  21 #include <boost/thread/mutex.hpp>
  22 #include <boost/thread/condition.hpp>
  23
  24 #include <yaz/zgdu.h>
  25 #include <yaz/log.h>
  26 #include <yaz/otherinfo.h>
  27 #include <yaz/diagbib1.h>
  28
  29 #include <yaz++/socket-manager.h>
  30 #include <yaz++/pdu-assoc.h>
  31 #include <yaz++/z-assoc.h>
  32
  33 namespace yf = yp2::filter;
  34
  35 namespace yp2 {
  36     namespace filter {
  37         class Z3950Client::Assoc : public yazpp_1::Z_Assoc{
  38             friend class Rep;
  39             Assoc(yazpp_1::SocketManager *socket_manager,
  40                   yazpp_1::IPDU_Observable *PDU_Observable,
  41                   std::string host, int timeout);
  42             ~Assoc();
  43             void connectNotify();
  44             void failNotify();
  45             void timeoutNotify();
  46             void recv_GDU(Z_GDU *gdu, int len);
  47             yazpp_1::IPDU_Observer* sessionNotify(
  48                 yazpp_1::IPDU_Observable *the_PDU_Observable,
  49                 int fd);
  50
  51             yazpp_1::SocketManager *m_socket_manager;
  52             yazpp_1::IPDU_Observable *m_PDU_Observable;
  53             Package *m_package;
  54             bool m_in_use;
  55             bool m_waiting;
  56             bool m_destroyed;
  57             bool m_connected;
  58             int m_queue_len;
  59             int m_time_elapsed;
  60             int m_time_max;
  61             std::string m_host;
  62         };
  63
  64         class Z3950Client::Rep {
  65         public:
  66             int m_timeout_sec;
  67             boost::mutex m_mutex;
  68             boost::condition m_cond_session_ready;
  69             std::map<yp2::Session,Z3950Client::Assoc *> m_clients;
  70             Z3950Client::Assoc *get_assoc(Package &package);
  71             void send_and_receive(Package &package,
  72                                   yf::Z3950Client::Assoc *c);
  73             void release_assoc(Package &package);
  74         };
  75     }
  76 }
  77
  78 using namespace yp2;
  79
  80 yf::Z3950Client::Assoc::Assoc(yazpp_1::SocketManager *socket_manager,
  81                               yazpp_1::IPDU_Observable *PDU_Observable,
  82                               std::string host, int timeout_sec)
  83     :  Z_Assoc(PDU_Observable),
  84        m_socket_manager(socket_manager), m_PDU_Observable(PDU_Observable),
  85        m_package(0), m_in_use(true), m_waiting(false),
  86        m_destroyed(false), m_connected(false), m_queue_len(1),
  87        m_time_elapsed(0), m_time_max(timeout_sec),
  88        m_host(host)
  89 {
  90     // std::cout << "create assoc " << this << "\n";
  91 }
  92
  93 yf::Z3950Client::Assoc::~Assoc()
  94 {
  95     // std::cout << "destroy assoc " << this << "\n";
  96 }
  97
  98 void yf::Z3950Client::Assoc::connectNotify()
  99 {
 100     m_waiting = false;
 101
 102     m_connected = true;
 103 }
 104
 105 void yf::Z3950Client::Assoc::failNotify()
 106 {
 107     m_waiting = false;
 108
 109     yp2::odr odr;
 110
 111     if (m_package)
 112     {
 113         m_package->response() = odr.create_close(Z_Close_peerAbort, 0);
 114         m_package->session().close();
 115     }
 116 }
 117
 118 void yf::Z3950Client::Assoc::timeoutNotify()
 119 {
 120     m_time_elapsed++;
 121     if (m_time_elapsed >= m_time_max)
 122     {
 123         m_waiting = false;
 124
 125         yp2::odr odr;
 126
 127         if (m_package)
 128         {
 129             if (m_connected)
 130                 m_package->response() = odr.create_close(Z_Close_lackOfActivity, 0);
 131             else
 132                 m_package->response() = odr.create_close(Z_Close_peerAbort, 0);
 133
 134             m_package->session().close();
 135         }
 136     }
 137 }
 138
 139 void yf::Z3950Client::Assoc::recv_GDU(Z_GDU *gdu, int len)
 140 {
 141     m_waiting = false;
 142
 143     if (m_package)
 144         m_package->response() = gdu;
 145 }
 146
 147 yazpp_1::IPDU_Observer *yf::Z3950Client::Assoc::sessionNotify(
 148     yazpp_1::IPDU_Observable *the_PDU_Observable,
 149     int fd)
 150 {
 151     return 0;
 152 }
 153
 154
 155 yf::Z3950Client::Z3950Client() :  m_p(new yf::Z3950Client::Rep)
 156 {
 157     m_p->m_timeout_sec = 30;
 158 }
 159
 160 yf::Z3950Client::~Z3950Client() {
 161 }
 162
 163 yf::Z3950Client::Assoc *yf::Z3950Client::Rep::get_assoc(Package &package)
 164 {
 165     // only one thread messes with the clients list at a time
 166     boost::mutex::scoped_lock lock(m_mutex);
 167
 168     std::map<yp2::Session,yf::Z3950Client::Assoc *>::iterator it;
 169
 170     Z_GDU *gdu = package.request().get();
 171     // only deal with Z39.50
 172     if (!gdu || gdu->which != Z_GDU_Z3950)
 173     {
 174         package.move();
 175         return 0;
 176     }
 177     it = m_clients.find(package.session());
 178     if (it != m_clients.end())
 179     {
 180         it->second->m_queue_len++;
 181         while(true)
 182         {
 183 #if 0
 184             if (gdu && gdu->which == Z_GDU_Z3950 &&
 185                 gdu->u.z3950->which == Z_APDU_initRequest)
 186             {
 187                 yazpp_1::SocketManager *s = it->second->m_socket_manager;
 188                 delete it->second;  // destroy Z_Assoc
 189                 delete s;    // then manager
 190                 m_clients.erase(it);
 191                 break;
 192             }
 193 #endif
 194             if (!it->second->m_in_use)
 195             {
 196                 it->second->m_in_use = true;
 197                 return it->second;
 198             }
 199             m_cond_session_ready.wait(lock);
 200         }
 201     }
 202     // new Z39.50 session ..
 203     Z_APDU *apdu = gdu->u.z3950;
 204     // check that it is init. If not, close
 205     if (apdu->which != Z_APDU_initRequest)
 206     {
 207         yp2::odr odr;
 208
 209         package.response() = odr.create_close(Z_Close_protocolError,
 210                                               "First PDU was not an "
 211                                               "Initialize Request");
 212         package.session().close();
 213         return 0;
 214     }
 215     // check virtual host
 216     const char *vhost =
 217         yaz_oi_get_string_oidval(&apdu->u.initRequest->otherInfo,
 218                                  VAL_PROXY,
 219                                  /* categoryValue */ 1, /* delete */ 1);
 220     if (!vhost)
 221     {
 222         yp2::odr odr;
 223         package.response() = odr.create_initResponse(
 224             YAZ_BIB1_INIT_NEGOTIATION_OPTION_REQUIRED,
 225             "Virtual host not given");
 226
 227         package.session().close();
 228         return 0;
 229     }
 230
 231     yazpp_1::SocketManager *sm = new yazpp_1::SocketManager;
 232     yazpp_1::PDU_Assoc *pdu_as = new yazpp_1::PDU_Assoc(sm);
 233     yf::Z3950Client::Assoc *as = new yf::Z3950Client::Assoc(sm, pdu_as, vhost,
 234                                                             m_timeout_sec);
 235     m_clients[package.session()] = as;
 236     return as;
 237 }
 238
 239 void yf::Z3950Client::Rep::send_and_receive(Package &package,
 240                                             yf::Z3950Client::Assoc *c)
 241 {
 242     Z_GDU *gdu = package.request().get();
 243
 244     if (c->m_destroyed)
 245         return;
 246
 247     if (!gdu || gdu->which != Z_GDU_Z3950)
 248         return;
 249
 250     c->m_time_elapsed = 0;
 251     c->m_package = &package;
 252     c->m_waiting = true;
 253     if (!c->m_connected)
 254     {
 255         c->client(c->m_host.c_str());
 256         c->timeout(1);
 257
 258         while (!c->m_destroyed && c->m_waiting
 259                && c->m_socket_manager->processEvent() > 0)
 260             ;
 261     }
 262     if (!c->m_connected)
 263     {
 264         return;
 265     }
 266
 267     // prepare response
 268     c->m_time_elapsed = 0;
 269     c->m_waiting = true;
 270
 271     // relay the package  ..
 272     int len;
 273     c->send_GDU(gdu, &len);
 274
 275     switch(gdu->u.z3950->which)
 276     {
 277     case Z_APDU_triggerResourceControlRequest:
 278         // request only..
 279         break;
 280     default:
 281         // for the rest: wait for a response PDU
 282         while (!c->m_destroyed && c->m_waiting
 283                && c->m_socket_manager->processEvent() > 0)
 284             ;
 285         break;
 286     }
 287 }
 288
 289 void yf::Z3950Client::Rep::release_assoc(Package &package)
 290 {
 291     boost::mutex::scoped_lock lock(m_mutex);
 292     std::map<yp2::Session,yf::Z3950Client::Assoc *>::iterator it;
 293
 294     it = m_clients.find(package.session());
 295     if (it != m_clients.end())
 296     {
 297         Z_GDU *gdu = package.request().get();
 298         if (gdu && gdu->which == Z_GDU_Z3950)
 299         {   // only Z39.50 packages lock in get_assoc.. release it
 300             it->second->m_in_use = false;
 301             it->second->m_queue_len--;
 302         }
 303
 304         if (package.session().is_closed())
 305         {
 306             // destroy hint (send_and_receive)
 307             it->second->m_destroyed = true;
 308
 309             // wait until no one is waiting for it.
 310             while (it->second->m_queue_len)
 311                 m_cond_session_ready.wait(lock);
 312
 313             // the Z_Assoc and PDU_Assoc must be destroyed before
 314             // the socket manager.. so pull that out.. first..
 315             yazpp_1::SocketManager *s = it->second->m_socket_manager;
 316             delete it->second;  // destroy Z_Assoc
 317             delete s;    // then manager
 318             m_clients.erase(it);
 319         }
 320         m_cond_session_ready.notify_all();
 321     }
 322 }
 323
 324 void yf::Z3950Client::process(Package &package) const
 325 {
 326     yf::Z3950Client::Assoc *c = m_p->get_assoc(package);
 327     if (c)
 328     {
 329         m_p->send_and_receive(package, c);
 330     }
 331     m_p->release_assoc(package);
 332 }
 333
 334 void yf::Z3950Client::configure(const xmlNode *ptr)
 335 {
 336     for (ptr = ptr->children; ptr; ptr = ptr->next)
 337     {
 338         if (ptr->type != XML_ELEMENT_NODE)
 339             continue;
 340         if (!strcmp((const char *) ptr->name, "timeout"))
 341         {
 342             std::string timeout_str = yp2::xml::get_text(ptr);
 343             int timeout_sec = atoi(timeout_str.c_str());
 344             if (timeout_sec < 2)
 345                 throw yp2::filter::FilterException("Bad timeout value "
 346                                                    + timeout_str);
 347             m_p->m_timeout_sec = timeout_sec;
 348         }
 349         else
 350         {
 351             throw yp2::filter::FilterException("Bad element "
 352                                                + std::string((const char *)
 353                                                              ptr->name));
 354         }
 355     }
 356 }
 357
 358 static yp2::filter::Base* filter_creator()
 359 {
 360     return new yp2::filter::Z3950Client;
 361 }
 362
 363 extern "C" {
 364     struct yp2_filter_struct yp2_filter_z3950_client = {
 365         0,
 366         "z3950_client",
 367         filter_creator
 368     };
 369 }
 370
 371 /*
 372  * Local variables:
 373  * c-basic-offset: 4
 374  * indent-tabs-mode: nil
 375  * c-file-style: "stroustrup"
 376  * End:
 377  * vim: shiftwidth=4 tabstop=8 expandtab
 378  */