src/filter_virt_db.cpp

   1 /* This file is part of Metaproxy.
   2    Copyright (C) 2005-2009 Index Data
   3
   4 Metaproxy is free software; you can redistribute it and/or modify it under
   5 the terms of the GNU General Public License as published by the Free
   6 Software Foundation; either version 2, or (at your option) any later
   7 version.
   8
   9 Metaproxy is distributed in the hope that it will be useful, but WITHOUT ANY
  10 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12 for more details.
  13
  14 You should have received a copy of the GNU General Public License
  15 along with this program; if not, write to the Free Software
  16 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  17 */
  18
  19 #include "config.hpp"
  20
  21 #include "filter.hpp"
  22 #include "package.hpp"
  23
  24 #include <boost/thread/mutex.hpp>
  25 #include <boost/thread/condition.hpp>
  26 #include <boost/shared_ptr.hpp>
  27
  28 #include "util.hpp"
  29 #include "filter_virt_db.hpp"
  30
  31 #include <yaz/zgdu.h>
  32 #include <yaz/otherinfo.h>
  33 #include <yaz/diagbib1.h>
  34 #include <yaz/match_glob.h>
  35
  36 #include <map>
  37 #include <iostream>
  38
  39 namespace mp = metaproxy_1;
  40 namespace yf = mp::filter;
  41
  42 namespace metaproxy_1 {
  43     namespace filter {
  44
  45         struct VirtualDB::Set {
  46             Set(BackendPtr b, std::string setname);
  47             Set();
  48             ~Set();
  49
  50             BackendPtr m_backend;
  51             std::string m_setname;
  52         };
  53         struct VirtualDB::Map {
  54             Map(std::string database, std::list<std::string> targets, std::string route);
  55             Map();
  56             bool match(const std::string db) const;
  57             std::string m_dbpattern;
  58             std::list<std::string> m_targets;
  59             std::string m_route;
  60         };
  61         struct VirtualDB::Backend {
  62             mp::Session m_backend_session;
  63             std::list<std::string> m_frontend_databases;
  64             std::list<std::string> m_targets;
  65             std::string m_route;
  66             bool m_named_result_sets;
  67             int m_number_of_sets;
  68         };
  69         struct VirtualDB::Frontend {
  70             Frontend(Rep *rep);
  71             ~Frontend();
  72             mp::Session m_session;
  73             bool m_is_virtual;
  74             bool m_in_use;
  75             yazpp_1::GDU m_init_gdu;
  76             std::list<BackendPtr> m_backend_list;
  77             std::map<std::string,VirtualDB::Set> m_sets;
  78
  79             void search(Package &package, Z_APDU *apdu);
  80             void present(Package &package, Z_APDU *apdu);
  81             void scan(Package &package, Z_APDU *apdu);
  82
  83             void close(Package &package);
  84             typedef std::map<std::string,VirtualDB::Set>::iterator Sets_it;
  85
  86             void fixup_package(Package &p, BackendPtr b);
  87             void fixup_npr_record(ODR odr, Z_NamePlusRecord *npr,
  88                                   BackendPtr b);
  89             void fixup_npr_records(ODR odr, Z_Records *records,
  90                                    BackendPtr b);
  91
  92             BackendPtr lookup_backend_from_databases(
  93                 std::list<std::string> databases);
  94             BackendPtr create_backend_from_databases(
  95                 std::list<std::string> databases,
  96                 int &error_code,
  97                 std::string &failing_database);
  98
  99             BackendPtr init_backend(std::list<std::string> database,
 100                                     Package &package,
 101                                     int &error_code, std::string &addinfo);
 102             Rep *m_p;
 103         };
 104         class VirtualDB::Rep {
 105             friend class VirtualDB;
 106             friend struct Frontend;
 107
 108             FrontendPtr get_frontend(Package &package);
 109             void release_frontend(Package &package);
 110         private:
 111             std::list<VirtualDB::Map>m_maps;
 112             typedef std::map<std::string,VirtualDB::Set>::iterator Sets_it;
 113             boost::mutex m_mutex;
 114             boost::condition m_cond_session_ready;
 115             std::map<mp::Session, FrontendPtr> m_clients;
 116             bool pass_vhosts;
 117         };
 118     }
 119 }
 120
 121 yf::VirtualDB::BackendPtr yf::VirtualDB::Frontend::lookup_backend_from_databases(
 122     std::list<std::string> databases)
 123 {
 124     std::list<BackendPtr>::const_iterator map_it;
 125     map_it = m_backend_list.begin();
 126     for (; map_it != m_backend_list.end(); map_it++)
 127         if ((*map_it)->m_frontend_databases == databases)
 128             return *map_it;
 129     BackendPtr null;
 130     return null;
 131 }
 132
 133 yf::VirtualDB::BackendPtr yf::VirtualDB::Frontend::create_backend_from_databases(
 134     std::list<std::string> databases, int &error_code, std::string &addinfo)
 135 {
 136     BackendPtr b(new Backend);
 137     std::list<std::string>::const_iterator db_it = databases.begin();
 138
 139     b->m_number_of_sets = 0;
 140     b->m_frontend_databases = databases;
 141     b->m_named_result_sets = false;
 142
 143     bool first_route = true;
 144
 145     std::map<std::string,bool> targets_dedup;
 146     for (; db_it != databases.end(); db_it++)
 147     {
 148         std::list<VirtualDB::Map>::const_iterator map_it;
 149         map_it = m_p->m_maps.begin();
 150         while (map_it != m_p->m_maps.end())
 151         {
 152             if (map_it->match(*db_it))
 153                 break;
 154             map_it++;
 155         }
 156
 157         if (map_it == m_p->m_maps.end())  // database not found
 158         {
 159             error_code = YAZ_BIB1_DATABASE_DOES_NOT_EXIST;
 160             addinfo = *db_it;
 161             BackendPtr ptr;
 162             return ptr;
 163         }
 164         std::list<std::string>::const_iterator t_it =
 165             map_it->m_targets.begin();
 166         for (; t_it != map_it->m_targets.end(); t_it++) {
 167             if (!targets_dedup[*t_it])
 168             {
 169                 targets_dedup[*t_it] = true;
 170                 b->m_targets.push_back(*t_it);
 171             }
 172         }
 173
 174         // see if we have a route conflict.
 175         if (!first_route && b->m_route != map_it->m_route)
 176         {
 177             // we have a conflict..
 178             error_code =  YAZ_BIB1_COMBI_OF_SPECIFIED_DATABASES_UNSUPP;
 179             BackendPtr ptr;
 180             return ptr;
 181         }
 182         b->m_route = map_it->m_route;
 183         first_route = false;
 184     }
 185     return b;
 186 }
 187
 188 yf::VirtualDB::BackendPtr yf::VirtualDB::Frontend::init_backend(
 189     std::list<std::string> databases, mp::Package &package,
 190     int &error_code, std::string &addinfo)
 191 {
 192     BackendPtr b = create_backend_from_databases(databases, error_code,
 193                                                  addinfo);
 194     if (!b)
 195         return b;
 196     Package init_package(b->m_backend_session, package.origin());
 197     init_package.copy_filter(package);
 198
 199     mp::odr odr;
 200
 201     Z_APDU *init_apdu = zget_APDU(odr, Z_APDU_initRequest);
 202
 203     mp::util::set_vhost_otherinfo(&init_apdu->u.initRequest->otherInfo, odr,
 204                                    b->m_targets);
 205     Z_InitRequest *req = init_apdu->u.initRequest;
 206
 207     // copy stuff from Frontend Init Request
 208     Z_GDU *org_gdu = m_init_gdu.get();
 209     Z_InitRequest *org_init = org_gdu->u.z3950->u.initRequest;
 210
 211     req->idAuthentication = org_init->idAuthentication;
 212     req->implementationId = org_init->implementationId;
 213     req->implementationName = org_init->implementationName;
 214     req->implementationVersion = org_init->implementationVersion;
 215
 216     ODR_MASK_SET(req->options, Z_Options_search);
 217     ODR_MASK_SET(req->options, Z_Options_present);
 218     ODR_MASK_SET(req->options, Z_Options_namedResultSets);
 219     ODR_MASK_SET(req->options, Z_Options_scan);
 220
 221     ODR_MASK_SET(req->protocolVersion, Z_ProtocolVersion_1);
 222     ODR_MASK_SET(req->protocolVersion, Z_ProtocolVersion_2);
 223     ODR_MASK_SET(req->protocolVersion, Z_ProtocolVersion_3);
 224
 225     init_package.request() = init_apdu;
 226
 227     init_package.move(b->m_route);  // sending init
 228
 229     Z_GDU *gdu = init_package.response().get();
 230     // we hope to get an init response
 231     if (gdu && gdu->which == Z_GDU_Z3950 && gdu->u.z3950->which ==
 232         Z_APDU_initResponse)
 233     {
 234         Z_InitResponse *res = gdu->u.z3950->u.initResponse;
 235         if (ODR_MASK_GET(res->options, Z_Options_namedResultSets))
 236         {
 237             b->m_named_result_sets = true;
 238         }
 239         if (!*res->result)
 240         {
 241             error_code = YAZ_BIB1_DATABASE_UNAVAILABLE;
 242             mp::util::get_init_diagnostics(res, error_code, addinfo);
 243             BackendPtr null;
 244             return null;
 245         }
 246     }
 247     else
 248     {
 249         error_code = YAZ_BIB1_DATABASE_UNAVAILABLE;
 250         // addinfo = database;
 251         BackendPtr null;
 252         return null;
 253     }
 254     if (init_package.session().is_closed())
 255     {
 256         error_code = YAZ_BIB1_DATABASE_UNAVAILABLE;
 257         // addinfo = database;
 258         BackendPtr null;
 259         return null;
 260     }
 261
 262     m_backend_list.push_back(b);
 263     return b;
 264 }
 265
 266 void yf::VirtualDB::Frontend::search(mp::Package &package, Z_APDU *apdu_req)
 267 {
 268     Z_SearchRequest *req = apdu_req->u.searchRequest;
 269     std::string vhost;
 270     std::string resultSetId = req->resultSetName;
 271     mp::odr odr;
 272
 273     std::list<std::string> databases;
 274     int i;
 275     for (i = 0; i<req->num_databaseNames; i++)
 276         databases.push_back(req->databaseNames[i]);
 277
 278     BackendPtr b; // null for now
 279     Sets_it sets_it = m_sets.find(req->resultSetName);
 280     if (sets_it != m_sets.end())
 281     {
 282         // result set already exist
 283         // if replace indicator is off: we return diagnostic if
 284         // result set already exist.
 285         if (*req->replaceIndicator == 0)
 286         {
 287             Z_APDU *apdu =
 288                 odr.create_searchResponse(
 289                     apdu_req,
 290                     YAZ_BIB1_RESULT_SET_EXISTS_AND_REPLACE_INDICATOR_OFF,
 291                     0);
 292             package.response() = apdu;
 293
 294             return;
 295         }
 296         sets_it->second.m_backend->m_number_of_sets--;
 297
 298         // pick up any existing backend with a database match
 299         std::list<BackendPtr>::const_iterator map_it;
 300         map_it = m_backend_list.begin();
 301         for (; map_it != m_backend_list.end(); map_it++)
 302         {
 303             BackendPtr tmp = *map_it;
 304             if (tmp->m_frontend_databases == databases)
 305                 break;
 306         }
 307         if (map_it != m_backend_list.end())
 308             b = *map_it;
 309     }
 310     else
 311     {
 312         // new result set.
 313
 314         // pick up any existing database with named result sets ..
 315         // or one which has no result sets.. yet.
 316         std::list<BackendPtr>::const_iterator map_it;
 317         map_it = m_backend_list.begin();
 318         for (; map_it != m_backend_list.end(); map_it++)
 319         {
 320             BackendPtr tmp = *map_it;
 321             if (tmp->m_frontend_databases == databases &&
 322                 (tmp->m_named_result_sets ||
 323                  tmp->m_number_of_sets == 0))
 324                 break;
 325         }
 326         if (map_it != m_backend_list.end())
 327             b = *map_it;
 328     }
 329     if (!b)  // no backend yet. Must create a new one
 330     {
 331         int error_code;
 332         std::string addinfo;
 333         b = init_backend(databases, package, error_code, addinfo);
 334         if (!b)
 335         {
 336             // did not get a backend (unavailable somehow?)
 337
 338             Z_APDU *apdu =
 339                 odr.create_searchResponse(
 340                     apdu_req, error_code, addinfo.c_str());
 341             package.response() = apdu;
 342             return;
 343         }
 344     }
 345     m_sets.erase(req->resultSetName);
 346     // sending search to backend
 347     Package search_package(b->m_backend_session, package.origin());
 348
 349     search_package.copy_filter(package);
 350
 351     std::string backend_setname;
 352     if (b->m_named_result_sets)
 353     {
 354         backend_setname = std::string(req->resultSetName);
 355     }
 356     else
 357     {
 358         backend_setname = "default";
 359         req->resultSetName = odr_strdup(odr, backend_setname.c_str());
 360     }
 361
 362     // pick first targets spec and move the databases from it ..
 363     std::list<std::string>::const_iterator t_it = b->m_targets.begin();
 364     if (t_it != b->m_targets.end())
 365     {
 366         mp::util::set_databases_from_zurl(odr, *t_it,
 367                                                 &req->num_databaseNames,
 368                                                 &req->databaseNames);
 369     }
 370
 371     *req->replaceIndicator = 1;
 372
 373     search_package.request() = yazpp_1::GDU(apdu_req);
 374
 375     search_package.move(b->m_route);
 376
 377     if (search_package.session().is_closed())
 378     {
 379         package.response() = search_package.response();
 380         package.session().close();
 381         return;
 382     }
 383     b->m_number_of_sets++;
 384
 385     m_sets[resultSetId] = VirtualDB::Set(b, backend_setname);
 386     fixup_package(search_package, b);
 387     package.response() = search_package.response();
 388 }
 389
 390 yf::VirtualDB::Frontend::Frontend(Rep *rep)
 391 {
 392     m_p = rep;
 393     m_is_virtual = false;
 394 }
 395
 396 void yf::VirtualDB::Frontend::close(mp::Package &package)
 397 {
 398     std::list<BackendPtr>::const_iterator b_it;
 399
 400     for (b_it = m_backend_list.begin(); b_it != m_backend_list.end(); b_it++)
 401     {
 402         (*b_it)->m_backend_session.close();
 403         Package close_package((*b_it)->m_backend_session, package.origin());
 404         close_package.copy_filter(package);
 405         close_package.move((*b_it)->m_route);
 406     }
 407     m_backend_list.clear();
 408 }
 409
 410 yf::VirtualDB::Frontend::~Frontend()
 411 {
 412 }
 413
 414 yf::VirtualDB::FrontendPtr yf::VirtualDB::Rep::get_frontend(mp::Package &package)
 415 {
 416     boost::mutex::scoped_lock lock(m_mutex);
 417
 418     std::map<mp::Session,yf::VirtualDB::FrontendPtr>::iterator it;
 419
 420     while(true)
 421     {
 422         it = m_clients.find(package.session());
 423         if (it == m_clients.end())
 424             break;
 425
 426         if (!it->second->m_in_use)
 427         {
 428             it->second->m_in_use = true;
 429             return it->second;
 430         }
 431         m_cond_session_ready.wait(lock);
 432     }
 433     FrontendPtr f(new Frontend(this));
 434     m_clients[package.session()] = f;
 435     f->m_in_use = true;
 436     return f;
 437 }
 438
 439 void yf::VirtualDB::Rep::release_frontend(mp::Package &package)
 440 {
 441     boost::mutex::scoped_lock lock(m_mutex);
 442     std::map<mp::Session,yf::VirtualDB::FrontendPtr>::iterator it;
 443
 444     it = m_clients.find(package.session());
 445     if (it != m_clients.end())
 446     {
 447         if (package.session().is_closed())
 448         {
 449             it->second->close(package);
 450             m_clients.erase(it);
 451         }
 452         else
 453         {
 454             it->second->m_in_use = false;
 455         }
 456         m_cond_session_ready.notify_all();
 457     }
 458 }
 459
 460 yf::VirtualDB::Set::Set(BackendPtr b, std::string setname)
 461     :  m_backend(b), m_setname(setname)
 462 {
 463 }
 464
 465
 466 yf::VirtualDB::Set::Set()
 467 {
 468 }
 469
 470
 471 yf::VirtualDB::Set::~Set()
 472 {
 473 }
 474
 475 yf::VirtualDB::Map::Map(std::string database,
 476                         std::list<std::string> targets, std::string route)
 477     : m_dbpattern(database), m_targets(targets), m_route(route)
 478 {
 479 }
 480
 481 yf::VirtualDB::Map::Map()
 482 {
 483 }
 484
 485 bool yf::VirtualDB::Map::match(const std::string db) const
 486 {
 487     std::string norm_db = mp::util::database_name_normalize(db);
 488     if (yaz_match_glob(m_dbpattern.c_str(), norm_db.c_str()))
 489         return true;
 490     return false;
 491 }
 492
 493 yf::VirtualDB::VirtualDB() : m_p(new VirtualDB::Rep)
 494 {
 495     m_p->pass_vhosts = false;
 496 }
 497
 498 yf::VirtualDB::~VirtualDB() {
 499 }
 500
 501 void yf::VirtualDB::Frontend::fixup_npr_record(ODR odr, Z_NamePlusRecord *npr,
 502                                              BackendPtr b)
 503 {
 504     if (npr->databaseName)
 505     {
 506         std::string b_database = std::string(npr->databaseName);
 507
 508         // consider each of the frontend databases..
 509         std::list<std::string>::const_iterator db_it;
 510         for (db_it = b->m_frontend_databases.begin();
 511              db_it != b->m_frontend_databases.end(); db_it++)
 512         {
 513             // see which target it corresponds to.. (if any)
 514             std::list<VirtualDB::Map>::const_iterator map_it =
 515                 m_p->m_maps.begin();
 516             while (map_it != m_p->m_maps.end())
 517             {
 518                 if (map_it->match(*db_it))
 519                     break;
 520                 map_it++;
 521             }
 522             if (map_it != m_p->m_maps.end())
 523             {
 524                 std::list<std::string>::const_iterator t
 525                     = map_it->m_targets.begin();
 526                 while (t != map_it->m_targets.end())
 527                 {
 528                     if (*t == b_database)
 529                     {
 530                         npr->databaseName = odr_strdup(odr, (*db_it).c_str());
 531                         return;
 532                     }
 533                     t++;
 534                 }
 535             }
 536
 537         }
 538         db_it = b->m_frontend_databases.begin();
 539         if (db_it != b->m_frontend_databases.end())
 540         {
 541             std::string database = *db_it;
 542             npr->databaseName = odr_strdup(odr, database.c_str());
 543         }
 544     }
 545 }
 546
 547 void yf::VirtualDB::Frontend::fixup_npr_records(ODR odr, Z_Records *records,
 548                                               BackendPtr b)
 549 {
 550     if (records && records->which == Z_Records_DBOSD)
 551     {
 552         Z_NamePlusRecordList *nprlist = records->u.databaseOrSurDiagnostics;
 553         int i;
 554         for (i = 0; i < nprlist->num_records; i++)
 555         {
 556             fixup_npr_record(odr, nprlist->records[i], b);
 557         }
 558     }
 559 }
 560
 561 void yf::VirtualDB::Frontend::fixup_package(mp::Package &p, BackendPtr b)
 562 {
 563     Z_GDU *gdu = p.response().get();
 564     mp::odr odr;
 565
 566     if (gdu && gdu->which == Z_GDU_Z3950)
 567     {
 568         Z_APDU *apdu = gdu->u.z3950;
 569         if (apdu->which == Z_APDU_presentResponse)
 570         {
 571             fixup_npr_records(odr, apdu->u.presentResponse->records, b);
 572             p.response() = gdu;
 573         }
 574         else if (apdu->which == Z_APDU_searchResponse)
 575         {
 576             fixup_npr_records(odr,  apdu->u.searchResponse->records, b);
 577             p.response() = gdu;
 578         }
 579     }
 580 }
 581
 582 void yf::VirtualDB::Frontend::present(mp::Package &package, Z_APDU *apdu_req)
 583 {
 584     Z_PresentRequest *req = apdu_req->u.presentRequest;
 585     std::string resultSetId = req->resultSetId;
 586     mp::odr odr;
 587
 588     Sets_it sets_it = m_sets.find(resultSetId);
 589     if (sets_it == m_sets.end())
 590     {
 591         Z_APDU *apdu =
 592             odr.create_presentResponse(
 593                 apdu_req,
 594                 YAZ_BIB1_SPECIFIED_RESULT_SET_DOES_NOT_EXIST,
 595                 resultSetId.c_str());
 596         package.response() = apdu;
 597         return;
 598     }
 599     Session *id =
 600         new mp::Session(sets_it->second.m_backend->m_backend_session);
 601
 602     // sending present to backend
 603     Package present_package(*id, package.origin());
 604     present_package.copy_filter(package);
 605
 606     req->resultSetId = odr_strdup(odr, sets_it->second.m_setname.c_str());
 607
 608     present_package.request() = yazpp_1::GDU(apdu_req);
 609
 610     present_package.move(sets_it->second.m_backend->m_route);
 611
 612     fixup_package(present_package, sets_it->second.m_backend);
 613
 614     if (present_package.session().is_closed())
 615     {
 616         package.response() = present_package.response();
 617         package.session().close();
 618         return;
 619     }
 620     else
 621     {
 622         package.response() = present_package.response();
 623     }
 624     delete id;
 625 }
 626
 627 void yf::VirtualDB::Frontend::scan(mp::Package &package, Z_APDU *apdu_req)
 628 {
 629     Z_ScanRequest *req = apdu_req->u.scanRequest;
 630     std::string vhost;
 631     mp::odr odr;
 632
 633     std::list<std::string> databases;
 634     int i;
 635     for (i = 0; i<req->num_databaseNames; i++)
 636         databases.push_back(req->databaseNames[i]);
 637
 638     BackendPtr b;
 639     // pick up any existing backend with a database match
 640     std::list<BackendPtr>::const_iterator map_it;
 641     map_it = m_backend_list.begin();
 642     for (; map_it != m_backend_list.end(); map_it++)
 643     {
 644         BackendPtr tmp = *map_it;
 645         if (tmp->m_frontend_databases == databases)
 646             break;
 647     }
 648     if (map_it != m_backend_list.end())
 649         b = *map_it;
 650     if (!b)  // no backend yet. Must create a new one
 651     {
 652         int error_code;
 653         std::string addinfo;
 654         b = init_backend(databases, package, error_code, addinfo);
 655         if (!b)
 656         {
 657             // did not get a backend (unavailable somehow?)
 658             Z_APDU *apdu =
 659                 odr.create_scanResponse(
 660                     apdu_req, error_code, addinfo.c_str());
 661             package.response() = apdu;
 662
 663             return;
 664         }
 665     }
 666     // sending scan to backend
 667     Package scan_package(b->m_backend_session, package.origin());
 668
 669     scan_package.copy_filter(package);
 670
 671     // pick first targets spec and move the databases from it ..
 672     std::list<std::string>::const_iterator t_it = b->m_targets.begin();
 673     if (t_it != b->m_targets.end())
 674     {
 675         mp::util::set_databases_from_zurl(odr, *t_it,
 676                                                 &req->num_databaseNames,
 677                                                 &req->databaseNames);
 678     }
 679     scan_package.request() = yazpp_1::GDU(apdu_req);
 680
 681     scan_package.move(b->m_route);
 682
 683     if (scan_package.session().is_closed())
 684     {
 685         package.response() = scan_package.response();
 686         package.session().close();
 687         return;
 688     }
 689     package.response() = scan_package.response();
 690 }
 691
 692
 693 void yf::VirtualDB::add_map_db2targets(std::string db,
 694                                      std::list<std::string> targets,
 695                                      std::string route)
 696 {
 697     m_p->m_maps.push_back(
 698         VirtualDB::Map(mp::util::database_name_normalize(db), targets, route));
 699 }
 700
 701
 702 void yf::VirtualDB::add_map_db2target(std::string db,
 703                                     std::string target,
 704                                     std::string route)
 705 {
 706     std::list<std::string> targets;
 707     targets.push_back(target);
 708
 709     add_map_db2targets(db, targets, route);
 710 }
 711
 712 void yf::VirtualDB::process(mp::Package &package) const
 713 {
 714     FrontendPtr f = m_p->get_frontend(package);
 715
 716     Z_GDU *gdu = package.request().get();
 717
 718     if (gdu && gdu->which == Z_GDU_Z3950 && gdu->u.z3950->which ==
 719         Z_APDU_initRequest && !f->m_is_virtual)
 720     {
 721         Z_InitRequest *req = gdu->u.z3950->u.initRequest;
 722
 723         std::list<std::string> vhosts;
 724         mp::util::get_vhost_otherinfo(req->otherInfo, vhosts);
 725
 726         if (vhosts.size() > 0 && m_p->pass_vhosts)
 727         {
 728             package.move();
 729         }
 730         else
 731         {
 732             f->m_init_gdu = gdu;
 733
 734             mp::odr odr;
 735             Z_APDU *apdu = odr.create_initResponse(gdu->u.z3950, 0, 0);
 736             Z_InitResponse *resp = apdu->u.initResponse;
 737
 738             int i;
 739             static const int masks[] = {
 740                 Z_Options_search,
 741                 Z_Options_present,
 742                 Z_Options_namedResultSets,
 743                 Z_Options_scan,
 744                 -1
 745             };
 746             for (i = 0; masks[i] != -1; i++)
 747                 if (ODR_MASK_GET(req->options, masks[i]))
 748                     ODR_MASK_SET(resp->options, masks[i]);
 749
 750             static const int versions[] = {
 751                 Z_ProtocolVersion_1,
 752                 Z_ProtocolVersion_2,
 753                 Z_ProtocolVersion_3,
 754                 -1
 755             };
 756             for (i = 0; versions[i] != -1; i++)
 757                 if (ODR_MASK_GET(req->protocolVersion, versions[i]))
 758                     ODR_MASK_SET(resp->protocolVersion, versions[i]);
 759                 else
 760                     break;
 761
 762             package.response() = apdu;
 763             f->m_is_virtual = true;
 764         }
 765     }
 766     else if (!f->m_is_virtual)
 767         package.move();
 768     else if (gdu && gdu->which == Z_GDU_Z3950)
 769     {
 770         Z_APDU *apdu = gdu->u.z3950;
 771         if (apdu->which == Z_APDU_initRequest)
 772         {
 773             mp::odr odr;
 774
 775             package.response() = odr.create_close(
 776                 apdu,
 777                 Z_Close_protocolError,
 778                 "double init");
 779
 780             package.session().close();
 781         }
 782         else if (apdu->which == Z_APDU_searchRequest)
 783         {
 784             f->search(package, apdu);
 785         }
 786         else if (apdu->which == Z_APDU_presentRequest)
 787         {
 788             f->present(package, apdu);
 789         }
 790         else if (apdu->which == Z_APDU_scanRequest)
 791         {
 792             f->scan(package, apdu);
 793         }
 794         else if (apdu->which == Z_APDU_close)
 795         {
 796             package.session().close();
 797         }
 798         else
 799         {
 800             mp::odr odr;
 801
 802             package.response() = odr.create_close(
 803                 apdu, Z_Close_protocolError,
 804                 "unsupported APDU in filter_virt_db");
 805
 806             package.session().close();
 807         }
 808     }
 809     m_p->release_frontend(package);
 810 }
 811
 812
 813 void mp::filter::VirtualDB::configure(const xmlNode * ptr, bool test_only)
 814 {
 815     for (ptr = ptr->children; ptr; ptr = ptr->next)
 816     {
 817         if (ptr->type != XML_ELEMENT_NODE)
 818             continue;
 819         if (!strcmp((const char *) ptr->name, "pass-vhosts"))
 820         {
 821             m_p->pass_vhosts = mp::xml::get_bool(ptr->children, false);
 822         }
 823         else if (!strcmp((const char *) ptr->name, "virtual"))
 824         {
 825             std::string database;
 826             std::list<std::string> targets;
 827             xmlNode *v_node = ptr->children;
 828             for (; v_node; v_node = v_node->next)
 829             {
 830                 if (v_node->type != XML_ELEMENT_NODE)
 831                     continue;
 832
 833                 if (mp::xml::is_element_mp(v_node, "database"))
 834                     database = mp::xml::get_text(v_node);
 835                 else if (mp::xml::is_element_mp(v_node, "target"))
 836                     targets.push_back(mp::xml::get_text(v_node));
 837                 else
 838                     throw mp::filter::FilterException
 839                         ("Bad element "
 840                          + std::string((const char *) v_node->name)
 841                          + " in virtual section"
 842                             );
 843             }
 844             std::string route = mp::xml::get_route(ptr);
 845             add_map_db2targets(database, targets, route);
 846         }
 847         else
 848         {
 849             throw mp::filter::FilterException
 850                 ("Bad element "
 851                  + std::string((const char *) ptr->name)
 852                  + " in virt_db filter");
 853         }
 854     }
 855 }
 856
 857 static mp::filter::Base* filter_creator()
 858 {
 859     return new mp::filter::VirtualDB;
 860 }
 861
 862 extern "C" {
 863     struct metaproxy_1_filter_struct metaproxy_1_filter_virt_db = {
 864         0,
 865         "virt_db",
 866         filter_creator
 867     };
 868 }
 869
 870
 871 /*
 872  * Local variables:
 873  * c-basic-offset: 4
 874  * c-file-style: "Stroustrup"
 875  * indent-tabs-mode: nil
 876  * End:
 877  * vim: shiftwidth=4 tabstop=8 expandtab
 878  */
 879