src/filter_virt_db.cpp

   1 /* This file is part of Metaproxy.
   2    Copyright (C) 2005-2010 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_virt_db.hpp"
  22 #include <metaproxy/package.hpp>
  23
  24 #include <boost/thread/mutex.hpp>
  25 #include <boost/thread/condition.hpp>
  26 #include <boost/shared_ptr.hpp>
  27
  28 #include <metaproxy/util.hpp>
  29
  30 #include <yaz/zgdu.h>
  31 #include <yaz/otherinfo.h>
  32 #include <yaz/diagbib1.h>
  33 #include <yaz/match_glob.h>
  34
  35 #include <map>
  36 #include <iostream>
  37
  38 namespace mp = metaproxy_1;
  39 namespace yf = mp::filter;
  40
  41 namespace metaproxy_1 {
  42     namespace filter {
  43
  44         struct VirtualDB::Set {
  45             Set(BackendPtr b, std::string setname);
  46             Set();
  47             ~Set();
  48
  49             BackendPtr m_backend;
  50             std::string m_setname;
  51         };
  52         struct VirtualDB::Map {
  53             Map(std::string database, std::list<std::string> targets, std::string route);
  54             Map();
  55             bool match(const std::string db) const;
  56             std::string m_dbpattern;
  57             std::list<std::string> m_targets;
  58             std::string m_route;
  59         };
  60         struct VirtualDB::Backend {
  61             mp::Session m_backend_session;
  62             std::list<std::string> m_frontend_databases;
  63             std::list<std::string> m_targets;
  64             std::string m_route;
  65             bool m_named_result_sets;
  66             int m_number_of_sets;
  67         };
  68         struct VirtualDB::Frontend {
  69             Frontend(Rep *rep);
  70             ~Frontend();
  71             mp::Session m_session;
  72             bool m_is_virtual;
  73             bool m_in_use;
  74             yazpp_1::GDU m_init_gdu;
  75             std::list<BackendPtr> m_backend_list;
  76             std::map<std::string,VirtualDB::Set> m_sets;
  77
  78             void search(Package &package, Z_APDU *apdu);
  79             void present(Package &package, Z_APDU *apdu);
  80             void scan(Package &package, Z_APDU *apdu);
  81
  82             void close(Package &package);
  83             typedef std::map<std::string,VirtualDB::Set>::iterator Sets_it;
  84
  85             void fixup_package(Package &p, BackendPtr b);
  86             void fixup_npr_record(ODR odr, Z_NamePlusRecord *npr,
  87                                   BackendPtr b);
  88             void fixup_npr_records(ODR odr, Z_Records *records,
  89                                    BackendPtr b);
  90
  91             BackendPtr lookup_backend_from_databases(
  92                 std::list<std::string> databases);
  93             BackendPtr create_backend_from_databases(
  94                 std::list<std::string> databases,
  95                 int &error_code,
  96                 std::string &failing_database);
  97
  98             BackendPtr init_backend(std::list<std::string> database,
  99                                     Package &package,
 100                                     int &error_code, std::string &addinfo);
 101             Rep *m_p;
 102         };
 103         class VirtualDB::Rep {
 104             friend class VirtualDB;
 105             friend struct Frontend;
 106
 107             FrontendPtr get_frontend(Package &package);
 108             void release_frontend(Package &package);
 109         private:
 110             std::list<VirtualDB::Map>m_maps;
 111             typedef std::map<std::string,VirtualDB::Set>::iterator Sets_it;
 112             boost::mutex m_mutex;
 113             boost::condition m_cond_session_ready;
 114             std::map<mp::Session, FrontendPtr> m_clients;
 115             bool pass_vhosts;
 116         };
 117     }
 118 }
 119
 120 yf::VirtualDB::BackendPtr yf::VirtualDB::Frontend::lookup_backend_from_databases(
 121     std::list<std::string> databases)
 122 {
 123     std::list<BackendPtr>::const_iterator map_it;
 124     map_it = m_backend_list.begin();
 125     for (; map_it != m_backend_list.end(); map_it++)
 126         if ((*map_it)->m_frontend_databases == databases)
 127             return *map_it;
 128     BackendPtr null;
 129     return null;
 130 }
 131
 132 yf::VirtualDB::BackendPtr yf::VirtualDB::Frontend::create_backend_from_databases(
 133     std::list<std::string> databases, int &error_code, std::string &addinfo)
 134 {
 135     BackendPtr b(new Backend);
 136     std::list<std::string>::const_iterator db_it = databases.begin();
 137
 138     b->m_number_of_sets = 0;
 139     b->m_frontend_databases = databases;
 140     b->m_named_result_sets = false;
 141
 142     bool first_route = true;
 143
 144     std::map<std::string,bool> targets_dedup;
 145     for (; db_it != databases.end(); db_it++)
 146     {
 147         std::list<VirtualDB::Map>::const_iterator map_it;
 148         map_it = m_p->m_maps.begin();
 149         while (map_it != m_p->m_maps.end())
 150         {
 151             if (map_it->match(*db_it))
 152                 break;
 153             map_it++;
 154         }
 155
 156         if (map_it == m_p->m_maps.end())  // database not found
 157         {
 158             error_code = YAZ_BIB1_DATABASE_DOES_NOT_EXIST;
 159             addinfo = *db_it;
 160             BackendPtr ptr;
 161             return ptr;
 162         }
 163         std::list<std::string>::const_iterator t_it =
 164             map_it->m_targets.begin();
 165         for (; t_it != map_it->m_targets.end(); t_it++) {
 166             if (!targets_dedup[*t_it])
 167             {
 168                 targets_dedup[*t_it] = true;
 169                 b->m_targets.push_back(*t_it);
 170             }
 171         }
 172
 173         // see if we have a route conflict.
 174         if (!first_route && b->m_route != map_it->m_route)
 175         {
 176             // we have a conflict..
 177             error_code =  YAZ_BIB1_COMBI_OF_SPECIFIED_DATABASES_UNSUPP;
 178             BackendPtr ptr;
 179             return ptr;
 180         }
 181         b->m_route = map_it->m_route;
 182         first_route = false;
 183     }
 184     return b;
 185 }
 186
 187 yf::VirtualDB::BackendPtr yf::VirtualDB::Frontend::init_backend(
 188     std::list<std::string> databases, mp::Package &package,
 189     int &error_code, std::string &addinfo)
 190 {
 191     BackendPtr b = create_backend_from_databases(databases, error_code,
 192                                                  addinfo);
 193     if (!b)
 194         return b;
 195     Package init_package(b->m_backend_session, package.origin());
 196     init_package.copy_filter(package);
 197
 198     mp::odr odr;
 199
 200     Z_APDU *init_apdu = zget_APDU(odr, Z_APDU_initRequest);
 201
 202     mp::util::set_vhost_otherinfo(&init_apdu->u.initRequest->otherInfo, odr,
 203                                    b->m_targets);
 204     Z_InitRequest *req = init_apdu->u.initRequest;
 205
 206     // copy stuff from Frontend Init Request
 207     Z_GDU *org_gdu = m_init_gdu.get();
 208     Z_InitRequest *org_init = org_gdu->u.z3950->u.initRequest;
 209
 210     req->idAuthentication = org_init->idAuthentication;
 211     req->implementationId = org_init->implementationId;
 212     req->implementationName = org_init->implementationName;
 213     req->implementationVersion = org_init->implementationVersion;
 214
 215     ODR_MASK_SET(req->options, Z_Options_search);
 216     ODR_MASK_SET(req->options, Z_Options_present);
 217     ODR_MASK_SET(req->options, Z_Options_namedResultSets);
 218     ODR_MASK_SET(req->options, Z_Options_scan);
 219
 220     ODR_MASK_SET(req->protocolVersion, Z_ProtocolVersion_1);
 221     ODR_MASK_SET(req->protocolVersion, Z_ProtocolVersion_2);
 222     ODR_MASK_SET(req->protocolVersion, Z_ProtocolVersion_3);
 223
 224     init_package.request() = init_apdu;
 225
 226     init_package.move(b->m_route);  // sending init
 227
 228     Z_GDU *gdu = init_package.response().get();
 229     // we hope to get an init response
 230     if (gdu && gdu->which == Z_GDU_Z3950 && gdu->u.z3950->which ==
 231         Z_APDU_initResponse)
 232     {
 233         Z_InitResponse *res = gdu->u.z3950->u.initResponse;
 234         if (ODR_MASK_GET(res->options, Z_Options_namedResultSets))
 235         {
 236             b->m_named_result_sets = true;
 237         }
 238         if (*res->result)
 239         {
 240             m_backend_list.push_back(b);
 241             return b;
 242
 243         }
 244         error_code = YAZ_BIB1_DATABASE_UNAVAILABLE;
 245         mp::util::get_init_diagnostics(res, error_code, addinfo);
 246     }
 247     if (!init_package.session().is_closed())
 248     {
 249         Package close_package(b->m_backend_session, package.origin());
 250         close_package.copy_filter(package);
 251         close_package.session().close();
 252         close_package.move(b->m_route);  // closing it
 253     }
 254     BackendPtr null;
 255     return null;
 256 }
 257
 258 void yf::VirtualDB::Frontend::search(mp::Package &package, Z_APDU *apdu_req)
 259 {
 260     Z_SearchRequest *req = apdu_req->u.searchRequest;
 261     std::string vhost;
 262     std::string resultSetId = req->resultSetName;
 263     mp::odr odr;
 264
 265     std::list<std::string> databases;
 266     int i;
 267     for (i = 0; i<req->num_databaseNames; i++)
 268         databases.push_back(req->databaseNames[i]);
 269
 270     Sets_it sets_it = m_sets.find(req->resultSetName);
 271     if (sets_it != m_sets.end())
 272     {
 273         // result set already exist
 274         // if replace indicator is off: we return diagnostic if
 275         // result set already exist.
 276         if (*req->replaceIndicator == 0)
 277         {
 278             Z_APDU *apdu =
 279                 odr.create_searchResponse(
 280                     apdu_req,
 281                     YAZ_BIB1_RESULT_SET_EXISTS_AND_REPLACE_INDICATOR_OFF,
 282                     0);
 283             package.response() = apdu;
 284
 285             return;
 286         }
 287         sets_it->second.m_backend->m_number_of_sets--;
 288     }
 289     // pick up any existing database with named result sets ..
 290     // or one which has no result sets.. yet.
 291     BackendPtr b; // null for now
 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         {
 301             b = *map_it;
 302             break;
 303         }
 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::string database,
 452                         std::list<std::string> targets, std::string route)
 453     : m_dbpattern(database), m_targets(targets), m_route(route)
 454 {
 455 }
 456
 457 yf::VirtualDB::Map::Map()
 458 {
 459 }
 460
 461 bool yf::VirtualDB::Map::match(const std::string db) const
 462 {
 463     std::string norm_db = mp::util::database_name_normalize(db);
 464     if (yaz_match_glob(m_dbpattern.c_str(), norm_db.c_str()))
 465         return true;
 466     return false;
 467 }
 468
 469 yf::VirtualDB::VirtualDB() : m_p(new VirtualDB::Rep)
 470 {
 471     m_p->pass_vhosts = false;
 472 }
 473
 474 yf::VirtualDB::~VirtualDB() {
 475 }
 476
 477 void yf::VirtualDB::Frontend::fixup_npr_record(ODR odr, Z_NamePlusRecord *npr,
 478                                              BackendPtr b)
 479 {
 480     if (npr->databaseName)
 481     {
 482         std::string b_database = std::string(npr->databaseName);
 483
 484         // consider each of the frontend databases..
 485         std::list<std::string>::const_iterator db_it;
 486         for (db_it = b->m_frontend_databases.begin();
 487              db_it != b->m_frontend_databases.end(); db_it++)
 488         {
 489             // see which target it corresponds to.. (if any)
 490             std::list<VirtualDB::Map>::const_iterator map_it =
 491                 m_p->m_maps.begin();
 492             while (map_it != m_p->m_maps.end())
 493             {
 494                 if (map_it->match(*db_it))
 495                     break;
 496                 map_it++;
 497             }
 498             if (map_it != m_p->m_maps.end())
 499             {
 500                 std::list<std::string>::const_iterator t
 501                     = map_it->m_targets.begin();
 502                 while (t != map_it->m_targets.end())
 503                 {
 504                     if (*t == b_database)
 505                     {
 506                         npr->databaseName = odr_strdup(odr, (*db_it).c_str());
 507                         return;
 508                     }
 509                     t++;
 510                 }
 511             }
 512
 513         }
 514         db_it = b->m_frontend_databases.begin();
 515         if (db_it != b->m_frontend_databases.end())
 516         {
 517             std::string database = *db_it;
 518             npr->databaseName = odr_strdup(odr, database.c_str());
 519         }
 520     }
 521 }
 522
 523 void yf::VirtualDB::Frontend::fixup_npr_records(ODR odr, Z_Records *records,
 524                                               BackendPtr b)
 525 {
 526     if (records && records->which == Z_Records_DBOSD)
 527     {
 528         Z_NamePlusRecordList *nprlist = records->u.databaseOrSurDiagnostics;
 529         int i;
 530         for (i = 0; i < nprlist->num_records; i++)
 531         {
 532             fixup_npr_record(odr, nprlist->records[i], b);
 533         }
 534     }
 535 }
 536
 537 void yf::VirtualDB::Frontend::fixup_package(mp::Package &p, BackendPtr b)
 538 {
 539     Z_GDU *gdu = p.response().get();
 540     mp::odr odr;
 541
 542     if (gdu && gdu->which == Z_GDU_Z3950)
 543     {
 544         Z_APDU *apdu = gdu->u.z3950;
 545         if (apdu->which == Z_APDU_presentResponse)
 546         {
 547             fixup_npr_records(odr, apdu->u.presentResponse->records, b);
 548             p.response() = gdu;
 549         }
 550         else if (apdu->which == Z_APDU_searchResponse)
 551         {
 552             fixup_npr_records(odr,  apdu->u.searchResponse->records, b);
 553             p.response() = gdu;
 554         }
 555     }
 556 }
 557
 558 void yf::VirtualDB::Frontend::present(mp::Package &package, Z_APDU *apdu_req)
 559 {
 560     Z_PresentRequest *req = apdu_req->u.presentRequest;
 561     std::string resultSetId = req->resultSetId;
 562     mp::odr odr;
 563
 564     Sets_it sets_it = m_sets.find(resultSetId);
 565     if (sets_it == m_sets.end())
 566     {
 567         Z_APDU *apdu =
 568             odr.create_presentResponse(
 569                 apdu_req,
 570                 YAZ_BIB1_SPECIFIED_RESULT_SET_DOES_NOT_EXIST,
 571                 resultSetId.c_str());
 572         package.response() = apdu;
 573         return;
 574     }
 575     Session *id =
 576         new mp::Session(sets_it->second.m_backend->m_backend_session);
 577
 578     // sending present to backend
 579     Package present_package(*id, package.origin());
 580     present_package.copy_filter(package);
 581
 582     req->resultSetId = odr_strdup(odr, sets_it->second.m_setname.c_str());
 583
 584     present_package.request() = yazpp_1::GDU(apdu_req);
 585
 586     present_package.move(sets_it->second.m_backend->m_route);
 587
 588     fixup_package(present_package, sets_it->second.m_backend);
 589
 590     if (present_package.session().is_closed())
 591     {
 592         package.response() = present_package.response();
 593         package.session().close();
 594         return;
 595     }
 596     else
 597     {
 598         package.response() = present_package.response();
 599     }
 600     delete id;
 601 }
 602
 603 void yf::VirtualDB::Frontend::scan(mp::Package &package, Z_APDU *apdu_req)
 604 {
 605     Z_ScanRequest *req = apdu_req->u.scanRequest;
 606     std::string vhost;
 607     mp::odr odr;
 608
 609     std::list<std::string> databases;
 610     int i;
 611     for (i = 0; i<req->num_databaseNames; i++)
 612         databases.push_back(req->databaseNames[i]);
 613
 614     BackendPtr b;
 615     // pick up any existing backend with a database match
 616     std::list<BackendPtr>::const_iterator map_it;
 617     map_it = m_backend_list.begin();
 618     for (; map_it != m_backend_list.end(); map_it++)
 619     {
 620         BackendPtr tmp = *map_it;
 621         if (tmp->m_frontend_databases == databases)
 622             break;
 623     }
 624     if (map_it != m_backend_list.end())
 625         b = *map_it;
 626     if (!b)  // no backend yet. Must create a new one
 627     {
 628         int error_code;
 629         std::string addinfo;
 630         b = init_backend(databases, package, error_code, addinfo);
 631         if (!b)
 632         {
 633             // did not get a backend (unavailable somehow?)
 634             Z_APDU *apdu =
 635                 odr.create_scanResponse(
 636                     apdu_req, error_code, addinfo.c_str());
 637             package.response() = apdu;
 638
 639             return;
 640         }
 641     }
 642     // sending scan to backend
 643     Package scan_package(b->m_backend_session, package.origin());
 644
 645     scan_package.copy_filter(package);
 646
 647     // pick first targets spec and move the databases from it ..
 648     std::list<std::string>::const_iterator t_it = b->m_targets.begin();
 649     if (t_it != b->m_targets.end())
 650     {
 651         mp::util::set_databases_from_zurl(odr, *t_it,
 652                                                 &req->num_databaseNames,
 653                                                 &req->databaseNames);
 654     }
 655     scan_package.request() = yazpp_1::GDU(apdu_req);
 656
 657     scan_package.move(b->m_route);
 658
 659     if (scan_package.session().is_closed())
 660     {
 661         package.response() = scan_package.response();
 662         package.session().close();
 663         return;
 664     }
 665     package.response() = scan_package.response();
 666 }
 667
 668
 669 void yf::VirtualDB::add_map_db2targets(std::string db,
 670                                      std::list<std::string> targets,
 671                                      std::string route)
 672 {
 673     m_p->m_maps.push_back(
 674         VirtualDB::Map(mp::util::database_name_normalize(db), targets, route));
 675 }
 676
 677
 678 void yf::VirtualDB::add_map_db2target(std::string db,
 679                                     std::string target,
 680                                     std::string route)
 681 {
 682     std::list<std::string> targets;
 683     targets.push_back(target);
 684
 685     add_map_db2targets(db, targets, route);
 686 }
 687
 688 void yf::VirtualDB::process(mp::Package &package) const
 689 {
 690     FrontendPtr f = m_p->get_frontend(package);
 691
 692     Z_GDU *gdu = package.request().get();
 693
 694     if (gdu && gdu->which == Z_GDU_Z3950 && gdu->u.z3950->which ==
 695         Z_APDU_initRequest && !f->m_is_virtual)
 696     {
 697         Z_InitRequest *req = gdu->u.z3950->u.initRequest;
 698
 699         std::list<std::string> vhosts;
 700         mp::util::get_vhost_otherinfo(req->otherInfo, vhosts);
 701
 702         if (vhosts.size() > 0 && m_p->pass_vhosts)
 703         {
 704             package.move();
 705         }
 706         else
 707         {
 708             f->m_init_gdu = gdu;
 709
 710             mp::odr odr;
 711             Z_APDU *apdu = odr.create_initResponse(gdu->u.z3950, 0, 0);
 712             Z_InitResponse *resp = apdu->u.initResponse;
 713
 714             int i;
 715             static const int masks[] = {
 716                 Z_Options_search,
 717                 Z_Options_present,
 718                 Z_Options_namedResultSets,
 719                 Z_Options_scan,
 720                 -1
 721             };
 722             for (i = 0; masks[i] != -1; i++)
 723                 if (ODR_MASK_GET(req->options, masks[i]))
 724                     ODR_MASK_SET(resp->options, masks[i]);
 725
 726             static const int versions[] = {
 727                 Z_ProtocolVersion_1,
 728                 Z_ProtocolVersion_2,
 729                 Z_ProtocolVersion_3,
 730                 -1
 731             };
 732             for (i = 0; versions[i] != -1; i++)
 733                 if (ODR_MASK_GET(req->protocolVersion, versions[i]))
 734                     ODR_MASK_SET(resp->protocolVersion, versions[i]);
 735                 else
 736                     break;
 737
 738             package.response() = apdu;
 739             f->m_is_virtual = true;
 740         }
 741     }
 742     else if (!f->m_is_virtual)
 743         package.move();
 744     else if (gdu && gdu->which == Z_GDU_Z3950)
 745     {
 746         Z_APDU *apdu = gdu->u.z3950;
 747         if (apdu->which == Z_APDU_initRequest)
 748         {
 749             mp::odr odr;
 750
 751             package.response() = odr.create_close(
 752                 apdu,
 753                 Z_Close_protocolError,
 754                 "double init");
 755
 756             package.session().close();
 757         }
 758         else if (apdu->which == Z_APDU_searchRequest)
 759         {
 760             f->search(package, apdu);
 761         }
 762         else if (apdu->which == Z_APDU_presentRequest)
 763         {
 764             f->present(package, apdu);
 765         }
 766         else if (apdu->which == Z_APDU_scanRequest)
 767         {
 768             f->scan(package, apdu);
 769         }
 770         else if (apdu->which == Z_APDU_close)
 771         {
 772             package.session().close();
 773         }
 774         else
 775         {
 776             mp::odr odr;
 777
 778             package.response() = odr.create_close(
 779                 apdu, Z_Close_protocolError,
 780                 "unsupported APDU in filter_virt_db");
 781
 782             package.session().close();
 783         }
 784     }
 785     m_p->release_frontend(package);
 786 }
 787
 788
 789 void mp::filter::VirtualDB::configure(const xmlNode * ptr, bool test_only)
 790 {
 791     for (ptr = ptr->children; ptr; ptr = ptr->next)
 792     {
 793         if (ptr->type != XML_ELEMENT_NODE)
 794             continue;
 795         if (!strcmp((const char *) ptr->name, "pass-vhosts"))
 796         {
 797             m_p->pass_vhosts = mp::xml::get_bool(ptr->children, false);
 798         }
 799         else if (!strcmp((const char *) ptr->name, "virtual"))
 800         {
 801             std::string database;
 802             std::list<std::string> targets;
 803             xmlNode *v_node = ptr->children;
 804             for (; v_node; v_node = v_node->next)
 805             {
 806                 if (v_node->type != XML_ELEMENT_NODE)
 807                     continue;
 808
 809                 if (mp::xml::is_element_mp(v_node, "database"))
 810                     database = mp::xml::get_text(v_node);
 811                 else if (mp::xml::is_element_mp(v_node, "target"))
 812                     targets.push_back(mp::xml::get_text(v_node));
 813                 else
 814                     throw mp::filter::FilterException
 815                         ("Bad element "
 816                          + std::string((const char *) v_node->name)
 817                          + " in virtual section"
 818                             );
 819             }
 820             std::string route = mp::xml::get_route(ptr);
 821             add_map_db2targets(database, targets, route);
 822         }
 823         else
 824         {
 825             throw mp::filter::FilterException
 826                 ("Bad element "
 827                  + std::string((const char *) ptr->name)
 828                  + " in virt_db filter");
 829         }
 830     }
 831 }
 832
 833 static mp::filter::Base* filter_creator()
 834 {
 835     return new mp::filter::VirtualDB;
 836 }
 837
 838 extern "C" {
 839     struct metaproxy_1_filter_struct metaproxy_1_filter_virt_db = {
 840         0,
 841         "virt_db",
 842         filter_creator
 843     };
 844 }
 845
 846
 847 /*
 848  * Local variables:
 849  * c-basic-offset: 4
 850  * c-file-style: "Stroustrup"
 851  * indent-tabs-mode: nil
 852  * End:
 853  * vim: shiftwidth=4 tabstop=8 expandtab
 854  */
 855