src/filter_virt_db.cpp

   1 /* $Id: filter_virt_db.cpp,v 1.50 2007-01-25 14:05:54 adam Exp $
   2    Copyright (c) 2005-2007, Index Data.
   3
   4    See the LICENSE file for details
   5  */
   6
   7 #include "config.hpp"
   8
   9 #include "filter.hpp"
  10 #include "package.hpp"
  11
  12 #include <boost/thread/mutex.hpp>
  13 #include <boost/thread/condition.hpp>
  14 #include <boost/shared_ptr.hpp>
  15
  16 #include "util.hpp"
  17 #include "filter_virt_db.hpp"
  18
  19 #include <yaz/zgdu.h>
  20 #include <yaz/otherinfo.h>
  21 #include <yaz/diagbib1.h>
  22
  23 #include <map>
  24 #include <iostream>
  25
  26 namespace mp = metaproxy_1;
  27 namespace yf = mp::filter;
  28
  29 namespace metaproxy_1 {
  30     namespace filter {
  31
  32         struct VirtualDB::Set {
  33             Set(BackendPtr b, std::string setname);
  34             Set();
  35             ~Set();
  36
  37             BackendPtr m_backend;
  38             std::string m_setname;
  39         };
  40         struct VirtualDB::Map {
  41             Map(std::list<std::string> targets, std::string route);
  42             Map();
  43             std::list<std::string> m_targets;
  44             std::string m_route;
  45         };
  46         struct VirtualDB::Backend {
  47             mp::Session m_backend_session;
  48             std::list<std::string> m_frontend_databases;
  49             std::list<std::string> m_targets;
  50             std::string m_route;
  51             bool m_named_result_sets;
  52             int m_number_of_sets;
  53         };
  54         struct VirtualDB::Frontend {
  55             Frontend(Rep *rep);
  56             ~Frontend();
  57             mp::Session m_session;
  58             bool m_is_virtual;
  59             bool m_in_use;
  60             yazpp_1::GDU m_init_gdu;
  61             std::list<BackendPtr> m_backend_list;
  62             std::map<std::string,VirtualDB::Set> m_sets;
  63
  64             void search(Package &package, Z_APDU *apdu);
  65             void present(Package &package, Z_APDU *apdu);
  66             void scan(Package &package, Z_APDU *apdu);
  67
  68             void close(Package &package);
  69             typedef std::map<std::string,VirtualDB::Set>::iterator Sets_it;
  70
  71             void fixup_package(Package &p, BackendPtr b);
  72             void fixup_npr_record(ODR odr, Z_NamePlusRecord *npr,
  73                                   BackendPtr b);
  74             void fixup_npr_records(ODR odr, Z_Records *records,
  75                                    BackendPtr b);
  76
  77             BackendPtr lookup_backend_from_databases(
  78                 std::list<std::string> databases);
  79             BackendPtr create_backend_from_databases(
  80                 std::list<std::string> databases,
  81                 int &error_code,
  82                 std::string &failing_database);
  83
  84             BackendPtr init_backend(std::list<std::string> database,
  85                                     Package &package,
  86                                     int &error_code, std::string &addinfo);
  87             Rep *m_p;
  88         };
  89         class VirtualDB::Rep {
  90             friend class VirtualDB;
  91             friend struct Frontend;
  92
  93             FrontendPtr get_frontend(Package &package);
  94             void release_frontend(Package &package);
  95         private:
  96             std::map<std::string, VirtualDB::Map>m_maps;
  97             typedef std::map<std::string,VirtualDB::Set>::iterator Sets_it;
  98             boost::mutex m_mutex;
  99             boost::condition m_cond_session_ready;
 100             std::map<mp::Session, FrontendPtr> m_clients;
 101         };
 102     }
 103 }
 104
 105 yf::VirtualDB::BackendPtr yf::VirtualDB::Frontend::lookup_backend_from_databases(
 106     std::list<std::string> databases)
 107 {
 108     std::list<BackendPtr>::const_iterator map_it;
 109     map_it = m_backend_list.begin();
 110     for (; map_it != m_backend_list.end(); map_it++)
 111         if ((*map_it)->m_frontend_databases == databases)
 112             return *map_it;
 113     BackendPtr null;
 114     return null;
 115 }
 116
 117 yf::VirtualDB::BackendPtr yf::VirtualDB::Frontend::create_backend_from_databases(
 118     std::list<std::string> databases, int &error_code, std::string &addinfo)
 119 {
 120     BackendPtr b(new Backend);
 121     std::list<std::string>::const_iterator db_it = databases.begin();
 122
 123     b->m_number_of_sets = 0;
 124     b->m_frontend_databases = databases;
 125     b->m_named_result_sets = false;
 126
 127     bool first_route = true;
 128
 129     std::map<std::string,bool> targets_dedup;
 130     for (; db_it != databases.end(); db_it++)
 131     {
 132         std::map<std::string, VirtualDB::Map>::iterator map_it;
 133         map_it = m_p->m_maps.find(mp::util::database_name_normalize(*db_it));
 134         if (map_it == m_p->m_maps.end())  // database not found
 135         {
 136             error_code = YAZ_BIB1_DATABASE_DOES_NOT_EXIST;
 137             addinfo = *db_it;
 138             BackendPtr ptr;
 139             return ptr;
 140         }
 141         std::list<std::string>::const_iterator t_it =
 142             map_it->second.m_targets.begin();
 143         for (; t_it != map_it->second.m_targets.end(); t_it++)
 144             targets_dedup[*t_it] = true;
 145
 146         // see if we have a route conflict.
 147         if (!first_route && b->m_route != map_it->second.m_route)
 148         {
 149             // we have a conflict..
 150             error_code =  YAZ_BIB1_COMBI_OF_SPECIFIED_DATABASES_UNSUPP;
 151             BackendPtr ptr;
 152             return ptr;
 153         }
 154         b->m_route = map_it->second.m_route;
 155         first_route = false;
 156     }
 157     std::map<std::string,bool>::const_iterator tm_it = targets_dedup.begin();
 158     for (; tm_it != targets_dedup.end(); tm_it++)
 159         b->m_targets.push_back(tm_it->first);
 160
 161     return b;
 162 }
 163
 164 yf::VirtualDB::BackendPtr yf::VirtualDB::Frontend::init_backend(
 165     std::list<std::string> databases, mp::Package &package,
 166     int &error_code, std::string &addinfo)
 167 {
 168     BackendPtr b = create_backend_from_databases(databases, error_code,
 169                                                  addinfo);
 170     if (!b)
 171         return b;
 172     Package init_package(b->m_backend_session, package.origin());
 173     init_package.copy_filter(package);
 174
 175     mp::odr odr;
 176
 177     Z_APDU *init_apdu = zget_APDU(odr, Z_APDU_initRequest);
 178
 179     mp::util::set_vhost_otherinfo(&init_apdu->u.initRequest->otherInfo, odr,
 180                                    b->m_targets);
 181     Z_InitRequest *req = init_apdu->u.initRequest;
 182
 183     // copy stuff from Frontend Init Request
 184     Z_GDU *org_gdu = m_init_gdu.get();
 185     Z_InitRequest *org_init = org_gdu->u.z3950->u.initRequest;
 186
 187     req->idAuthentication = org_init->idAuthentication;
 188     req->implementationId = org_init->implementationId;
 189     req->implementationName = org_init->implementationName;
 190     req->implementationVersion = org_init->implementationVersion;
 191
 192     ODR_MASK_SET(req->options, Z_Options_search);
 193     ODR_MASK_SET(req->options, Z_Options_present);
 194     ODR_MASK_SET(req->options, Z_Options_namedResultSets);
 195     ODR_MASK_SET(req->options, Z_Options_scan);
 196
 197     ODR_MASK_SET(req->protocolVersion, Z_ProtocolVersion_1);
 198     ODR_MASK_SET(req->protocolVersion, Z_ProtocolVersion_2);
 199     ODR_MASK_SET(req->protocolVersion, Z_ProtocolVersion_3);
 200
 201     init_package.request() = init_apdu;
 202
 203     init_package.move(b->m_route);  // sending init
 204
 205     Z_GDU *gdu = init_package.response().get();
 206     // we hope to get an init response
 207     if (gdu && gdu->which == Z_GDU_Z3950 && gdu->u.z3950->which ==
 208         Z_APDU_initResponse)
 209     {
 210         Z_InitResponse *res = gdu->u.z3950->u.initResponse;
 211         if (ODR_MASK_GET(res->options, Z_Options_namedResultSets))
 212         {
 213             b->m_named_result_sets = true;
 214         }
 215         if (!*res->result)
 216         {
 217             error_code = YAZ_BIB1_DATABASE_UNAVAILABLE;
 218             mp::util::get_init_diagnostics(res, error_code, addinfo);
 219             BackendPtr null;
 220             return null;
 221         }
 222     }
 223     else
 224     {
 225         error_code = YAZ_BIB1_DATABASE_UNAVAILABLE;
 226         // addinfo = database;
 227         BackendPtr null;
 228         return null;
 229     }
 230     if (init_package.session().is_closed())
 231     {
 232         error_code = YAZ_BIB1_DATABASE_UNAVAILABLE;
 233         // addinfo = database;
 234         BackendPtr null;
 235         return null;
 236     }
 237
 238     m_backend_list.push_back(b);
 239     return b;
 240 }
 241
 242 void yf::VirtualDB::Frontend::search(mp::Package &package, Z_APDU *apdu_req)
 243 {
 244     Z_SearchRequest *req = apdu_req->u.searchRequest;
 245     std::string vhost;
 246     std::string resultSetId = req->resultSetName;
 247     mp::odr odr;
 248
 249     std::list<std::string> databases;
 250     int i;
 251     for (i = 0; i<req->num_databaseNames; i++)
 252         databases.push_back(req->databaseNames[i]);
 253
 254     BackendPtr b; // null for now
 255     Sets_it sets_it = m_sets.find(req->resultSetName);
 256     if (sets_it != m_sets.end())
 257     {
 258         // result set already exist
 259         // if replace indicator is off: we return diagnostic if
 260         // result set already exist.
 261         if (*req->replaceIndicator == 0)
 262         {
 263             Z_APDU *apdu =
 264                 odr.create_searchResponse(
 265                     apdu_req,
 266                     YAZ_BIB1_RESULT_SET_EXISTS_AND_REPLACE_INDICATOR_OFF,
 267                     0);
 268             package.response() = apdu;
 269
 270             return;
 271         }
 272         sets_it->second.m_backend->m_number_of_sets--;
 273
 274         // pick up any existing backend with a database match
 275         std::list<BackendPtr>::const_iterator map_it;
 276         map_it = m_backend_list.begin();
 277         for (; map_it != m_backend_list.end(); map_it++)
 278         {
 279             BackendPtr tmp = *map_it;
 280             if (tmp->m_frontend_databases == databases)
 281                 break;
 282         }
 283         if (map_it != m_backend_list.end())
 284             b = *map_it;
 285     }
 286     else
 287     {
 288         // new result set.
 289
 290         // pick up any existing database with named result sets ..
 291         // or one which has no result sets.. yet.
 292         std::list<BackendPtr>::const_iterator map_it;
 293         map_it = m_backend_list.begin();
 294         for (; map_it != m_backend_list.end(); map_it++)
 295         {
 296             BackendPtr tmp = *map_it;
 297             if (tmp->m_frontend_databases == databases &&
 298                 (tmp->m_named_result_sets ||
 299                  tmp->m_number_of_sets == 0))
 300                 break;
 301         }
 302         if (map_it != m_backend_list.end())
 303             b = *map_it;
 304     }
 305     if (!b)  // no backend yet. Must create a new one
 306     {
 307         int error_code;
 308         std::string addinfo;
 309         b = init_backend(databases, package, error_code, addinfo);
 310         if (!b)
 311         {
 312             // did not get a backend (unavailable somehow?)
 313
 314             Z_APDU *apdu =
 315                 odr.create_searchResponse(
 316                     apdu_req, error_code, addinfo.c_str());
 317             package.response() = apdu;
 318             return;
 319         }
 320     }
 321     m_sets.erase(req->resultSetName);
 322     // sending search to backend
 323     Package search_package(b->m_backend_session, package.origin());
 324
 325     search_package.copy_filter(package);
 326
 327     std::string backend_setname;
 328     if (b->m_named_result_sets)
 329     {
 330         backend_setname = std::string(req->resultSetName);
 331     }
 332     else
 333     {
 334         backend_setname = "default";
 335         req->resultSetName = odr_strdup(odr, backend_setname.c_str());
 336     }
 337
 338     // pick first targets spec and move the databases from it ..
 339     std::list<std::string>::const_iterator t_it = b->m_targets.begin();
 340     if (t_it != b->m_targets.end())
 341     {
 342         mp::util::set_databases_from_zurl(odr, *t_it,
 343                                                 &req->num_databaseNames,
 344                                                 &req->databaseNames);
 345     }
 346
 347     *req->replaceIndicator = 1;
 348
 349     search_package.request() = yazpp_1::GDU(apdu_req);
 350
 351     search_package.move(b->m_route);
 352
 353     if (search_package.session().is_closed())
 354     {
 355         package.response() = search_package.response();
 356         package.session().close();
 357         return;
 358     }
 359     b->m_number_of_sets++;
 360
 361     m_sets[resultSetId] = VirtualDB::Set(b, backend_setname);
 362     fixup_package(search_package, b);
 363     package.response() = search_package.response();
 364 }
 365
 366 yf::VirtualDB::Frontend::Frontend(Rep *rep)
 367 {
 368     m_p = rep;
 369     m_is_virtual = false;
 370 }
 371
 372 void yf::VirtualDB::Frontend::close(mp::Package &package)
 373 {
 374     std::list<BackendPtr>::const_iterator b_it;
 375
 376     for (b_it = m_backend_list.begin(); b_it != m_backend_list.end(); b_it++)
 377     {
 378         (*b_it)->m_backend_session.close();
 379         Package close_package((*b_it)->m_backend_session, package.origin());
 380         close_package.copy_filter(package);
 381         close_package.move((*b_it)->m_route);
 382     }
 383     m_backend_list.clear();
 384 }
 385
 386 yf::VirtualDB::Frontend::~Frontend()
 387 {
 388 }
 389
 390 yf::VirtualDB::FrontendPtr yf::VirtualDB::Rep::get_frontend(mp::Package &package)
 391 {
 392     boost::mutex::scoped_lock lock(m_mutex);
 393
 394     std::map<mp::Session,yf::VirtualDB::FrontendPtr>::iterator it;
 395
 396     while(true)
 397     {
 398         it = m_clients.find(package.session());
 399         if (it == m_clients.end())
 400             break;
 401
 402         if (!it->second->m_in_use)
 403         {
 404             it->second->m_in_use = true;
 405             return it->second;
 406         }
 407         m_cond_session_ready.wait(lock);
 408     }
 409     FrontendPtr f(new Frontend(this));
 410     m_clients[package.session()] = f;
 411     f->m_in_use = true;
 412     return f;
 413 }
 414
 415 void yf::VirtualDB::Rep::release_frontend(mp::Package &package)
 416 {
 417     boost::mutex::scoped_lock lock(m_mutex);
 418     std::map<mp::Session,yf::VirtualDB::FrontendPtr>::iterator it;
 419
 420     it = m_clients.find(package.session());
 421     if (it != m_clients.end())
 422     {
 423         if (package.session().is_closed())
 424         {
 425             it->second->close(package);
 426             m_clients.erase(it);
 427         }
 428         else
 429         {
 430             it->second->m_in_use = false;
 431         }
 432         m_cond_session_ready.notify_all();
 433     }
 434 }
 435
 436 yf::VirtualDB::Set::Set(BackendPtr b, std::string setname)
 437     :  m_backend(b), m_setname(setname)
 438 {
 439 }
 440
 441
 442 yf::VirtualDB::Set::Set()
 443 {
 444 }
 445
 446
 447 yf::VirtualDB::Set::~Set()
 448 {
 449 }
 450
 451 yf::VirtualDB::Map::Map(std::list<std::string> targets, std::string route)
 452     : m_targets(targets), m_route(route)
 453 {
 454 }
 455
 456 yf::VirtualDB::Map::Map()
 457 {
 458 }
 459
 460 yf::VirtualDB::VirtualDB() : m_p(new VirtualDB::Rep)
 461 {
 462 }
 463
 464 yf::VirtualDB::~VirtualDB() {
 465 }
 466
 467 void yf::VirtualDB::Frontend::fixup_npr_record(ODR odr, Z_NamePlusRecord *npr,
 468                                              BackendPtr b)
 469 {
 470     if (npr->databaseName)
 471     {
 472         std::string b_database = std::string(npr->databaseName);
 473
 474         // consider each of the frontend databases..
 475         std::list<std::string>::const_iterator db_it;
 476         for (db_it = b->m_frontend_databases.begin();
 477              db_it != b->m_frontend_databases.end(); db_it++)
 478         {
 479             // see which target it corresponds to.. (if any)
 480             std::map<std::string,VirtualDB::Map>::const_iterator map_it;
 481             map_it = m_p->m_maps.find(*db_it);
 482             if (map_it != m_p->m_maps.end())
 483             {
 484                 VirtualDB::Map m = map_it->second;
 485
 486                 std::list<std::string>::const_iterator t;
 487                 for (t = m.m_targets.begin(); t != m.m_targets.end(); t++)
 488                 {
 489                     if (*t == b_database)
 490                     {
 491                         npr->databaseName = odr_strdup(odr, (*db_it).c_str());
 492                         return;
 493                     }
 494                 }
 495             }
 496
 497         }
 498         db_it = b->m_frontend_databases.begin();
 499         if (db_it != b->m_frontend_databases.end())
 500         {
 501             std::string database = *db_it;
 502             npr->databaseName = odr_strdup(odr, database.c_str());
 503         }
 504     }
 505 }
 506
 507 void yf::VirtualDB::Frontend::fixup_npr_records(ODR odr, Z_Records *records,
 508                                               BackendPtr b)
 509 {
 510     if (records && records->which == Z_Records_DBOSD)
 511     {
 512         Z_NamePlusRecordList *nprlist = records->u.databaseOrSurDiagnostics;
 513         int i;
 514         for (i = 0; i < nprlist->num_records; i++)
 515         {
 516             fixup_npr_record(odr, nprlist->records[i], b);
 517         }
 518     }
 519 }
 520
 521 void yf::VirtualDB::Frontend::fixup_package(mp::Package &p, BackendPtr b)
 522 {
 523     Z_GDU *gdu = p.response().get();
 524     mp::odr odr;
 525
 526     if (gdu && gdu->which == Z_GDU_Z3950)
 527     {
 528         Z_APDU *apdu = gdu->u.z3950;
 529         if (apdu->which == Z_APDU_presentResponse)
 530         {
 531             fixup_npr_records(odr, apdu->u.presentResponse->records, b);
 532             p.response() = gdu;
 533         }
 534         else if (apdu->which == Z_APDU_searchResponse)
 535         {
 536             fixup_npr_records(odr,  apdu->u.searchResponse->records, b);
 537             p.response() = gdu;
 538         }
 539     }
 540 }
 541
 542 void yf::VirtualDB::Frontend::present(mp::Package &package, Z_APDU *apdu_req)
 543 {
 544     Z_PresentRequest *req = apdu_req->u.presentRequest;
 545     std::string resultSetId = req->resultSetId;
 546     mp::odr odr;
 547
 548     Sets_it sets_it = m_sets.find(resultSetId);
 549     if (sets_it == m_sets.end())
 550     {
 551         Z_APDU *apdu =
 552             odr.create_presentResponse(
 553                 apdu_req,
 554                 YAZ_BIB1_SPECIFIED_RESULT_SET_DOES_NOT_EXIST,
 555                 resultSetId.c_str());
 556         package.response() = apdu;
 557         return;
 558     }
 559     Session *id =
 560         new mp::Session(sets_it->second.m_backend->m_backend_session);
 561
 562     // sending present to backend
 563     Package present_package(*id, package.origin());
 564     present_package.copy_filter(package);
 565
 566     req->resultSetId = odr_strdup(odr, sets_it->second.m_setname.c_str());
 567
 568     present_package.request() = yazpp_1::GDU(apdu_req);
 569
 570     present_package.move(sets_it->second.m_backend->m_route);
 571
 572     fixup_package(present_package, sets_it->second.m_backend);
 573
 574     if (present_package.session().is_closed())
 575     {
 576         package.response() = present_package.response();
 577         package.session().close();
 578         return;
 579     }
 580     else
 581     {
 582         package.response() = present_package.response();
 583     }
 584     delete id;
 585 }
 586
 587 void yf::VirtualDB::Frontend::scan(mp::Package &package, Z_APDU *apdu_req)
 588 {
 589     Z_ScanRequest *req = apdu_req->u.scanRequest;
 590     std::string vhost;
 591     mp::odr odr;
 592
 593     std::list<std::string> databases;
 594     int i;
 595     for (i = 0; i<req->num_databaseNames; i++)
 596         databases.push_back(req->databaseNames[i]);
 597
 598     BackendPtr b;
 599     // pick up any existing backend with a database match
 600     std::list<BackendPtr>::const_iterator map_it;
 601     map_it = m_backend_list.begin();
 602     for (; map_it != m_backend_list.end(); map_it++)
 603     {
 604         BackendPtr tmp = *map_it;
 605         if (tmp->m_frontend_databases == databases)
 606             break;
 607     }
 608     if (map_it != m_backend_list.end())
 609         b = *map_it;
 610     if (!b)  // no backend yet. Must create a new one
 611     {
 612         int error_code;
 613         std::string addinfo;
 614         b = init_backend(databases, package, error_code, addinfo);
 615         if (!b)
 616         {
 617             // did not get a backend (unavailable somehow?)
 618             Z_APDU *apdu =
 619                 odr.create_scanResponse(
 620                     apdu_req, error_code, addinfo.c_str());
 621             package.response() = apdu;
 622
 623             return;
 624         }
 625     }
 626     // sending scan to backend
 627     Package scan_package(b->m_backend_session, package.origin());
 628
 629     scan_package.copy_filter(package);
 630
 631     // pick first targets spec and move the databases from it ..
 632     std::list<std::string>::const_iterator t_it = b->m_targets.begin();
 633     if (t_it != b->m_targets.end())
 634     {
 635         mp::util::set_databases_from_zurl(odr, *t_it,
 636                                                 &req->num_databaseNames,
 637                                                 &req->databaseNames);
 638     }
 639     scan_package.request() = yazpp_1::GDU(apdu_req);
 640
 641     scan_package.move(b->m_route);
 642
 643     if (scan_package.session().is_closed())
 644     {
 645         package.response() = scan_package.response();
 646         package.session().close();
 647         return;
 648     }
 649     package.response() = scan_package.response();
 650 }
 651
 652
 653 void yf::VirtualDB::add_map_db2targets(std::string db,
 654                                      std::list<std::string> targets,
 655                                      std::string route)
 656 {
 657     m_p->m_maps[mp::util::database_name_normalize(db)]
 658         = VirtualDB::Map(targets, route);
 659 }
 660
 661
 662 void yf::VirtualDB::add_map_db2target(std::string db,
 663                                     std::string target,
 664                                     std::string route)
 665 {
 666     std::list<std::string> targets;
 667     targets.push_back(target);
 668
 669     m_p->m_maps[mp::util::database_name_normalize(db)]
 670         = VirtualDB::Map(targets, route);
 671 }
 672
 673 void yf::VirtualDB::process(mp::Package &package) const
 674 {
 675     FrontendPtr f = m_p->get_frontend(package);
 676
 677     Z_GDU *gdu = package.request().get();
 678
 679     if (gdu && gdu->which == Z_GDU_Z3950 && gdu->u.z3950->which ==
 680         Z_APDU_initRequest && !f->m_is_virtual)
 681     {
 682         Z_InitRequest *req = gdu->u.z3950->u.initRequest;
 683
 684         std::list<std::string> vhosts;
 685         mp::util::get_vhost_otherinfo(req->otherInfo, vhosts);
 686         if (vhosts.size() == 0)
 687         {
 688             f->m_init_gdu = gdu;
 689
 690             mp::odr odr;
 691             Z_APDU *apdu = odr.create_initResponse(gdu->u.z3950, 0, 0);
 692             Z_InitResponse *resp = apdu->u.initResponse;
 693
 694             int i;
 695             static const int masks[] = {
 696                 Z_Options_search,
 697                 Z_Options_present,
 698                 Z_Options_namedResultSets,
 699                 Z_Options_scan,
 700                 -1
 701             };
 702             for (i = 0; masks[i] != -1; i++)
 703                 if (ODR_MASK_GET(req->options, masks[i]))
 704                     ODR_MASK_SET(resp->options, masks[i]);
 705
 706             static const int versions[] = {
 707                 Z_ProtocolVersion_1,
 708                 Z_ProtocolVersion_2,
 709                 Z_ProtocolVersion_3,
 710                 -1
 711             };
 712             for (i = 0; versions[i] != -1; i++)
 713                 if (ODR_MASK_GET(req->protocolVersion, versions[i]))
 714                     ODR_MASK_SET(resp->protocolVersion, versions[i]);
 715                 else
 716                     break;
 717
 718             package.response() = apdu;
 719             f->m_is_virtual = true;
 720         }
 721         else
 722             package.move();
 723     }
 724     else if (!f->m_is_virtual)
 725         package.move();
 726     else if (gdu && gdu->which == Z_GDU_Z3950)
 727     {
 728         Z_APDU *apdu = gdu->u.z3950;
 729         if (apdu->which == Z_APDU_initRequest)
 730         {
 731             mp::odr odr;
 732
 733             package.response() = odr.create_close(
 734                 apdu,
 735                 Z_Close_protocolError,
 736                 "double init");
 737
 738             package.session().close();
 739         }
 740         else if (apdu->which == Z_APDU_searchRequest)
 741         {
 742             f->search(package, apdu);
 743         }
 744         else if (apdu->which == Z_APDU_presentRequest)
 745         {
 746             f->present(package, apdu);
 747         }
 748         else if (apdu->which == Z_APDU_scanRequest)
 749         {
 750             f->scan(package, apdu);
 751         }
 752         else if (apdu->which == Z_APDU_close)
 753         {
 754             package.session().close();
 755         }
 756         else
 757         {
 758             mp::odr odr;
 759
 760             package.response() = odr.create_close(
 761                 apdu, Z_Close_protocolError,
 762                 "unsupported APDU in filter_virt_db");
 763
 764             package.session().close();
 765         }
 766     }
 767     m_p->release_frontend(package);
 768 }
 769
 770
 771 void mp::filter::VirtualDB::configure(const xmlNode * ptr)
 772 {
 773     for (ptr = ptr->children; ptr; ptr = ptr->next)
 774     {
 775         if (ptr->type != XML_ELEMENT_NODE)
 776             continue;
 777         if (!strcmp((const char *) ptr->name, "virtual"))
 778         {
 779             std::string database;
 780             std::list<std::string> targets;
 781             xmlNode *v_node = ptr->children;
 782             for (; v_node; v_node = v_node->next)
 783             {
 784                 if (v_node->type != XML_ELEMENT_NODE)
 785                     continue;
 786
 787                 if (mp::xml::is_element_mp(v_node, "database"))
 788                     database = mp::xml::get_text(v_node);
 789                 else if (mp::xml::is_element_mp(v_node, "target"))
 790                     targets.push_back(mp::xml::get_text(v_node));
 791                 else
 792                     throw mp::filter::FilterException
 793                         ("Bad element "
 794                          + std::string((const char *) v_node->name)
 795                          + " in virtual section"
 796                             );
 797             }
 798             std::string route = mp::xml::get_route(ptr);
 799             add_map_db2targets(database, targets, route);
 800         }
 801         else
 802         {
 803             throw mp::filter::FilterException
 804                 ("Bad element "
 805                  + std::string((const char *) ptr->name)
 806                  + " in virt_db filter");
 807         }
 808     }
 809 }
 810
 811 static mp::filter::Base* filter_creator()
 812 {
 813     return new mp::filter::VirtualDB;
 814 }
 815
 816 extern "C" {
 817     struct metaproxy_1_filter_struct metaproxy_1_filter_virt_db = {
 818         0,
 819         "virt_db",
 820         filter_creator
 821     };
 822 }
 823
 824
 825 /*
 826  * Local variables:
 827  * c-basic-offset: 4
 828  * indent-tabs-mode: nil
 829  * c-file-style: "stroustrup"
 830  * End:
 831  * vim: shiftwidth=4 tabstop=8 expandtab
 832  */